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Malalignment and Degenerative Arthropathy

Authors:
  • Paley Orthopedic and Spine Institute

Abstract

The axial relationship of the joints of the lower extremity reflects both alignment and orientation. Static considerations are useful for preoperative planning and deformity correction, but dynamic considerations including compensatory gait may be more relevant clinically. Laboratory animal models have been developed that simulate the deleterious effect of malalignment on articular cartilage. Malalignment disturbs the normal transmission of force across the knee, and altered stress distribution related to deformity has been demonstrated in cadaver models using pressure-sensitive film. No prospective data are available to document the natural history of malalignment, but several retrospective studies suggest the clinical course is one of gradual progression resulting in degenerative arthropathy. The long-term follow-up of fractures is less definitive, and difficult to interpret considering the bias inherent in patient selection. Although direct clinical evidence of a cause-and-effect relationship between malalignment and arthrosis has not been possible, substantial evidence from the orthopedic literature supports this hypothesis.
... Knee osteoarthritis is a degenerative disease associated with factors such as age, trauma, obesity, and lower extremity malalignment; increased prevalence may be due to additional factors, including economic development, changes in lifestyle, and increase in sports activities [1][2][3]. Specifically, alignment of the lower extremities plays a crucial role in the efficient use and preservation of energy in the musculoskeletal system [1][2][3], and is important for older as well as young adults [4][5][6][7][8] because proper alignment supports the body's weight, aids in walking, and plays an important biomechanical role [4][5][6]. The axes of the hip, knee, and ankle help distribute appropriate loads towards the knee joint. ...
... Knee osteoarthritis is a degenerative disease associated with factors such as age, trauma, obesity, and lower extremity malalignment; increased prevalence may be due to additional factors, including economic development, changes in lifestyle, and increase in sports activities [1][2][3]. Specifically, alignment of the lower extremities plays a crucial role in the efficient use and preservation of energy in the musculoskeletal system [1][2][3], and is important for older as well as young adults [4][5][6][7][8] because proper alignment supports the body's weight, aids in walking, and plays an important biomechanical role [4][5][6]. The axes of the hip, knee, and ankle help distribute appropriate loads towards the knee joint. ...
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Identification of lower extremity misalignment requires radiation exposure and complex imaging. We developed and tested a smartphone application to facilitate quick identification of misalignment using photographs. Lower extremity alignment was measured by two independent researchers using a proprietary smartphone application and conventional radiographs. The results were compared between the methods and evaluators for interrater and intrarater reliability. Ninety datasets were obtained from 45 patients, with 90 lower extremity alignment angles measured via radiographs and the smartphone application. The intrarater reliability of the hip–knee–ankle angle (HKAA), measured twice by evaluator A using the radiographic imaging program, was 0.985, whereas that measured by evaluator B was 0.995. The intrarater reliability of the predicted lower extremity alignment angle (PLEAA) measured using the smartphone application was 0.970 and 0.968 for evaluators A and B, respectively. Thus, all results showed excellent reliability. In validity analysis, the correlation between PLEAA and HKAA measured twice by evaluators A and B was analyzed using Pearson’s correlation coefficient. HKAA (A) and PLEAA (A) had a positive correlation coefficient of 0.608 (p < 0.01), whereas HKAA (B) and PLEAA (B) had a positive correlation coefficient of 0.627 (p < 0.01). Thus, our smartphone application can facilitate for self-diagnosis of lower extremity misalignment.
... About 60-80% of the load is taken by the medial compartment in a neutrally aligned knee. So, even a five-degree increase in varus malalignment leads to a 20% increase in the compressive load of the medial compartment [5]. This overload leads to stress in the articular cartilage and ultimately degenerative changes in the knee joint [1,5]. ...
... So, even a five-degree increase in varus malalignment leads to a 20% increase in the compressive load of the medial compartment [5]. This overload leads to stress in the articular cartilage and ultimately degenerative changes in the knee joint [1,5]. ...
