Article

Patellofemoral contact pressure following high tibial osteotomy: A cadaveric study

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Abstract

Patella infera is a known complication of high tibial osteotomy (HTO) that can cause anterior knee pain due to excessive stresses associated with abnormal patellofemoral (PF) joint biomechanics. However, the translation of these abnormal biomechanics to native cartilage pressure has not been explored. The present study was designed to compare the PF contact pressures of three different HTOs in a human cadaveric model of valgus tibiofemoral correction. Nine fresh cadaveric knees underwent (1) medial opening wedge (OWHTO) with a proximal tuberosity osteotomy (PTO), (2) OWHTO with a distal tuberosity osteotomy (DTO), and (3) a lateral closing wedge (CWHTO). The specimens were mounted in a custom knee simulation rig, with muscle forces being simulated using a pulley system and weights. The PF contact pressure was recorded using an electronic pressure sensor at 15 degrees , 30 degrees , 60 degrees , 90 degrees , and 120 degrees of knee flexion, with results of the intact knees obtained as relative control. Compared to the intact knee, the DTO OWHTO and CWHTO did not significantly (P > 0.05) influence PF pressure at any flexion angle. On the other hand, PTO OWHTO lead to a significant elevation in PF cartilage pressure at 30 degrees (P < 0.05), 60 degrees (P < 0.005), and 90 degrees (P < 0.0005) knee flexion. We conclude from these results that DTO OWHTO maintains normal joint biomechanics and has no significant effect on PF cartilage pressure. In patients who complain of pre-existing anterior knee pain, DTO OWHTO or CWHTO should be considered.

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... Increased PF pressure can cause cartilage deterioration [13]. In a biomechanical study, the contact pressure of the PF joint significantly increased in the cadaveric knees with a medial opening gap of 10 and 15 mm [14,15]. Clinically, PF OA tends to progress after OWHTO in knees with a medial open gap ≥ 13 mm [11]. ...
... In biomechanical studies, the contact pressure at the PF joint was increased after OWHTO [15]. A low patella, which increases PF pressure, might lead to knee pain and reduce the range of motion [14]. Our study showed that there was no significant between-group difference in the postoperative Kujara score, but the change in ROM in the OWHTO group were lower than that in the DLO group. ...
... These findings may imply that an opening gap > 15° should be avoided in a cadaveric study. Stoffel et al. reported that PF contact pressure increased at 30, 60, and 120° of flexion with a 14 mm opening gap using an electronic pressure sensor [14]. Javidan et al. reported that the PF contact pressure increased at 30 and 120° of flexion with a 10-mm opening gap using a pressure-sensitive film and increased at 30, 60, 90, and 120° of flexion at a 15 mm opening gap in a cadaveric study [15]. ...
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Purpose To compare radiographic, clinical, and arthroscopic findings in patellofemoral (PF) osteoarthritis (OA) between open wedge high tibial osteotomy (OWHTO) and double-level osteotomy (DLO) with the same operative indication. Methods After adjustment for patient age, and coronal alignment, 36 knees with OWHTO alone and 36 knees with DLO were compared. Radiographic, clinical, and arthroscopic findings were documented before osteotomy. Arthroscopic findings were observed 1 year after osteotomy, and clinical and radiographic findings were observed 2 years after osteotomy. Patellar height was evaluated using the Insall-Salvati (IS) ratio, Carton-Deschamps (CD) index, and Blackburne-Peel (BP) index. Lateral patellar tilt and patellar shift were measured. A power analysis was performed. Results The postoperative CD and BP indices in the OWHTO group were lower than those in the DLO group (p < 0.001 and p = 0.001, respectively). The CD and BP indices in both groups significantly decreased postoperatively (all p < 0.001). Tilting angles in the OWHTO and DLO groups significantly decreased postoperatively (p < 0.001 and p = 0.002, respectively). There were no significant differences in American Knee Society scores, Kujala score, and the Knee Injury and Osteoarthritis Outcome Scores between both groups. The PF OA progression of the trochlear in the OWHTO group was higher than that in the DLO group (p = 0.002), and the PF OA progression of the patellar facet in the DLO group and anterior femoral condyle in both groups on the lateral side were higher than those on the medial side (p = 0.006, 0.032, and 0.041, respectively). Conclusions DLO decreased the rate of low patellar height compared with OWHTO. DLO decreased the rate of PF OA progression in the trochlea compared with OWHTO. There were no significant differences in clinical outcomes in both groups. Level of evidence Level III, case–control study.
... High tibial osteotomy is one of the surgical methods for treating medial compartment knee osteoarthritis. Traditional HTO is divided into closing-wedge high tibial osteotomy (CWHTO) and open-wedge high tibial osteotomy (OWHTO), and both procedures can effectively correct the coronal weight-bearing line of the knee joint, transfer the lower limb alignment from the medial compartment of the knee joint to the lateral compartment, increase the stress area of the tibiofemoral joint, and reduce the pressure of the medial compartment to relieve medial compartment knee pain and help patients recover walking function [1][2][3][4][5][6][7][8][9][10][11][12][13]. The mechanical properties of a biostructure depend on its Young's modulus (E). ...
... Patellar height disorder can lead to cartilage degeneration of the patellofemoral joint, loss of function, knee pain, and recurrent patellofemoral dislocation. The pressure on the patellofemoral joint increases during the bending of the patella baja; therefore, the possibility of patellofemoral joint degeneration increases [2]. Patellar instability is often associated with patellar alta, and long-term patellar instability can lead to knee pain, functional limitations, and osteoarthritis. ...
... In a large number of clinical studies, it has been 6 Computational and Mathematical Methods in Medicine confirmed that whether the osteotomy line passes through the tibial tuberosity is one of the evaluation criteria for the change in patellar height, and subtubercle osteotomy can effectively avoid this [3][4][5][7][8][9][10][11][12]. Some studies [2] have shown that open-wedge proximal tibial osteotomy can significantly increase the pressure on the patellofemoral articular cartilage at 30°, 60°, and 90°knee flexion and accelerate the degeneration of the patellofemoral articular cartilage. Sim et al. [30] found that patellar height decreased after OWHTO, and single-photon emission computed tomography and conventional computed tomography (SPECT/CT) were used to capture the contact stress of the patellofemoral joint. ...
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Objective: To explore the effect of age stratification on patellar height after single-plane high tibial osteotomy of the distal tibial tuberosity (DTT-HTO). Methods: A retrospective analysis was performed on 110 knee joints undergoing DTT-HTO. Patients were divided into three groups according to age: under 60 years old, 28 cases; 60 to 70 years old, 61 cases; and over 70 years old, 21 cases. All patients were followed up for no less than 12 months, and at each follow-up, short-leg radiographs and whole-leg radiographs were taken. The values of the Caton-Deschamps index (CDI) and Blackburne-Peel index (BPI) of single-short-leg radiographs and the femoral-tibial angle (FTA) and weight-bearing line ratio (WBLR) of whole-leg radiographs were measured before and at the last follow-up. The Lysholm score before and at the last follow-up and the visual analogue scale (VAS) score before and 3 days after surgery and at the last follow-up were calculated. The frequency of classification of the normal-height patella, patella alta, and patella baja before and after surgery was recorded. Results: There were no significant differences in CDI and BPI preoperatively or postoperatively among the three groups (P > 0.05), and there were no statistically significant differences in FTA and WBLR. There were no significant differences in CDI, BPI, FTA, or WBLR between the three groups before and after the operation (P > 0.05). The Lysholm score increased from 48.84 ± 10.10 before surgery to 91.96 ± 3.082 after surgery (P < 0.05); the VAS score decreased from 8.23 ± 0.99 before surgery to 1.93 ± 0.953 at 3 days after surgery and 1.07 ± 0.53 at the last follow-up (P < 0.01). No significant difference was observed in the incidence of each patellar height classification between the three groups preoperatively and postoperatively. Conclusion: Patellar height is not influenced by DTT-HTO. The age of patients is not a limiting factor for the selection of this surgical procedure. Without affecting the height of the patella, DTT-HTO can effectively reduce pain in the knee joint, restore the function of the knee joint, and delay the progression of patellar arthritis.
... 3,10 Reduction of the patellar height may lead to postoperative complications, such as anterior knee pain (AKP), patellar locking, crepitus, and limitation of knee motion. 16,35 Eventually, the altered patellofemoral (PF) congruency and contact stress may lead to PF joint osteoarthritis (OA). 11 Previous studies have revealed a decrease in lateral patellar tilt after OWHTO. ...
... It is generally accepted that OWHTO with an ascending tibial tubercle osteotomy decreases the patellar height, which potentially leads to AKP, crepitus, extension lag, and decreased range of motion. 14,35 Our study presented a statistically significant decrease of the patellar height and degradation of the PF cartilage after OWHTO. OWHTO is often associated with decreased patellar height due to distal and lateral movement of the tibial tuberosity. ...
... Furthermore, lower patellar height potentially increases the load of the PF joint, resulting in PF OA and AKP. 35 Tigani et al 38 reported that >15 of knee axis correction significantly decreased patellar height. Stoffel et al 35 reported that OWHTO led to a significant elevation in PF cartilage pressure at 30 , 60 , and 90 of knee flexion in a cadaveric biomechanical experiment. ...
Article
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Background Medial open-wedge high tibial osteotomy (OWHTO) theoretically causes distalization and lateralization of the tibial tuberosity and the patella. Purpose/Hypothesis The purpose of the study was to identify any changes in the stress distribution of subchondral bone density across the patellofemoral (PF) joint before and after OWHTO through the use of computed tomography (CT) osteoabsorptiometry. We hypothesized that OWHTO would alter the distribution of contact stress in the PF joint. Study Design Case series; Level of evidence, 4. Methods A total of 17 patients (17 knees) who underwent OWHTO were enrolled in this study between September 2013 and September 2015. All patients underwent radiologic examination preoperatively and at 1 year postoperatively, and the distribution patterns of subchondral bone density through the articular surface of the femoral trochlea and patella were assessed preoperatively and >1 year postoperatively using CT osteoabsorptiometry. The quantitative analysis of the obtained mapping data focused on location of the high-density area (HDA) through the articular surface of the PF joint. The percentage of HDA at each divided region of the articular surface of the femoral trochlea and the patella was calculated. Results In the radiologic evaluation, the Blackburne-Peel ratio was significantly reduced ( P < .001) after surgery, and the tilting angle of the patella was significantly decreased ( P < .001). On CT evaluation, the percentage of HDA in the lateral notch and lateral trochlea of the femur and in the medial portion of the lateral facet of the patella increased significantly after OWHTO surgery ( P ≤ .038). Conclusion OWHTO significantly increased the stress distribution pattern of the lateral trochlea of the femur and the medial portion of the lateral facet of the patella. The procedure significantly lowered the patellar height and significantly decreased the patellar tilting angle after surgery.
... 12 The progression of patellofemoral OA after HTO has been widely discussed because changes to patellar height caused by HTO might accelerate OA development, 13,14 and HTO has been shown to cause significant and unfavorable changes in patellofemoral mechanics, which are particularly profound after OWHTO. 15,16 All these indicate considering patellofemoral congruity after OWHTO might be essential for the clinical outcomes following HTO. However, the indication of OWHTO based on the preoperative patellar height is still controversial. ...
... HTO changes the patellofemoral contact pressure, 23 and cartilage pressure within the patellofemoral joint following OWHTO has been reported to be significantly greater than in an intact knee. 15 Several reports have described changes in postoperative patellar height after HTO procedures, 9,[24][25][26] and the degree of change correlates with the magnitude of the correction angle. 11,12 In contrast, Lee et al. suggested that mild patellofemoral problems should not be considered a contraindication for the OWHTO procedure. ...
Article
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Purpose: Medial opening-wedge high tibial osteotomy (OWHTO) induces a lower patellar position, and the subsequent degree of patellar movement may not be predicted preoperatively. The purpose of this study was to clarify the relationship between preoperative and postoperative patellar height based on the correction angle of OWHTO and to create a formula to predict the appearance of patella baja following OWHTO. Materials and methods: Seventy-five knees with varus knee osteoarthritis treated with OWHTO were included in this study. The Caton-Deschamps index was used to evaluate patellar height preoperatively and postoperatively, and the cut-off value for preoperative parameters was determined by a receiver operating characteristic curve to determine the risk ratio for postoperative patella baja. Results: The Caton-Deschamps index significantly decreased from 0.93 to 0.77 after OWHTO ( p < 0.01). The OWHTO correction angle negatively correlated with the delta Caton-Deschamps index ( r = -0.44, p < 0.01), and a 1.7% decrease in the Caton-Deschamps index was shown with a 1° correction angle. Receiver operating characteristic curve analysis revealed that a Caton-Deschamps index of 0.8 was the cutoff for OWHTO; knees with a preoperative Caton-Deschamps index of < 0.8 tended to develop patella baja after OWHTO, with a risk ratio of 9.5 (95% confidence interval [4.3-20.7]). Conclusions: OWHTO can induce patella baja, and a 1.7% decrease in the Caton-Deschamps index was shown with a 1°-correction angle. A preoperative Caton-Deschamps index < 0.8 should be considered a risk factor for postoperative patella baja. Level of evidence: Retrospective study, Level IV.
... Additionally, OWHTO can increase patellofemoral contact pressure and cause patellofemoral degeneration overtime even when patellar height has not been modified. (Stoffel et al. 2007) For those reasons, some surgeons advise against OWHTO when patellofemoral pain or patellofemoral chondral alterations are present even in patients with normal patellar height (Il et al. 2017;Kim et al. 2016;Kloos et al. 2018). A study recently has shown that an alteration of the axial alignment of the patella with a change of the lateral patellar tilt can be observed with a standard OWHTO. ...
... (Amzallag et al. 2013) These changes would negatively affect the functional results of the osteotomy. Likewise, several recent studies confirmed the advantages of the closed-wedge HTO over the OWHTO in relation to patellar height preservation (Bin et al. 2016;Gaasbeek et al. 2004;El-Amrani et al. 2010;Ozel et al. 2015;Brinkman et al. 2008;Noyes et al. 2005;Stoffel et al. 2007;Ferner et al. 2018). This is even more important in higher axial deviations as a correlation between the degree of axial correction and the lowering of the patella has been shown (Amzallag et al. 2013). ...
