Outcomes of Knee Dislocations and Subluxations in Polytrauma Patients at a Major Trauma Center

Abstract

Background This is a retrospective service evaluation of outcomes of polytrauma patients sustaining knee dislocations and subluxations within a major trauma center (MTC). Polytrauma patients with knee dislocations are complex to manage and often sustain multiple life-threatening injuries. Although treatments have progressed, no consensus remains on management timing and strategy. Methods Information on knee dislocations and subluxations sustained in polytrauma patients was extracted using the Trauma Audit and Research Network database. This included demographic information on age, gender, and BMI, as well as information regarding their initial assessment in the emergency department (ED), including the Glasgow Coma Scale, Injury Severity Score, mechanism of injury, and time spent in ED. Associated injuries to the knee joint, including vascular compromise, associated bony injury, and ligamentous damage, were extracted from the patient notes. The management of these injuries was also examined, including the operative time, whether they required single or multistage surgery, and post-operative range of movement. Results Over eight years, from 2013 to 2021, there were a total of 187 polytrauma patients sustaining knee injuries, of which 17 had a knee joint dislocation and seven had a knee joint subluxation. The mean age of the patients was 46, their BMI was 28, and 19 out of the 24 had been involved in a vehicle incident or collision. In 80% of patients, there was an associated fracture of the lower limb, and just under half of patients had associated ligamentous injury (11 patients), with one-third of the patients sustaining an associated vascular injury (eight patients). One-third of the patient cohort was managed conservatively in a brace. Of the remaining, 12 required operative fixation, three underwent an amputation, and one was managed non-operatively with plaster of Paris. The mean operative time was 80 minutes in patients with vascular injury compared to 159 minutes without. This could be attributed to the more complex injuries in polytrauma that accompany a vascular injury. The median operative time was 71 minutes and 80 minutes, respectively. Within this study, the distance to the MTC did not appear to be a key determinant of amputation, though the low patient numbers limit the statistical power of this study. Conclusions Polytrauma patients are a complex cohort, often sustaining multiple injuries that require operative management with a multidisciplinary approach. Knee dislocations are a rare injury and are high energy, primarily caused by vehicle collisions in a polytrauma setting. A third of patients have an associated vascular injury, and 80% have an associated fracture, which is a much higher rate than is observed in a non-polytrauma setting.

Keywords: knee dislocation; knee injuries; knee trauma; multiple trauma; polytrauma; traumatic knee dislocation.

Figure 1. Number of patients sustaining a dislocation or subluxation with a concurrent vascular injury

Figure 2. Number of patients sustaining a dislocation or subluxation with a concurrent ligamentous injury

Figure 3. Number of patients who received each management option after sustaining either a dislocation or subluxation

MLKI: multi-ligament knee injury

Figure 4. Total time from injury to surgical intervention