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Technique Corner: MCL
Abstract
Medial collateral ligament and posteromedial corner knee injuries are among the most frequently diagnosed conditions in sports medicine. These injuries can cause medial knee pain, side-to-side instability, and lead to secondary damage to both cruciate ligaments and articular cartilage. Understanding the anatomy and native healing properties of the medial knee structures is crucial for successful treatment. An accurate diagnosis is best achieved through a combination of physical exam, objective valgus stress radiographs, and magnetic resonance imaging. Surgical management of medial ligament injuries with anatomic reconstruction has been validated biomechanically and has demonstrated favorable clinical outcomes. Failure to successfully restore medial knee laxity can lead to chronic instability, knee pain, cruciate ligament injury, and degenerative changes. Despite the potential complexity of these injuries, relying on surgically relevant anatomical landmarks and current rehabilitation principles helps optimize outcomes following surgical treatment.
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Background
The importance of repair in medial meniscus posterior root tears (MMPRTs) has been increasingly recognized because it restores hoop tension. However, no study has compared the long-term outcomes between meniscectomy and repair.
Hypothesis
Survivorship and clinical outcomes of repair would be better than those of meniscectomy after long-term follow-up.
Study Design
Cohort study; Level of evidence, 3.
Methods
Between 2005 and 2009, patients with MMPRTs who had been followed up for at least 10 years after partial meniscectomy (n = 18) or pullout repair (n = 37) were recruited. Clinical assessments, including the Lysholm score and International Knee Documentation Committee (IKDC) subjective score, were evaluated preoperatively and at the final follow-up. The final results in each group were compared with the preoperative results, and the final results of the groups were compared. Clinical failure was defined as conversion to total knee arthroplasty (TKA), and the final clinical scores were assessed just before TKA. Kaplan-Meier survival analysis was used to investigate the survival rates of surgical procedures.
Results
Mean ± SD follow-up period was 101.4 ± 45.9 and 125.9 ± 21.2 months in the meniscectomy and repair groups, respectively ( P = .140). The mean Lysholm and IKDC scores, respectively, in the meniscectomy group were 50.8 ± 7.7 and 37.6 ± 7.0 preoperatively and 58.2 ± 22.1 and 44.4 ± 19.0 postoperatively ( P = .124; P = .240). In the repair group, the mean Lysholm score and IKDC score, respectively, significantly increased from 52.3 ± 10.9 and 41.0 ± 9.6 preoperatively to 77.1 ± 24.0 and 63.7 ± 20.6 postoperatively ( P < .001; P < .001). The final Lysholm and IKDC scores in the repair group were significantly better than those in the meniscectomy group ( P = .004; P = .003). In cases of clinical failure, 10 patients (56%) in the meniscectomy group and 8 patients (22%) in the repair group converted to TKA in the follow-up period ( P = .016). According to Kaplan-Meier analysis, the 10-year survival rates for the meniscectomy and repair groups were 44.4% and 79.6%, respectively ( P = .004).
Conclusion
In MMPRTs, root repair was superior to partial meniscectomy in terms of clinical results for at least 10 years of follow-up. From a long-term perspective, repair with restoration of hoop tension is more effective management than meniscectomy.
Purpose:
High tibial osteotomy (HTO) is an effective treatment option in early osteoarthritis. However, preoperative planning and surgical execution can be challenging. Computer assisted three-dimensional (3D) planning and patient-specific instruments (PSI) might be helpful tools in achieving successful outcomes. Goal of this study was to assess the accuracy of HTO using PSI.
Methods:
All medial open wedge PSI-HTO between 2014 and 2016 were reviewed. Using pre- and postoperative radiographs, hip-knee-ankle angle (HKA) and posterior tibial slope (PTS) were determined two-dimensionally (2D) to calculate 2D accuracy. Using postoperative CT-data, 3D surface models of the tibias were reconstructed and superimposed with the planning to calculate 3D accuracy.
Results:
Twenty-three patients could be included. A mean correction of HKA of 9.7° ± 2.6° was planned. Postoperative assessment of HKA correction showed a mean correction of 8.9° ± 3.2°, resulting in a 2D accuracy for HKA correction of 0.8° ± 1.5°. The postoperative PTS changed by 1.7° ± 2.2°. 3D accuracy showed average 3D rotational differences of - 0.1° ± 2.3° in coronal plane, - 0.2° ± 2.3° in transversal plane, and 1.3° ± 2.1° in sagittal plane, whereby 3D translational differences were calculated as 0.1 mm ± 1.3 mm in coronal plane, - 0.1 ± 0.6 mm in transversal plane, and - 0.1 ± 0.6 mm in sagittal plane.
Conclusion:
The use of PSI in HTO results in accurate correction of mechanical leg axis. In contrast to the known problem of unintended PTS changes in conventional HTO, just slight changes of PTS could be observed using PSI. The use of PSI in HTO might be preferable to obtain desired correction of HKA and to maintain PTS.
Background:
Inaccurate meniscus allograft size is still an important problem of the currently used sizing methods. The purpose of this study was to evaluate a new three-dimensional (3D) meniscus-sizing method to increase the accuracy of the selected allografts.
Methods:
3D triangular surface models were generated from 280 menisci based on 50 bilateral and 40 unilateral knee joint magnetic resonance imaging (MRI) scans. These models served as an imaginary meniscus allograft tissue bank. Meniscus sizing and allograft selection was simulated for all 50 bilateral knee joints by (1) the closest mean surface distance (MeSD) (3D-MRI sizing with contralateral meniscus), (2) the smallest meniscal width/length difference in MRI (2D-MRI sizing with contralateral meniscus), and (3) conventional radiography as proposed by Pollard (2D-radiograph (RX) sizing with ipsilateral tibia plateau). 3D shape and meniscal width, length, and height were compared between the original meniscus and the selected meniscus using the three sizing methods.
Results:
Allograft selection by MeSD (3D MRI) was superior for all measurement parameters. In particular, the 3D shape was significantly improved (p < 0.001), while the mean differences in meniscal width, length, and height were only slightly better than the allograft selected by the other methods. Outliers were reduced by up to 55% (vs. 2D MRI) and 83% (vs. 2D RX) for the medial meniscus and 39% (vs. 2D MRI) and 56% (vs. 2D RX) for the lateral meniscus.
Conclusion:
3D-MRI sizing by MeSD using the contralateral meniscus as a reconstruction template can significantly improve meniscus allograft selection. Sizing using conventional radiography should probably not be recommended.
Trial registration:
Kantonale Ethikkommission Zürich had given the approval for the study (BASEC-No. 2018-00856).
Introduction
The purpose of this study was to perform a systematic review and meta-analysis comparing intra-articular knee injection of PRP and hyaluronic acid and investigate clinical outcomes and pain at both 6 and 12 months.
Methods
A systematic review of Medline, Embase, Scopus, and Google Scholar was performed in the English and German literature reporting on intra-articular knee injections for knee osteoarthritis. All level 1 and 2 studies with a minimum of 6-month follow-up in patients with knee osteoarthritis from 2010 to 2019 were included. Clinical outcome was assessed by WOMAC and IKDC scores and pain by VAS and WOMAC pain scores. Subgroup analysis for autologous platelet-rich plasma (ACP) was performed. Publication bias and risk of bias were assessed using the Cochrane Collaboration’s tools. The GRADE system was used to assess the quality of the body of evidence. Heterogeneity was assessed using χ² and I2 statistics.
Results
Twelve studies (1,248 cases; 636 PRP, 612 HA) met the eligibility criteria. The pooled estimate demonstrated non-significant differences between PRP and HA for clinical outcomes at 6 months (p = 0.069) and at 12 months (p = 0.188). However, the pooled estimate for pain did demonstrate significant differences in favour of PRP at 6 months (p = 0.001) and 12 months (p = 0.001). For the ACP subgroup (249 cases), the pooled estimate for these studies demonstrated significant differences in favour of PRP (p < 0.0001) at 6 months.
Conclusion
The results of this systematic review and meta-analysis suggest that PRP is superior to HA for symptomatic knee pain at 6 and 12 months. ACP appears to be clearly superior over HA for pain at both 6 and 12 months. There were no advantages of PRP over HA for clinical outcomes at both 6 and 12 months.
Level of evidence
Level 2; systematic review and meta-analysis.
PurposeAn anterior cruciate ligament (ACL) injury is often combined with injury to the lateral extra-articular structures, which may cause a combined anterior and rotational laxity. It was hypothesised that addition of a ‘monoloop’ lateral extra-articular tenodesis (mLET) to an ACL reconstruction would restore anteroposterior, internal rotation and pivot-shift laxities better than isolated ACL reconstruction in combined injuries.Method
Twelve cadaveric knees were tested, using an optical tracking system to record the kinematics through 0°–100° of knee flexion with no load, anterior and posterior translational forces (90 N), internal and external rotational torques (5 Nm), and a combination of an anterior translational (90 N) plus internal rotational load (5 Nm). They were tested intact, after sectioning the ACL, sectioning anterolateral ligament (ALL), iliotibial band (ITB) graft harvest, releasing deep ITB fibres, hamstrings tendon ACL reconstruction, mLET combined with ACL reconstruction, and isolated mLET. Two-way repeated-measures ANOVA compared laxity data across knee states and flexion angles. When differences were found, paired t tests with Bonferroni correction were performed.ResultsIn the ACL-deficient knee, cutting the ALL significantly increased anterior laxity only at 20°–30°, and only significantly increased internal rotation at 50°. Additional deep ITB release significantly increased anterior laxity at 40°–90° and caused a large increase of internal rotation at 20°–100°. Isolated ACL reconstruction restored anterior drawer, but significant differences remained in internal rotation at 30°–100°. After adding an mLET there were no remaining differences with anterior translation or internal rotation compared to the intact knee. With the combined injury, isolated mLET allowed abnormal anterior translation and rotation to persist.Conclusions
Cutting the deep fibres of the ITB caused large increases in tibial internal rotation laxity across the range of knee flexion, while cutting the ALL alone did not. With ACL deficiency combined with anterolateral deficiency, ACL reconstruction alone was insufficient to restore native knee rotational laxity. However, combining a ‘monoloop’ lateral extra-articular tenodesis with ACL reconstruction did restore native knee laxity.