Article
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Background High tibial osteotomy is an established and helpful treatment for unicompatimental osteoarthritis associated with varus deformity. However, asupratubercle high tibial osteotomy leads to a decrease in patellar height making the technique not suitable in case of concomitant patella baja. Moreover, this kind of osteotomy can change in situ forces at patellofemoral joint and the lateral patellar tilt. With the aim to widen the indication of high tibial osteotomy was proposed a biplane opening wedge high tibial osteotomy with a distal tuberosity osteotomy (B-OWHTO). This technique provide that the tibial tuberosity remains joined to the tibial metaphysis so as not to theoretically alter the patellar height. However, some Authors claim that BOWHTO could lead to an increase in tibial slope. The purpose of the present study was to assess the tibial slope, patella-femoral changes and axial correction as well as functional outcomes following a B-OWHTO. Methods Patients operated on with a B-OWHTO and a minimum 24 months of follow-up were included. The mechanical alignment of the lower limb, patellar height, lateral patellar tilt and posterior tibial slope were calculated preoperatively, immediately after surgery and at the 24-month follow-up. The clinical results were evaluated using the Lysholm, Kujala and Hospital for Special Surgery knee scores. The possible postoperative development of patellofemoral pain or radiologic patellofemoral alteration was also evaluated. Results Twenty-three patients were included with a mean follow-up of 33 months (range 27-41). The mechanical alignment of the lower limb shifted from a mean 9.3º ± 2.5 varus preoperatively to a mean 0.2º ± 2.2 valgus postoperatively. No changes in patellar height, lateral patellar tilt or in the posterior tibial slope were observed. The mean Lysholm and HSS scores improved from 68.3 ± 9.1 and 64.2 ± 5.2 preoperatively to 93.2 ± 2.1 and 94.1 ± 3.6 at final follow-up (p < 0.01). The mean Kujala score improved from 67.3 ± 9.8 to 86.4 ± 7.6 at final follow up (p < 0.01). No patients developed both radiological or clinical symptoms at patellofemoral joint. Conclusions Open wedge high tibial osteotomy with a dihedral L-cut distal and posterior to the tibial tubercle accurately corrected axial malalignment without any change at patella-femoral joint or any modification to the posterior tibial slope while providing improved knee function at short-term follow-up. The radiographic as well as the clinical results support the use of this technique to treat medial compartment knee osteoarthritis and varus malalignment in young and middle-aged patients with a normal-to-low patellar height. Level of evidence Case series with no comparison group, Level IV.
... Several biomechanical studies have shown that distalization and lateralization of the tibial tuberosity caused by MOWHTO lead to loss in patellar height. [12][13][14][15] Loss in patellar height leads to an increase in patellofemoral contact pressure, which in turn may cause a higher incidence of arthritic change of patellofemoral joint and anterior knee pain. [15,16] On the basis of this biomechanical finding, a few researchers have performed clinical studies with secondlook arthroscopy on the knee treated with MOWHTO to examine the postoperative state of patellofemoral joint. ...
... [12][13][14][15] Loss in patellar height leads to an increase in patellofemoral contact pressure, which in turn may cause a higher incidence of arthritic change of patellofemoral joint and anterior knee pain. [15,16] On the basis of this biomechanical finding, a few researchers have performed clinical studies with secondlook arthroscopy on the knee treated with MOWHTO to examine the postoperative state of patellofemoral joint. [17][18][19] Although these clinical studies have agreed that the MOWHTO cause some degenerative progression in the patellofemoral joint of many patients, the reported postoperative functional assessment showed inconsistent results between the studies, making it difficult to reach a definite conclusion on the clinical effect of MOWHTO on the patellofemoral joint. ...
Preprint
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Background: To investigate clinical and radiologic effects of medial open wedge high tibial osteotomy (MOWHTO) on the patellofemoral joint in relation to the correction angle by comparing changes in cartilage from before to after the surgery. Methods: A total of 124 MOWHTO cases were divided into the three groups of small, moderate, and large, depending on the correction angle. Clinical and radiologic outcomes were compared at the mean follow-up time of 38.8 months. Postoperative cartilage changes were assessed during implant removal completed at two years after MOWHTO. Results: There was no significant difference evident in most clinical outcomes measured, including Lysholm score and the Knee Injury and Osteoarthritis Outcome score subscales, with the exception of postoperative Shelbourne and Trumper score between the groups (P< 0.001). International Knee Documentation Committee scale value on radiologic evaluation did not significantly differ among the groups. A progression of cartilage degeneration was noted in 40.3% of femoral trochleas and 22.6% of patellas. Cartilage degeneration was significantly progressed in the large correction angle group versus in the other two groups. Regression analysis showed that the correction angle had a significant effect on cartilage deterioration (Trochela, P=0.009; Patella, P=0.034). Conclusion: Patellofemoral joint was more adversely affected by MOWHTO in conjunction with the requirement of a larger correction angle. Thus, cases necessitating considerable correction should be forewarned of patellofemoral joint symptoms within a relatively short time after the procedure. Keywords: medial open wedge high tibial osteotomy, osteoarthritis, patellofemoral arthritis, correction angle
... Patella infra and patellofemoral malalignment have been reported to result from tibial tuberosity distalization and patellar tendon adherence [7,9] . To prevent patella infera, several studies have reported that osteotomy in the distal tibial tuberosity or below the tuberosity should be performed [10][11][12][13] . ...
... Patella infra and patellofemoral joint OA progression are frequently-occurring complications of OWHTO. Tibial tuberosity distalization and patellar tendon adherence, which cause patellar infra, have been well demonstrated anatomically and biomechanically [9,16] . In a meta-analysis, Lee et al [5] showed that the patella height decreased signi cantly after HTO in a total of 831 OWHTO patients. ...
Preprint
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Background: Distal tibial tuberosity high tibial osteotomy (DTT-HTO) can prevent distalization of the tibial tuberosity and thus patella infra. However, no studies on the clinical and radiological effects of DTT-HTO on the patellofemoral joint have been conducted. The purpose of the study was to evaluate the effect of DTT-HTO on patella height and patellofemoral joint congruity based on the severity of patellofemoral joint OA. Methods: Twenty-nine patients (33 knees) who underwent DTT-HTO and second-look arthroscopy when implant removal between January 2018 and May 2020 were eligible for the study. Among them, 6 were males, and 23 were females, with ages from 51-78 years old. The Caton-Deschamps index (CDI), congruence angle (CA) and lateral patellar tilt (LPT) were measured to evaluate the effect of surgery on patellar height and patellofemoral joint congruity. The weightbearing line ratio (WBLR) was measured to assess lower limb alignment. The cartilage lesion in the patellofemoral joint was assessed arthroscopically during surgery and implant removal by the International Cartilage Repair Society (ICRS) grading system at 18-24 months after surgery. The Hospital for Special Surgery scale (HSS) was used to evaluate knee joint function. Results: Twenty-nine patients were followed up for 18-28 months. The preoperative CDI, CA and LPT changed from 0.92±0.16 to 0.89±0.14, from 5.52±2.19 to 5.44±2.27 and from 6.95±2.88 to 6.54±2.42, respectively, and the differences were not statistically significant (p>0.05). The preoperative WBLR significantly increased from 16.72±6.77% to 58.77±7.69% (p < 0.001). The cartilage lesions in the patella and femoral trochlea did not progress significantly from the first- to the second-look arthroscopy, according to the ICRS grades (p>0.05). The HSS score significantly improved from 50.64±19.18 preoperatively to 67.33±14.72, 81.63±11.92 and 82.73±8.05 at the 3-month, 12-month, and last follow-up after surgery (p < 0.001). Conclusion: DTT-HTO can effectively prevent patellar infra, and its effects on postoperative patellofemoral joint congruity and patellofemoral joint OA progression are inconspicuous. It can be recommended as a treatment of varus knee combined with patella infra or patellofemoral joint OA.
... Patellar infera and patellofemoral malalignment have been reported to result from tibial tuberosity distalization and patellar tendon adherence [7,9]. To prevent patella infera, several studies have reported that osteotomy in the distal tibial tuberosity or below the tuberosity should be performed [10][11][12][13]. ...
... Patellar infera and patellofemoral joint OA progression are frequently occurring complications of OWHTO. Tibial tuberosity distalization and patellar tendon adherence, which cause patellar infera, have been well demonstrated anatomically and biomechanically [9,16]. In a meta-analysis, Lee et al. [5] showed that the patella height decreased significantly after HTO in a total of 831 OWHTO patients. ...
Article
Full-text available
Background: Distal tibial tuberosity high tibial osteotomy (DTT-HTO) can prevent distalization of the tibial tuberosity and thus patellar infera. However, no studies on the clinical and radiological effects of DTT-HTO on the patellofemoral joint have been conducted. The purpose of the study was to evaluate the effect of DTT-HTO on patella height and patellofemoral joint congruity based on the severity of patellofemoral joint OA. Methods: Twenty-nine patients (33 knees) who underwent DTT-HTO and second-look arthroscopy when implant was removed between January 2018 and May 2020 were eligible for the study. Among them, 6 were males, and 23 were females, with ages from 51 to 78 years old. The Caton-Deschamps index (CDI), congruence angle (CA), and lateral patellar tilt (LPT) were measured to evaluate the effect of surgery on patellar height and patellofemoral joint congruity. The weight-bearing line ratio (WBLR) was measured to assess lower limb alignment. The cartilage lesion in the patellofemoral joint was assessed arthroscopically during surgery and implant removal by the International Cartilage Repair Society (ICRS) grading system at 18-24 months after surgery. The Hospital for Special Surgery (HSS) scale was used to evaluate knee joint function. Results: Twenty-nine patients were followed up for 18-28 months. The preoperative CDI, CA, and LPT changed from 0.92 ± 0.16 to 0.89 ± 0.14, from 5.52 ± 2.19 to 5.44 ± 2.27, and from 6.95 ± 2.88 to 6.54 ± 2.42, respectively, and the differences were not statistically significant (p > 0.05). The preoperative WBLR significantly increased from 16.72 ± 6.77 to 58.77 ± 7.69% (p < 0.001). The cartilage lesions in the patella and femoral trochlea did not progress significantly from the first- to the second-look arthroscopy, according to the ICRS grades (p > 0.05). The HSS score significantly improved from 50.64 ± 19.18 preoperatively to 67.33 ± 14.72, 81.63 ± 11.92, and 82.73 ± 8.05 at the 3-month, 12-month, and last follow-up after surgery (p < 0.001). Conclusion: DTT-HTO can effectively prevent patellar infera, and its effects on postoperative patellofemoral joint congruity and patellofemoral joint OA progression are inconspicuous. It can be recommended as a treatment of varus knee combined with patellar infera or patellofemoral joint OA.
... In addition, the positive effects of OWHTO on regeneration of the articular cartilage of the medial compartment have been also confirmed by second-look arthroscopy after OWHTO [13,20]. Conversely, previous biomechanical studies have suggested that OWHTO can alter the patellofemoral (PF) congruency and elevate the joint pressure by lowering the patella, thus negatively affecting the PF joint [11,27]. Further, several clinical studies have reported that cartilage injuries in PF joints was progressed in 41-45% of the patients at the time of second-look arthroscopy after OWHTO [7,15]. ...
... Despite a recent trend to choose OWHTO to treat patients with OA, surgical indication of OWHTO has not yet been clearly determined, especially in patients with severe varus deformity or patients with PF osteoarthritis. Previous studies examined the difference in patellar alignment and positions between OWHTO and closed-wedge high tibial osteotomy (CWHTO) and recommended to perform CWHTO or other type of osteotomy such as OWHTO combined with distal tuberosity osteotomy [22,27]. Further, a recent study reported that hybrid high tibial osteotomy provided an increased PF joint space and a larger improvement in clinical scores compared with OWHTO in patients with a severe PF OA [21]. ...
Article
Purpose To identify parameters associated with deterioration of patellofemoral (PF) cartilage after open-wedge high tibial osteotomy (OWHTO) and determine predictive values. It was hypothesized that cartilage injuries in PF joints would progress after OWHTO in patients who need a large alignment correction. Methods Fifty-two knees in 47 patients who underwent bi-planer OWHTO for the treatment of medial compartment osteoarthritis from 2012 to 2017 and received a second-look arthroscopy at the time of plate removal (mean 14 months post-OWHTO) were assessed. Clinical outcomes were evaluated by the Knee Society Scores. Cartilage status in PF joints were evaluated arthroscopically using the International Cartilage Repair Society (ICRS) grading system. Patients were divided into two groups and patients who had progressed PF cartilage injury (progressed group) were compared with those who did not have progressed PF cartilage injuries (non-progressed group) using various parameters. The relationships between medial opening gap or change in the medial proximal tibial angle (ΔmPTA) and progression of PF cartilage injuries were examined by receiver operating characteristic (ROC) curve analysis. Results The mean Knee Society Scores were significantly improved after surgery (P < 0.01). The grades for the patella and trochlea progressed in 12 (23.0%) and 16 knees (30.8%), respectively. The mean preoperative hip–knee–ankle (HKA) angle, mechanical axis, and mPTA in the progressed group were significantly smaller than those in the non-progressed group (P < 0.01). The mean medial opening gap and ΔmPTA in the progressed group were significantly larger than those in the non-progressed group (P < 0.01). ROC curve analysis showed that the cut-off values of the medial opening gap and ΔmPTA for progression of PF cartilage injuries were 13 mm and 9°, respectively. Progression of PF cartilage injuries was more frequently observed in knees with a medial opening gap ≥ 13 mm (P = 0.019, odds ratio = 4.60) or a ΔmPTA ≥ 9° (P = 0.003, odds ratio 6.93) than knees with those of < 13 mm or 9°, respectively. Conclusions Cartilage injuries in PF joints tended to progress after OWHTO in patients with medial opening gap ≥ 13 mm or ΔmPTA ≥ 9°. If medial opening gap is ≥ 13 mm or ΔmPTA is ≥ 9° in planning for OWHTO, other type of surgery may need to be considered to avoid early progression of PF cartilage injuries. Level of evidence Level IV, therapeutic case series.
... The two main previously described methods used either a supratubercle or infratubercle osteotomy. Supratubercle HTO's have reported successful results but can alter patellar height and patellofemoral mechanics, 8 which can lead to pain and decreased satisfaction. Infratubercle HTO's can provide more rigid fixation but have the potential for delayed union due to cortical bone involvement. ...
... 9 One advantage of the technique described in this article is that it allows for a significant increase in PTS, while minimizing any change in patellar height, which can lead to patellofemoral pain and other symptoms. 8 Limitations of this technique compared to supratubercle or infratubercle HTO's include the potential for interference between the osteotomy screws and the tibial tunnel, delayed union, and tubercle fracture. 10 There is no established cut-off for the amount of slope necessitating a concomitant osteotomy. ...
Article
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Despite multiple advances in techniques for posterior cruciate ligament reconstruction (PCL-R), residual posterior laxity continues to be a commonly reported complication. Multiple studies demonstrated a decreased or flat posterior tibial slope, increases posterior laxity, and forces placed across the native and reconstructed PCL. Anterior opening wedge high tibial osteotomies (aOW-HTO) can be used to increase posterior tibial slope, thereby reducing tibial sag and posterior laxity. Depending on the technique used, anterior opening wedge osteotomies can lead to changes in patellar height, affecting patient pain and satisfaction. The purpose of this article is to describe a technique for an aOW-HTO with a tibial tubercle osteotomy and concomitant PCL-R to increase the posterior tibial slope while minimizing changes to patellar height.
