BACKGROUND: Multiligament knee injuries (MLKIs) due to high-energy (HE) or polytraumatic (PT) mechanisms result in worse patient outcomes after surgery versus low-energy (LE) or nonpolytraumatic (NPT) mechanisms. There remains a paucity of research in the literature investigating MLKIs resulting from these mechanisms of injury. PURPOSE: To characterize differences in ligamentous injury/surgery patterns between different mechanism groups: HE versus LE and PT versus NPT. STUDY DESIGN: Cross-sectional study
Level of evidence, 3. METHODS: This is a retrospective chart review of consecutive surgical MLKIs from a single institution. Demographics, clinical/radiographic findings, and intraoperative variables were obtained. HE versus LE mechanisms were stratified. Patients with inadequate data were excluded. PT versus NPT classifications were based on presence of concurrent nonknee injuries. Subgroup comparisons were made based on body mass index, age, sex, number/type of ligaments injured, and surgeries performed. RESULTS: From a total of 226, 176 (78%) patients were included (41 PT [23%] and 135 NPT [77%]
62 HE [35%] and 114 LE [65%]). PT mean age was 30.7 ± 13.7 years (male, 32 [78%)], while NPT mean age was 27.1 ± 12.3 years [male, 91/135 [67%]). HE mean age was 31.4 ± 13.1 years (male, 49/62 [79%]), and LE mean age was 25.6 ± 11.8 years (male, 73/114 [64%]). Posterior cruciate ligament (PCL) injuries were higher in PT (27/41 [66%]) and HE (42/62 [68%]) versus NPT (58/135 [43%]) and LE (44/114 [39%]), respectively. Lateral collateral ligament (LCL) injuries were higher in PT (29/41 [71%]) and HE (41/62 [66%]) versus NPT (66/135 [49%]) and LE (55/114 [48%]), respectively. The mean number of ligaments injured was higher in PT versus NPT (2.9 vs 2.4) and in HE versus LE (2.8 vs 2.4). LCL surgical interventions were more common in PT (23/41 [55%]) versus NPT (49/135 [36%]) and in HE (33/62 [53%]) versus LE (39/114 [34%]). No other differences in injuries/surgeries existed between PT and NPT or HE and LE, in anterior cruciate, medial collateral, or medial patellofemoral ligaments. CONCLUSION: PT and HE MLKIs are characterized by increased rates of PCL and LCL injuries compared with LE and NPT. HE and PT patients experience more injured ligaments than LE and NPT and are more likely to require reconstruction/repair of the LCL. These findings suggest injury severity and mechanism may facilitate clinical decision making in MLKIs.