Incidence and risk factors of heterotopic ossification following major elbow trauma

Heterotopic ossification is a common complication of Orthopaedic Trauma Association (OTA) type C distal humerus fractures and ulnohumeral fracture dislocations. The purpose of this study was to precisely define the incidence of heterotopic ossification following major elbow trauma and to identify risk factors for the development of clinically significant heterotopic ossification and for surgical excision of elbow heterotopic ossification.Current Procedural Terminology codes identified 156 patients who underwent operative intervention for a distal humerus fracture or an ulnohumeral fracture dislocation at 2 Level I trauma centers over 6 years. The incidence of elbow heterotopic ossification was recorded at >90 days following the definitive procedure. Risk factors for the development of class 3 or 4 heterotopic ossification and for surgical excision of heterotopic ossification were evaluated using separate multivariable logistic regression analyses. Brooker class 3 or 4 heterotopic ossification occurred following 18 (14%) of 125 distal humerus fractures, 15 (22%) of 69 OTA type C distal humerus fractures, and 11 (35%) of 31 ulnohumeral fracture dislocations. Surgical excision of heterotopic ossification was performed after 12 (10%) of 125 distal humerus fractures, 10 (14%) of 69 OTA type C distal humerus fractures, and 8 (26%) of 31 ulnohumeral fracture dislocations. Sustaining a severe elbow injury (P<.05) or a delay of fixation (P=.05) was found to be independent risk factors for Brooker class 3 or 4 heterotopic ossification. Severe elbow injury (P<.05) and male sex (P<.05) were associated with operative excision of heterotopic ossification.