Objective
The purpose of this study is to systematically review the literature and to evaluate the reported rehabilitation protocols, return-to-play guidelines, and subsequent rates of return to play following cartilage restoration procedures in the knee.
Design
MEDLINE, EMBASE, and the Cochrane Library were searched according to the PRISMA guidelines to find studies on cartilage restoration procedures in the knee, including (1) microfracture (Mfx), (2) osteochondral autograft transfer (AOT), (3) osteochondral allograft implantation (OCA), and (4) autologous chondrocyte implantation (ACI). Studies were included if they reported return-to-play data or rehabilitation protocols.
Results
Overall, 179 studies fit our inclusion criteria, with 48 on Mfx, 34 on AOT, 54 on OCA, and 51 on ACI. The rate of return to play was reported as high as 88.2% with AOT, and as low as 77.2% following OCA, with rates of return to play at the same/higher level as high as 79.3% with AOT, and as low as 57.3% following ACI. The average reported time of return to play was as low as 4.9 months with AOT, and as high as 11.6 months following ACI.
Conclusions
The majority of patients are able to return to play following cartilage restoration procedures in the knee, regardless of surgical procedure utilized. However, while the rate of return to play at the same level was similar to the overall rate of return following AOT, there was a large number of patients unable to return to the same level following Mfx, OCA, and ACI. Additionally, there is wide variety in the rehabilitation protocols, and scant literature on return-to-play protocols.
Background
Increased posterior tibial slope and posterior medial meniscus root tears increase the force experienced by the anterior cruciate ligament (ACL) and predispose patients to higher rates of primary ACL injury or ACL graft failure after an ACL reconstruction (ACLR). However, the interplay among sagittal plane tibial slope, medial meniscus root tears, and ACLR graft force remains inadequately defined.
Purpose/Hypothesis
The purpose was to quantify the effect of sagittal plane tibial slope on ACLR graft force at varying knee flexion angles with an intact medial meniscus, a posterior medial meniscus root tear, and a medial meniscus root repair. Our null hypothesis was that changes in slope and meniscal state would have no effect on the forces experienced by the ACLR graft.
Study Design
Controlled laboratory study.
Methods
Ten male fresh-frozen cadaveric human knees underwent a posteriorly based high tibial osteotomy. A spanning external fixator and wedges of varying sizes were used to stabilize the osteotomy and allow for accurate slope adjustment. After ACLR, specimens were compressed with a 1000-N axial load at flexion angles of 0° and 30° for each of the 3 meniscal states and at tibial slopes of 0° to 15° at 3° increments. Graft loads were recorded through a force transducer clamped to the graft.
Results
Increasing tibial slope led to a linear increase in ACLR graft force at 0° and 30° of knee flexion. Posterior medial meniscus root tear led to significant increases in ACLR graft forces over the intact state, while root repair restored the function of the medial meniscus as a secondary stabilizer. At 30° of knee flexion, the tibial slope effect on ACLR graft force was potentiated in the root tear state as compared with the intact and root repair states—test of interaction effect: t(139) = 2.67 ( P = .009).
Conclusion
Increases in tibial slope lead to a linear increase in ACLR graft forces, and this effect is magnified in the setting of a posterior medial meniscus root tear. At slopes >12°, a slope-changing osteotomy could be considered in the setting of a revision ACLR with a concomitant medial meniscus root tear.
Clinical Relevance
Defining the relationship between tibial slope and varying states of meniscal insufficiency can help determine when it may be necessary to perform a slope-decreasing proximal tibial osteotomy before ACLR and meniscal repair.
Objective
The purpose of this study was to compare results of osteochondral fractures (OCF) after first-time lateral patella dislocation, when either refixation or debridement was performed in a mid- to long-term follow-up and to analyze redislocation and reintervention rates.
Design
Fifty-three consecutive patients with OCF were included in this retrospective comparative study. Indication for refixation was presence of subchondral bone at the fragment. Thirty-six OCF were located at the patellar surface, and 17 at the lateral condyle of the distal femur. Refixation was performed in 28 patients while 25 patients underwent removal and debridement. Mean follow-up was 8.9 years (±4.4, range 2.0-16.7 years). For assessment of clinical outcome, the International Knee Documentation Committee (IKDC) Score, Knee Injury and Osteoarthritis Outcome Score (KOOS), and Lysholm score were used. Redislocation rate and further surgical interventions within follow-up were evaluated.
Results
All clinical scores in the refixation group yielded significantly better results at mid- to long term follow-up (IKDC P < 0.001, KOOS P = 0.006, Lysholm P = 0.001). Significantly more surgical reinterventions were necessary after debridement (48% vs. 7.1%, P = 0.001). The overall redislocation rate in cases with medial reefing as single stabilizing procedure was 43.3%.
Conclusions
Refixation of OCF after lateral patella dislocation shows improved clinical outcome at mid- to long-term follow-up compared with debridement. Therefore, effort to try fragment refixation is recommended. Redislocation rate is high without proper restoration of patellofemoral instability.
We summarized the clinical outcomes and predictors of clinical outcomes after microfracture for chondral lesions in the patellofemoral joint (PFJ).
Methods:
Embase, PubMed, CENTRAL, BIOSIS, and CINAHL databases were searched between January 1, 1980, and January 1, 2019, to identify all articles that examined outcomes or predictors of outcomes of microfracture in patients with patellofemoral chondral lesions. Studies of full-thickness chondral lesions in the PFJ were included, whereas those involving adolescents, partial-thickness chondral lesions, and underlying patellar instability were excluded.
Results:
We found a total of 257 articles, of which 8 articles (174 patients) met our inclusion criteria. All studies found improvement in clinical outcomes after microfracture in the PFJ. Younger patients showed greater improvement in clinical outcomes than older patients. However, the effect of size, severity (grade), or location of chondral lesions on clinical outcomes after microfracture is unclear.
Conclusion:
We found improvement in clinical outcomes after microfracture in the PFJ at midterm follow-up. Age may be a predictor of successful outcomes and longevity of the repair; however, there is insufficient evidence regarding the influence of defect size, severity, and location on clinical outcomes.
Background
Increased posterior tibial slope has been identified as a possible risk factor for injury to the anterior cruciate ligament (ACL) and has also been shown to be associated with ACL reconstruction graft failure. It is currently unknown whether increased posterior tibial slope is an additional risk factor for further injury in the context of revision ACL reconstruction.
Purpose
To determine the relationship between posterior tibial slope and further ACL injury in patients who have already undergone revision ACL reconstruction.
Study Design
Cohort study; Level of evidence, 3.
Methods
A total of 330 eligible patients who had undergone revision ACL reconstruction between January 2007 and December 2015 were identified from a clinical database. The slope of the medial and lateral tibial plateaus was measured on perioperative lateral radiographs by 2 fellowship-trained orthopaedic surgeons using a digital software application. The number of subsequent ACL injuries (graft rupture or a contralateral injury to the native ACL) was determined at a minimum follow-up of 2 years (range, 2-8 years). Tibial slope measurements were compared between patients who sustained further ACL injury to either knee and those who did not.
Results
There were 50 patients who sustained a third ACL injury: 24 of these injuries were to the knee that underwent revision ACL reconstruction, and 26 were to the contralateral knee. Medial and lateral slope values were significantly greater for the third-injury group compared with the no–third injury group (medial, 7.5° vs 6.3° [ P = .01]; lateral, 13.6° vs 11.9° [ P = .001]).
Conclusion
Increased posterior tibial slope, as measured from lateral knee radiographs, was associated with increased risk of graft rupture and contralateral ACL injury after revision ACL reconstruction. This is consistent with the concept that increased posterior slope, particularly of the lateral tibial plateau, is an important risk factor for recurrent ACL injury.
There has been considerable advancement over the last few years in the treatment of osteoarthritis, common chronic disease and a major cause of disability in older adults. In this pathology, the entire joint is involved and the regeneration of articular cartilage still remains one of the main challenges, particularly in an actively inflammatory environment. The recent strategies for osteoarthritis treatment are based on the use of different therapeutic solutions such as cell and gene therapies and tissue engineering. In this review, we provide an overview of current regenerative strategies highlighting the pros and cons, challenges and opportunities, and we try to identify areas where future work should be focused in order to advance this field.
Background:
We used multimodal compositional magnetic resonance imaging (MRI) techniques, combined with clinical outcomes, to differentiate the alternations of composition in repair cartilage with allogeneic human adipose-derived mesenchymal progenitor cells (haMPCs) in knee osteoarthritis (KOA) patients.
Methods:
Eighteen patients participated a phase I/IIa clinical trial. All patients were divided randomly into three groups with intra-articular injections of haMPCs: the low-dose (1.0 × 107 cells), mid-dose (2.0 × 107), and high-dose (5.0 × 107) groups with six patients each. Compositional MRI examinations and clinical evaluations were performed at different time points.
Results:
Significant differences were observed in quantitative T1rho, T2, T2star, R2star, and ADC measurements in patients of three dose groups, suggesting a possible compositional changes of cartilage with the treatment of allogeneic haMPCs. Also significant reduction in WOMAC and SF-36 scores showed the symptoms might be alleviated to some extent with this new treatment. As regards sensibilities of multi-parametric mappings to detect compositional or structural changes of cartilage, T1rho mapping was most sensitive to differentiate difference between three dose groups.
