Epidemiology and outcomes of traumatic knee dislocations: Isolated vs multi-trauma injuries

Traumatic dislocation of the knee (TKD) is a rare injury, accounting for approximately 0.02% of orthopaedic injuries. They are a challenging entity for orthopaedic surgeons to manage, and can have devastating consequences. The aim of this study was to describe the epidemiology of traumatic knee dislocations (TKD'S) and contrast the incidence of neurovascular injury between isolated and multi-trauma dislocations as well as key patient reported outcomes achieved between these groups.

Patients who had a traumatic disruption of the tibiofemoral articulation between March 1 2007 and February 31, 2015 were identified from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Data was cross-checked with medical records and radiological reports to confirm true multi-ligamentous dislocation. VOTOR collects information pertaining to orthopaedic injuries, treatment, complications and outcomes from four adult hospitals in Victoria, Australia, including the major trauma centers. Patient-reported outcomes are collected by VOTOR at 12 months post-injury including the EQ-5D-3L (EQ-5D) and Glasgow Extended Outcome Scores (GOS-E) and return to work status. Patient reported functional and quality of life outcomes at 12 months after injury were analysed.

A cohort of 88 patients were identified that fit the inclusion criteria for the study, and at 12 months post-injury there was data available for 80 patients (90.9%). There were 38 (42.9%) patients who experienced an isolated traumatic knee dislocation and 52 (57.1%) who experienced a traumatic knee dislocation in association with another injury. Of the 88 patients identified as eligible for the study, two had bilateral knee dislocations, hence there were 90 multi-ligamentous knee injuries. Those who were injured at a higher velocity were more likely to have additional injuries. Dislocations that occurred at a lower velocity were shown to have better overall outcomes, as did dislocations that occurred in isolation.

Traumatic knee dislocations that occur in isolation typically result in better outcomes than those that occur with associated injuries. TKD's are a rare but severe injury that requires further research in order for functional outcomes to be optimized.