Increased Neurovascular Morbidity Is Seen in Documented Knee Dislocation Versus Multiligamentous Knee Injury.

Background The terms "knee dislocation" and "multiligamentous knee injury" (MLKI) have been used interchangeably in the literature, and MLKI without a documented knee dislocation has often been described as a knee dislocation that "spontaneously reduced." We hypothesized that MLKI with documented tibiofemoral dislocation represents a more severe injury than MLKI without documented dislocation. We aimed to better characterize the injuries associated with documented knee dislocations versus MLKIs without evidence of tibiofemoral dislocation. Methods A total of 124 patients who were treated for a MLKI or knee dislocation to a single level-I trauma center between January 2001 and January 2020 were retrospectively reviewed. Patients were stratified into 2 groups, those with and those without a documented knee dislocation, and 123 of 124 patients were included in the analysis (78 in the non-dislocated group and 45 in the dislocated group). Data regarding patient demographics, injury pattern, and associated neurovascular injury were collected and compared between groups. Results Dislocated MLKIs, compared with non-dislocated MLKIs, had higher rates of peroneal nerve injury (38% versus 14%, respectively; p = 0.004), vascular injury (18% versus 4%; p = 0.018), and an increased number of medial-sided injuries (53% versus 30%; p = 0.009). There was no difference between dislocated and non-dislocated MLKIs in the number of bicruciate ligament injuries (82% versus 77%, respectively; p = 0.448), or lateral-sided injuries (73% versus 74%; p = 0.901). Conclusions Dislocated MLKIs were found to have increased rates of neurovascular injury compared with non-dislocated MLKIs, suggesting that knee dislocation and MLKI may not be synonymous in terms of associated injuries. Not all MLKIs are the result of a knee dislocation, and thus a documented tibiofemoral dislocation is a distinct entity that carries a greater risk of neurovascular compromise. We propose that these terms not be used interchangeably as previously described, and also that a high degree of vigilance must be maintained to evaluate for potential limb-threatening neurovascular injuries in any type of MLKI. Level of evidence Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.