Conclusions:
These results showed that multi-compositional MRI sequences might be an effective tool to evaluate the promotion of the repair of cartilage with allogeneic haMPCs by providing information of compositional alterations of cartilage.
Trial registration:
Clinicaltrials, NCT02641860 . Registered 3 December 2015.
The stromal vascular fraction (SVF) is a heterogeneous population of stem/stromal cells isolated from perivascular and extracellular matrix (ECM) of adipose tissue complex (ATC). Administration of SVF holds a strong therapeutic potential for regenerative and wound healing medicine applications aimed at functional restoration of tissues damaged by injuries or chronic diseases. SVF is commonly divided into cellular stromal vascular fraction (cSVF) and tissue stromal vascular fraction (tSVF). Cellular SVF is obtained from ATC by collagenase digestion, incubation/isolation, and pelletized by centrifugation. Enzymatic disaggregation may alter the relevant biological characteristics of adipose tissue, while providing release of complex, multiattachment of cell‐to‐cell and cell‐to‐matrix, effectively eliminating the bioactive ECM and periadventitial attachments. In many countries, the isolation of cellular elements is considered as a “more than minimal” manipulation, and is most often limited to controlled clinical trials and subject to regulatory review. Several alternative, nonenzymatic methods of adipose tissue processing have been developed to obtain via minimal mechanical manipulation an autologous tSVF product intended for delivery, reducing the procedure duration, lowering production costs, decreasing regulatory burden, and shortening the translation into the clinical setting. Ideally, these procedures might allow for the integration of harvesting and processing of adipose tissue for ease of injection, in a single procedure utilizing a nonexpanded cellular product at the point of care, while permitting intraoperative autologous cellular and tissue‐based therapies. Here, we review and discuss the options, advantages, and limitations of the major strategies alternative to enzymatic processing currently developed for minimal manipulation of adipose tissue. Stem Cells Translational Medicine 2019 Main strategies for adipose tissue processing.
Introduction:
Osteoarthritis (OA) is the leading cause of disability in elderly people. Several non-invasive solutions have been proposed with varying success rates. Recently, new therapeutic approaches, such as the use of minimally manipulated tissue products, have gained increasing popularity. The purpose of this study was to investigate the safety and feasibility of a single intra-articular injection of autologous, microfragmented adipose tissue in patients with knee OA.
Methods:
The study was performed as a prospective cohort study. Microfragmented adipose tissue was obtained using a minimal manipulation technique (Lipogems). The safety of the procedure was evaluated by recording the type and incidence of any adverse events at three months. The clinical outcomes were determined using the Knee injury and Osteoarthritis Outcome Score (KOOS) scale at three, six and 12 months of follow-up.
Results:
Twenty patients were included in the study and all participated in the follow-up. Only one adverse event was registered; a patient complaint of cosmetic changes to the abdominal subcutaneous tissue. The improvements in KOOS were significant at all follow-up. At one year, KOOS pain had improved by 14 points, symptoms by seven, activity of daily living by 13, sports by 19 and quality of life by 15.
Conclusions:
The intra-articular injection of autologous, microfragmented adipose tissue for treatment of knee OA seems safe. Randomised controlled trials are needed to elucidate the efficacy of the treatment.
Trial registration:
This study was registered in ClinicalTrials.gov (NCT02697682).
Funding:
none.
Purpose
To investigate the influence of medial and lateral posterior tibial slope (PTS) on long-term clinical outcomes and survivorship after anterior cruciate ligament (ACL) reconstruction using hamstring autografts.
Methods
A total of 232 patients (mean age, 28.2 ± 8.9 years) who underwent primary ACL reconstruction from October 2002 to July 2007 were retrospectively reviewed. Patients with multiple ligament reconstruction, total meniscectomy, contralateral knee surgery before ACL reconstruction, open growth plate, and less than 10-year follow-up were excluded in the study. The medial and lateral PTS were measured from preoperative magnetic resonance imaging. Based on Li et al.’s previous study, the patients were divided into two groups according to their medial PTS (≤5.6° vs. >5.6°) and lateral PTS (≤3.8° vs. >3.8°), respectively. Clinical outcomes (clinical scores, stability tests and failure rate) were compared between the groups at the last follow-up. Furthermore, survival analysis was performed using the Kaplan–Meier method.
Results
All clinical scores (International Knee Documentation Committee subjective, Lysholm, and Tegner activity scores) and stability tests (physical examinations and side-to-side difference in Telos stress radiographs) were insignificantly different between the two groups classified based on medial or lateral PTS. However, the failure rate was significantly higher in patients with medial PTS >5.6° (16.1% vs. 5.1%, p=0.01) or lateral PTS >3.8° (14.5% vs. 4.7%; p=0.01). The odds ratios of graft failure due to increased medial and lateral PTS were 3.18 (95% confidence interval, 1.22–8.28; p=0.02) and 3.43 (95% confidence interval, 1.29–9.09; p=0.01), respectively. Additionally, the 10-year survivorship was significantly lower in patients with medial PTS >5.6° (83.9% vs. 94.9%, p=0.01) or lateral PTS >3.8° (85.5% vs. 96.0%; p=0.01).
Conclusions
Increased medial (>5.6°) and lateral (>3.8°) PTS were associated with higher failure rate and lower survivorship at a minimum of 10-year follow-up after primary ACL reconstruction using hamstring autografts.
Background
Factors associated with graft survival after lateral meniscal allograft transplantation (MAT) have not been fully determined, and survival analysis focused on effect of varus alignment has not been performed.
Hypothesis
Varus alignment of the knee leads to better graft survival and clinical outcomes after lateral MAT than normal alignment.
Study Design
Cohort study; Level of evidence, 2.
Methods
The records of 204 consecutive patients who underwent lateral MAT were reviewed. After exclusion of cases undergoing revision MAT, cases without hip-knee-ankle standing radiographs, and cases with valgus alignment, the patients were categorized into 2 groups, those with normal alignment within −3° to 3° of the mechanical axis and those with varus alignment >3°. Cumulative graft survival rates were compared in the 2 groups before and after controlling for other covariates, including sex, age, body mass index (BMI), time from meniscectomy, the number of accompanying procedures, and cartilage status. Failure was defined as (1) a graft tear involving >50% or unstable peripheral rim of the allograft; (2) a Lysholm score <65 that was not improved afterward; (3) meniscectomy >50% or to the zone of meniscocapsular junction; or (4) conversion to revision MAT, realignment osteotomy, or arthroplasty. Clinical outcomes were compared between the 2 groups by Lysholm score.
Results
Of the 190 patients, 149 showed normal alignment of 0.3° ± 1.3° (range, –3° to 3°) and 41 showed varus alignment of 4.8° ± 0.6° (range, 4°-8°). A total of 22 patients (11.6%) experienced MAT failure: 21 patients with normal alignment and 1 with varus alignment. Kaplan-Meier survival analysis showed a significant difference in the cumulative graft survival rates between the 2 groups (log-rank test, P = .001). After controlling for age, sex, BMI, time from meniscectomy, the number of accompanying procedures, and cartilage status, varus alignment was found to be a significant protective factor ( P = .004). On the other hand, there was no difference in clinical improvement measured by the Lysholm score between the 2 groups ( P = .651).
Conclusion
Varus alignment was associated with better graft survival after lateral MAT than normal alignment. However, no significant differences in clinical outcomes were observed.
Isolated posterior cruciate ligament (PCL) injuries are uncommon and can be easily missed with physical examination. The purpose of this article is to give an overview of the clinical, diagnostic and arthroscopic evaluation of a PCL injured knee. There are some specific injury mechanisms that can cause a PCL including the dashboard direct anterior blow and hyperflexion mechanisms. During the diagnostic process it is important to distinguish between an isolated or multiligament injury and whether the problem is acute or chronic. Physical examination can be difficult in an acutely injured knee because of pain and swelling, but there are specific functional tests that can indicate a PCL tear. Standard x-ray's and stress views are very useful imaging modalities but magnetic resonance imaging remains the gold standard imaging study for detecting ligament injuries. Every knee scope should be preceded by an examination under anesthesia. Specific arthroscopic findings are indicative of a PCL tear such as the "floppy ACL sign" and the posteromedial drive through sign. History, physical examination and imaging should all be combined to make an accurate diagnosis and initiate appropriate treatment.
PurposeThis study was undertaken to retrospectively determine the incidence of postoperative knee infection following ACL reconstruction, to identify the most common causative pathogen and to evaluate our diagnostic and treatment approach, as well as to review current recommendations for the management of septic arthritis.Methods
From January 2007 to December 2017, a total of 1891 arthroscopic ACL reconstructions were performed at our institution. Twenty-nine cases with clinical suspicion of post-operative septic knee arthritis following ACL reconstruction were identified and retrospectively analysed with regard to incidence, clinical presentation, microbiological spectrum, laboratory parameters and number of arthroscopic debridements. Three patients were classified as aseptic effusion and were excluded from the further analysis. Patients were treated with antibiotic therapy (IV and oral) and repeated arthroscopic debridement.ResultsTwenty-six (1.4%) out of 1891 patients were diagnosed with joint infection and were treated with arthroscopic debridement and intravenous antibiotics. In the majority of cases (58.69%), microbiological analysis failed to identify the causative pathogen and in those where the pathogen was isolated, the most common was methicillin-resistant Staphylococcus epidermidis (45.45%). Mean time interval from reconstruction to onset of symptoms was 23.54 ± 21.00 (6–100) days. The mean number of arthroscopic irrigations and debridements was 1.23 ± 0.51 (1–3) per patient. In all, twenty-six cases of graft was retained.Conclusion
Septic arthritis following ACL reconstruction is a rare but serious complication. We conclude that prompt treatment consisting of repeated arthroscopic irrigation and debridement with course of antibiotic therapy is an effective therapeutic intervention that leads to graft and hardware retention.
