Medial Collateral Ligament Reconstruction in Patients With Medial Knee Instability: A Systematic Review

BACKGROUND: The medial collateral ligament (MCL) is the most frequently injured ligament of the knee, but it infrequently requires surgical treatment. Current literature on MCL reconstructions is sparse and offers mixed outcome measures. PURPOSE/HYPOTHESIS: The purpose of this study was to compare the outcomes of isolated MCL reconstruction and multiligamentous MCL reconstruction. Our hypothesis was that in selective patients, MCL reconstruction would significantly improve objective and subjective patient knee performance measures, those being baseline valgus laxity, range of motion, objective and subjective International Knee Documentation Committee (IKDC) scores, Tegner score, and Lysholm knee activity scores. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and utilizing 3 computer-based databases. Studies reporting clinical outcomes of patients undergoing MCL reconstruction due to chronic instability or injury with mean follow-up of at least 2 years and levels of evidence 1 to 4 were eligible for inclusion. All relevant subject demographics and study data were statistically analyzed using 2-sample and 2-proportion z tests. RESULTS: Ten studies involving 275 patients met our inclusion criteria. Of these patients, 46 underwent isolated MCL reconstruction while another 229 underwent reconstruction of the MCL in addition to a variety of concomitant reconstructions. Overall outcomes for all patients were significant for (1) reducing the medial opening of the knee (8.1 ± 1.3 vs 1.4 ± 1.0 mm; P < .001), (2) improving the patient’s objective IKDC score (1.2% vs 88.4%; P < .001), (3) improving the patient’s subjective IKDC score (49.8 ± 6.9 vs 82.4 ± 9.6; P < .001), and (4) improving the Lysholm knee activity score (69.3 ± 5.9 vs 90.5 ± 6.6; P < .001). No differences existed between concomitant reconstruction groupings except that postoperative Lysholm scores were better for MCL/anterior cruciate ligament reconstruction than MCL/posterior cruciate ligament reconstruction (94.3 ± 4.5 vs 84.0 ± 11.7; P < .001). Normal or nearly normal range of motion was obtained by 88% of all patients. CONCLUSION: The systematic review of 10 studies and 275 knees found that the reported patient outcomes after MCL reconstruction were significantly improved across all measures studied, with no significant difference in outcomes between concomitant reconstructions.