Article
Background: The effect of osteoarthritis (OA) with tibiofemoral (TF) subluxation on patients undergoing total knee arthroplasty (TKA) has been less studied, and there have been no studies on sagittal knee subluxation which is a component of a three-dimensional problem. We aim to analyze the influence of preoperative coronal and sagittal knee subluxation with OA on other radiological parameters and the functional outcome in patients undergoing TKA. Methods: We retrospectively reviewed the 179-consecutive primary TKA in 151 patients from January 2017 to June 2017. The radiological parameters analyzed were the mechanical tibiofemoral angle (HKA), joint line congruence angle (JLCA) and coronal tibiofemoral (CTF) subluxation in long leg films. In the lateral view, posterior tibial slope, the settlement area of the femur over the tibia and the sagittal tibiofemoral (STF) subluxation were calculated. Preoperative and postoperative knee society and knee society functional scores were documented. Multivariate regression analysis was done to determine the association of preoperative radiological parameters with coronal and sagittal TF subluxation. Results: The average follow-up was 31 months (2.6 years). 102 knees (57%) had CTF subluxation (< 5 mm) within normal range, and 77 knees (43%) had CTF subluxation. There was a direct correlation between the magnitude of CTF subluxation and poor preoperative functional scores compared with the non-subluxation group (p < 0.05). CTF subluxation was not associated with the magnitude of varus deformity as it is correlated more with mild deformity (odds ratio [OR] 10.07, 95% confidence interval [CI] 3.47-29.25) than with moderate and severe varus deformity. The degree of the joint line convergence angle was positively correlated with the amount of CTF subluxation (p = 0.003). STF subluxation had a significant correlation with the posterior slope (p < 0.001), but not with the magnitude of varus deformity (p = 0.26). Conclusion: Coronal and sagittal tibiofemoral subluxation had a significant association with poor preoperative clinical scores. The degree of CTF subluxation reduces with the increasing magnitude of varus deformity and JLCA. STF subluxation was associated with the posterior tibial slope. Patients who underwent posterior stabilized TKA had excellent clinical outcomes irrespective of preoperative knee subluxation.
... Knee osteoarthritis is a common cause of debilitating knee pain that leads to health and financial burdens [1]. While the aetiology is multifactorial, mechanical axis deviation of the knee joint and altered biomechanics ultimately cause compartmental knee osteoarthritis [2]. Treatments are aimed at unloading the diseased compartment to relieve and prevent further deterioration. ...
Article
Purpose: High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are commonly performed procedures for the treatment of compartmental knee osteoarthritis; however, the optimal procedure remains controversial. We conducted this systematic review and meta-analysis to compare the functional outcomes and assess complications and revision rates between the two techniques. Methods: We searched electronic databases for relevant studies comparing HTO versus UKA for unicompartmental knee osteoarthritis. Continuous data as visual analogue scale (VAS), range of motion, and free walking speed were pooled as mean differences (MDs). Dichotomous data as functional knee outcomes, complications, and revision were pooled as odds ratios (ORs), with 95% confidence interval (CI), using R software for windows. Results: Twenty-five studies involving 8185 patients were included. Meta-analysis showed that HTO was associated with higher risk of complications (OR = 2.47, 95% CI [1.52, 4.04]), poorer functional results (excellent/good) (OR = 0.32, 95% CI [0.21, 0.49]), and greater range of motion (MD = 7.05, 95% CI [2.41, 11.68]) compared to UKA. No significant differences were found between the compared groups in terms of VAS (MD = 0.14, 95% CI [- 0.08, 0.36]), revision rates (OR = 1.30, 95% CI [0.65, 2.60]), and free walking speed (MD = - 0.05, 95% CI [- 0.11, 0.00]). Conclusion: This study showed that UKA achieved fewer complications, better functional outcomes, and less range of motion compared to HTO. No significant differences were detected between HTO and UKA in terms of VAS and revision rate. Treatment options should be personalized to each patient considering factors such as their age, activities of daily living, their body mass index, and severity of osteoarthritis. Level of evidence: II. Supplementary information: The online version contains supplementary material available at 10.1007/s43465-022-00620-9.