PurposeThere is paucity in studies regarding double-bundle anterior cruciate ligament reconstruction (DB-ACLR) in teenagers. The purpose of this study is to investigate clinical outcome after DB-ACLR and analyze whether any differences exist between teenagers and young adults.MethodsA retrospective study was performed between 2009 and 2017. Teenagers were defined as patients between 15 and 19 years and young adults between 20 and 25 years old. Isolated anterior cruciate ligament (ACL) injuries with DB-ACLR with minimum two-year follow up were included. Pre and post-operative Lysholm score, Tegner activity scale, KT-2000 arthrometer, manual pivot-shift grade, were assessed with post-operative one-leg hop test, isokinetic knee extensor strength test at 60°/sec, International Knee Documentation Committee Score (IKDC score), and re-injury rate.ResultsOne-hundred and thirty-one patients, 75 patients in the teenage group (Group A) and 56 patients in the young adult group (Group B), were enrolled. Lysholm score was significantly lower in Group A (89.6 ± 21.1) compared to Group B (95.9 ± 4.6) (p = 0.04). Side to side difference in KT-2000 arthrometer (2.3 ± 2.2 mm vs 1.0 ± 2.3 mm, Group A vs Group B, respectively, p < 0.01) and ratio of post-operative positive pivot shift was significantly greater in Group A (30.7%) compared to Group B (7.1%) (p < 0.01). No significant difference was seen in re-injury rate (n.s.).Conclusion
Teenage patients have a greater tendency for residual knee joint laxity after DB-ACLR. Although teenagers and patients in the early twenties are close in age, characteristic in knee joint laxity may be different and, therefore, may require attention upon surgery and post-operative follow-up.Level of evidence III.
Purpose:
The purpose of this study was to analyze the long-term clinical and radiological outcomes of patients who underwent closing-wedge High Tibial Osteotomy (HTO) for the treatment of medial compartment osteoarthritis and to evaluate the conversion rate to knee arthroplasty.
Methods:
A retrospective, non-randomized, monocentric study was performed in our Institution considering 166 patients between 1989 and 2012. The final population was composed by 82 patients (94 knees), median age at time of operation was 53 (range 45-73) years. All patients were evaluated clinically (HSS Score, Tegner Scale, VAS and Crosby-Insall Grading) and radiographically (osteoarthritis staging, hip-knee-ankle (HKA) angle, tibial slope and metaphyseal varus).
Results:
Mean follow-up was 11.9 ± 7.2 years. HSS Score increased significantly from 70.8 ± 10 to 93.2 ± 9.1 (p < 0.05) instead Tegner Scale increased from 1.3 ± 0 (range 1-4) to 2.8 ± 0.7 (range 2-6) at the last control (n.s.); VAS score significantly decreased from 7.9 ± 1.4 to 1.6 ± 1.1 (p < 0.05) at last follow-up. According to the Crosby-Insall Grading System, 80 patients (97.4%) reported excellent-good results. HKA angle decreased from 6.9° ± 3.5 to 2.6° ± 2.6 (p < 0.01), tibial slope decreased from 10.1° ± 1.4 to 6.8° ± 2.1 (p < 0.05) and finally the metaphyseal varus decreased from 4.2° ± 0 to 2.1° ± 1.2 (n.s.) at the last follow-up. Adverse events were reported in 4.8%. Osteotomy survivorship rate resulted 92% at 10 years, 82% at 15 years and 80% at 20 years. Sixteen revisions (9.6%) were reported at a mean period of 12.8 years.
Conclusions:
CW-HTO is a valid option for medial osteoarthritis treatment, with successful results in both clinical and radiological outcomes.
Level of evidence:
IV.
Purpose The aim of the present meta-analysis is to provide a direct comparison between MPFL reconstruction and the other medial patellofemoral soft tissue surgeries in the restoration of the medial patellar restraint after lateral patellar dislocations in the absence of untreated predisposing factors such as high grade trochlear dysplasia, knee malalignment, patella alta or high TT-TG distance.
Methods PubMed, Cochrane-library, WebOfScience, and grey literature databases were searched to find all the relevant records. Study selection, data extraction and risk of bias assessment were performed following the Cochrane and PRISMA guidelines. Different techniques to treat lateral patellar dislocation in the absence of untreated predisposing factors were compared in terms of redislocation and complication rates, Kujala, Lysholm, IKDC, and Tegner scores at the short-term (3 years) and long-term (>3years) follow-ups through meta-analyses.
Results Six studies involving 319 knees were included in the meta-analysis. The analyses of redislocation (0.7% vs 2.9%) and minor complication rates (12% vs 9%) showed no significant differences between MPFL reconstruction and other medial soft tissue surgeries. Significant differences favoring MPFL reconstruction were documented in Kujala and Lysholm scores at short-term (8.6 p<0.001; 10.9 p<0.001) and long-term follow-ups (6.3 p=0.02; 13.5 p<0.001). No significant differences were found in the analyses of IKDC (p=0.10) and Tegner scores (p=0.19). Level of evidence was low or very low.
Conclusions MPFL reconstruction and medial patellofemoral soft tissue surgery procedures were both effective in restoring the medial restraining forces preventing redislocation, but MPFL reconstruction provided better functional outcomes both at short-term and long-term follow-ups. Thus, besides the treatment of predisposing factors, MPFL reconstruction seems to be, based on the results of this meta-analysis, a suitable strategy to restore the medial restraining function in the treatment of recurrent LPD.
Background:
The effects of a partial lateral meniscectomy on knee kinematics and forces in the lateral meniscus are critical to understand. The purpose of this study was to quantify the effects of varying sizes of partial lateral meniscectomies of the posterior horn and a total lateral meniscectomy on knee kinematics and resultant forces in the lateral meniscus.
Methods:
Using a robotic testing system, loads (134-N anterior tibial load + 200-N axial compression, 5-Nm internal tibial torque + 5-Nm valgus torque, and 5-Nm external tibial torque + 5-Nm valgus torque) were applied to 10 fresh-frozen cadaveric knees. The resulting joint motion and resultant forces in the lateral meniscus were determined for 4 knee states: intact, one-third and two-thirds partial lateral meniscectomies of the posterior horn, and total lateral meniscectomy.
Results:
A decrease in lateral translation of the tibia (up to 166.7%) was observed after one-third partial lateral meniscectomies of the posterior horn compared with the intact knee, in response to an anterior load at all knee flexion angles tested (p < 0.05). One-third partial lateral meniscectomies of the posterior horn decreased the resultant forces in the lateral meniscus compared with the intact knee at all knee flexion angles tested in response to an anterior load (p < 0.05) and to an internal tibial torque (p < 0.05). The results of two-thirds partial lateral meniscectomies of the posterior horn were similar to those of one-third partial meniscectomies (p > 0.05). Total lateral meniscectomies further decreased the lateral translation of the tibia (up to 316.6%) compared with the intact knee in response to an anterior load (p < 0.05).
Conclusions:
The changes in joint motion and meniscal forces observed in this study after even small partial lateral meniscectomies may predispose knees to further injury.
Clinical relevance:
Surgeons should always consider repairing and minimizing the resection of even small lateral meniscal tears to prevent the potential deleterious effects of partial meniscectomy reported in this cadaveric study.
Purpose:
To determine (1) the demographic characteristics as well as radiographic findings of medial versus lateral meniscal root tears at time of presentation, (2) treatment decisions and clinical outcomes of patients undergoing medial versus lateral root repair, and (3) risk factors for worse clinical and radiographic outcomes.
Methods:
A retrospective review was performed to identify patients with symptomatic, medial, or lateral meniscus posterior root tears with a minimum 2-year follow-up. Radiographs were graded using Kellgren-Lawrence scores. Subanalysis was performed on 62 patients who underwent root repair. Tegner, Lysholm, International Knee Documentation Committee scores, and progression to arthroplasty were analyzed in the repair groups. Patient demographics, radiographic findings, and clinical outcomes were compared between medial meniscus posterior horn root tear (MMRT) and lateral meniscus root repair (LMRT).
Results:
Of the 141 root tears, 109 were MMRTs, 30 were LMRTs, and 2 patients had both. At the time of injury, patients with MMRTs had a significantly higher age (MMRT = 51.4 vs LMRT=24.6, P < .0001), body mass index (MMRT = 32.1 vs LMRT 25.8, P < .0001), Kellgren-Lawrence score (MMRT = 1.3 vs LMRT=0.6, P < .0001), and higher rate of major meniscal extrusion (MMRT = 72% vs LMRT = 20%, P < .0001). Of the 30 LMRT, 30/30 (100.0%) were treated with meniscal repair. With MMRT, 52/109 (48%) were treated nonoperatively, 27/109 (25%) with partial meniscectomy, and 30/109 (27%) with meniscal repair. Sixty-two patients underwent meniscus root repair with an average 41-month follow-up. LMRT had significantly increased International Knee Documentation Committee (LMRT = 89.5, MMRT = 80.4, P = .02) and Tegner scores (LMRT = 6.5, MMRT = 5.1, P < .05) compared with MMRT.
Conclusions:
Compared with MMRTs, LMRTs occur in younger male patients with lower body mass index, less cartilage degeneration, less extrusion on magnetic resonance imaging, and more commonly with a ligament injury. Although good to excellent clinical outcomes were attained in select patients for both medial and lateral meniscus root repair, LMRTs may have better results after repair, suggesting that differences in injury and patient characteristics may contribute to differences in these outcomes.
