The current epidemiology of vascular injuries associated with knee dislocation in the United States from 2010 to 2022

Despite the recognized importance of managing vascular injury associated with knee dislocation, studies have been limited by small patient sizes, data older than five years, and lack of inclusion of newer procedural and diagnoses codes. This has been reflected in the reported frequency of knee dislocation associated with vascular injury ranging from 1.6 % to 64 %. As such, we sought to determine: (1) the frequency of knee dislocations associated with vascular injuries; (2) the frequency of knee dislocations associated with vascular injuries that required repair; as well as (3) independent risk factors for knee dislocation with vascular injury that require repair, across different age groups, sexes, and United States geographic regions.

A national, all-payer database was queried from January 1, 2010 to June 31, 2022. The frequency of a vascular injury was calculated by dividing the number of vascular injuries within 30 days of all knee dislocations by the total number of knee dislocations in each category. The frequency of a vascular injury that required repair was calculated by dividing the number of vascular injuries that required repair associated with knee dislocation by the total number of vascular injuries associated with knee dislocations. Patients were categorized by year of diagnosis, age, sex, and US geographic region. Multivariable logistic regressions were calculated to determine independent risk factors for knee dislocation with vascular injury.

From 2010 to 2022, there were 99,688 knee dislocations. Of the total knee dislocations, there were 1066 (1.1 %) vascular injuries associated with knee dislocations, 96,530 (96.8 %) were closed dislocations, and 3158 (2.2 %) were open dislocations. Of the 1066 vascular injuries associated with knee dislocations, 262 (24.6 %) vascular injuries required repair. Male sex (P < 0.001), Elixhauser Comorbidity Index (ECI) > 3 (P < 0.001), alcohol abuse (P = 0.006), congestive heart failure (P = 0.01), hypothyroidism (P = 0.003), and obesity (P < 0.001), were independent risk factors for knee dislocation with vascular injuries.

Our study provides a refined understanding of the historically low incidence of knee dislocation with vascular injury as well as an increase in vascular injuries requiring repair from 2010 to 2022. Given the large expense of irreversible injury in these patients, vulnerable patient populations identified in our study, such as obese patients with additional comorbidities, should be a focus of future intervention. These findings can guide physicians in a clinical setting to appropriately manage the expectations of patients as well as minimize the morbidity and mortality associated with this presentation.