Article
Background: Three-dimensional (3D) virtual surgical planning technology has advanced applications in the correction of deformities of long bones by enabling the production of 3D stereolithographic models, patient-specific instruments and surgical-guiding templates. Herein, we describe the implementation of this technology in young patients who required a corrective osteotomy for a complex 3-plane (oblique plane) lower-limb deformity. Patients and methods: A total of 17 patients (9 males, average age 14.7 y) participated in this retrospective study. As part of preoperative planning, the patients' computerized tomographic images were imported into a post-processing software, and virtual 3D models were created by a segmentation process. Femoral and tibial models and cutting guides with locking points were designed according to the deformity correction plan. They were used for both planning and as intraoperative guides. Clinical parameters, such as blood loss and operative time were compared with a traditional surgical approach group. Results: All osteotomies in the 3D group were executed with the use intraoperative customized cutting guides which matched the preoperative planning simulation and allowed easy fixation with prechosen plates. Surgical time was 101±6.2 minutes for the 3D group and 126.4±16.1 minutes for the control group. The respective intraoperative hemoglobin blood loss was 2.1±0.2 and 2.5+0.3 g/dL.Clinical and radiographic follow-up findings showed highly satisfactory alignment of the treated extremities in all 3D intervention cases, with an average time-to-bone union (excluding 2 neurofibromatosis 1 patients) of 10.3 weeks (range 6 to 20 wk). Conclusion: The use of 3D-printed models and patient-specific cutting guides with locking points improves the clinical outcomes of osteotomies in young patients with complex bone deformities of the lower limbs. Level of evidence: Level III.
Article
Background Several studies have investigated the distribution of hip-knee-ankle (HKA) angle in healthy populations; however, few have evaluated this metric in patients undergoing total knee arthroplasty (TKA). The purpose of this study is to compare HKA angle distribution in early and advanced knee osteoarthritis (OA) patients. Methods Full limb radiographs were used to measure HKA angle for 983 subjects from the Osteoarthritis Initiative (OAI) cohort and 4,901 pre-TKA patients from an institutional cohort. Measurements were made using a previously validated deep learning algorithm. Linear regression models were used to determine the association of HKA alignment angle with patient characteristics. Results The mean ± standard deviation HKA angle was −1.3° ± 3.2° in the OAI cohort and −4.1° ± 6.1° in the pre-TKA cohort. In the OAI cohort, normal alignment (64%) was the most common knee alignment followed by varus (29%), and valgus (7%). In pre-TKA patients, the most common alignment was varus (62%), followed by normal (27%) and valgus (11%). In pre-TKA patients, mean HKA angle in primary knee OA, post-traumatic knee OA, and rheumatoid arthritis patients were −4.3° ± 6.1°, −3.2° ± 6.4°, and −2.9° ± 6.1°, respectively. HKA angle was strongly associated (P < .001) with gender and body mass index. Conclusion TKA patients have a wider alignment distribution and more severe varus and valgus alignment than individuals “at risk” for knee OA from the OAI cohort. These epidemiologic findings improve our understanding of HKA angle distribution and its correlation with demographic characteristics in early and late-stage arthritis.