Level of evidence:
Retrospective comparative study, Level III.
Background
Persistent anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been correlated with poor clinical outcomes and graft failure.
Hypothesis
We hypothesized that a single-bundle, hamstring ACLR in combination with a lateral extra-articular tenodesis (LET) would reduce the risk of ACLR failure in young, active individuals.
Study Design
Randomized controlled trial; Level of evidence, 1.
Methods
This is a multicenter, prospective, randomized clinical trial comparing a single-bundle, hamstring tendon ACLR with or without LET performed using a strip of iliotibial band. Patients 25 years or younger with an ACL-deficient knee were included and also had to meet at least 2 of the following 3 criteria: (1) grade 2 pivot shift or greater, (2) a desire to return to high-risk/pivoting sports, (3) and generalized ligamentous laxity (GLL). The primary outcome was ACLR clinical failure, a composite measure of rotatory laxity or a graft rupture. Secondary outcome measures included the P4 pain scale, Marx Activity Rating Scale, Knee injury Osteoarthritis and Outcome Score (KOOS), International Knee Documentation Committee score, and ACL Quality of Life Questionnaire. Patients were reviewed at 3, 6, 12, and 24 months postoperatively.
Results
A total of 618 patients (297 males; 48%) with a mean age of 18.9 years (range, 14-25 years) were randomized. A total of 436 (87.9%) patients presented preoperatively with high-grade rotatory laxity (grade 2 pivot shift or greater), and 215 (42.1%) were diagnosed as having GLL. There were 18 patients lost to follow-up and 11 who withdrew (~5%). In the ACLR group, 120/298 (40%) patients sustained the primary outcome of clinical failure, compared with 72/291 (25%) in the ACLR+LET group (relative risk reduction [RRR], 0.38; 95% CI, 0.21-0.52; P < .0001). A total of 45 patients experienced graft rupture, 34/298 (11%) in the ACLR group compared with 11/291 (4%) in the ACL+LET group (RRR, 0.67; 95% CI, 0.36-0.83; P < .001). The number needed to treat with LET to prevent 1 patient from graft rupture was 14.3 over the first 2 postoperative years. At 3 months, patients in the ACLR group had less pain as measured by the P4 ( P = .003) and KOOS ( P = .007), with KOOS pain persisting in favor of the ACLR group to 6 months ( P = .02). No clinically important differences in patient-reported outcome measures were found between groups at other time points. The level of sports activity was similar between groups at 2 years after surgery, as measured by the Marx Activity Rating Scale ( P = .11).
Conclusion
The addition of LET to a single-bundle hamstring tendon autograft ACLR in young patients at high risk of failure results in a statistically significant, clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after surgery.
Registration
NCT02018354 ( ClinicalTrials.gov identifier)
Background
Physicians’ and patients’ decision-making process between bone–patellar tendon–bone (BTB) and hamstring tendon autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) may be influenced by a variety of factors in the young, active athlete.
Purpose
To determine the incidence of both ACL graft revisions and contralateral ACL tears resulting in subsequent ACLR in a cohort of high school– and college-aged athletes who initially underwent primary ACLR with either a BTB or a hamstring autograft.
Study Design
Cohort study; Level of evidence, 2.
Methods
Study inclusion criteria were patients aged 14 to 22 years who were injured in sports, had a contralateral normal knee, and were scheduled to undergo unilateral primary ACLR with either a BTB or a hamstring autograft. All patients were prospectively followed for 6 years to determine whether any subsequent ACLR was performed in either knee after their initial ACLR. Multivariable regression modeling controlled for age, sex, ethnicity/race, body mass index, sport and competition level, baseline activity level, knee laxity, and graft type. The 6-year outcomes were the incidence of subsequent ACLR in either knee.
Results
A total of 839 patients were eligible, of which 770 (92%) had 6-year follow-up for the primary outcome measure of the incidence of subsequent ACLR. The median age was 17 years, with 48% female, and the distribution of BTB and hamstring grafts was 492 (64%) and 278 (36%), respectively. The incidence of subsequent ACLR at 6 years was 9.2% in the ipsilateral knee, 11.2% in the contralateral normal knee, and 19.7% for either knee. High-grade preoperative knee laxity (odds ratio [OR], 2.4 [95% confidence interval [CI], 1.4-3.9]; P = .001), autograft type (OR, 2.1 [95% CI, 1.3-3.5]; P = .004), and age (OR, 0.8 [95% CI, 0.7-1.0]; P = .009) were the 3 most influential predictors of ACL graft revision in the ipsilateral knee. The odds of ACL graft revision were 2.1 times higher for patients receiving a hamstring autograft than patients receiving a BTB autograft (95% CI, 1.3-3.5; P = .004). No significant differences were found between autograft choices when looking at the incidence of subsequent ACLR in the contralateral knee.
Conclusion
There was a high incidence of both ACL graft revisions and contralateral normal ACL tears resulting in subsequent ACLR in this young athletic cohort. The incidence of ACL graft revision at 6 years after index surgery was 2.1 times higher with a hamstring autograft compared with a BTB autograft.
The meniscal roots and supporting structures anchor the menisci to the tibial plateau and resist hoop stress, thereby preventing radial displacement of the menisci and secondary degenerative tibiofemoral compartment changes that may occur if this is compromised. The anatomy of the four meniscal roots and their supporting structures on magnetic resonance imaging (MRI) will be outlined in this review article, as well as the imaging appearances of meniscal root-related pathology, namely meniscal root degeneration and tears, meniscal extrusion and tibial plateau cystic lesions.
Purpose:
Posterolateral corner (PLC) injuries commonly occur in the setting of a dislocated knee and often require multiple procedures due to concomitant vascular, nerve, and soft tissue involvement. Debate persists regarding single vs staged surgery. The purpose of this study was to compare knee function after single and staged surgery for PLC injury.
Methods:
Patients who underwent surgery for a PLC injury (KD I, IIIL, IV) with minimum follow-up of 2 years were included. Patients treated with staged and single surgery were matched according to age, sex, and KD grade. Lysholm and International Knee Documentation Committee (IKDC) subjective scores were obtained. Risk factors for poor knee function were assessed, including age, nerve, vascular, meniscal and articular cartilage injuries.
Results:
Twenty single-surgery patients with a median age of 24 years (median follow-up 5.3 years, range 2-18.3) and 20 staged surgery patients with a median age of 26 years (median follow-up 4.3 years, range 2-19.8) were studied. The mean Lysholm score was 78.7 (± 20.3) in the single surgery and 84.2 (± 17.8) in the staged surgery cohort (n.s.). The mean IKDC score was 80.8 (± 21.1) in the single and 74.9 (± 18.9) in the staged surgery cohort (n.s.). Age at injury, peroneal, vascular, meniscal or cartilage injury were not associated with poor knee outcome.
Conclusion:
This study demonstrates similar knee function among patients with PLC injuries treated with single or staged surgical procedures. The need for staged surgery for the dislocated knee with PLC involvement should be individualized based on specific knee and patient-related factors.
Level of evidence:
III.
Introduction: Treatment of multiple ligament-injured knees (MLIKs) remains complex and most often requires ligament reconstruction surgery. Reconstruction effectively restores knee stability but the procedure is invasive and can be complicated by stiffness or arthrofibrosis. There has been recent resurgence of interest in primary repair of knee ligaments. The goal was therefore to assess incidence of repairable ligaments in MLIKs, and determine patient and injury characteristics associated with potential for primary repair. Methods:
A retrospective review of all MLIKs patients surgically treated between 2009 and 2018 was conducted. All patients were treated with the same algorithm: primary repair was performed if the ligament was proximally or distally avulsed, and otherwise, reconstruction was performed. Patient characteristics, injury patterns, treatment specifics, and short-term outcomes were compared using independent t-tests and chi-square tests. Results: Forty-eight patients were included (mean age 32 years ± 14; 54% were male). Ultimately, 55% of ACL, 73% of PCL, 88% of MCL/PMC, and 87% of LCL/PLC injuries were repaired. Patients above 35 years (OR 6.9, P = .010) and higher BMI (OR 3.5, P = .046) were more likely to undergo ACL repair. No significant correlation was found in other ligaments. At minimum of 6-month follow-up (range 0.5–7.2 years), ACL repair failed in 9%, PCL repair in 17%, MCL/PMC repair in 0%, and LCL/PLC repair in 18% of patients. Conclusion: This study noted high incidences of repairable ligaments when MLIKs are treated within six weeks following injury. Although preliminary outcomes following primary repair in MLIK are good, further long-term follow-up studies are needed.
Meniscus root tears biomechanically disrupt normal joint loading and lead to joint overload with the possible development of spontaneous osteonecrosis of the knee and early-onset osteoarthritis. Proper identification and treatment of meniscal root tears has been proven to restore joint loading and improve patient outcomes.
The meniscus is a crucial player in knee joint homeostasis. Loss of meniscus tissue can result in early onset of clinical symptoms like pain and loss of function, and structural degeneration of the articular cartilage. In case of a symptomatic segmental defect of the medial or lateral meniscus, different innovative options using biological or synthetic scaffolds are now available to regenerate meniscuslike tissue, with the aim of allowing a satisfactory clinical improvement to patients. However, the role of any of these procedures in terms of chondroprotection is questionable, and the overall outcomes in the long term still can be improved.
Purpose:
The purpose of this retrospective study was to evaluate the survival rates and analyze the factors that affect survival rate after primary treatment with medial open wedge high tibial osteotomy (MOWHTO) for medial unicompartmental knee osteoarthritis.
