Combined Anterior Cruciate Ligament and Medial Collateral Ligament Reconstruction Shows High Rates of Return to Activity and Low Rates of Recurrent Valgus Instability: An Updated Systematic Review

PURPOSE: To examine the clinical outcomes and return to sport rates after treatment of combined, complete (grade III) injuries of the anterior cruciate ligament (ACL) and medial collateral ligament (MCL). METHODS: A literature search of the following databases was completed using key words related to combined ACL and (MCL) tears: MEDLINE, Embase, Cochrane Controlled Trials Register, Cochrane Database of Systematic Reviews, Cumulative Index to Nursing and Allied Health Literature, and SPORTDiscus. Level I-IV studies that examined patients with complete tears of the ACL and grade III tears of the MCL, diagnosed by either magnetic resonance imaging or clinical examination of valgus instability, were included. Study inclusion was determined by 2 independent reviewers. Patient demographics, treatment choices, and patient outcomes, including clinical examination (i.e., range of motion, hamstring strength) and subjective assessments (i.e., International Knee Documentation Committee, Lysholm scores, Tegner activity scores) were collected. RESULTS: Six possible treatment combinations were assessed. Good or excellent outcomes related to range of motion, knee stability, subjective assessments, and return to play were reported after ACL reconstruction regardless of MCL treatment. Those with combined ACL and MCL reconstruction returned to their previous level of activity at a high rate (range, 87.5%-90.6%) with low rates of recurrent valgus instability. Triangular MCL reconstruction with a posterior limb that serves to reconstruct the posterior-oblique ligament best-restored anteromedial rotatory stability of the knee when compared with anatomic MCL reconstruction (90.6% and 65.6%, respectively). Nonsurgical management of the ACL injury, regardless of MCL treatment, demonstrated low return to activity (29%) and frequent secondary knee injuries. CONCLUSIONS: High rates of return to sport with low risk of recurrent valgus instability have been demonstrated after MCL reconstruction, and triangular MCL reconstruction can more effectively restore anteromedial rotatory instability compared with MCL repair. Restoration of valgus stability can be common after reconstruction of the ACL with or without surgical management of the MCL, although patients with grade III tibial-sided or mid-substance injuries were less likely to regain valgus stability with nonoperative treatment than femoral-sided injuries. LEVEL OF EVIDENCE: Level IV; systematic review of Level I-IV studies.