... This is because the distance between the knee joint line and tibial tuberosity is lengthened due to the position of the osteotomy proximal to the tibial tuberosity, which is the site where the patellar tendon is inserted [59]. The patella baja caused by the distally transferred patella increases the contact pressure of the patellofemoral joint, causing a degenerative change in the patellofemoral joint and resulting in anterior knee pain and limit of motion [60]. In the overcorrected valgus knee, Q-angle alteration is inevitable and increases the lateral pull on the patella, causing patellar maltracking during knee flexion [31,59]. ...
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Medial opening wedge high tibial osteotomy (MOWHTO) is a widely used surgical treatment option for medial compartmental osteoarthritis with varus deformity. It is important that proper lower limb alignment is achieved. However, there has been no consensus about an optimal alignment in MOWHTO. Most studies suggest that achieving valgus alignment is necessary, and recent studies support slight valgus mechanical alignment of less than 3° of mechanical femorotibial angle. Overcorrection and undercorrection is not recommended for achieving good surgical outcomes. To prevent undercorrection and overcorrection in MOWHTO, the method of placing the weight-bearing line in the target range must be precise. There are several ways to place a weight-bearing line within the target range. While the most important factor for a successful MOWHTO is achieving an ideal mechanical axis correction, there are a few other factors to consider, including joint line obliquity, posterior tibial slope, ligament balancing, and patellar height. Several factors exist that lead to undercorrection and overcorrection. Preoperative amount of varus deformity, lateral hinge fracture, and fixation failure can result in undercorrection, while medial soft tissue laxity and the amount of correction angle and target point beyond hypomochlion can result in overcorrection. This study aimed to review the literature on optimal alignment in MOWHTO and report on the factors to be considered to prevent correction errors and how to achieve an optimal alignment.
... The patellofemoral contact pressure is significantly greater after OWHTO than that in the intact knee [24]. Moreover, Yang et al. [12] investigated the patellofemoral contact pressure in a biomechanical cadaver study and reported patellofemoral contact pressure was a 4fold increase with the knee in 10°of flexion and a 7-fold increase at 20°of flexion compared with full extension. ...
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Purpose The purpose of the study was to determine the effect of cartilage degeneration at the patellofemoral joint on clinical outcomes after open wedge high tibial osteotomy and to investigate the predisposing factors for progressive patellofemoral cartilage degeneration. Methods Seventy-two knees were evaluated on second-look arthroscopy in patients who opted for plate and screw removal at an average of 20.1 months after osteotomy. Cartilage degeneration at the patellofemoral joint was evaluated using the International Cartilage Repair Society grading system, with cases divided into progression and nonprogression groups. Radiographic parameters of the patellofemoral anatomy, knee range of motion, and clinical outcomes were evaluated from the preoperative baseline to the final follow up, on average 50 months after osteotomy. A contracture > 5° was considered a flexion contracture. Results Cartilage degeneration progressed in 31 knees, and preoperative knee flexion contracture was significantly associated with progressive degeneration ( P < 0.01). The Lysholm and Kujala scores were significantly lower in the progression group (87.9 and 85.3, respectively) than in the nonprogression group (91.6 and 93.6, respectively) ( P < 0.05). The odds ratio of the flexion contracture resulting in progression of patellofemoral cartilage degeneration was 4.63 (95% confidence interval, 1.77–12.1). No association was detected between progressive degeneration and age, sex, body mass index, Kellgren-Lawrence grade, or radiographic parameters. Conclusions Flexion contracture may be associated with progression of cartilage degeneration at the patellofemoral joint and may negatively affect the clinical outcomes after open wedge, high tibial osteotomy.
... [1][2][3][4][5][6][7] With an HTO, the surgeon aims to change the coronal alignment of the leg in order to shift the center of force passing axially through the knee from the arthritic region of the knee towards the unaffected side. [8][9][10][11][12][13][14][15][16][17][18] The amount of alignment correction to be performed is calculated before surgery based on the extent of knee arthrosis and on the alignment of the patient's lower limbs on long-leg weightbearing radiographs. Clinical outcomes are better when the anatomic axis of the patient's knee is between 7°and 13°of valgus alignment, 19,20 3°to 5°being the ideal range for mechanical axis. ...
Article
Objectives To develop an accurate intraoperative method to estimate changes in intraarticular contact pressures during high tibial osteotomy (HTO). Methods Changes in knee alignment and pressure were monitored in real time in seven cadaver specimens that received HTO. Intraarticular contact pressure (N/mm²) in each knee compartment was estimated based on extraarticularly acquired data (leg alignment, correction, ankle tilt) and based on the application of an axial force of half bodyweight (400‐450 N). Results Contact pressure estimation was more accurate in the lateral compartment (R² = .940) than in the medial compartment of the knee (R² = .835). The optimism‐corrected R² was.936 for the lateral compartment and.821 for the medial compartment. Conclusions We have established a framework for estimating the change in intraarticular contact pressures based on extraarticular data. This research could be helpful in generating appropriate algorithms to estimate joint alignment changes based on applied loads.
... With regard to OWHTO, Stoffel et al. 26) have investigated patel lofemoral pressure in their prior cadaveric study and reported that the pressure associated with OWHTO was significantly higher at 15°, 30°, or 60° flexion compared with CWHTO. Oh et al. 20) reported that the patellofemoral OA grade progressed or worsened in 15 of 42 knees (35.7%) after OWHTO over a mini mum followup of 5 years. ...
Article
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Purpose: High tibial valgus osteotomy (HTO) is a well-established surgical procedure for patients with medial compartment osteoarthritis (OA) of the knee. The hybrid closed-wedge HTO (CWHTO) procedure permits extensive correction in patients with severe deformities or patellofemoral joint OA. The aim of this study was to report the short-term results in a consecutive series of patients treated with hybrid CWHTO. Materials and methods: We retrospectively evaluated the clinical outcomes and radiographic parameters in 29 consecutive knees that underwent hybrid CWTHO to correct medial compartment OA at an average follow-up of 52.6 months. Clinical outcomes were assessed using the Lysholm score and knee scoring system of the Japanese Orthopedic Association (JOA). The Kellgren-Lawrence grading system and pre- and postoperative mechanical axis (MA), femorotibial angle (FTA), posterior tibial slope, and patella height were assessed. Results: The FTA and MA significantly changed from 180.7° to 170.4° and from 22.0° to 60.2°, respectively. No significant differences were observed between the mean pre- and postoperative posterior tibial slope, Insall-Salvati ratio, or Caton-Deschamps index. The postoperative JOA and Lysholm scores significantly improved from 76.7 to 95.8 and from 58.8 to 90.2, respectively. Conclusions: Satisfactory outcomes can be achieved with hybrid CWHTO in patients with medial OA.
... [2] A cadaveric study reported that medial open-wedge HTO significantly increased pressure on the patellofemoral cartilage at 30°, 60°, and 90°flexion. [15] Moreover, medial open-wedge HTO was found to significantly aggravate degeneration of the patellofemoral joint cartilage. [5] In the present study, degeneration of the patellofemoral joint cartilage progressed similarly in 30 of the 57 knees that underwent medial open-wedge HTO. ...
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To evaluate retrospectively any association between the degree of deformity correction by medial open-wedge high tibial osteotomy (HTO) and patellofemoral joint degeneration. We hypothesized that development of patellofemoral joint degeneration depended on the degree of intraoperative deformity correction.Fifty-seven patients who underwent medial open-wedge HTO for treatment of osteoarthritis in one knee were included in this study. Knees were classified into degeneration (D) and non-degeneration (ND) groups according to worsening of the patellar and/or femoral trochlear cartilage at the time of hardware removal (D group, 27 knees) and no degeneration or improvement (ND group, 30 knees). We compared pre- to post-surgery change in hip-knee-ankle angle (HKA) and medial-proximal-tibial angle (MPTA), open-wedge HTO correction angle, and arthroscopic findings between groups.Mean age, height, weight, and body mass index were 54.1 ± 9.9 years, 160.4 ± 8.7 cm, 66.4 ± 12.1 kg, and 25.7 ± 3.3 kg/m, respectively. Change in both HKA and MPTA differed significantly between groups. The MPTA cut-off values to predict patellofemoral degeneration were determined to be 10°, associated with an AUC of 0.75 (95% confidence interval [CI] 0.62-0.87).This study evaluated retrospectively the effect of the correction angle during medial open-wedge HTO on patellofemoral joint degeneration. If deformity correction exceeds an MPTA of 10° during open-wedge HTO, degeneration of patellofemoral joint needs to be considered.Level of evidence: Level IV.
... [2][3][4] As potential drawbacks of OWHTO, patella infra and patellofemoral malalignment have been reported to result from the tibial tuberosity distalization that is part of the OWHTO procedure. [5][6][7][8][9] Increased patellofemoral joint pressure and contact forces after patella infra carry a risk for the onset or progression of patellofemoral OA. [10][11][12] Goshima et al. 9 have reported progression of patellofemoral OA in 27% of cases by radiographs and of chondral damage in 45% of cases by arthroscopy. ...
Article
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Open-wedge high tibial osteotomy is considered to be an effective surgical intervention for medial compartmental knee osteoarthritis. However, patella infra, which has been reported to be a result of tuberosity distalization after open-wedge high tibial osteotomy, changes the native patellofemoral biomechanics. This could raise abnormal patellofemoral contact stresses, which might be the trigger of patellofemoral arthrosis. To minimize the reduction in patellar height, we have developed a technique called open-wedge distal tuberosity tibial osteotomy. The benefits of this technique include increased bone-to-bone contact of the distal tuberosity cut surface after correction by cutting an arc osteotomy around the hinge position, which is the center of rotation. This technique also provides cortical support at the anterior osteotomy site without additional bone defect and, therefore, may be advantageous against weight-bearing stress on the osteotomy site. In all, open-wedge distal tuberosity tibial osteotomy could potentially be a unique open-wedge osteotomy that eliminates the risk for postoperative patellofemoral osteoarthritis and also could theoretically encourage rapid healing of the osteotomy, which could lead to early return to full physical activity.
... While studies report that HTO causes an improvement in the knee extension mechanism and cartilage tissue, and that patellofemoral joint complaints are eliminated, that patellofemoral OA progresses in the opposite studies [27,28]. It is stated that patellar maltracking such as decreased patellar height, increased medial patellar tilt, and decreased medial patellar rotation in traditional OWHTO techniques cause progression in arthrosis, while osteotomies made from distal tibial tubercle preserve the patellofemoral joint [29][30][31][32]. In our study, in which we performed STO, a statistically significant progression in patellofemoral arthrosis was detected, while the patellofemoral joint was preserved in most patients. ...
Article
Background We evaluated the long-term clinical and radiographic outcomes of patients who underwent subtubercular tibial osteotomy (STO) with Ilizarov external fixation used for high tibial osteotomy for medial knee osteoarthritis (MKOA). Methods Between October 2003 and December 2011, 42 knees of 40 patients who had undergone STO with Ilizarov external fixator with a diagnosis of MKOA were evaluated. Survival analysis was performed by examining the duration of total knee arthroplasty (TKA). Clinical and radiological variables were collected at the time of admission after removal of the fixator and at outpatient follow up. Results Mean age was 49.3 ± 5.68 (range 37–61) years, mean postoperative follow up time was 14.22 ± 2.93 (range 9–18) years, and mean fixator duration was 14.6 (range 13–20) weeks. Survival analysis showed 100% at 5 years, 95.2% at 10 years and 88.1% at 15 years. Clinical examination of the patients showed significant improvement in American Knee Society score (KSS), KSS functional score and Oxford Knee Score (OKS) score (P = 0.005). In the study, it was observed that the patients' knee osteoarthritis had progressed over time. On examination, radiographic measurements including mechanical axis deviation, medial proximal tibial angle, femorotibial angle, and joint line alignment angle improved significantly after deformity correction (P = 0.001). Conclusion STO using the Ilizarov method offers long-term survival. It provides effective treatment in young patients with isolated MKOA. Achieving the desired amount of correction in the coronal and sagittal planes can be presented as a surgical technique for the treatment of MKOA as an effective method in clinical and radiological correction.
... Another group using a proximal ascending tuberosity osteotomy reported that the patellar height and the angle of correction were related: the larger the correction angle, the lower the postoperative patellar height and the higher the patellofemoral contact stress. 42 It should be kept in mind that a painful retropatellar OA should be an exclusion criterion for MOWHTO because of the risk of increased retropatellar pressure and pain impairment postoperatively. ...
Article
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Background Outcomes and complications at mid- or long-term follow-up after medial open-wedge high tibial osteotomy (MOWHTO) with the TomoFix locking plate have not been fully evaluated. Purpose To evaluate the complications and midterm clinical outcomes after MOWHTO using a TomoFix. Study Design Case series; Level of evidence, 4. Methods Enrolled in this study were 80 patients (85 knees) who underwent MOWHTO with the TomoFix locking plate between 2009 and 2013. There were 66 women and 14 men, with a mean age of 61.5 years at the time of surgery. The diagnosis was medial osteoarthritis in 76 knees and spontaneous osteonecrosis of the knee in 9 knees. Metal removal and second-look arthroscopy were performed in all cases. Clinical and radiological examinations were performed at final follow-up after surgery (mean, 4.5 years). Results The mean Japanese Orthopaedic Association score and Knee injury and Osteoarthritis Outcome Score improved significantly from pre- to postoperatively ( P < .0001). The weightbearing line percentage shifted to pass through a point 67.7% lateral from the medial edge of the tibial plateau. The Caton-Deschamps index changed significantly from 0.88 to 0.66 at final follow-up ( P < .0001). The mean posterior tibial slope changed significantly from 8.9° to 11.9° at final follow-up ( P < .0001). Limb length was significantly increased after MOWHTO (10.3 mm; P < .0001). During plate removal, 14 locking screws were found to be broken in 9 knees (10.6%). The articular cartilage grade of the patellofemoral joint was significantly higher in the second arthroscopy than in the first arthroscopy ( P < .0001). The cumulative rate of all complications was 41.2%, with major complications (ie, those requiring additional or extended treatment) in 24.7%. Conclusion Postoperative outcome scores indicated significant improvement after MOWHTO, although the cumulative rate of all complications was 41.2% and the rate of major complications was 24.7%. These results indicate that MOWHTO with the TomoFix is a technically demanding procedure. Careful preoperative planning and meticulous surgical technique are needed to decrease the incidence of complications associated with MOWHTO.
... Conversely, there are observations indicating that the patellofemoral pressure increases after OWHTO (Javidan et al., 2013;Stoffel et al., 2007), and patellofemoral cartilage injuries progress in 41-45 % of patients in second-look arthroscopy (Goshima et al., 2017;Kim et al., 2017). ...
