Posteromedial vertical capsulotomy selectively increases the extension gap in posterior stabilized total knee arthroplasty

Management of fixed flexion contracture in primary total knee arthroplasty: recent systematic review

INTRODUCTION

This study aimed to systematically review the literature and identify the surgical management strategy for fixed flexion contracture in primary total knee arthroplasty (TKA) surgery, pre-, intra-, and post-operatively. Secondary endpoints were etiologies and factors favoring flexion contracture.

MATERIALS AND METHODS

Searches were carried out in November 2023 in several databases (Pubmed, Scopus, Cochrane, and Google Scholar) using the following keywords: "flexion contracture AND TKA", "fixed flexion deformity AND TKA", "posterior capsular release AND TKA", "posterior capsulotomy in TKA", "distal femoral resection AND TKA". Study quality was assessed using the STROBE checklist and the Downs and Black score. Data concerning factors or strategies leading to the development or prevention of flexion contracture after TKA were extracted from the text, figures, and tables of the included references. The effect of each predictive factor on flexion contracture after TKA was recorded.

RESULTS

Thirty-one studies were identified to meet the inclusion and exclusion criteria. These studies described a variety of preoperative and intraoperative factors that contribute to the development or correction of postoperative flexion contracture. The only clearly identified predictor of postoperative flexion contracture was preoperative flexion contracture. Intraoperative steps described to correct flexion contracture were: soft-tissue balancing (in posterior and medial compartments), distal femoral resection, flexion of the femoral component, and posterior condylar resection. However, no study has investigated these factors in a global model.

DISCUSSION

This review identified various pre-, intra-, and post-operative factors predictive of post-operative flexion contracture. In practice, these factors are likely to interact, and it is therefore crucial to further investigate them in a comprehensive model to develop an algorithm for the management of flexion contracture.

LEVEL OF EVIDENCE

IV.

Effect of posteromedial vertical capsulotomy with medial collateral ligament liberation on intraoperative medial component gap mismatch between extension and mid-flexion during total knee arthroplasty

PURPOSE

The aim of this study was to quantify the effect of posteromedial vertical capsulotomy on intraoperative component gaps and angles from extension through mid-flexion to flexion during total knee arthroplasty (TKA).

METHODS

In the present study, 47 cases of primary posterior-stabilized TKA using the measured resection technique for varus knee osteoarthritis (hip-knee-ankle angles < 0°) were reviewed. Component gaps and angles at 0°, 10°, 45°, 90°, and maximum flexion were measured intraoperatively, before and after posteromedial vertical capsulotomy. Differences in pre- and post-posteromedial vertical capsulotomy medial and lateral component gaps and angles and medial component gap mismatches among knee flexion angles were assessed using the Wilcoxon signed rank test for two paired samples.

RESULTS

The medial component gaps at 0° and 10° of flexion of post-posteromedial vertical capsulotomy were significantly greater, exceeding the minimal detectable change, than those pre posteromedial vertical capsulotomy (change of the gap after the procedure at 0° of flexion was 0.7 ± 0.7 mm and at 10° of flexion was 0.8 ± 0.8 mm; all P values < 0.05). The medial component gap mismatches between both 0° and 10°, and 45°, 90°, and maximum flexion were significantly smaller post posteromedial vertical capsulotomy than pre posteromedial vertical capsulotomy, with the values of the change exceeding the minimal detectable change (change of the gap mismatch after the procedure: knee flexion at 0° and 45° was - 0.6 ± 0.9 [mm], at 0° and 90° was 0.7 ± 1.0, at 0° and maximum flexion was - 0.6 ± 1.2, at 10° and 45° was - 0.7 ± 0.9, at 10° and 90° was - 0.8 ± 0.9, at 10° and maximum flexion was - 0.7 ± 1.1; all P values < 0.05).

CONCLUSIONS

Posteromedial vertical capsulotomy increased the medial component gaps during knee extension but not during mid-flexion or full flexion during posterior-stabilized TKA. Posteromedial vertical capsulotomy improved mild medial component gap mismatch between extension and mid-flexion and full flexion during posterior-stabilized TKA. Surgeons can consider posteromedial vertical capsulotomy when there is intraoperative constriction of the medial component gap during extension in patients undergoing posterior-stabilized TKA.

Posteromedial vertical capsulotomy selectively expands the intraoperative extension gap in cruciate-retaining total knee arthroplasty

PURPOSE

Effective soft-tissue balancing procedures for expanding the extension gap (EG) are needed in cases of gap mismatch in total knee arthroplasty (TKA). A posteromedial vertical capsulotomy (PMVC) is performed to restore mobility in a knee with a flexion contracture. The purpose of this study was to evaluate the effectiveness and safety of PMVC for intraoperative gap adjustment in cruciate-retaining TKA.

METHODS

A total of 120 consecutive knees undergoing cruciate-retaining TKA for varus osteoarthritis were examined. The EG and flexion gap (FG) with a trial femoral component were measured using spacer blocks before and after PMVC. PMVC was performed when the first FG was larger than the first EG by > 2 mm.