Methods:
Clinical evaluation using Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index score and radiographic evaluation, including mechanical axis, were done before and after surgery. The main failure criteria for survival included the conversion to total knee arthroplasty or KSS of <60 points. Furthermore, risk factors that affected the survival after MOWHTO were analyzed.
Results:
Three hundred thirty-nine knees were included after a minimum of 5 years' follow-up. Their mean age was 56 years, and mean follow-up duration was 9.6 years. The mean KSS and Western Ontario and McMaster Universities Osteoarthritis Index scores were significantly improved after surgery (87.3 and 18.5 points at 5 years and 81.7 and 23.6 points at 10 years). The mean hip-knee-ankle (HKA) angle was corrected from 7.2° varus to 3.4° valgus 1 year after surgery, which was maintained until 10 years after surgery (2.9° valgus at 5 years and 2.3° valgus at 10 years, P > .05). Using Kaplan-Meier survival estimates, the probability of survival for MOWHTO was 96.8% at 5 years, 87.1% at 10 years, and 85.3% at 13 years. The multivariate regression analysis revealed that age ≥65 years (hazard ratio [HR] = 2.34, P = .046), medial compartment cartilage damage International Cartilage Repair Society grade ≥4 (HR = 2.46, I = .045), lateral compartment cartilage damage International Cartilage Repair Society grade≥2 (HR = 3.38, P = .006), postoperative HKA angle <0° (HR = 4.69, P < .001) were associated with failure.
Conclusion:
MOWHTO seems to be a good treatment option for young and active patients with medial knee osteoarthrosis and varus alignment, with acceptable survival rates and satisfactory outcomes. Age ≥65 years, grade 4 cartilage damage in medial compartment, grade ≥2 cartilage damage in lateral compartment, and undercorrection of HKA angle appear to be significant risk factors associated with failure.
Level of evidence:
Level IV: retrospective case series.
Medial open- and lateral closed-wedge high tibial osteotomy (hybrid CWHTO) can overcome the limitations of conventional CWHTO and open-wedge HTO (OWHTO) for medial compartmental osteoarthritis (OA) of the knee. Hybrid CWHTO increases stability by using a rigid locking plate and allows early full weight-bearing. However, the literature contains no information about time to bone union after this new procedure. The aim of this study is to evaluate the time to bone union after hybrid CWHTO. We reviewed 44 knees treated with hybrid CWHTO. Patients were able to stand on both legs on the day after surgery and walked with full weight-bearing within 4 weeks of the procedure. The time to achievement of bone union at the osteotomy site was defined as the number of months until bone union was confirmed on radiographic imaging. The mean time to radiographic confirmation of bone union was 4.5±1.5 months after surgery. Eleven knees (25.0%) required 6 months or more. Radiographic analysis and JOA score improved significantly between before and 1 year after surgery (p<0.01). Hybrid CWHTO is a very useful method for treating medial OA, but radiographic bone union requires 4.5 months on average. We must be aware of bone union after hybrid CWHTO.
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.
Purpose
Medial patellofemoral ligament reconstruction (MPFLR) shows low recurrent rates and high satisfaction. Reports on outcome at mid-term follow-up in a large cohort with or without tibial tubercle transfer (TTT) are scarce.
Methods
One hundred six patients (115 knees; 24.3 ± 8.7 years) with recurrent patellar dislocation underwent MPFLR with ipsilateral gracilis autograft and were included in this retrospective follow-up study. In 43 knees, simultaneous TTT was performed for patellar maltracking due to patella alta or increased tibial tubercle trochlear groove distance (TT-TG). Kujala and subjective knee scores were recorded pre- and post-operatively.
Results
Eighty-seven percent of the patients were satisfied at a mean follow-up of 5.4 ± 3.1 years. The Kujala score increased in 81.7% of all knees from 50.9 to 76.2 points (p < 0.01). Patients with a decreased Kujala score were not different in terms of follow-up time, age, trochlear dysplasia, or post-operative patellar height. The decline was related to an increase in pain, whereas functional scores remained identical. There were six patients with persisting instability, three with patellar re-dislocation. Re-operation was necessary in 24 patients (21.2%), mainly for implant removal after TTT and loss of flexion. Performing TTT had no significant influence on the subjective outcome. Patients with more than eight years of follow-up (n = 27) did not show any difference in the subjective outcome parameters, or in osteoarthritis progression.
Conclusion
MPFLR with and without TTT is a reliable treatment option for recurrent patellar dislocation without deterioration at mid-term follow-up. Persisting pain is a major post-operative issue that seems to be unrelated to patellofemoral anatomy.
Background
Although many studies have reported successful functional outcomes after proximal tibial osteotomy (PTO), a paucity of literature has sought to quantify outcomes and current rates of return to sport (RTS) and return to work (RTW) after PTO.
Purpose
To (1) determine current rates of RTS and RTW after PTO and (2) quantify the incidence of complications and conversion to total knee arthroplasty (TKA) after PTO for all patients as well as those undergoing opening and closing wedge PTO.
Study Design
Systematic review and meta-analysis; Level of evidence, 4.
Methods
The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), EMBASE (2008-2019), and MEDLINE (2008-2019) databases were queried. Data pertaining to article information, patient demographics, surgical techniques, rates of complication and conversion to TKA, patient-reported outcome scores, RTS, and RTW were extracted. Data were synthesized, and a random effects meta-analysis of proportions using continuity correction methods was performed to determine the proportion of patients receiving opening and closing wedge PTO who experienced adverse events.
Results
The review and meta-analysis included 33 studies involving 1914 patients who underwent PTO with a weighted mean ± SD age of 50.3 ± 9.9 years and body mass index of 26.9 ± 2.3 kg/m ² . The pooled RTS and RTW rates were 75.7% (range, 55%-100%) in 814 patients and 80.8% (range, 41%-100%) in 505 patients, respectively. The pooled TKA rate was 12.5% (range, 0%-35.7%) at a mean of 70.6 months and the pooled complication rate was 11.1% (range, 0%-28.6%). The overall random pooled summary estimate of the proportion of patients who underwent opening wedge PTO and subsequently converted to TKA was 2.0% (95% CI, 1.0%-4.0%; I ² = 63.65) at a mean of 43.4 ± 31.9 months and who experienced a complication was 6.0% (95% CI, 3.0%-9.0%; I ² = 87.10%). For closing wedge PTO, the proportion of patients who converted to TKA was 5.0% (95% CI, 1.0%-9.0%; I ² = 93.1%) and experienced a complication was 2.0% (95% CI, 1.0%-3.0%; I ² = 90.0%). Only 53.8% of studies that referenced RTS provided postoperative RTS rates, and 80% of studies that referenced RTW provided RTW rates. Only 1 study defined RTS criteria, no studies defined RTW criteria, and 31 different outcome measures were reported across all studies.
Conclusion
Patients undergoing PTO for osteoarthritis, cartilage defects, and symptomatic malalignment of the knee experience high rates of RTS and RTW. These patients also experience low rates of complications and conversion to TKA, regardless of opening or closing wedge technique. Significant heterogeneity exists with regard to criteria used to define RTS and RTW and patient-reported outcome measures used to assess clinical and functional improvements after PTO.
Purpose
This study aimed to assess the effect of soft tissue correction due to knee joint laxity, which induces alignment error after hybrid closed-wedge high tibial osteotomy (CWHTO). In addition, to verify whether postoperative soft tissue correction can be predicted from preoperative radiographic parameters.
Methods
A retrospective evaluation of data from patients treated by CWHTO in 2016–2019 was performed. Standing full-length anteroposterior radiograph measurement was performed pre- and post-surgery, and short anteroposterior radiographs of the knee under maximal manual varus and valgus stress were taken preoperatively. The weight-bearing line, hip–knee–ankle angle (HKA), medial proximal tibial angle (MPTA), and joint line convergence angle (JLCA) were measured, in addition to JLCA under varus or valgus conditions. Soft tissue correction was defined as ΔHKA minus ΔMPTA. Multiple regression analysis was performed to evaluate preoperative factors that could influence soft tissue correction.
Results
Data from 49 knees were included in the analysis. The mean soft tissue correction was 3.2°, which indicates an over-correction. Multiple regression analysis revealed that JLCA (β = 0.642; p < 0.001) and valgus JLCA (β = − 0.422; p = 0.001) were significantly associated with postoperative soft tissue correction. The final model of the regression formula was described by the following equation: postoperative soft tissue correction = 0.691 × JLCA − 0.411 × valgus JLCA − 0.399.
Conclusion
Preoperative values for JLCA and JLCA under valgus stress are associated with soft tissue correction. Surgeons should, therefore, consider these measurements to achieve postoperative limb alignment.
Joint stiffness due to fibrosis/capsule contracture is a seriously disabling complication of articular injury that surgical interventions often fail to completely resolve. Fibrosis/contracture is associated with the abnormal persistence of myofibroblasts, which over‐produce and contract collagen matrices. We hypothesized that intra‐articular therapy with drugs targeting myofibroblast survival (sulfasalazine), or collagen production (beta‐aminopropionitrile and cis‐hydroxyproline), would reduce joint stiffness in a rabbit model of fibrosis/contracture. Drugs were encapsulated in poly[lactic‐co‐glycolic] acid pellets, and implanted in joints after fibrosis/contracture induction. Capsule alpha‐smooth muscle actin (α‐SMA) expression and intimal thickness were evaluated by immunohistochemistry and histomorphometry respectively. Joint stiffness was quantified by flexion‐extension testing. Drawer tests were employed to determine if the drugs induced cruciate ligament laxity. Joint capsule fibroblasts were tested in vitro for contractile activity and α‐SMA expression. Stiffness in immobilized joints treated with blank pellets (control) was significantly higher than in non‐immobilized, untreated joints (normal) (p=0.0008), and higher than in immobilized joints treated with sulfasalazine (p=0.0065). None of the drugs caused significant cruciate ligament laxity. Intimal thickness was significantly lower than control in the normal and sulfasalazine‐treated groups (p = 0.010 and 0.025 respectively). Contractile activity in cells from controls was significantly increased versus normal (p=0.001). Sulfasalazine and beta‐aminopropionitrile significantly inhibited this effect (p=0.005 and 0.0006 respectively). α‐SMA expression was significantly higher in control versus normal (p=0.0021) and versus sulfasalazine (p=0.0007). These findings support the conclusion that sulfasalazine reduced stiffness by clearing myofibroblasts from fibrotic joints. Clinical significance: The results provide proof‐of‐concept that established joint stiffness can be resolved non‐surgically. This article is protected by copyright. All rights reserved.
