Risk factors for dysfunctional elbow stiffness following operative fixation of distal humerus fractures.

Background: Elbow stiffness is 1 of the most common complications after operative fixation of distal humerus fractures; however, there is relatively limited literature assessing which factors are associated with this problem. The purpose of this study is to identify risk factors associated with dysfunctional elbow stiffness in distal humerus fractures after operative fixation.

Methods: A retrospective review of all distal humerus fractures that underwent operative fixation (AO/OTA 13A-C) at a single level 1 trauma center from November 2014 to October 2021. A minimum 6-month follow-up was required for inclusion or the outcome of interest. Dysfunctional elbow stiffness was defined as a flexion-extension arc of less than 100° at latest follow-up or any patient requiring surgical treatment for limited elbow range of motion.

Results: A total of 110 patients with distal humerus fractures were included in the study: 54 patients comprised the elbow stiffness group and 56 patients were in the control group. Average follow-up of 343 (59 to 2079) days. Multiple logistic regression showed that orthogonal plate configuration (adjusted odds ratio [aOR]: 5.70, 95% confidence interval [CI]: 1.91-16.99, P = .002), and longer operative time (aOR: 1.86, 95% CI: 1.11-3.10, P = .017) were independently associated with an increased odds of elbow stiffness. OTA/AO 13A type fractures were significantly associated with a decreased odds of stiffness (aOR: 0.16, 95% CI: 0.03-0.80, P = .026). Among 13C fractures, olecranon osteotomy (aOR: 5.48, 95% CI: 1.08-27.73, P = .040) was also associated with an increased odds of elbow stiffness. There were no significant differences in injury mechanism, Gustilo-Anderson classification, reduction quality, days to surgery from admission, type of fixation, as well as rates of ipsilateral upper extremity fracture, neurovascular injury, nonunion, or infection between the 2 groups.

Conclusion: Dysfunctional elbow stiffness was observed in 49.1% of patients who underwent operative fixation of distal humerus fractures in the present study. Orthogonal plate configuration, olecranon osteotomy, and longer operative time were associated with increased odds of dysfunctional elbow stiffness; however, 13A type fractures were associated with decreased odds of stiffness. Patients with these injuries should be counseled on their risk of stiffness following surgery and modifiable risk factors like plate positioning and performing an olecranon osteotomy should be considered by surgeons.