Vascular complications and reduction outcomes between direct versus transferred emergency room presentation of knee dislocations: a retrospective cohort study.

Abstract

Knee dislocations are rare orthopedic injuries with potentially limb-threatening complications if not recognized and managed appropriately. The greatest risk is concomitant vascular injury, particularly popliteal artery injury, which can lead to amputation when ischemia is prolonged. This study evaluated knee dislocations transferred from outside institutions compared with those presenting directly to a Level I trauma center. A retrospective cohort study was performed of patients with a diagnosis of knee dislocation between 2018 and 2023 at a Level I trauma center. Fifty-four patients were identified; 13 were excluded, leaving 41 patients with radiographically confirmed knee dislocations. Patients either presented directly or were transferred from outside hospitals. Demographics, injury characteristics, and outcomes were collected. Primary outcomes included vascular injury, neurological injury, and limb loss. Among 41 dislocations, average age was 38 years, mean BMI was 33.2, and 61% were male. Twenty-four patients were transferred from outside institutions and 17 presented directly to the trauma center. Of the transferred patients, 11 arrived with an unreduced knee dislocation. Five of these patients sustained popliteal artery injuries and three ultimately required amputation. Mean time to reduction was 4.96 h for unreduced transfers compared with 0.24 h for patients reduced in the trauma center emergency department. Patients transferred with unreduced dislocations were associated with vascular injury and limb loss. Unreduced knee dislocations transferred from outside institutions were associated with increased vascular injury and limb loss. Early recognition and prompt reduction may be critical to optimizing outcomes.