RESUMO
Objective:To study the locational distribution characteristics of the heterotopic ossification (HO) following traumatic elbow stiffness and the risk factors for HO development at different locations.Methods:Consecutively included according to our inclusion criteria in the present study were the patients who had been admitted to Department of Orthopaedic Trauma, Beijing Jishuitan Hospital from January 2018 to December 2018 for elbow release due to traumatic elbow stiffness but developed postoperative HO. Their baseline data and CT data were collected and processed using Mimics 20.0. The HO distribution for each patient was characterized at the anteromedial, anterolateral, posteromedial, posterolateral, posterior, medial, lateral, and proximal radioulnar locations. The patient's original injury was categorized into 5 types: distal humerus fracture, olecranon fracture, radial head fracture, coronoid fracture, and elbow dislocation. After the univariate analysis with the HO occurrence at a specific location as the dependent variable and the original injury and baseline data as the independent variables, the factors with P value less than 0.1 were included in the logistic regression analysis to determine the risk factors for HO at each location.Results:A total of 91 patients were included in this study. Of them, 88 had posteromedial HO (96.7%, 88/91), 62 posterior HO (68.1%, 62/91), 60 posterolateral HO (65.9%, 60/91), 41 anteromedial HO (45.1%, 41/91), 26 anterolateral HO (28.6%, 26/91), 13 proximal radioulnar HO (14.3%, 13/91), 8 lateral HO (8.8%, 8/91), and 7 medial HO (7.7%, 7/91). Logistic regression analysis showed that presence of ulnar nerve symptoms ( OR=4.354, P=0.017) and presence of original elbow dislocation ( OR=2.927, P=0.042) were the independent risk factors for the anteromedial HO development and that presence of original olecranon fracture ( OR=0.277, P=0.023) was the protective factor for the anteromedial HO development. Presence of original radial head fracture was the independent risk factor for the anterolateral HO development ( OR=2.891, P=0.033) and the posterolateral HO development ( OR=3.123, P=0.043). Conclusions:HO development in patients with post-traumatic elbow stiffness is closely related to their original injury. Posteromedial HO may develop in almost all the patients. Patients with ulnar nerve symptoms and original elbow dislocation are more prone to anteromedial HO development, but patients with original olecranon fracture are less likely to develop anteromedial HO. Patients with original radial head fracture are more likely to develop anterolateral and posterolateral HO.