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Medial open-wedge high tibial osteotomy is a surgical treatment for patients with a varus deformity and early-stage medial knee osteoarthritis. Observations suggest that this surgery can negatively affect the patellofemoral joint and change the patellofemoral kinematics. However, what causes these effects and how the correction angle can change the surgery's impact on the patellofemoral joint has not been investigated before. The objective of this study was to develop a biomechanical model that can predict the surgery's impact on the patellar position and find the correlation between the opening angles and the patellar position after the surgery. A combined finite element and multibody model of the lower limb was developed. The model's capabilities for predicting the patellofemoral kinematics were evaluated by performing a passive deep flexion simulation of the native knee and comparing the outcomes with magnetic resonance images of the study subject at various flexion angles. The model at a fixed knee flexion angle was then used to simulate the high tibial osteotomy surgery virtually. The results showed a correlation between the wedge opening angles and the patellar position in various degrees of freedom. These results indicate that larger wedge openings result in increased values of patellar distalization, lateral patellar shift, patellar rotation, and patellar internal tilt. The developed model in this study can be used in future studies to monitor the stress distribution on the patellar cartilage and connecting tissues to investigate their relationship with observations of pain and cartilage injury due to post-operative altered patellar kinematics.
... Therefore, the position of the patella often decreases after the operation [33,35]; In addition, the greater the degree of intraoperative correction of varus deformity, the higher the possibility of patella infera after operation. The lower the position of patella, the greater the pressure of patellofemoral joint in the process of knee flexion, which is easy to accelerate the degeneration of patellofemoral joint [36]. In view of this, in recent years, the MOWHTO infra the tibial tubercle has gradually been used in the treatment of genu varus with medial compartment KOA. ...
Article
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Objective Medial opening wedge high tibial osteotomy (MOWHTO) is a mainstream surgical method for treating early medial compartment knee osteoarthritis. Undesirable sequelae such as patella infera may happen following tuberosity osteotomy. We conducted this systematic review and meta-analysis to compare the change in patellar position after proximal tibial tubercle osteotomy (PTO) versus distal tibial tubercle osteotomy (DTO) intervention. Methods The 11 studies were acquired from PubMed, Medline, Embase and Cochrane Library. The data were extracted by two of the coauthors independently and were analyzed by RevMan5.3. Mean differences, odds ratios and 95% confidence intervals were calculated. Cochrane Collaboration’s Risk of Bias Tool and Newcastle–Ottawa Scale were used to assess risk of bias. Results Eleven observational studies were assessed. The methodological quality of the trials ranged from moderate to high. The pooled results of postoperative patellar height (Caton-Deschamps index and Blackburne-Peel index) and postoperative complications showed that the differences were statistically significant between PTO and DTO interventions. Patellar index ratios decreased significantly in the PTO groups, and 12 (9.2%) complications under DTO surgery and 2 (1.6%) complications under PTO surgery were reported. The differences of postoperative posterior tibial slope (angle) was not statistically significant, but postoperative posterior tibial slope of both groups increased. Sensitivity analysis proved the stability of the pooled results and the publication bias was not apparent. Conclusions DTO in MOWHTO maintained the postoperative patellar height, and clinically, for patients with serious patellofemoral osteoarthritis, DTO can be preferred. Postoperative complications are easily preventable with caution. In view of the heterogeneity and small sample size, whether these conclusions are applicable should be further determined in future studies.
... Conversely, there are observations indicating that the patellofemoral pressure increases after OWHTO (Javidan et al., 2013;Stoffel et al., 2007), and patellofemoral cartilage injuries progress in 41-45 % of patients in second-look arthroscopy (Goshima et al., 2017;Kim et al., 2017). ...
Article
Full-text available
Medial open-wedge high tibial osteotomy is a surgical treatment for patients with a varus deformity and early-stage medial knee osteoarthritis. Observations suggest that this surgery can negatively affect the patellofemoral joint and change the patellofemoral kinematics. However, what causes these effects and how the correction angle can change the surgery’s impact on the patellofemoral joint has not been investigated before. The objective of this study was to develop a biomechanical model that can predict the surgery’s impact on the patellar position and find the correlation between the opening angles and the patellar position after the surgery. A combined finite element and multibody model of the lower limb was developed. The model’s capabilities for predicting the patellofemoral kinematics were evaluated by performing a passive deep flexion simulation of the native knee and comparing the outcomes with magnetic resonance images of the study subject at various flexion angles. The model at a fixed knee flexion angle was then used to simulate the high tibial osteotomy surgery virtually. The results showed a correlation between the wedge opening angles and the patellar position in various degrees of freedom. These results indicate that larger wedge openings result in increased values of patellar distalization, lateral patellar shift, patellar rotation, and patellar internal tilt. The developed model in this study can be used in future studies to monitor the stress distribution on the patellar cartilage and connecting tissues to investigate their relationship with observations of pain and cartilage injury due to post-operative altered patellar kinematics.
... The topic of patellofemoral contact stress is, furthermore, contrarily discussed in the literature. Stoffel et al. [20] reported no alteration of patellofemoral contact stress in 2 medial open wedge HTOs performed on human cadaveric specimens. ...
Article
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PurposeThe purpose of this study was to quantify the influence of medial open wedge high tibial osteotomy on patellar kinematics using optical computer navigation, as anterior knee pain infrequently occurs postoperatively and the reason is still being unknown.Methods Ten medial open wedge high tibial osteotomies at supratuberosity level in 5 full body specimens were performed. The effect of the surgical procedure on patellar kinematics, measured at 5 and 10 degrees of leg alignment correction angle, was analyzed and compared to native patellar kinematics during passive motion—regarding patella shift, tilt, epicondylar distance and rotation. Linear mixed models were used for statistical analysis, a two‐sided p value of ≤ 0.05 was considered statistically significant.ResultsTilt behavior, medial shift and epicondylar distance did not show a significant difference regarding natural patellar kinematics at both osteotomy levels. Both osteotomy correction angles showed a significant less external rotation of the patella (p < 0.001, respectively) compared to natural kinematics.Conclusions Except less external rotation of the patella, medial open wedge high tibial osteotomy does not seem to relevantly alter patellar alignment during passive motion. Future clinical studies have to prove the effect of MOWHTO on patellar kinematics measured in this experimental setup, especially regarding its influence on anterior knee pain.
... Distal tibial tubercle osteotomy (DTO) in medial opening wedge high tibial osteotomy (MOWHTO) is a safe surgical intervention with good clinical outcomes for knee osteoarthritis patients [1][2][3][4]. In DTO, a technique in which the tibial tubercle is attached to the proximal tibial fragment, prevents patella infera [2,5], an increase in contact pressure at the patellofemoral joint [6,7], and decreases the eventual progression to patellofemoral osteoarthritis [1,2]. ...
Article
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Purpose To investigate whether tibial tubercle fracture affected clinical outcomes and bony union in medial opening wedge high tibial osteotomy with distal tibial tubercle osteotomy (DTO) and to determine the anatomical risk factors for tibial tubercle fracture. Materials and methods All patients who underwent DTO were retrospectively reviewed, and 104 successive patients were included. The Knee Society Score and complications including tibial tubercle fracture were recorded. On radiographs and computed tomography scans, the length, thickness, width, height, and bony union of the osteotomized tibial tubercle and the posterior tibial slope were statistically analysed. Results Fracture of the tibial tubercle occurred intraoperatively in 11 patients (10.6%) and in the postoperative period in 1 (1.0%). The case of postoperative fracture showed non-union. There was no significant difference in the Knee Society Score between the non-fracture and fracture groups. There were significant differences in the posterior tibial slope and the height of the tibial tubercle between the groups (p < 0.0001 for each comparison). The logistic regression analysis showed that the height of the tibial tubercle was associated with a higher risk of the fracture of the tibial tubercle (p < 0.01; OR, 1.548; 95% CI, 1.149–2.085). However, there were no significant differences in the bony union rate of the tibial tubercle at 6 months after surgery between the groups. Conclusions Tibial tubercle fracture did not affect the clinical outcome and bony union in spite of the relatively high occurrence rate. Anatomical risk factors for the fractures was a lower tibial tubercle position. Level of evidence Level IV.
... Furthermore, we performed proximal tuberosity osteotomies for all cases in this study. P-F joint pressure increases, and articular cartilage damage progresses after proximal tuberosity osteotomy [22][23][24]. In addition, P-F joint reaction forces gradually increased up to 90 of knee flexion and can reach up to 8 times the patient's body weight, depending on the type of activity (ie, stair climbing, squatting, and so on) [25]. ...
Article
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Background Globally, total knee arthroplasty (TKA) is widely performed on patients with osteoarthritis. Meanwhile, open wedge high tibial osteotomy (OWHTO) has garnered attention in our country as a joint-preserving procedure. This study aimed to retrospectively compare the postoperative clinical outcomes of TKA and OWHTO for patients with osteoarthritis. Methods We selected 94 patients (106 knees) who underwent OWHTO or TKA between 2013 and 2018, had complete clinical data, and were followed up for >2 years. Patients were classified into 2 groups depending on the procedure (TKA: n = 49; OWHTO: n = 45). Patients in the A (= arthroplasty) group were significantly older, with a worse range of motion (ROM) than those in the O (osteotomy) group. There were no significant differences regarding sex and body mass index between groups. Operative time, perioperative blood loss, knee ROM, and Japanese Knee Injury and Osteoarthritis Outcome Score (J-KOOS) were compared between the groups. Results Significant differences were found between the A and O groups regarding operative time (120 ± 27.2 vs 80.3 ± 23.3 minutes), perioperative blood loss (505.4 ± 271.8 vs 322.6 ± 196.1 mL), knee ROM (flexion; 123.4 ± 16.3° vs 133.7 ± 12.8°), and J-KOOS for pain (87.4 ± 12.5 vs 78.1 ± 15.2 points) and symptoms (86.6 ± 12.3 vs 79.1 ± 13.3 points). There were no significant differences regarding other J-KOOS subscales. Conclusions OWHTO involved shorter operative times and less blood loss. However, the O group reported less pain relief. The A group represents an older, likely less active patient population. Therefore, OWHTO is a possible joint-preserving treatment options in younger active patients who may not be interested in arthroplasty.
... Since the inception of this new technique, many authors have pointed out that patella height was not altered as compared with the conventional procedure. [5][6][7][8][9][10][11][12][13] In addition, Stoffel et al. 14 experimentally revealed that OWHTO with DTO maintained normal patellofemoral joint biomechanics with no significant increase in patellofemoral cartilage pressure. However, setting the DTO (the second osteotomy) line perpendicular to the OWHTO (the first osteotomy) line, which prevents creating a gap at the DTO site, is quite difficult during the actual procedure due to the triangular shape of the proximal tibia. ...
Article
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Medial open wedge high tibial osteotomy (OWHTO) is usually performed with proximal tuberosity osteotomy or setting the osteotomy line proximal to the tuberosity. However, OWHTO can result in patellofemoral complications due to postoperative patella infera. A new OWHTO technique, biplanar osteotomy with a distal tuberosity osteotomy, was reported in 2004 to prevent postoperative patella infera. To ensure that the 2 osteotomy lines maintain perpendicular, we describe the OWHTO procedure with a distal tuberosity osteotomy technique using a TriS Medial HTO Plate System (Olympus Terumo Biomaterials Corp., Tokyo, Japan) and a right angle guide we developed. In this Technical Note, we describe the procedure and advantages, risks, and limitations, as well as the pearls and pitfalls based on our experience.
... A standard biplane osteotomy with a proximal tubercle cut will result in distalisation of the patella and a conse-quent decrease in the Caton Deschamps Index [29]. The degree of distalisation is proportionate to the amount of correction, with biomechanical studies demonstrating a resultant increase in patella contact pressures [30]. As a guide, a biplanar osteotomy with a proximal tubercle cut will decrease patella height by 2 mm per 10°of valgus correction [31]. ...
Article
Background There are significant deficiencies in the evidence base of modern-day osteotomy which result in significant variation in practice between surgeons. The purpose of this statement was to develop a consensus statement on the practice of osteotomy so that a more standardized approach to the indications, surgical technique, and postoperative care could be outlined. The article is also intended to educate and inform the practice of individuals who are early in their experience and/or clinical practice. Method A group of 29 specialist knee surgeons who regularly perform osteotomy was convened to form the Knee Osteotomy consensus Group (KOG). Consensus was determined utilizing the consensus group technique described by List. A total of 37 questions were asked covering all aspects of clinical practice. Results 20 statements were generated and debated until a criterion level of 70% was met. Conclusions Consensus was achieved regarding 20 statements concerning Indications for surgery, decision making, surgical planning, technique, post-operative assessment and recovery.
... The most important findings of this study were the following three: Firstly, preoperative elevated BTU values in the patellar region correlated significantly with a worse clinical outcome. It was previously shown that MOWHTO leads to an increase of the contact pressure in the patellofemoral joint (PFJ) [15,19,20,25,37,39]. Kim et al. [19] suggested that the increased loading of the PFJ may be the cause of postoperative pain and be associated with the development and progression of OA in the PFJ. ...
Article
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Purpose The purpose of this study was to investigate whether specific bone tracer uptake (BTU) patterns on preoperative SPECT/CT could predict which patients with varus alignment and medial overload would particularly benefit from medial opening-wedge high tibial osteotomy (MOWHTO). It was the hypothesis that an increased preoperative BTU relative to the reference BTU of the femur on SPECT/CT in the lateral and patellar compartments of the knee are predictive factors for inferior clinical outcome and that the clinical outcome correlates with the extent of alignment correction. Methods Twenty-three knees from 22 patients who underwent MOWHTO for medial compartment overload were investigated preoperatively using Tc-99m-SPECT/CT. BTU was quantified and localised to specific joint areas according to a previously validated scheme. Pre- and postoperative mechanical alignment was measured. Clinical outcome was assessed at a median of 24 months (range 11–30) after MOWHTO by collecting the WOMAC score. Results Significant correlations between BTU in the patellar area and the total WOMAC score and its subcategories pain and stiffness were found. Thus, BTU in the 1sPat area (superior lateral patellar compartment) correlated with total WOMAC (rho = 0.43, p = 0.04), pain subcategory (rho = 0.43, p = 0.04), and stiffness subcategory (rho = 0.59, p = 0.003). No significant correlations were found between alignment correction, age, gender and WOMAC. Conclusion This study highlights the role of preoperative SPECT in modern knee surgery to obtain information about the loading pattern on different compartments of the knee. Despite the limited number of participants, the present study shows that a preoperative SPECT/CT scan can help the treating surgeons to identify patients who may be at risk of inferior clinical outcome if an MOWHTO is considered, as an elevated BTU in the patellar region on preoperative SPECT/CT appears to be a potential risk factor for postoperative pain and stiffness. Level of evidence Level III.
