Percutaneous Medial Collateral Ligament Release Improves Medial Compartment Access During Knee Arthroscopy.

PURPOSE: To quantify intraoperative joint space widening afforded by the outside-in, percutaneous release of the medial collateral ligament (MCL) and to evaluate its impact on medial compartment width and functional outcomes at 6-week follow-up for patients undergoing a partial medial meniscectomy without postoperative bracing. METHODS: Patients with posteromedial meniscus tears and no evidence of ipsilateral knee pathology, undergoing partial medial meniscectomy, were enrolled. Intraoperatively, medial compartment width was quantified with fluoroscopy before and after the percutaneous MCL release with an 18-gauge spinal needle proximal to the joint line. At 6-week follow-up, valgus stress radiographs re-evaluated medial compartment width. International Knee Documentation Committee (IKDC) and Patient-Reported Outcomes Measurement Information System (PROMIS) scores were completed preoperatively and at 6-week follow-up to evaluate functional outcomes. A paired sample t test performed at a 95% confidence interval (CI) was used to compare these variables. RESULTS: Forty-two patients, mean (± standard deviation) age 55.3 ± 10.7 years, were available for analysis of intraoperative medial compartment widening. Medial compartment width increased from 5.95 ± 1.32 to 11.09 ± 1.74 mm intraoperatively after MCL release. At 6-week follow-up, radiographic assessment demonstrated a mean medial compartment width of 5.85 ± .99 mm, which represented an insignificant change compared with the preoperative value (CI -0.68 to .33, P = .474). PROMIS and IKDC scores significantly improved from baseline, with increases of 6.9 ± 12.4 (CI 2.0 to 11.8, P = .008) and 11.7 ± 17.8 (CI 4.7 to 18.8, P = .002), respectively. CONCLUSIONS: Percutaneous MCL release during knee arthroscopy improves visualization and facilitates instrumentation by providing an almost 2× wider working space within the medial tibiofemoral joint. In this study, the performance of percutaneous MCL release did not result in any complications. Radiographic and clinical resolution of iatrogenic laxity was demonstrated by 6-weeks postoperatively, without the use of postoperative bracing. LEVEL OF EVIDENCE: IV, therapeutic case series.