Risk factors for nonunion in patients with transcondylar fracture of the distal humerus after open reduction and internal fixation

Background: Transcondylar fractures have been reported to rarely occur in the distal humerus, and stable fixation is difficult because of the unique fracture pattern. However, few studies have reported the risk factors for nonunion after open reduction and internal fixation (ORIF). This study aimed to evaluate the demographic and surgical risk factors for nonunion in patients who had undergone ORIF for transcondylar fractures. Methods: We retrospectively reviewed 68 patients who underwent ORIF for transcondylar fractures. Preoperative demographic factors, including diabetes mellitus (DM) and smoking, and operative factors, including fixation methods (eg, dual plate/single plate/tension band wiring [TBW]) were assessed as risk factors for nonunion. Results: Nonunion occurred in 8 out of 68 patients (11.8%). Univariate analysis revealed that among the demographic factors, DM (4/8 [50%] vs. 8/60 [13.3%], P =.028) and smoking (3/8 [37.5%] vs. 4/60 [6.7%], P =.031) were significantly different between nonunion and union patients. Regarding operative factors, the fixation method (dual plate/single plate/TBW; 2 [25.0%]/2 [25.0%]/4 [50%] vs. 29 [48.3%]/25 [41.7%]/6 [10.0%], P =.033) showed significant differences between nonunion and union patients. Multivariate regression analysis showed that DM (odds ratio [OR], 10.560; 95% confidence interval [CI], 1.308-85.247; P =.027), smoking (OR 22.371; 95% CI, 2.111-237.081; P =.010), and TBW (OR 15.390; 95% CI, 1.348-175.666; P =.028) were independent risk factors for nonunion. Conclusions: Nonunion occurred in approximately 12% of the patients who underwent ORIF in the transcondylar region of the distal humerus. The risk of nonunion was higher in patients with DM than those who smoked. In addition, among the fixation methods, the TBW technique was a significant risk factor for nonunion.