Surgical Repair of Medial Collateral Ligament and Posteromedial Corner Injuries of the Knee: A Systematic Review

Purpose: To systematically evaluate surgical techniques and objective clinical outcomes of primary repair of the medial collateral ligament (MCL) and posteromedial corner of the knee. Methods: A systematic review of the PubMed/Medline Database (1966 to August 2014) was performed to identify all clinical studies describing MCL and other medial-based repairs of the knee. Exclusion criteria were applied to reconstruction techniques, animal models, and non-English publications. Descriptive analysis identified surgical technique, International Knee Documentation Committee (IKDC) objective form valgus stability subscore, functional outcome measures, and laxity on valgus stress. Results: After exclusion of 165 references, 16 publications with 355 knees were included in the final analysis. Fixation construct included suture-only repair (49.5%), staples (12.1%), suture anchors (11.2%), and mixed or unknown fixation (27.0%). When isolating knees with available relative valgus stress opening (n = 223), 75.8% had side-to-side difference of <3mmor <1+ (n = 169; 10 studies; range, 36% to 100%). Similarly, an IKDC valgus stability grade of A or B was identified in 126 of 140 knees (90.0%; 6 studies; range, 60% to 100%). Of 93 knees with quantified values, the mean side-to-side difference in medial joint space opening was 1.25 mm (SD +/- 0.85) after primary repair. Thirteen of 212 knees (6.1%) met the criteria for failure, and the average Lysholm score was 91.6 (n = 210; range, 85.5 to 98.5). Conclusions: This systematic review demonstrated that repair of the MCL and posteromedial corner of the knee may be an effective and reliable treatment for medial-sided knee injuries, resulting in improved valgus stability and patient-reported functional scores with low rates of secondary failure. However, repair techniques may vary significantly depending on the chronicity and extent of medial ligamentous knee injuries, and appropriate patient selection is critical in determining ultimate clinical outcomes.