Both arthroscopic and open posterior knee capsulotomy are effective in terms of extension recovery and functional improvement-systematic review

Complete Arthroscopic Posterior Knee Capsulotomy in Patients With Knee Extension Deficit: Preliminary Results of a Clinical Trial

Background

Guided physiotherapy and surgical arthrolysis are effective in most patients with knee extension deficit. However, in refractory cases, posterior knee capsulotomy may be needed.

Purpose

To assess extension restoration, pain reduction, and functional improvement after arthroscopic complete posterior knee capsulotomy in patients with extension deficit refractory to guided physiotherapy and surgical arthrolysis.

Study Design

Case series; Level of evidence, 4.

Methods

Included were patients with symptomatic asymmetric extension deficit >3° refractory to at least 6 months of guided physiotherapy and initial arthrolysis (15 patients with 12-month follow-up and 8 patients with 24-month follow-up). The mean duration of extension deficit was 24.6 months. An arthroscopic complete posterior knee capsulotomy was performed with transection of the posteromedial, posterolateral and central capsule, and the posterior septum. The primary outcome measure was knee extension, with hyperextension denoted as negative knee extension values. Secondary outcome measures included visual analog scale (VAS) for pain during maximum effort and exercise, International Knee Documentation Committee (IKDC) score, and Knee injury and Osteoarthritis Outcome Score (KOOS).

Results

The mean patient age was 40.0 years (range, 26-70 years); 6 out of 15 patients had developed knee contracture after isolated anterior cruciate ligament reconstruction. The mean knee extension deficit decreased from 16.9° (range, 7° to 45°) preoperatively to -0.2° (range, -5° to 5°) at 12-month follow-up (P = .003) and to -0.3° (range, -5° to 5°) at 24-month follow-up (P = .035). The mean VAS pain score decreased from 3.5 (range, 1-6) preoperatively to 1.1 (range, 0-2) at 12-month follow-up (P = .004) and to 1.5 (range, 0-4) at 24-month follow-up (P = .005). The mean IKDC increased from 37.9 (range, 21-62) preoperatively to 63.9 (range, 46-87) at 12-month follow-up (P < .001) and to 60.9 (range, 39-80) at 24-month follow-up (P = .003). The mean KOOS increased from 45.0 (range, 30-62) preoperatively to 75.3 (range, 49-94) at 12-month follow-up (P < .001) and to 72.3 (range, 49-92) at 24-month follow-up (P = .003). There were no significant differences between 12- and 24-month follow-up in extension deficit or functional outcomes. One patient had a midcalf subcutaneous hematoma 5 weeks postoperatively, requiring evacuation.

Conclusion

Arthroscopic complete posterior knee capsulotomy was able to restore knee extension, reduce pain, and improve function, with 12-month follow-up results sustained at 24-month follow-up.

Registration

NCT05385393 (ClinicalTrials.gov identifier).

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.

Arthroscopic Trans-septal Portal of the Knee With Direct Visualization and No Need for Posterolateral Portal Creation

Arthroscopic visualization and access of the posterior knee are limited when using standard anterior and posterior portals. The creation of a trans-septal portal allows for complete access to the posterior compartment as arthroscopic instruments are able to be passed back and forth between the posteromedial and posterolateral compartments. Due to the close proximity of the popliteal artery and its branches, precise portal placement and safe orientation of arthroscopic instruments are critical to avoid iatrogenic injury. The conventional technique of trans-septal portal creation, involving a posterolateral portal, can be difficult in some cases. To overcome these obstacles, a posteromedial technique of trans-septal portal creation is presented. By using the medial parapatellar portal as the viewing portal, our technique allows for direct visualization of the posterior septum on each step of creation of the trans-septal portal, eliminating the need for "blind" maneuvers. What is more, no posterolateral portal is needed, decreasing the risk of potential complications. Using the posterior cruciate ligament fibers as a main landmark for trans-septal portal placement, preservation of the posterior part of the septum is achieved. This ensures optimal safe-margin distance away from the popliteal neurovascular bundle and making the technique safe and reproducible.

Cam Impingement of the Knee: Arthroscopic Correction of Posteromedial Tibiofemoral Incongruence

One of the anatomic variations observable within the knee joint is a reduction in the posterior curvature of the femoral metaphysis proximal to the medial femoral condyle. This curvature is usually concave enough to fit the posterior horn of the medial meniscus (PHMM) during full knee flexion. A reduction in curvature may result in posteromedial tibiofemoral incongruence, a condition characterized by compression of the PHMM in full knee flexion, similar to cam incongruence in the hip joint. Clinical symptoms may occur in deep knee flexion, and progressive degeneration of the PHMM can be observed if this position is not prohibited. For patients in whom activity modification and conservative treatment have failed, surgery may be indicated. We describe arthroscopic treatment allowing for final intraoperative confirmation of the clinical indication for posteromedial tibiofemoral incongruence correction, as well as allowing for the least possible, yet sufficient, amount of correction.