... Medial open wedge high tibial osteotomy (MOWHTO) proximal to the tibial tuberosity is an established treatment option for patients with varus alignment and medial compartment OA, showing good clinical outcomes and high survival rates in long-term follow-ups [13,25,27,31]. However, different associated problems such as patella baja, increased patellofemoral contact pressures and alterations of patellofemoral tracking have been described following MOWHTO [9,17,28,33,35]. Increased contact pressure is reported to be an important factor in the development of OA [17,29]. ...
Article
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Purpose: Medial open wedge high tibial osteotomy (MOWHTO) is an effective treatment option for realignment of a varus knee. However, a simple supra-tuberositary osteotomy can lead to patella baja and potentially increases the tibial tuberosity-trochlear groove distance (TTTG). The purpose of this study was to quantify the influence of MOWHTO on TTTG. Methods: Three-dimensional (3D) surface models of five lower extremities with a varus hip-knee-ankle angle (HKA) and a borderline TTTG (≥ 15 mm), five lower extremities with a varus HKA and a normal TTTG (< 15 mm) and a 3D statistical shape model (SSM) of a neutrally aligned healthy knee were analysed by simulating MOWHTO with a stepwise increment of one degree of valgisation from the preoperative coronal deformity (0°-15°) for each patient, resulting in a total of 165 simulations. Postoperative 3D TTTG and tibial torsion (TT) were measured for each simulation. A mathematical formula was developed to calculate the increase of TTTG after MOWHTO. Mean differences between simulated and calculated TTTG were analysed. Results: Mean preoperative HKA was 6.5 ± 3.0° varus (range 0.8°-11.5°). Mean TTTG increased from 14.2 ± 3.2 mm (range 9.6-19.1) preoperatively to 18.8 ± 3.8 mm (range 14.5-25.0) postoperatively (p = 0.001). TTTG increased approximately linear by + 0.5 ± 0.2° (range 0.3-0.8) per 1° of valgisation with a high positive correlation (0.99, p = 0.001) from 0° to 15°. Mean difference between simulated and calculated TTTG was 0.03 ± 0.02 mm (range 0.01-0.07) per 1° of valgisation (p < 0.001). Conclusion: MOWHTO results in an approximately linear increase in TTTG of + 0.5 mm per 1° of valgisation in the range from 0° to 15° and the lateralisation of the tibial tuberosity can be calculated reliably using the described formula. Preoperative analysis of TTTG in patients undergoing MOWHTO may prevent unintentional patellofemoral malalignment. Level of evidence: III.
Article
Purpose The purpose of this study was to quantify the effect of clinically relevant open-wedge high tibial osteotomies on medial collateral ligament (MCL) strain and the resultant tibiofemoral contact mechanics during knee extension and 30° knee flexion. Methods Six human cadaveric knee joints were axially loaded (1 kN) in knee extension and 30° knee flexion. Strains at the anterior and posterior regions of the MCL were determined using strain gauges. Tibiofemoral contact mechanics (contact area, mean and maximum contact pressure) were investigated using pressure-sensitive sensors. Open-wedge osteotomy was performed using biplanar cuts and osteotomy angles of 5° and 10° were maintained using an external fixator. Tests were performed first with intact and then with dissected MCL. Results Nonparametric statistical analyses indicated a significant strain increase (p < 0.01) in the anterior and posterior fibres of the MCL with increasing osteotomy angle of up to 8.3% and 6.0%, respectively. Only after releasing the MCL the desired lateralisation of the mechanical axis was achieved, indicating a significant decrease in the maximum contact pressure in knee extension of − 25% (p = 0.028) and 30° knee flexion of − 21% (p = 0.027). Conclusions The results of the present biomechanical study suggest, that an open-wedge high tibial osteotomy is most effective in reducing the medial contact pressure when spreading the osteotomy to 10° and concomitantly releasing the MCL. To transfer the results of this biomechanical study to the clinical day-to-day practice, it is necessary to factor in the individual ligamentous laxity of each patient into the treatment options e.g. particularly for patients with distinct knee ligament laxity or medial ligamentary instability, the release of the MCL should be performed with care. Level of evidence Controlled laboratory study.
Article
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Purpose Valgus high tibial osteotomy (HTO) and a recently introduced extra-articular absorber have been shown to efficiently unload the medial compartment of the knee. However, only little is known about the influence of these treatment modalities on biomechanics of the patellofemoral joint. The purpose of this study was to investigate and compare the impact of different HTO techniques and implantation of an extra-articular absorber on patellofemoral contact forces. Methods Fourteen fresh frozen cadaveric knees were tested in a specially designed knee simulator that allowed simulation of isokinetic flexion–extension motions under physiological loading. Mean contact pressure (ACP) and peak contact pressure (PCP) of the patellofemoral joint was measured continuously between 0° and 120° of knee flexion using a pressure sensitive film in the following conditions: native, after biplanar medial open-wedge HTO with 5° and 10° correction angle performing an ascending frontal osteotomy of the tibial tuberosity, and after implantation of an extra-articular absorber system (KineSpring®). Including a second testing cycle with a biplanar medial open-wedge HTO with 5° and 10° correction angle performing descending frontal osteotomy of the tibial tuberosity. Values after each procedure were compared to the corresponding values of the native knee. Results Biplanar proximal osteotomy leaded to a significant increase of retropatellar compartment area contact pressure compared to the first untreated test cycle (Δ 0.04 ± 0.01 MPa, p = 0.04). Similar results were observed measuring peak contact pressure (Δ 1.41 ± 0.15 MPa, p = 0.03). With greater correction angle 5°, respectively, 10° peak and contact pressure increased accordingly. In contrast, the biplanar distal osteotomy group showed significant decrease of pressure values (p = 0.004). The extracapsular, extra-articular absorber had no significant influence on pressure levels in the patellofemoral joint. Conclusion HTO with a proximal biplanar osteotomy of the tuberositas tibia significantly increased patellofemoral pressure conditions depending on the correction angle. In contrast a distally directed biplanar osteotomy diminished these effects while implantation of an extracapsular, extra-articular absorber had no influence on the patellofemoral compartment at all. Consequently, patients with varus alignment with additional retropatellar chondropathia should be treated with a distally adverted osteotomy to avoid further undesirable pressure elevation in the patellofemoral joint.
Article
Background: Recent studies have reported that medial opening wedge (OW) high tibial osteotomy (HTO) induces patella baja, resulting in degenerative changes in the patellofemoral joint. We have developed an inverted V-shaped (iV) HTO, which is classified as a neutral wedge osteotomy. Hypotheses: The study hypotheses were as follows: (1) patellar height, posterior tibial slope, and tibial length will not change between pre- and postoperative evaluations after iV-HTO; (2) the lateral shift ratio of the patella and the distance between the tibial tubercle and the trochlear groove may be significantly decreased after iV-HTO. Study design: Cohort study; Level of evidence, 3. Methods: A total of 191 patients (220 knees) who underwent HTO for medial osteoarthritis were enrolled retrospectively in this study: 107 knees underwent OW-HTO and 113 knees underwent iV-HTO. Clinical and radiological evaluations were performed before and at least 3 years after surgery. Results: Postoperatively, the mean Caton-Deschamps ratio was significantly decreased (P < .0001) from 0.95 to 0.79 in the OW group, while there were no significant changes in the iV group. The mean posterior tibial slope was significantly increased (P < .0001) from 8.5° to 10.5° in the OW group, while there were no significant differences in the iV group. Although the entire leg length was significantly increased (P < .0003) in both groups after HTO, there were no significant differences in tibial length between the pre- and postoperative periods in the iV group. Regarding the congruity of the patellofemoral joint, the mean lateral shift ratio did not significantly change in the OW group, whereas it was significantly decreased (P = .0012) from 11.5% to 8.8% in the iV group. The mean tibial tubercle-trochlear groove distance was significantly decreased (P < .0001) from 12.8 to 9.7 mm in the iV group, while it was significantly increased in the OW group (P < .0001). Concerning the clinical outcome, the Japanese Orthopaedic Association (JOA) and Lysholm knee scores at final follow-up (OW vs iV: JOA, 91.2 vs 90.1; Lysholm, 92.5 vs 89.0) were significantly increased (P < .0001) as compared with the preoperative values (OW vs iV: JOA, 68.3 vs 66.8; Lysholm, 67.9 vs 61.0). Conclusion: Patellar height, posterior tibial slope, and tibial length did not change after the iV-HTO, while they were significantly changed after the OW-HTO. Although the preoperative degrees of varus knee and patellofemoral osteoarthritis were more severe in the iV group than the OW group, the iV-HTO led to altered patellofemoral joint congruity.
Article
Purpose To evaluate clinical outcomes and radiographic changes in patellofemoral (PF) joint congruity between open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge HTO (HCWHTO). Methods From 2011 to 2013, 36 knees in 31 patients who underwent OWHTO and 21 knees in 17 patients who underwent HCWHTO were evaluated in this retrospective study with a minimum 5-year follow-up. Radiological outcomes including hip–knee–ankle angle (HKA), femoral patellar height index (FPHI), preoperative PF osteoarthritis (OA) grade, medial and lateral joint spaces of the PF joint, and congruence angle were measured. Clinical parameters including the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Oxford Knee Score (OKS) were also evaluated. Preoperative and final follow-up values for each procedure were compared in outcome analyses. Results Mean preoperative HKA and the degree of PF-OA were significantly more severe for patients treated with HCWHTO compared with those treated with OWHTO (p = 0.001, p = 0.0001). Mean postoperative FPHI was significantly decreased with proximalization of the patella in HCWHTO (p = 0.01) but showed no significant change in OWHTO (n.s.). Regarding PF joint congruity after HCWHTO, lateral joint space and congruence angle were significantly improved (p = 0.0001, p = 0.005), while medial joint space was not significantly changed (n.s.). After OWHTO, congruence angle showed no significant difference (n.s.), but medial and lateral joint spaces were significantly decreased (p = 0.0001, p = 0.018). There were no significant differences in KOOS and OKS between the groups (n.s., n.s.). Conclusions Although degrees of varus knee and PF-OA were more severe in HCWHTO than those in OWHTO, HCWHTO led to improved PF joint congruity, and its mid-term clinical outcomes were equivalent to those of OWHTO. Therefore, in patients with varus knee combined with PF-OA preoperatively, HCWHTO is a more effective treatment than OWHTO. Level of evidence Therapeutic level III.
Article
Full-text available
Background Patients suffering cartilage defects of the medial compartment with underlying varus deformity do benefit from high tibial osteotomy (HTO) even in the long term. Nonetheless, kinematic and geometric changes especially in the patellofemoral joint have been described. Purpose of the present study was to evaluate the influence of patellofemoral cartilage defects detected during the diagnostic arthroscopy and their influence on HTO’s postoperative outcome. Methods Ninety patients with a mean follow-up of 10.08 ± 2.33 years after surgery were included. Patients were divided into four groups according to their cartilage status in the patellofemoral joint (A = no defects, B = isolated lesions of the patella, C = isolated lesions of the trochlea, D = kissing lesions). Functional outcome was evaluated before surgery and about ten years thereafter by relying on the IKDC, Lysholm, and KOOS scores. Radiological parameters were assessed pre- and six weeks postoperatively. Results In groups A to D, the HTO led to significant patellar distalisation in the sagittal view, with the mean indices remaining at or above the limit to a patella baja. All patients in all groups profited significantly from HTO (higher Lysholm score, lower VAS p < 0.001), patients in group D had the lowest outcome scores. Patella height negatively influenced outcome scores in group C (Blackburne-Peel-Index—VAS p = 0.033) and D (Caton-Deschamps-Index—Tegner p = 0.018), a larger valgus correction was associated with lower outcome scores in group D (Lysholm p = 0.044, KOOSpain 0.028, KOOSQOL p = 0.004). Conclusion Long-term results of HTO for varus medial compartment osteoarthritis remain good to excellent even in the presence of patellofemoral defects. Overcorrection should be avoided. Distal biplanar HTO should be considered for patients presenting trochlear or kissing lesions of the patellofemoral joint. Trial registration DRKS00015733 in the German Registry of Clinical Studies.
Article
Purpose: To identify risk factors for patellofemoral degenerative progression after opening-wedge high tibial osteotomy (HTO) and to investigate the effect of patellofemoral degeneration on the patellofemoral specific patient-reported outcomes. Methods: Between March 2010 and June 2016, 94 knees (86 patients) underwent hardware removal with second-look arthroscopy at 21.4 months after opening-wedge HTO with first-look arthroscopy (mean follow-up duration, 49.8 months). Predictive factors for patellofemoral degeneration, including demographics, preoperative and postoperative mechanical axis (MA) of the lower limb (positive and negative MA indicating varus and valgus, respectively), tibial slope, and modified Blackburne-Peel ratio, were evaluated. Patients were divided into the progression and nonprogression groups according to their patellofemoral degenerative progression from first to second arthroscopy. Clinical outcomes, including the Kujala score and Knee Injury and Osteoarthritis Outcome Score, and radiographic outcomes were compared between the 2 groups. Results: Postoperative MA (adjusted odd ratio, 0.62; P < .001) was the most significant predictive factor for progressive change in the patellofemoral joint (Rn2 = 0.31). Twenty-eight knees (30%) showed patellofemoral degenerative progression. Mean postoperative Kujala score (progression group 60.5 vs nonprogression group, 72.3; P = .005) and Knee Injury and Osteoarthritis Outcome Score scales (except for the symptom subscale) were lower in the progression group. Postoperative MA was significantly more corrected in the progression group (progression group -5.1° ± 2.7° vs nonprogression group -2.4° ± 2.3°; P < .001). Conclusions: Postoperative MA, which might be related to overcorrection, is correlated with patellofemoral degenerative progression after opening-wedge HTO. Patients with patellofemoral degenerative progression showed inferior patient-reported outcomes. Level of evidence: Level IV, case series with subgroup analysis.
Article
Purpose To investigate the progression of patellofemoral (PF) osteoarthritis (OA) after medial open wedge high tibial osteotomy (OWHTO), and whether PF OA progression has an influence on clinical outcomes. Methods According to Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA), EMBASE, PubMed and Cochrane Library were searched in June 2020 for English-language studies that presented data on PF OA or cartilage degeneration before and after OWHTO. Descriptive statistics are presented. Results Twenty studies comprising 1,173 patients were included. The mean age was 57.1 years (range, 18-84) with 826 (70.4%) female. The mean follow-up was 27.1 months (range, 7-144). Ten studies reported the trochlear International Cartilage Research Society (ICRS) scores, with each of these studies reporting a higher proportion of patients with grades 2-4 OA post-operatively compared to pre-operatively (relative risks=1.19 to 2.76, I2=1.9%). Similarly, seven studies reported patellar ICRS scores and found a higher proportion with grades 2-4 OA post-operatively (relative risks=1.08 to 2.44, I2=0%). Four studies assessed PF Kellgren-Lawrence (K-L) grade each of which reported a higher proportion of patients with grades 2-4 OA post-operatively (relative risks=1.25 to 21.0, I2=31%). The PF OA assessments were heterogenous, and studies using classifications except ICRS score or K-L grade were not included in statistical analysis. Fifteen studies assessed patellar height; ten studies reported significant decrease in patellar height after OWHTO. Only three studies reported clinical outcomes for patients with and without PF OA progression. Outcome reporting was variable across these studies, and relationship between PF OA progression and clinical outcome could not be definitively determined. Conclusion Patients appear to have progression of PF OA after medial OWHTO. However, there are currently insufficient studies with inconsistent measurements of outcomes to make meaningful conclusions for the impact of PF OA on clinical outcomes.