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Obesity is a primary risk factor for osteoarthritis. While previous work has addressed relationships between in vivo cartilage mechanics, composition, and obesity in the tibiofemoral joint, there is limited information on these relationships in the patellofemoral joint. The purpose of this study was to compare the patellofemoral cartilage mechanical response to walking in participants with normal and obese body mass indices (BMIs). Additionally, patellar cartilage T1rho relaxation times were measured before exercise to characterize the biochemical composition of the tissue. Fifteen participants (eight with normal BMI and seven with obese BMI) underwent baseline magnetic resonance imaging (MRI) of their right knee. They then walked on a treadmill for 20 minutes at a speed normalized to their leg length before a second MRI scan. Subsequently, three-dimensional models of the bones and articular surfaces of the patellofemoral joint were created via manual segmentation of the pre- and post-exercise MR images to compute cartilage thickness and strain. Strain was defined as the change in patellofemoral cartilage thickness normalized to the baseline thickness. Results showed that participants with an obese BMI exhibited significantly increased patellofemoral cartilage strain compared to those with a normal BMI (5.4±4% vs. 1.7±3%, respectively; p=0.003). Furthermore, patellar cartilage T1rho values were significantly higher in participants with obese versus normal BMIs (95 ms vs. 83 ms, respectively; p=0.049), indicative of decreased proteoglycan content in those with an obese BMI. In summary, the altered patellofemoral cartilage strain and composition observed in those with an obese BMI may be indicative of cartilage degeneration.
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Background To describe the longitudinal associations between the morphological parameters of proximal tibiofibular joint (PTFJ) and joint structural changes in tibiofemoral compartments in patients with knee osteoarthritis (OA). Methods The participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. PTFJ morphological parameters were measured on coronal and sagittal MRI. The contacting area (S) of PTFJ and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ), and coronal plane (posterior stress-bolstering area, Sυ) were assessed. Knee structural abnormalities, including cartilage defects, bone marrow lesions (BMLs), and cartilage volume, were evaluated at baseline and after 2 years. Log binominal regression models and linear regression models were used to assess the associations between PTFJ morphological parameters and osteoarthritic structural changes. Results In the longitudinal analyses, the S (RR: 1.45) and Sτ (RR: 1.55) of PTFJ were significantly and positively associated with an increase in medial tibial (MT) cartilage defects. The Sτ (β: − 0.07), Sυ (β: − 0.07), and S (β: − 0.06) of PTFJ were significantly and negatively associated with changes in MT cartilage volume. The Sτ (RR: 1.55) of PTFJ was positively associated with an increase in MT BMLs, and Sφ (RR: 0.35) was negatively associated with an increase in medial femoral BMLs. Conclusions This longitudinal study suggests that higher load-bearing area of PTFJ could be a risk factor for structural changes in medial tibiofemoral (MTF) compartment in knee OA. Trial registration Clinicaltrials.gov Identifier: NCT01176344 Anzctr.org.au Identifier: ACTRN12610000495022 Date of registration: 7 May 2010
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Purpose of review: Lower extremities axis alterations are a frequent cause for consultation in the medical practice of the care of paediatric patients. When it corresponds to pathological situations, guided growth surgery has been positioned as a possibility of well tolerated, reproducible and predictable resolution. For this reason, its use has increased significantly in recent years. In this review, its current indications, preoperative study, results and complications described in the updated literature will be discussed. Recent findings: The success of the technique remains high in the current literature, expanding the technique to other segments and disorders, and describing new ways of performing tension band with sutures. In addition, there is an increase in its incidence and a decrease in the associated hospitalized days, which can associate with techniques of lower morbidity. Summary: As guided growth surgery allows for successful correction of axis alterations, to achieve this, it is important to know the main indications, preoperative analysis and theoretical bases on which this technique is based, to carry it out in an adequate and timely manner, seeking an adequate resolution of the child's problem.
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Angular deformities of the tibia or femur in the frontal plane lead to mechanical axis deviation of the lower limb and malorientation of the joints above and below the level of deformity. Accurate correction of the malalignment and of the joint orientation is important for function and to prevent joint degeneration. An accurate yet simple method to determine the apex of deformity and the type of correction required is based on the joint reference lines of the hip, knee, and ankle, and the individual mechanical axis lines of each bone segment. If the osteotomy is performed at the level of the apex of the deformity, then the only correction needed is angulation. If the osteotomy is performed at a level proximal or distal to the apex, then translation in addition to angulation is necessary to accurately correct the deformity.
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