Prolonged dislocation and delay to surgery are associated with higher rates of heterotopic ossification in operatively treated terrible triad injuries

BACKGROUND: Heterotopic ossification (HO) formation after complex elbow injuries can significantly impact function. Prior studies have reported a 3%-45% incidence of HO following elbow trauma in a heterogeneous cohort of fracture patterns. The purpose of our study was to evaluate the prevalence of and identify risk factors for HO specifically in patients with terrible triad injuries. METHODS: A total of 61 patients (64 elbows) underwent operative treatment for terrible triad injuries with an average follow-up period of 19.8 months (range, 3-138 months). The medical records were reviewed for demographic data, duration of dislocation, number of reduction attempts, time to surgery, presence of radiographic HO, elbow motion at final follow-up, functional limitations, and need for secondary procedures. RESULTS: Radiographic HO developed in 77% of patients, and 63% had some level of functional restriction. Thirteen patients (26%) underwent a secondary procedure for HO excision. Patients with HO had a longer time to surgery (4.9 days vs. 2.8 days, P = .02), longer duration of dislocation (21 hours vs. 6 hours, P = .04), and reduced flexion-extension (94° vs. 112°, P = .04) and pronation-supination (109° vs. 163°, P = .002) arcs of motion compared with patients without HO. HO was also more likely to develop in patients who required closed reduction than in those with spontaneous reduction prior to presentation. CONCLUSION: The prevalence of radiographic and clinically relevant HO after terrible triad injuries was higher than previously reported. Persistent dislocation necessitating a closed reduction, a longer duration of dislocation, and a delay to surgery were associated with the development of HO. Providers should consider earlier surgical stabilization or urgent referral to a specialist for patients with unstable injuries.