Article
Purpose The purpose of the present study was to use arthroscopy to evaluate the effect of distal tuberosity osteotomy (DTO) in open-wedge high tibial osteotomy (OW-HTO) on patellofemoral (PF) cartilage degradation. Methods Between 2012 and 2017, 46 knees underwent DTO in OW-HTO, and 65 knees underwent conventional OW-HTO (cOW-HTO). To assess changes in patellar height, the Blackburne–Peel (BP) ratio and the Caton–Deschamps (CD) index were measured. Arthroscopic evaluation on the PF joint was performed at the initial osteotomy and at the second-look procedure 1 year later. Statistical analyses were performed to compare difference between the DTO and the cOW-HTO group. Results In the cOW-HTO group, the mean BP ratio and CD index decreased significantly from 0.81 and 0.89 preoperatively, respectively, to 0.69 and 0.76 postoperatively, respectively (p < 0.001). In contrast, the DTO group maintained a consistent patellar height; the mean BP ratio and CD index were 0.77 and 0.83 preoperatively, respectively, and 0.73 and 0.80 postoperatively, respectively. Upon arthroscopic evaluation, 39 of 46 patients (84.8%) in the DTO group showed no progression of PF cartilage degradation at the second look; indeed, five of 46 patients (10.9%) even demonstrated improvement. In contrast, 21 of 65 patients (32.3%) in the cOW-HTO group exhibited increased PF cartilage degradation. There was a significant difference in progression of PF cartilage degradation between DTO and cOW-HTO (p < 0.001). Conclusion DTO in OW-HTO maintained the preoperative patellar height, which could help prevent progression of cartilage degeneration in the PF joint after surgery. In respect of the biplanar osteotomy direction in OW-HTO, the DTO, rather than cOWHTO, is the preferred technique for the treatment of varus knee osteoarthritis to avoid progression of PF cartilage degradation. Level of evidence III.
Article
Background: No study has yet assessed the effect of medial open-wedge high tibial osteotomy (MOWHTO) on the patellofemoral joint according to postoperative alignment. Purpose: To evaluate the effect of MOWHTO on the patellofemoral joint according to postoperative alignment by comparing the cartilage status before and after surgery and assessing the clinical and radiological outcomes. Study design: Cohort study; Level of evidence, 3. Methods: A total of 135 patients who underwent MOWHTO were retrospectively investigated. The patients were divided into 3 groups according to the postoperative weightbearing line ratio (WBLR): undercorrection (WBLR <58.3%, lowest quartile), acceptable correction (WBLR of 58.3%-66.3%, middle 2 quartiles), and overcorrection (WBLR >66.3%, highest quartile). The postoperative change in the cartilage status was assessed arthroscopically during implant removal at 2 years after MOWHTO. The clinical and radiological outcomes were evaluated at a mean follow-up of 52.1 months. A regression analysis was performed to identify the factors affecting the deterioration of the patellofemoral joint cartilage status. A receiver operating characteristic curve was employed to identify the cutoff point for the postoperative WBLR associated with the deterioration of the cartilage status in the patellofemoral joint. Results: Of all patients, progression of cartilage degeneration was noted in 39.3% for femoral trochlea and 23.7% for patella. The incidence of cartilage progression was significantly higher in the overcorrection group than in the undercorrection and acceptable correction groups (femoral trochlea: undercorrection group = 30.3%, acceptable correction group = 32.4%, and overcorrection group = 61.8% [ P = .008]; patella: undercorrection group = 15.2%, acceptable correction group = 17.7%, and overcorrection group = 44.1% [ P = .005]). The functional outcomes, including Lysholm knee score, Knee injury and Osteoarthritis Outcome Score (Pain, Symptoms, and Activities of Daily Living subscales), and Shelbourne and Trumper score, were significantly worse in the overcorrection group. The regression analysis showed that only the postoperative WBLR had a significant effect on cartilage deterioration. The cutoff point for the postoperative WBLR associated with progression of the International Cartilage Repair Society grade was 62.1% for the femoral trochlea (sensitivity = 61.5%, specificity = 62.7%, accuracy = 66.2%) and 62.2% for the patella (sensitivity = 59.4%, specificity = 60.2%, accuracy = 67.8%). Conclusion: The patellofemoral joint was adversely affected by MOWHTO. Overcorrection causing excessive valgus alignment led to further progression of degenerative changes in the patellofemoral joint and inferior clinical outcomes. The postoperative WBLR can be used as a predictive factor for deterioration of the cartilage status in the patellofemoral joint after MOWHTO.
Article
Imaging of the patellofemoral joint (PFJ) is useful to evaluate for injury and to better understand the relationship between osseous and soft tissue structures. Interpretation of PFJ imaging findings should be used in the context of patient's history and physical examination. X-rays and advanced imaging technology can provide information to confirm diagnosis and to help customize individual treatment plans. This chapter reviews relevant imaging studies utilized in the work-up and treatment of patients with patellofemoral disorders.
Article
Purpose To investigate the effect of proximal tibial tubercle osteotomy (PTO) and distal tibial tubercle osteotomy (DTO) in medial opening wedge high tibial osteotomy on patellofemoral alignment, patellofemoral osteoarthritis and clinical outcomes. Methods PTO (n = 41) and DTO (n = 43) for the same surgical indications were included. Radiographic measurements of the Caton-Deschamps index, patellar tilt and shift, and arthroscopic cartilage evaluation at the patellofemoral joint were performed at osteotomy and plate removal. The Knee Society Score (KSS) was evaluated preoperatively and at the latest follow-up. Results The follow-up period was longer in the PTO group (33.7 months; range 23–40 years) than in the DTO group (22.2 months; range 18–29 months) (p < 0.0001), whereas the period from osteotomy to plate removal was not different between the groups. The Caton-Deschamps index of the DTO group was unchanged from 0.9 (range 0.7–1.2) to 0.9 (range 0.6–1.4), whereas that of the PTO group changed from 0.9 (0.7–1.2) to 0.7 (0.5–1.0) (p < 0.0001). There were fewer deteriorated cases of cartilage status in the trochlear groove in the DTO group (20.9%) than in the PTO group (56.1%, p < 0.05). There were more improved cases in the DTO group (23.3%) than in the PTO group (4.9%, p < 0.05). Postoperative KSS was better in the DTO group than in the PTO group (p < 0.05). Conclusion DTO is associated not only with reduced deterioration but also with increased improvement of cartilage status in the trochlear groove and better KSS as compared with PTO. Level of evidence IV.
Article
Objectives To assess the impact of a biplanar ascending opening-wedge high tibial osteotomy (OWHTO) on the alignment of the knee extensor mechanism and patellar height using preoperative and postoperative MRI. Methods Medical records of all patients submitted to ascending biplanar OWHTO between July 2008 and March 2017 were retrospectively assessed. Five parameters of the patellofemoral joint—tibial tubercle–trochlear groove distance (TT-TG), patellofemoral (PF) axial engagement index, lateral patellar tilt, Blackburne-Peel index (BPI) and Caton-Deschamps index (CDI)—were measured by two blinded independent observers on both preoperative and postoperative MRIs. Interobserver reliability was assessed with the intraclass correlation coefficient (ICC). Paired t-test was performed to compare preoperative and postoperative measurements. The association of the amount of HTO opening and the assessed PF joint parameters was also investigated with Pearson correlation coefficient. Results 26 patients who underwent ascending biplanar OWHTO were enrolled in this imaging analysis (63.4%) with a mean follow-up of 16.3 months (SD, 16.9). ICC for all measurements ranged between 73.3% and 89.3%. Postoperatively, TT-TG distance significantly increased by 2.0 mm±2.3 mm (p<0.001). Patellar height significantly decreased when evaluated by the BPI (p<0.001) and CDI (p=0.001). The amount of osteotomy opening significantly correlates with the postoperative BPI (p=0.023) and CDI (p=0.013). Conclusion This study comprehensively reports significant increase on TT-TG distance after an ascending biplanar OWHTO using MRI. Small but significant decreases in patellar height were also observed and are correlated to the amount of axis correction. Level of evidence Level IV, retrospective case study.
Article
Background: To investigate the morphological changes in the tibiofibular joint following open wedge high tibial osteotomy (OWHTO). Methods: We studied 397 joints in 341 patients. Standing femorotibial angle (FTA), %mechanical axis (%MA), corrected tibial angle, distance (D) to tibial joint surface (T) and fibular head (F) and angle (A; proximal, distal), proximal tibiofibular joint (PTFJ) osteoarthritis (OA) onset, and tibiofibular joint-related complications were the parameters assessed. Results: FTA improved from 181.1° to 168.8° and %MA from 28.7 to 68.7, whereas the mean tibia corrected angle was 10.4°. Proximal TFD changed from 9.4 mm preoperatively to 7.8 mm during the investigation. The fibular head was displaced 1.6 mm upwards, and proximal tibial femoral angle (TFA) moved approximately 10° in the valgus direction from 82.5° to 92.4°. However, no significant changes were noted for the distal TFD or TFA. PTFJ OA was observed in 57 cases (14.7%), and lateroposterior knee pain in 11 cases (2.8%). Additional resection of the fibula was performed in cases with marked pain. Conclusions: With OWHTO, increased load is placed on the PTFJ postoperatively. In rare cases, this can cause pain and is therefore a complication that physicians should be aware of.
Article
Background: After high tibial osteotomy (HTO), the loading of the lateral compartment can be increased. Moreover, the change of patellar height may adversely affect the patellofemoral joint and functional outcomes. Hypothesis: We hypothesized that the cartilage of the lateral compartment and patellofemoral joint would worsen after open-wedge HTO and the overcorrection of HTO could worsen the cartilage state of the patellofemoral joint. We evaluated the cartilage status and clinical results after medial open-wedge HTO and the factors affecting the outcomes. Materials and Methods: From 2011 to 2018, 49 patients who had a mean age of 54.9 years and who underwent medial open-wedge HTO were selected. Plate removal was performed at a mean of 37.0 (range, 13–89) months after HTO, whereas diagnostic arthroscopy was performed during medial open-wedge HTO and plate removal. The cartilage status of each joint and the clinical results, including the Hospital for Special Surgery (HSS) score, Knee Society knee score (KS) and function score (FS), and patellar score, were compared. We evaluated the postoperative changes in the cartilage status and clinical scores. Additionally, we evaluated whether the postoperative correction degree could affect the clinical results. Result: After medial open-wedge HTO, the patellar height decreased. There was no change in the cartilage at the patellar and femoral trochlear groove. The HSS score, KS, and FS improved, but the patellar score remained unchanged. In the overcorrection group, the cartilage status significantly deteriorated at the lateral tibia condyle as compared with that in the undercorrection group. Higher preoperative clinical scores were associated with less postoperative improvement. Discussion and Conclusion: The outcomes in the patellofemoral joint, including the cartilage condition and clinical scores, did not change after open-wedge HTO, despite patellar infera. Additionally, they were not influenced by the correction degree. Higher preoperative clinical scores were associated with less postoperative improvement. Level of evidence: IV; Retrospective study.
Article
Purpose The purpose of this study was to identify whether or not retro-tubercle opening-wedge high tibial osteotomy (RT-OWHTO) produces more favorable radiographic outcomes on patellofemoral joint alignment and clinical outcomes than supra-tubercle opening-wedge high tibial osteotomy (ST-OWHTO). Methods From January 2017 to July 2018, patients who underwent bi-planar OWHTO were allocated to one of two groups (ST-OWHTO and RT-OWHTO). Plain radiographs and computed tomography were used to analyze patellofemoral alignment and other radiological parameters representing osteotomy configurations. Clinical outcomes were assessed using American Knee Society Score and Western Ontario and McMaster Universities Osteoarthritis Index. Results In total, 50 knees that underwent ST-OWHTO and 44 knees that underwent RT-OWHTO were enrolled. Patellar height was significantly decreased only after ST-OWHTO (Caton-Deschamps ratio: p=0.007; Blackburne-Peel ratio: p=0.012). Patellar tilt angle was decreased in both groups (p=0.009 and 0.004, respectively). Postoperative posterior tibial slope (PTS) (p=0.013), PTS (△) (p<0.001), retro-tuberosity gap distance (p=0.001), and retro-tuberosity tip distance (p=0.001) were significantly larger in RT-OWHTO. Retro-tuberosity tip distance was significantly correlated with retro-tuberosity gap distance (p=0.002), thickness of 2nd plane osteotomy fragment (p=0.027), and anterior osteotomy ratio (p=0.031) in ST-OWHTO. In RT-OWHTO, it was significantly correlated with PTS (△) (p<0.001), retro-tuberosity gap distance (p<0.001), and sagittal angle of bi-planar osteotomy (p=0.005). There were 2 cases of tibial tuberosity fracture, 9 cases of delayed union on 2nd plane osteotomy and 5 cases of tuberosity protrusion in RT-OWHTO. Conclusion While the RT-OWHTO technique maintains patellofemoral joint alignment, no difference in clinical outcome was detected. The RT-OWHTO has increased risk of tuberosity fracture, delayed union, and prominent tibial tuberosity. The surgeon should consider these negative aspects of the technique and consider adjusting additional stabilization. Level of Evidence Level III, Retrospective cohort study
Article
Background Previous studies have reported patellofemoral cartilage degeneration and analyzed the factors affecting degeneration after open-wedge high tibial osteotomy (OWHTO). However, no studies have evaluated patellofemoral cartilage degeneration or examined the factors affecting degeneration after closed-wedge high tibial osteotomy (CWHTO). Purpose To investigate and compare patellofemoral cartilage degeneration after CWHTO and OWHTO via arthroscopic evaluation and to analyze the factors affecting the degeneration. Study Design Cohort study; Level of evidence, 3. Methods A total of 54 CWHTOs and 50 OWHTOs were performed with first-look arthroscopy between 2013 and 2017 at one institution. Hardware removal and second-look arthroscopy were performed, on average, 30.2 months after CWHTO and 26.8 months after OWHTO ( P = .178). Patient characteristics did not differ significantly between the groups. Radiographically, the mechanical axis, posterior tibial slope, and modified Blackburne-Peel ratio were evaluated. Arthroscopically, the percentage of patient with patellofemoral cartilage degeneration was evaluated according to the International Cartilage Repair Society grading system. Logistic regression analysis was used to identify the factors affecting patellofemoral cartilage degeneration in terms of demographics and the change of mechanical axis (correction angle), tibial posterior slope angle, and modified Blackburne-Peel ratio. The Anterior Knee Pain Scale was used for clinical comparison between the patellofemoral degenerative and nondegenerative groups. Results No significant differences were observed in pre- and postoperative radiographic results between the CWHTO and OWHTO groups, except that the postoperative modified Blackburne-Peel ratio was significantly smaller among the OWHTOs. The percentage of patients with patellofemoral cartilage degeneration were 29.6% in the CWHTO group and 44% in the OWHTO group ( P = .156) at second-look arthroscopy. The correction angle was the only significant factor affecting cartilage degeneration in the CWHTO group (odds ratio, 2.324; P = .013; cutoff value, 9.6°) and the OWHTO group (odds ratio, 1.440; P = .041; cutoff value, 10.1°). The postoperative Anterior Knee Pain Scale score was significantly lower in the patellofemoral degenerative group as compared with the nondegenerative group among the OWHTO group (81.6 vs 76.4; P = .039); among the CWHTO group, there was a lower tendency in the degenerative group, but this was without significance (81.1 vs 79.6; P = .367). Conclusion Patellofemoral cartilage degeneration progressed after CWHTO and OWHTO with large alignment correction. High tibial osteotomy should be selected with careful consideration of the osteoarthritic status of the patellofemoral joint and required correction angle, regardless of applying a closed- or open-wedge technique.