Purpose
To biomechanically investigate the influence of osseous valgus alignment, with and without deficiency of the posteromedial ligament complex (PMC), on ACL-graft forces under axial load.
Methods
ACL reconstruction was performed on ten cadaveric knee joints. A lateral distal femur osteotomy was then done to adjust for three different alignment conditions according to the position, where the axial weight bearing line (WBL) dissected the tibial plateau (% from medial to lateral): 50%, 85% and 115%. Each alignment was tested with the PMC intact, deficient and reconstructed. Axial loads of 400 N were applied in 15° of knee flexion and changes of ACL-graft forces and dynamic valgus angle (DVA) were recorded.
Results
In the PMC intact state, lateralization of the WBL to 85% and to 115% led to significantly increased ACL graft forces (85%: p = 0.010; 115%: p < 0.001) and DVAs (85%: p = 0.027; 115%: p = 0.027). Dissection of the PMC led to a significant increase of ACL graft forces and DVAs at 85% and 115% valgus alignment (p < 0.001) only.
In comparison to valgus aligned knees with additional PMC deficiency, ligament reconstruction alone was able to significantly decrease ACL graft forces (p < 0.001) and DVAs (p < 0.001). However, alignment correction alone was significantly more effective in reducing ACL graft forces (p < 0.001) and DVAs (p = 0.010).
Conclusion
Osseous valgus alignment led to significantly increased forces on ACL grafts under axial joint compression, which was even further enhanced, when the PMC was deficient. In the valgus aligned and PMC deficient knee, correction to a straight leg axis was significantly more effective in decreasing forces on the ACL graft than reconstruction of the PMC. In patients with valgus alignment and combined injuries of the ACL and PMC, a correction osteotomy to a straight leg axis as well as reconstruction of the PMC should be considered to protect the reconstructed ACL.
Background
There is evidence that tibial slope may play a role in revision risk after anterior cruciate ligament reconstruction (ACLR); however, prior studies are inconsistent.
Purpose
To determine (1) whether there is a difference in lateral tibial posterior slope (LTPS) or medial tibial posterior slope (MTPS) between patients undergoing revised ACLR and those not requiring revision and (2) whether the medial-to-lateral slope difference is different between these 2 groups.
Study Design
Case-control study; Level of evidence, 3.
Methods
We conducted a matched case-control study (2006-2015). Cases were patients aged ≤21 years who underwent revision surgery after primary unilateral ACLR; controls were patients aged ≤21 years without revision who were identified from the same source population. Controls were matched to cases by age, sex, body mass index, race, graft type, femoral fixation device, and post-ACLR follow-up time. Tibial slope measurements were made by a single blinded reviewer using magnetic resonance imaging. The Wilcoxon signed rank test and McNemar test were used for continuous and categorical variables, respectively.
Results
No difference was observed between revised and nonrevised ACLR groups for LTPS (median: 6° vs 6°, P = .973) or MTPS (median: 4° vs 5°, P = .281). Furthermore, no difference was found for medial-to-lateral slope difference (median: −1 vs −1, P = .289). A greater proportion of patients with revised ACLR had an LTPS ≥12° (7.6% vs 3.8%) and ≥13° (4.7% vs 1.3%); however, this was not statistically significant after accounting for multiple testing.
Conclusion
We failed to observe an association between revision ACLR surgery and LTPS, MTPS, or medial-to-lateral slope difference. However, there was a greater proportion of patients in the revision ACLR group with an LTPS ≥12°, suggesting that a minority of patients who have more extreme values of LTPS have a higher revision risk after primary ACLR. A future cohort study evaluating the angle that best differentiates patients at highest risk for revision is needed.
Purpose:
To compare radiologic and clinical outcomes between patients who underwent medial meniscus posterior root tear (MMPRT) repair and were subsequently classified as having lax healing based on second-look arthroscopy and patients who underwent subtotal meniscectomy for an MMPRT.
Methods:
The patients who received pullout repair or subtotal meniscectomy due to MMPRT between January 2011 and December 2014 were retrospectively reviewed. Among the patients who underwent MMPRT repair, those whose lax healing of the repair site was confirmed by second-look arthroscopy (repair/lax healing group) and among the patients who received subtotal meniscectomy, those who have varus deformity of <5° and a Kellgren-Lawrence grade of ≤2 (meniscectomy group) were included in the study population. Medial joint space width, Kellgren-Lawrence grade, International Knee Documentation Committee Subjective Knee Evaluation Form score, and Lysholm Knee score were used for radiologic and clinical assessment.
Results:
The meniscectomy group included 24 patients (average follow-up, 37.2 months), and the repair/lax healing group included 21 patients (average follow-up, 39.2 months). The 2 groups showed improved patient-reported outcomes postoperatively (P < .001). However, medial joint space width (P < .001) became narrow and Kellgren-Lawrence grade (P = .002 and P = .005, respectively) worsened. Comparison of the radiologic outcomes between the 2 groups revealed that the repair/lax healing group had less Kellgren-Lawrence grade progression than the meniscectomy group (P = .014). The grade progressed by ≥2 grades in 4 patients (16.7%) and 0 patients in the meniscectomy and repair/lax healing groups, respectively (P < .001).
Conclusions:
Although the repair/lax healing group showed improved functional outcomes on short-term follow-up, arthritic change progressed radiologically. Nevertheless, the repair/lax healing group showed better radiologic outcomes than the meniscectomy group, despite lax healing of the repair site. However, because of the small number of cases in this study, the results of this study could be associated with potential for type II or β errors.
Level of evidence:
Level III, retrospective comparative study.
Background
Limited in vivo kinematic information exists on the effect of clinical-based partial medial and lateral meniscectomy in the context of anterior cruciate ligament (ACL) reconstruction.
Hypothesis
In patients with ACL deficiency, partial medial meniscus removal increases the anteroposterior (AP) laxity with compared with those with intact menisci, while partial lateral meniscus removal increases dynamic laxity. In addition, greater postoperative laxity would be identified in patients with partial medial meniscectomy.
Study design
Cross-sectional study; Level of evidence, 3.
Methods
A total of 164 patients with ACL tears were included in the present study and divided into 4 groups according to the meniscus treatment they underwent: patients with partial lateral meniscectomy (LM group), patients with partial medial meniscectomy (MM group), patients with partial medial and lateral meniscectomy (MLM group), and patients with intact menisci who did not undergo any meniscus treatment (IM group). A further division in 2 new homogeneous groups was made based on the surgical technique: 46 had an isolated single-bundle anatomic ACL reconstruction (ACL group), while 13 underwent a combined single-bundle anatomic ACL reconstruction and partial medial meniscectomy (MM-ACL group). Standard clinical laxities (AP translation at 30° of knee flexion, AP translation at 90° of knee flexion) and pivot-shift (PS) tests were quantified before and after surgery by means of a surgical navigation system dedicated to kinematic assessment. The PS test was quantified through 3 different parameters: the anterior displacement of the lateral tibial compartment (lateral AP); the posterior acceleration of the lateral AP during tibial reduction (posterior acceleration); and finally, the area included by the lateral AP translation with respect to the flexion/extension angle (area).
Results
In the ACL-deficient status, the MM group showed a significantly greater tibial translation compared with the IM group ( P < .0001 for AP displacement at 30° [AP30] and 90° [AP90] of flexion) and the LM group ( P = .002 for AP30 and P < .0001 for AP90). In the PS test, the area of LM group was significantly larger (57%; P = .0175) than the one of the IM group. After ACL reconstruction, AP translation at 30° was restored, while the AP90 remained significantly greater at 1.3 mm ( P = .0262) in the MM-ACL group compared with those with intact menisci.
Conclusion
Before ACL reconstruction, partial medial meniscectomy increased AP laxity at 30° and 90° and lateral meniscectomy increased dynamic PS laxity with respect to intact menisci. Anatomic single-bundle ACL reconstruction decreased laxities, but a residual anterior translation of 1.3 mm at 90° remained in patients with partial medial meniscectomy, with respect to those with intact menisci.
Purpose:
To comparatively evaluate the clinical outcomes and rates of recurrent instability in young patients with primary medial patellofemoral ligament (MPFL) repair or reconstruction, as well as to assess for radiologic risk factors for worse outcomes.
Methods:
A retrospective review identified all patients with lateral patellar instability who underwent either MPFL repair and/or imbrication or MPFL reconstruction without any additional osseous procedures between 2008 and 2015 at a single center. Demographic variables and preoperative magnetic resonance imaging were analyzed, and Kujala scores were obtained at a minimum 2-year follow-up. Risk factors for worse outcomes were assessed, including the Caton-Deschamps Index (CDI) Insall-Salvati Index, tibial tubercle-trochlear groove distance, and tibial tubercle-posterior cruciate ligament distance.
