Heterotopic ossification after complex elbow fracture-dislocations - Mid-term outcome and risk factor analysis

Heterotopic ossification (HO) is a major complication following complex elbow fracture-dislocations and often leads to postoperative stiffness and impaired functional recovery. However, data focusing exclusively on complex elbow fracture-dislocations remain limited. The aim of this study was to determine the incidence and severity of HO, identify independent risk factors, and evaluate its impact on mid-term functional outcome.

A retrospective cohort study was performed including 169 patients who underwent surgical treatment for complex elbow fracture-dislocations between 2010 and 2020 at a level I trauma centre. Injury patterns comprised terrible triad injuries, Monteggia(-like) fractures, anteromedial coronoid fractures, and transolecranon fracture-dislocations. HO was classified according to Hastings and Graham. Functional outcome was assessed using range of motion (ROM), Mayo Elbow Performance Score (MEPS), Oxford Elbow Score (OES), and Disabilities of the Arm, Shoulder and Hand (DASH) score at a mean follow-up of 4.6 years (2.0 to 10.3). Multivariable logistic regression analysis was performed to identify independent predictors of HO.

HO developed in 55 patients (32.5%), with 28 cases (50.8%) classified as higher-grade (≥ grade II). Surgical excision of symptomatic HO was required in 12 patients. HO was associated with significantly reduced ROM (Flexion/Extension 107° ±25 vs. 119° ±26, p=0.005; Pronation/Supination 153 ±31 vs. 163 ±27, p=0.040), and inferior MEPS, OES, and DASH scores (all p<0.05). Male sex (OR 2.8; 95% CI 1.44-5.55; p=0.003), terrible triad injuries (OR 3.04; 95% CI 1.55-5.98; p=0.002), and delayed surgery (>5 days) (OR 2.2; p=0.040) were independently associated with HO formation. The strongest association was observed for terrible triad injuries, whereas delayed surgery showed a more moderate association. Age, BMI, ASA classification, smoking, operative duration, and non-steroidal anti-inflammatory drug (NSAID) prophylaxis were not significantly associated.

HO occurs in approximately one third of patients after surgical treatment of complex elbow fracture-dislocations and is associated with inferior elbow mobility and elbow performance scores. Male sex and terrible triad injuries showed the strongest associations with HO formation, whereas delayed definitive surgery was associated with a more moderate increase in the odds of HO. Early stabilization and close postoperative surveillance are particularly important in high-risk patients.

Level III, retrospective cohort comparison, prognosis study.