Article
Objectives Several studies have reported negative effects of open wedge high tibial osteotomy (OWHTO) on patellofemoral joints with cartilage degeneration and recommended performing other procedures. However, if chondral resurfacing surgery could promote improvement of cartilage degeneration in the patellofemoral joint, OWHTO would be an acceptable option. The purposes of this study were to arthroscopically evaluate the femoral trochlear articular cartilage after abrasion arthroplasty combined with OWHTO and to investigate the factors promoting improvement of that cartilage. Methods The present study cohort comprised 18 knees of 18 patients with varus osteoarthritis of the knee who had (1) International Cartilage Repair Society (ICRS) grade 4 femoral trochlear chondral lesions at the time of OWHTO; (2) undergone abrasion arthroplasty of the femoral trochlear cartilage in combination with OWHTO; (3) undergone second-look arthroscopy; and (4) been followed up for more than 2 years. Cartilage status was arthroscopically graded at the time of OWHTO and second-look arthroscopy. Patients were allocated to two groups according to the status of the femoral trochlear cartilage at the time of second-look arthroscopy: the improved group comprised patients with an ICRS grade of less than 3, and the not improved group comprised those with an ICRS grade of 4. Clinical outcomes, expressed as Knee Injury and Osteoarthritis Outcome Score (symptoms, pain, activities of daily living, function in sports/recreation and quality of life) and selected radiographic variables were compared between the two groups. Results There were 11 (61%) knees in the improved group and 7 (39%) in the not improved group. A comparison of radiographic variables between the two groups revealed that neither limb alignment nor patellar height affected cartilage changes. The two groups had similar results on the symptoms, pain, sports/recreation and activities of daily living subscales of the Knee Injury and Osteoarthritis Outcome Score. However, the quality of life subscale significantly differed between the two groups (p=0.025). Conclusion Degenerated femoral trochlear cartilage can improve after combined abrasion arthroplasty and OWHTO. A comparison of clinical outcomes between the improved and not improved groups revealed that neither radiographic variables nor clinical symptoms, including pain, affected cartilage changes at short-term follow-up. Level of evidence Case series, level V.
Article
Background To evaluate the effect of adductor canal block (ACB) on short-term postoperative outcomes in patients who underwent medial open-wedge high tibial osteotomy (MOWHTO) compared to that of a placebo. Methods 35 patients who underwent unilateral MOWHTO between 2017 and 2019 were prospectively reviewed and randomly divided into two groups: 19 patients who received a single-shot ACB and 16 patients who received a saline injection (a placebo group). Primary outcomes were (1) pain measured using the visual analog scale and range of motion, (2) patient satisfaction, (3) postoperative need for additional opioids, (3) quadriceps strength (the time to straight leg raising [SLR]), (4) clinical outcomes, and (5) complications. Results The pain score was lower in the ACB group than in the placebo group in the first 12 h (p = 0.04). ACB did not exhibit significantly less quadriceps strength weakness postoperatively. There was no statistical difference in the time to SLR (23.5 ± 17.7 h in ACB vs. 27.6 ± 11.4 in placebo, p = 0.520). The opioid consumption rate within postoperative 12 h was significantly decreased after ACB (16.7% in ACB, 70% in placebo, p = 0.017). The proportion of patients with more than 5 opioid injections within 72 h postoperatively was lower in the ACB group (8.3% in ACB, 50% in placebo, p = 0.043). Both groups did not show any localized and systemic complications. Conclusion ACB following MOWHTO exhibited better outcomes than a placebo with respect to opioid consumption with no changes in the quadriceps strength and complications. Level of Evidence II, Prospectively comparative study
Article
Objective Closing-wedge high tibial osteotomy (CWHTO) for medial osteoarthritis of the knee is one of the effective osteotomy methods, especially for patients with cartilage damage of the patellofemoral joint, flexion contracture, and requiring a large correction angle.While the bone union at the osteotomy site is finally obtained after CWHTO, there are often differences in the period of the bone union. The purpose of the present study is to investigate the factors affecting the timing of bone union after CWHTO. Methods 16 cases of CWHTO were included; they were performed by the same surgeon using precisely the same implants. Among 16 cases in the present study, nobody used low-intensity pulsed ultrasound (LIPUS) within three months after the operation. The patients were divided into two Groups using Plane X-ray and CT within three months after surgery: Group D (8 knees; bone healing was not seen at all) and Group E (8 knees; bone healing was seen). Results There were no significant differences in mean age between the two groups, but body mass index (BMI) and bone mineral density (BMD) were significantly higher in Group D (p < 0.05). Conclusion The present study suggests that BMI and BMD may affect the timing of bone union after CWHTO. Background Closing-wedge high tibial osteotomy (CWHTO) for medial osteoarthritis of the knee is one of the effective osteotomy methods. The frequency of selecting CWHTO in our hospital in Japan is high, especially for patients with cartilage damage of the patellofemoral joint, flexion contracture, and requiring a large correction angle. On the other hand, while the bone union at the osteotomy site is obtained with both procedures, there are often differences in bone union time for CWHTO compared to Opening-wedge high tibial osteotomy (OWHTO). This difference might affect the early clinical outcome of the operations. We hypothesized that there is some factor to affect bone healing of CWHTO for individual patients. Purpose To investigate the factors affecting the timing of bone union after CWHTO.
Article
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The in Vivo pathomechanics of osteoarthritis (OA) at the knee is described in a framework that is based on an analysis of studies describing assays of biomarkers, cartilage morphology, and human function (gait analysis). The framework is divided into an Initiation Phase and a Progression Phase. The Initiation Phase is associated with kinematic changes that shift load bearing to infrequently loaded regions of the cartilage that cannot accommodate the loads. The Progression Phase is defined following cartilage breakdown. During the Progression Phase, the disease progresses more rapidly with increased load. While this framework was developed from an analysis of in Vivopathomechanics, it also explains how the convergence of biological, morphological, and neuromuscular changes to the musculoskeletal system during aging or during menopause lead to the increased rate of idiopathic OA with aging. Understanding the in Vivo response of articular cartilage to its physical environment requires an integrated view of the problem that considers functional, anatomical, and biological interactions. The integrated in Vivoframework presented here will be helpful for the interpretation of laboratory experiments as well as for the development of new methods for the evaluation of OA at the knee.
Article
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Forty-five total knee replacements in forty-one patients who had continued to have progressive osteoarthritis after a proximal tibial osteotomy were evaluated prospectively. There were 51 per cent excellent, 29 per cent good, 4 per cent fair, and 16 per cent poor results after a minimum follow-up of two years. The resection of tibial bone that was produced by the osteotomy could not be related causally to the fair or poor clinical results that were found after arthroplasty. Radiographic study, however, showed that 80 per cent of the knees had patella infera before the arthroplasty, which may contribute to altered biomechanics of the patellofemoral joint of the arthroplasty. The procedure for total knee replacement is made more difficult by the previous osteotomy, and a custom-made prosthesis may be required. The clinical results that were obtained in this series are similar to those for the revision total knee arthroplasties that have been done at this institution, but they were not as satisfactory as those that were obtained after primary total knee replacement. Our results should be considered when a surgeon compares the advantages and disadvantages of proximal tibial osteotomy with those of total knee arthroplasty for an older patient who has unicompartmental osteoarthritis of the knee.
Article
Full-text available
We analysed two series of patients affected by unicompartmental arthrosis or axial malalignment of the knee treated with two different techniques of high tibial osteotomy. Forty-seven knees were treated with a closing wedge osteotomy (CWO) and 40 with an opening wedge osteotomy (OWO). The two groups were comparable with respect to age, gender and deformity. For each patient the patellar height was measured by Caton's method before surgery, and at the latest assessment (at least 1 year after operation). The correction rate for the two series was analysed to assess any possible correlation between the variation of the patellar height and the degree of correction of the knee axis. We concluded that a high tibial osteotomy modifies the patellar height and that this depends on the technique employed. Patellar 'lowering' occurred more often with OWO than with CWO and the latter also produced a high degree of patellar elevation.
Article
The results of 73 total knee arthroplasties in 67 patients after a high tibial osteotomy (HTO) were carefully reviewed at an average follow-up period of 73 months (range, 24-132 months). An extensive clinical as well as radiographic review was performed in an attempt to evaluate parameters that might portend more favorable or worse outcomes. Additional comparisons were made with two groups of 73 primary TKAs matched according to age, gender, diagnosis, prosthetic fixation, and length of follow-up period. The two comparison groups differed in that one (Group A) was additionally matched to deformity before TKA with a second comparison group (B) matched to pre-HTO deformity. On the basis of a 100-point knee rating scale, 36% of the study group patients had either a fair or poor result or required additional surgery. This was significantly greater than either comparison group (p < 0.01). Factors that prognosticated a worse outcome in the HTO patients (p < 0.01) included (1) workmen's compensation patient, (2) history of reflex sympathetic dystrophy after HTO, (3) early onset (less than one year) or no period of relief of pain after HTO, (4) multiple surgeries before HTO, and (5) an occupation as a laborer.
Article
Forty-three patients who had undergone revision total knee arthroplasty following either primary, medial unicondylar arthroplasty (23 patients) or valgus tibial osteotomy (20 patients) for medial compartment osteoarthritis were reviewed. Although the two groups had similar knee scores and range of motion at review, six patients (30%) who had undergone prior tibial osteotomy suffered serious postoperative complications. Of these, four patients had a deep infection. It was felt that several factors were responsible, resulting largely from difficulties in gaining access to the lateral tibial plateau and subsequently causing impairment of wound vascularity and healing. In contrast, those patients undergoing revision of unicondylar prostheses did not experience wound healing problems, but it was noted that in half of the cases, there was significant bone loss from the medial tibial plateau.
Article
High tibial osteotomy (HTO) is an established technique for the treatment of the symptomatic varus malaligned knee. Correction is usually acheived by closed wedge osteotomy from a lateral exposure. This procedure has a certain risk potential regarding peroneal nerve injuries, instability of the osteotomy and secondary loss of correction. We present four technical modifications of HTO which improve safety and reproducability of this operation. 1) Open wedge osteotomy from a medial exposure avoids lateral muscle detachment, dissection of the peroneal nerve, proximal fibula osteotomy and leg shortening. Only one osteotomy needs to be performed and the correction can be adapted intraoperatively. 2) A biplanar osteotomy provides improved rotational stability of the osteotomy and creates an anterior buttress against sagittal tilting. 3) An incomplete osteotomy with plastic deformation of the intact lateral bone bridge avoids fractures of the lateral cortex and instabilities and promotes bone healing. 4) Rigid fixation with a medial plate-fixator1 (Tomofix®) allows for early mobilsation and avoids loss-of-correction. 262 patients were consecutively operated using the described modified technique until now. No loss-of-correction occurred in this group, two patients with delayed healing received secondary cancellous bone grafts.
Article
Die zuklappende valgisierende Tibiakopfosteotomie ist eine effiziente Methode zur Behandlung der medialen Gonarthrose. Die korrekte Indikationsstellung und Planung setzen das Verstndnis der Biomechanik und der Pathophysiologie voraus und sind Grundlage fr eine erfolgreiche Therapie. Die Art der Osteotomie (Lokalisation, aufklappend oder zuklappend) richtet sich nach der Fehlstellung und den Begleitpathologien.Die Operationstechnik erfordert eine hohe Przision, um die geplante Achsenkorrektur zu verwirklichen und um Komplikationen zu vermeiden. Die Winkelstabilitt der Implantate bietet Vorteile gegenber konventionellen Fixationstechniken. Bei geeigneter Indikation und Technik behalten die Patienten eine hohe Kniefunktion, die im Idealfall ber 10Jahre anhlt. Der Effekt auf die Langzeitprognose beim jungen Patienten mit Knorpelschden ist noch unklar.Closing wedge high tibial osteotomy is an efficient method for the treatment of medial osteoarthritis of the knee. Prerequisites of successful surgery are proper indication and planning as well as the understanding of biomechanics and pathophysiology. The technique of osteotomy to choose (opening or closing wedge) depends on the type of malalignment and on additional pathologies.The surgical technique demands high precision to realize the planned correction and to avoid complications. Implants with angular stability provide advantages compared to traditional implants. Correct indication and surgical technique results in a desirable follow-up, which often lasts for at least 10years. The effect on the prognosis of the young patient with cartilage damage is still unclear.
Article
From this study of 213 knees it appears that 61.8% of the patients rated themselves as having less pain than before osteotomy even after 10 years from the time of surgery. Functionally, 64.7% were better. Rarely did a patient believe that his pain was worse than it was preoperatively, even up to 10 years after the surgery; nor did any patient believe that his functional status was compromised further by the operation. The conclusions drawn from the most recent study are the following. Upper tibial osteotomy for gonarthrosis and varus deformity relieves pain and restores function in more than 60% of the patients, even 10 years after the operation. The major complication is recurrence of deformity, in part, at least, the cause of recurring pain. It can be minimized by achieving at least 7 degrees of valgus axial alignment (up to 10 degrees is allowable), and by excluding from operation knees with bicompartmental involvement.
Article
The authors report their experience in substituting cement for full-thickness iliac crest wedge in medial tibial wedge osteotomy using buttress plate fixation. A review of 107 osteotomies performed between January 1985 and March 1989, demonstrated that using cement wedge do not expose to any special complication and raise the accuracy of frontal mechanical axes correction. At last, cement wedge seems not to evolve as a stranger corpus able to give long or mean terms complications; it perhaps make unnecessary bone substitute or allografts wedges.
