Intra-articular findings in the reconstructed multiligament-injured knee

Purpose: Intra-articular chondral and meniscal injury in the multiligament-injured knee has not been examined. The purpose of this study was to determine the pattern of intra-articular chondral and meniscal damage in subjects with multiligament knee injuries undergoing surgery. Type of study: Prospective cohort study. Methods: Analysis was performed on prospectively collected data for the presence of meniscal tears and significant chondral injury on subjects who underwent knee ligament surgery. Subjects were grouped by their multiligament injury combination. Chondral injury was graded using the Modified Outerbridge Classification system. Criteria for significant chondral defect were any grade 2 lesion involving 50% or more of condylar width and all grade 3 or 4 lesions. Groups with more than 10 subjects were compared against the anterior cruciate ligament (ACL)-only group. Results: Data were collected on 2,265 subjects. The ACL/medial collateral ligament (MCL) injury pattern was the most common multiligament injury, comprising 70.5% of all multiligament injuries. Lateral meniscal damage was significantly higher in the ACL/MCL group (P < .01). Medial meniscal damage was significantly lower in the ACL/MCL group (P < .01). Medial and lateral meniscal damage was significantly lower in the ACL/lateral collateral ligament (LCL) group (P < .01). Articular damage to the medial tibial plateau was significantly lower in the ACL/MCL group (P < .01). All other multiligament injury patterns showed chondral damage similar to the ACL-only group. Ligament injuries repaired acutely had significantly less articular and medial meniscal damage than chronic repairs (P < .01). Conclusions: The ACL/MCL injury pattern was the most common multiligament injury pattern and showed a high incidence of lateral meniscal tears. ACL/LCL injuries had fewer meniscal injuries. Multiligament-injured knees showed increased risk of a torn medial meniscus as chronicity increased. Level of evidence: Level IV.