RESULTS

Sixty-five knees underwent PMVC, and the mean EG significantly increased by 2.4 mm (p < 0.001). This increase was significantly larger than that of the FG by 2.0 mm (p < 0.001). The preoperative extension range of motion (ROM) was negatively correlated with the EG change after PMVC (r = - 0.39, p = 0.001). A receiver operating characteristic (ROC) curve indicated a preoperative extension ROM cut-off of -10° for predicting PMVC (sensitivity 72.3%, specificity 56.4%). No associated complications were observed during a minimum 2-year follow-up period, and there was no difference in the postoperative Knee Society Score between the PMVC and non-PMVC groups.

CONCLUSION

PMVC may be a useful soft-tissue treatment for gap adjustment with a selective EG expansion in TKA, especially in cases of a limited preoperative extension of - 10° or less.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Combination of Fusiform Capsulectomy of the Posterior Capsule and Percutaneous Flexion Tendon Release in the Treatment of Fused Knee with Severe Flexion Contracture During Total Knee Arthroplasty—A Report of Six Cases

Purpose

This clinical research aims to assess the safety and efficacy of a combination of fusiform capsulectomy of the posterior capsule and percutaneous flexion tendon release in the treatment of a fused knee with severe flexion contracture during total knee arthroplasty (TKA).

Methods

A retrospective analysis was performed in three patients (six knees) who had preoperative severe bony fused flexion contracture (>80°) prior to TKA and received a combination of fusiform capsulectomy of posterior capsule and percutaneous flexion tendon release during TKA between January 2016 and December 2019. The range of motion (ROM), knee functional score, postoperative complications, and radiographic results were evaluated.

Result

Three patients (six knees) were enrolled in this study. The mean duration of follow-up was 42.83 ± 15.77 months. The postoperative knee ROM was 100.0 (76.0, 102.75) (p < 0.01). The knee society score (KSS) clinical score increased from a preoperative 30.0 (25.0, 36.0) to a postoperative 64.0 (65.0, 78.0) (p < 0.01), and the KSS function score increased from a preoperative 0.0 (0.0, 30.0) to a postoperative 55.0 (40.0, 55.0) (p < 0.01). No implant loosening, infection, neurovascular complications, or revision were recorded in the cohort until the last follow-up.

Conclusion

The technique of a combination of fusiform capsulectomy of the posterior capsule and percutaneous flexion tendon release is an effective and safe method during primary TKA for a fused knee with severe flexion contracture.

Large flexion contracture angle predicts tight extension gap during navigational posterior stabilized-type total knee arthroplasty with the pre-cut technique: a retrospective study

Background

This study aimed to determine the predictors of tight extension gap (EG) compared with the flexion gap (FG) during navigational posterior stabilized-type total knee arthroplasty using the pre-cut technique.

Methods

Nineteen patients with tight EG (defined as FG-EG ≥2 mm after pre-cut; group T) and 84 patients with an approximately equal gap (defined as FG-EG = 0–1 mm after pre-cut; group E) were enrolled. Medial tibial slope angle, hip knee ankle angle, flexion contracture angle, and active maximum flexion angle were compared between the two groups.

Results

The multivariate logistic regression model indicated that the probability of tight EG increased with flexion contracture angle (odds ratio, 1.13; 95% confidence interval 1.05–1.20; P ≤ 0.001). According to the receiver operating characteristic analysis, the flexion contracture angle cut-off value associated with tight EG was 15.0° (sensitivity, 85%; specificity, 78%).

Conclusion

This study demonstrated that a large flexion contracture angle (cut-off 15.0°) was associated with tight EG after pre-cut osteotomy during posterior stabilized-type total knee arthroplasty. Awareness of this risk factor may help improve preoperative predictability of tight EGs and preparedness for additional procedures, such as soft tissue release or capsulotomy, to correct them.

Level of evidence

Level III.

Correcting severe flexion contracture with fusiform capsulectomy of posterior capsule during total knee arthroplasty

PURPOSE

This study aimed to evaluate the safety and efficacy of fusiform capsulectomy of posterior capsule in correcting severe flexion contracture during total knee arthroplasty (TKA).

METHODS

A retrospective analysis was performed in the patients who had preoperative severe flexion contracture (> 30 degrees) prior to TKA and received fusiform capsulectomy of posterior capsule during TKA between December 2013 and November 2018. Range of motion (ROM), knee functional score, forgotten joint score (FJS), post-operative complications, and radiographic results were collected and evaluated.

RESULT

Twenty patients (32 knees) were enrolled in this study. The mean duration of follow-up was 27.19 ± 15.92 months. The flexion contracture improved from pre-operative 37.69 ± 11.79° to post-operative 5.78 ± 4.44° (p < 0.001), and ROM increased from pre-operative 63.50 ± 21.74° to post-operative 97.88 ± 13.20° (p < 0.001). KSS clinical score increased from pre-operative 32.94 ± 11.03 to post-operative 82.34 ± 10.73 (p < 0.001), and KSS function score increased from pre-operative 28.97 ± 18.43 to post-operative 68.75 ± 15.96 (p < 0.001). The post-operative FJS was 76.08 ± 2.14. There was no implant loosening, infection, obvious haematoma formation, resultant instability, neurovascular complications, or revision for any reasons in the cohort until the last follow-up.

CONCLUSIONS

The technique of fusiform capsulectomy of posterior capsule to correct the severe flexion contracture during primary TKA is safe and effective and could provide good short-term results.