Results:
We identified 51 knees with isolated MPFL surgery (reconstruction in 32 and imbrication and/or repair in 19) at a mean of 59.7 months' follow-up (range, 24-121 months). The overall rate of recurrent dislocations was significantly greater in the repair group (36.9%) versus the reconstruction group (6.3%, P = .01), despite the average CDI being significantly higher in the reconstruction group (1.34 vs 1.23 in repair group, P = .04). No significant difference in the rate of return to baseline activity was found between the groups (77.8% in reconstruction group vs 70% in repair group, P = .62). The average Kujala score showed no significant difference between the repair and reconstruction groups (84.15 ± 14.2 vs 84.83 ± 14.38, P = .72). No imaging measurements were found to be predictive of a worse postoperative Kujala score; however, the average CDI among the MPFL repair failures (1.30 ± 0.05) was significantly higher than among the MPFL repair nonfailures (1.18 ± 0.12, P = .03).
Conclusions:
MPFL reconstruction may provide improved midterm clinical outcomes and a decreased recurrence rate compared with MPFL repair. Increased patellar height as measured by the CDI may be a risk factor for recurrent patellar instability in patients who undergo isolated MPFL repair.
Level of evidence:
Level III, retrospective comparative study.
Posttraumatic arthritis (PTA) is a form of joint degeneration that occurs after physical trauma to a synovial joint. Development of PTA is multifactorial and results from mechanical damage at the time of trauma, a cell-mediated inflammatory response, and abnormal articulation due to persistent malalignment or joint instability. Although some risk factors may be unavoidable, preventing the development of PTA of the knee after intra-articular fracture (IAF) requires restoring anatomic articulation and alignment. Reconstruction with total knee arthroplasty is the treatment of choice for PTA and may be a useful primary treatment for IAF in some.
Purpose
Collagen meniscal implants (CMI) have variable imaging findings on MRI and it remains ambiguous, if alterations may be present in asymptomatic patients. The aim was, to evaluate MR morphological characteristics and volume of CMI in the early, mid- and long-term follow-up.
Methods
Fifty-seven patients (mean age, 43.6±11 years; 41 male/16 female) with good clinical outcome (subjective visual analogue scale for satisfaction < 2 and a Lysholm-score ≥ 84) after CMI were assessed retrospectively using MRI 1, 2 and 3–8 years postoperatively. CMI morphology, signal intensity (SI), homogeneity and size were assessed and a meniscal score was calculated. Chondral defects and bone marrow edema pattern were reported and summarized in a chondral score. Meniscal extrusion and volume were evaluated. Intra- and inter-reader reliabilities were calculated. Spearman and partial correlations were used (p < 0.05).
Results
One year postoperatively, the CMI varied in size [10% (4/40) normal, 30% (12/40) small, 60% (24/40) hypertrophic] and was hyperintense and inhomogeneous in all patients. At long-term follow-up, the size of CMI decreased [6% (1/17) resorbed, 18% (3/17) normal, 41% (7/17) small, 35% (6/17) hypertrophic]. The SI of the CMI changed to normal in only 13% (2/16). The majority was still hyperintense [87% (14/16)]. Less meniscal extrusion was present in the follow-up [71% (11/16) versus initially 93% (37/40)]. The meniscal score improved significantly (ρ = 0.28). Over time, full-thickness femoral chondral defects were increasingly present [65% (10/17) versus initially 33% (13/40)] and the chondral score worsened significantly (p = 0.017).
Conclusion
Abnormal and inhomogeneous SI and irregular margins of the early postoperative CMI on MRI are findings seen in patients with good clinical results and should not necessarily be overcalled when reporting MRI. These features tend to decrease over time.
Level of evidence
IV.
Objective
Trochlear dysplasia is a major predisposing factor of patellar instability (PI). Dysplasia types are generally evaluated using the Dejour classification, but it is unclear whether this classification covers the entire spectrum. The objective of this study was to confirm whether the trochlear types on an axial view categorised according to the classification represent the entire trochlear shape.
Methods
Ninety knees from 81 patients with PI and 15 knees from 10 healthy volunteers (HVs) were evaluated. Three-dimensional knee models were created by MRIs. The femoral trochlear planes (FTPs) were defined as virtual cross sections including the transepicondylar axis, closer to the perpendicular plane of the articular surface. FTP 0 was defined as the reference plane including the proximal edge of the femoral trochlea and FTP θ as the plane making optional angle θ to FTP 0. Trochlear dysplasia types according to the classification were evaluated at every 10 degrees of FTPs up to 60 degrees (FTP 10, 20, 30, 40, 50 and 60). A trochlea with a sulcus angle <145 ° was defined as normal. Changes in the trochlear type according to FTPs, and agreement with clinical classification were evaluated.
Results
Eighty-six knees (96%) in patients with PI and 12 (80%) in HVs showed changing trochlear types in different FTPs. Patterns of change varied among patients with PI and HVs. This suggests morphological variation of dysplastic trochleae. Agreement of trochlear type on each FTP with the clinically used Dejour classification was 42% on FTP 10, 49% on FTP 20, 33% on FTP 30, 22% on FTP 40, 22% on FTP 50% and 22% on FTP 60 in patients with PI, and 20% at FTP 10, 80% at FTP 20 and 100% on FTP 30 through FTP 60 in HVs. This suggests that the trochlear types in the clinically used plane do not always match the ones on the planes describing the contact surface to the patella.
Conclusion
The trochlear types on an axial view provided by the Dejour classification do not represent the entire trochlear geometry. Multiple axial planes should be clinically used to more precisely describe the entire trochlear shape.
Purpose
Quadriceps tendon (QT) autograft ACL reconstruction was hypothesized to possess less anterior knee laxity, pivot shift laxity, and lower failure rates than hamstring tendon (HT) autografts.
Methods
Terms “hamstring tendon autograft” and “ACL reconstruction” or “quadriceps tendon autograft” and “ACL reconstruction” were searched in Embase and PubMed. Inclusion criteria required that studies included patients treated for primary ACL injury with reconstruction using either a QT autograft (Group 1) or a HT autograft (Group 2) and instrumented anterior knee laxity assessment. Extracted information included surgical fixation method, graft type, graft thickness or diameter, single vs. double bundle surgical method, publication year, time between the index knee injury and surgery, % women, initial and final subject number, subject age, follow-up length, side-to-side anterior knee laxity difference, Lysholm Score, Subjective IKDC score, anterior knee laxity side-to-side difference grade, ipsilateral pivot shift laxity grade, and failure rate. The Methodological Index for Nonrandomized Studies was used to evaluate study methodological quality.
Results
The QT group (Group 1) had 17 studies and the HT group (Group 2) had 61 studies. Overall, Group 2 had greater pivot shift laxity (OR 1.29, 95% CI 1.05–1.59, p = 0.005). Group 2 suspensory femoral fixation had greater pivot shift laxity (OR 1.26, 95% CI 1.01–1.58, p = 0.02) than Group 1 compression femoral fixation. Group 2 compression femoral fixation also had more anterior knee laxity (OR 1.25, 95% CI 1.03–1.52, p = 0.01) than Group 1 compression femoral fixation and higher failure rates based on initial (OR 1.69, 95% CI 1.18–2.4, p = 0.002) and final (OR 1.89, 95% CI 1.32–2.71, p = 0.0003) subject number. Failure rate for HT compression femoral fixation was greater than suspensory femoral fixation based on initial (OR 2.08, 95% CI 1.52–2.84, p < 0.0001) and final (OR 2.26, 95% CI 1.63–3.16, p < 0.0001) subject number.
Conclusions
Overall, QT autografts had less pivot shift laxity and lower failure rates based on final subject number than HT autografts. Compression QT autograft femoral fixation had lower pivot shift laxity than suspensory HT autograft femoral fixation. Compression QT autograft femoral fixation had less anterior knee laxity and lower failure rates than compression HT autograft femoral fixation. Suspensory HT autograft femoral fixation had lower failure rates than compression HT autograft femoral fixation. Greater knee laxity and failure rates may be related to a combination of HT autograft diameter and configuration (tissue quality and dimensions, strands, bundles, and suturing method) variability and fixation mode.
Level of evidence
Level IV.
Purpose
Assessment of medial meniscus extrusion (MME) has become increasingly popular in clinical practice to evaluate the dynamic meniscus function and diagnose meniscus pathologies. The purpose of this biomechanical study was to investigate the correlation between MME and the changes in joint contact pressure in varus and valgus alignment. It was hypothesized that varus alignment would result in significantly higher MME along with a higher joint contact pressure in the medial compartment.
Methods
Eight fresh-frozen human cadaveric knees were axially loaded, with a 750 N compressive load, in full extension with the mechanical axis shifted to intersect the tibial plateau at 30% and 40% (varus), 50% (neutral), 60% and 70% (valgus) of its width (TPW). Tibiofemoral peak contact pressure (PCP), mean contact pressure (MCP) and contact area (CA) were determined using pressure-sensitive films. MME was obtained via ultrasound at maximum load.
Results
MME was significantly increased from valgus (1.32 ± 0.22 mm) to varus alignment (3.16 ± 0.24 mm; p < 0.001). Peak contact pressure at 30% TPW varus alignment was significantly higher compared to 60% TPW valgus (p = 0.018) and 70% TPW valgus (p < 0.01). MME significantly correlated with PCP (r = 0.56; p < 0.001) and MCP (r = 0.47, p < 0.01) but not with CA (r = 0.23; n.s.).
Conclusion
MME was significantly increased in varus alignment, compared to neutral or valgus alignment, with an intact medial meniscus. It was also significantly correlated with PCP and MCP within the medial compartment. However, valgus malalignment and neutral axis resulted in reduced MME and contact pressure. Lower limb alignment must be taken into account while assessing MME in clinical practice.
Level of evidence
Controlled laboratory study.