Background Vascular injury secondary to an acute knee dislocation is a known complication. However, there exist wide discrepancies in the reported rate of vascular injury in this setting. Questions/purposes Using a large private insurance database, we determined the frequency of vascular injury in knee dislocations across year of diagnosis, age, sex, and US geographic region and the proportion of these injuries requiring surgical repair.
MethodsThe PearlDiver database, which contains records from 11 million orthopaedic patients, was searched using ICD-9 diagnostic codes for all knee dislocation events from 2004 to 2009. Within this subset, we identified which knee dislocations had an associated vascular injury ICD-9 code. Patients were stratified by year of diagnosis, age, sex, and US geographic region, and Current Procedural Terminology codes were used to identify the subset of patients with vascular injury requiring surgical repair. Differences in frequency across demographic groups and over time were analyzed with Poisson regression analysis. Results Among the 8050 limbs with knee dislocation identified over the study period, 267 had a concomitant vascular injury for an overall frequency of 3.3%. Males were found to have an increased risk of vascular injury compared to females (odds ratio = 2.59, p \ 0.001). Additionally, patients aged 20 to 39 years had a higher risk of vascular injury when compared to those aged 0 to 19 years (odds ratio = 1.93, p = 0.001), 40 to 59 years (odds ratio = 1.57, p = 0.014), and 60 years or older (odds ratio = 2.81, p = 0.036). There were no differences in vascular injury frequency across US geographic regions or diagnosis year. Thirty-four of the 267 cases of vascular injury (13%) underwent surgical treatment. Conclusions This is the largest study, to our knowledge, that analyzes the proportion of knee dislocations that result in vascular injury. Our data suggest that there is a lower frequency of vascular injury associated with knee