Article
Recorded here is a comprehensive review of the current literature on high tibial osteotomy with emphasis on postponing an inevitable total knee arthroplasty (TKA). Accompanying this review is a confirmatory, retrospective study of 35 patients with 39 high tibial osteotomies with an average follow-up study of 8.5 years (range, 3.8-15.1 years). Twenty-two of the patients (57%) had good results, seven (18%) fair, and ten (25%) poor at final follow-up examination. Nine of the 35 patients required TKA at an average of 4.7 years post-osteotomy. The percentage of good results diminished with time of follow-up study, starting at two years with 87% good results and ending at 15 years with only 57% of the patients remaining in that category. Patients lost an average of 8 degrees of flexion post-osteotomy, regardless of good, fair, or poor result. Patients with favorable results were usually younger than 60 years of age, and had less than 12 degrees of angular deformity, pure unicompartmental disease, ligamentous stability, and a preoperative range of motion are of at least 90 degrees.
Article
In a prospective clinical and roentgenographic analysis of 79 knees treated by a valgus closing wedge high tibial osteotomy, the average follow-up period was 5.8 years (three to nine years); 80% of the patients had good or excellent results. Correction to a femorotibial angle between 6 degrees and 14 degrees of femorotibial valgus was associated with an optimal clinical result. Undercorrection to less than 5 degrees of femorotibial valgus was associated with a high (62.5%) failure rate. Patients whose distal femur had a femoral shaft-transcondylar (FS-TC) angle of less than 9 degrees have an increased incidence of undercorrection. A poor prognosis was noted in knees whose patellofemoral joint preoperatively had moderate or severe roentgenographic evidence of osteoarthritis (OA) when compared to the group whose patellofemoral compartment had no or mild roentgenographic evidence of OA. Accurate femorotibial realignment was essential for success. The slope of the distal femoral articular surface, the FS-TC angle, affects the degree of correction and should be considered in preoperative planning.
Article
The authors assessed the effect of proximal tibial osteotomy on the results of a subsequent total knee arthroplasty. A retrospective, clinical and radiographic analysis was carried out between a study group of 39 patients with 42 total knee arthroplasties following osteotomy and a control group of 39 patients with 41 primary arthroplasties. Outcome was assessed using the Hospital for Special Surgery (HSS) knee score, pain, function, range of motion, and radiographic evaluation. The follow-up period averaged 37 months (range, 24-50 months). The study group had 88% good or excellent results using the HSS score, compared to 90% in the control group. Function and pain improved equally in both groups. The control group had, on average, 14 degrees greater range of motion (115 degrees v. 101 degrees) after arthroplasty. The control group had, on average, posterior inclination of the tibial plateau of 7 degrees before operation and 3 degrees after operation; the corresponding values in the study group were 2 degrees and 1 degree. Using the HSS score and pain and function as parameters, previous osteotomy does not seem to affect the outcome of total knee arthroplasty. Conversely, range of motion following arthroplasty appears to be less in those with prior osteotomy. In addition, a high tibial osteotomy may alter the inclination of the tibial plateau.
Article
Sixty-six knees (sixty patients) that had had a proximal tibial osteotomy were evaluated to determine if any alteration of the patellar height had occurred as a result of the operation. Eighty-nine per cent of the patellae, as measured by the Insall-Salvati index, and 76.3 per cent, as measured by the Blackburne-Peel index, were observed to be lowered as they appeared on the postoperative lateral radiograph. This was probably due to shortening of the patellar ligament after prolonged immobilization in a cast, interstitial scarring of the patellar ligament, and new-bone formation in the area of insertion of the patellar ligament. There was no correlation between the postoperative height of the patella and the need for subsequent revision to a total knee replacement.
Article
We examined 54 patients (60 knees) referred to us because of their failure to improve, or because of a worsening of their preoperative symptoms, following an arthroscopic lateral retinacular release. Thirty knees developed medial subluxation of the patella postoper atively. This disabling condition is new to us. It is previously unreported as a complication of arthroscopic lateral retinacular release. Anterior knee pain was the only reported preoperative symptom in 14 knees. Six teen knees had a preoperative diagnosis of lateral patellar subluxation on the basis of a positive appre hension sign only. Eighteen of 30 knees had no surgery of the extensor mechanism other than the arthroscopic lateral release. The remainder additionally underwent varying types and numbers of operations in an attempt to resolve their disability. CAT scan evaluation of three patients who volun teered for the procedure demonstrated severe atrophy and retraction of the vastus lateralis. Loss of this dy namic lateral stabilizer contributed to the medial sub luxation of the patella.
Article
Survival analysis studies of 40 patients treated with high tibial osteotomy for arthritis with angular deformity were performed to determine the dominant factors that adversely affected long-term knee function. Obesity, advanced age, and postoperative overcorrection or undercorrection resulted in short durations of successful function. On the average, the probabilities for continued useful function of the knee at tested intervals were: one year, 86%; three years, 64%; five years, 50%; and nine years, 28%.
Article
The progressive radiological changes in the patello-femoral joint after upper tibial osteotomy performed for arthrosis of the knee were studied more than 10 years after the surgical procedure. The changes were found to be minimal. In cases where the patello femoral joint space was normal before the osteotomy, it was still so 10 years later. In half of the cases where the patello-femoral joint space was abnormal before the osteotomy, it had deteriorated 10 years later, the lesions being more severe on the medial facet of the patella. This change occurred in 11 cases. It was not affected by the extent of the valgus osteotomy, changes in the tibio femoral joint space or the technique of the osteotomy. The functional results could only be correlated with the changes in the tibio femoral joint space and not with those in the patello-femoral joint space. However, excellent results as regards the tibio femoral joint space could still be associated with pain in the patello-femoral joint when it was arthrotic before the osteotomy. Nevertheless, the authors conclude that an associated transposition of the tibial tubercle in association with upper tibial osteotomy is not worthwhile, since no failure in their series could be attributed to impairment of the patello-femoral joint.
Article
Ninety three high tibial valgus osteotomies have been performed by the authors for degenerative arthritis and reviewed more than 10 years later. The mean age of the 66 patients was 70 years. The results were somewhat disappointing. Seventeen knees had to be operated on before the tenth post-operative year and only 42 knees were painless at the time of review. Radiological improvement in the medial tibio-femoral joint was rarely seen. Fortunately, deterioration in the lateral tibio femoral joint was exceptional and joint laxity was rarely troublesome. The authors conclude that the amount of correction at the time of the osteotomy is of extreme importance. The results were satisfactory only in cases where valgus ranging between 3 and 6 degrees had been obtained. When an osteotomy produced a greater amount of valgus, deterioration of the lateral tibio-femoral joint was seen. When the osteotomy produced less than 3 degrees of valgus, recurrence of the varus deformity developed. In these cases, functional deterioration was noted after seven years. Thus, the osteotomy appeared to have slowed down the natural evolution of the disease. The results of valgus osteotomy were satisfactory in most of the cases, but they were excellent only in cases in which a valgus ranging from 3 to 6 degrees had been produced. The importance of a precise radiological measurement is stressed, the accuracy of measurement being doubtful in cases with associated flexion deformity or joint laxity. The precision of the surgical procedure is also very important.
Article
The cases of twenty-one consecutive patients who had a minimally constrained total knee arthroplasty (six of whom had a cemented and fifteen, an uncemented prosthesis) after a failed proximal tibial osteotomy for osteoarthritis were compared with those of a non-consecutive group of twenty-one patients who had had a primary total knee arthroplasty for osteoarthritis. The groups were matched according to age and sex of the patient, type of prosthesis and fixation, and length of follow-up. At an average length of follow-up of 2.9 years, a good or excellent result was obtained in 81 per cent of the patients who had had a previous osteotomy. At an average length of follow-up of 2.8 years, a good or excellent result was obtained in 100 per cent of the patients who had had a primary arthroplasty. Two patients in the osteotomy group and none in the primary arthroplasty group required additional surgery. At the time of arthroplasty, technical difficulties in exposing the proximal part of the tibia were noted in three patients in the group that had undergone an osteotomy. The results of total knee arthroplasty after failed proximal tibial osteotomy approached but did not equal the results after primary total knee arthroplasty.
Article
The results in ninety-three knees that had been treated by proximal tibial opening-wedge osteotomy for varus deformity and osteoarthritis of the medial compartment were evaluated after a mean length of follow-up of 11.5 years (range, ten to thirteen years). After ten years, only forty-two (45 per cent) of the ninety-three knees had an excellent or good result, and in fifty-one knees there was recurrent pain for which seventeen had another operation. At five years, on the other hand, 90 per cent of the knees had a good result. Deterioration occurred at an average of seven years after the osteotomy and was always associated with recurrence of pain. Although the results deteriorated with time, time was not the only determinant of the result. Alignment, measured as the hip-knee-ankle angle on radiographs of the whole limb that were made with the patient bearing weight, was also a determinant of long-term results. The best results were obtained in the twenty knees that had a hip-knee-ankle angle of 183 to 186 degrees. In these knees, there was no pain and no progression of the arthrosis in either the medial or the lateral tibiofemoral compartment. Of the five knees that had an angle of more than 186 degrees, all five had progressive degenerative changes in the lateral compartment. In the sixty-eight undercorrected knees (an angle of less than 183 degrees), the results were less satisfactory, and there was a tendency toward recurrence of the varus deformity and progression of the arthritis of the medial compartment. However, when the correction was insufficient the deterioration was slow (average, seven years), and it was not associated with lateral laxity and deterioration of the lateral compartment, which are the changes that characterize the natural course of gonarthrosis as described by Hernborg and Nilsson. Therefore, proximal tibial osteotomy is a very suitable operation for patients who have gonarthrosis of the medial compartment, but a rigidly standardized and precise operative technique is required as well as accurate radiographic measurements of the mechanical axis of the limb, because exact postoperative alignment is the prerequisite for the longest possible period of relief of symptoms after osteotomy.
Article
High tibial and fibular osteotomy have an established place in the treatment of osteoarthrosis of the knee joint; however, complications and poor results will occur if careful selection of patients and meticulous surgical technic are not done.
Article
1. A series of 226 upper tibial osteotomies is reviewed with special reference to the complications occurring in each of the six different operative techniques that have been used. 2 Wedge osteotomy above the tuberosity is the safest operation, but care must be taken to avoid a fracture into the joint. 3. Wedge osteotomy through the lowest part of the tuberosity may be indicated in the presence of large subarticular cysts or collapse of a tibial condyle. 4. The significance of weakness of dorsiflexion of the foot and the dangers of injury to the anterior tibial artery in osteotomies below the tuberosity are discussed.
Article
We evaluated the results in eighty-three patients (ninety-five knees) who had had a high tibial osteotomy for either unicompartmental osteoarthritis or osteonecrosis. The operations were performed between 1965 and 1976. The mean length of follow-up was 8.9 years (range, five to fifteen years). The early results were promising: at two years 97 per cent and at five years 85 per cent of the knees had either an excellent or a good result. At subsequent follow-up, however, only sixty knees (63 per cent) had an excellent or good result, and in the remainder recurrent pain had developed. Twenty-two knees (23 per cent) had been revised to a total knee arthroplasty because of pain. The alignment obtained by the osteotomy was not as important in determining the long-term result as we had previously believed. Although recurrent varus deformity was observed in more than one-quarter of the knees, it was not necessarily associated with an unsatisfactory result. The passage of time was the most important factor in determining the result, as only fifteen (37 per cent) of the knees that had been followed for more than nine years were pain-free. We now believe that total knee arthroplasty is a more suitable operation for patients who are more than sixty years old and that high tibial osteotomy should be reserved for patients who have a strenuous occupation or who wish to continue to participate in sports activities.
Article
Controlled bending moments were applied to twelve human cadaver knee joints using a special loading fixture that allowed variation of both the Q-angle and the flexion angle. The joints were tested at three different Q-angles (physiological, increased 10 degrees, and decreased 10 degrees) and five different angles of flexion (ranging from 20 to 120 degrees). Based on one-third of values in the literature for maximum voluntary isometric quadriceps moments, we applied resultant knee moments of 23.6, 30.7, 47.2, and 35.0 newton-meters at 20, 30, 60, and 90 degrees of flexion, respectively. Based on two-thirds of reported maximum moments, we applied 47.2 newton-meters at 120 degrees of flexion. Normal patellofemoral-contact pressures, measured with a pressure-sensitive film, were remarkably uniformly distributed (+/- 0.25 megapascal ), with approximately the same pressure on the lateral and medial patellar facets. The maximum contact force occurred at 90 degrees of flexion. Extrapolating our measurements to full in vivo moments, we estimated maximum contact forces of 4600 newtons , or approximately 6.5 times body weight. Tendofemoral contact at 120 degrees of knee flexion supported one-third of the total contact force on the patella. A 10-degree increase in the Q-angle resulted in increased peak pressures (an increase of 45 per cent at 20 degrees of flexion). A decrease in the Q-angle resulted in unloading of the vertical crest and, in some knees, of parts of the lateral facet. However, these decreases were always associated with increased peak pressures (50 per cent more at 20 degrees of flexion) at other locations.
Article
Patellar pain must be separated from other causes of internal derangement of the knee by a careful history and precise examination followed by appropriate investigations. Once the cause of the pain is determined, malalignment or malposition of the patella must be sought. The Merchant view of the patellar femoral joint is recommended in this regard to demonstrate patellar incongruence. The malalignment syndrome may or may not show the pathologic changes described as "chondromalacia" and respond particularly well after proximal patellar realignment. In the remaining cases, pain may be caused by overuse, trauma, the odd-facet syndrome, an abnormal femoral ridge, or degenerative arthritis. This group of cases should be managed conservatively if possible because the results of surgical treatment are often disappointing. In selected cases some improvement may occur after excision of abnormal cartilage, tibial tubercle elevation, patellar replacement, or patellectomy.
Article
Results of 213 upper tibial osteotomies for osteoarthritis with varus in patients older than 30 were studied from 1 to 16 years after surgery. Pain, function, and motion were evaluated, and the results were related to age, preoperative and postoperative appearance of the medial compartment, amount of preoperative varus, and degree of operative correction. Complications were few. A favorable operative result correlated closely with 7 to 9° of valgus and with 'opening' of the medial joint space, which actually fills with articular cartilage. More than 60% of all patients were still relieved of pain after 10 years.
Article
Valgus tibial osteotomy is a well-accepted procedure for the treatment of unicompartmental degenerative joint disease of the knee. For a good result to be obtained, at least for degrees of valgus angulation with the leg in the weight-bearing position must be achieved. Experience with 20 procedures showed a tendency for undercorrection, which led to poor results. After analyzing the technical reasons for these poor results, we devised a detailed protocol that included patient selection, preoperative planning, and an operative technique that minimizes the chance of technical error.