Outcomes of Humerus Nonunion Surgery in Patients With Initial Operative Fracture Fixation.

Objectives: To describe outcomes following humerus aseptic nonunion surgery in patients whose initial fracture was treated operatively and to identify risk factors for nonunion surgery failure in the same population.

Design: Retrospective case series.

Setting: Eight, academic, level 1 trauma centers.

Patients Selection Criteria: Patients with aseptic humerus nonunion (OTA/AO 11 and 12) after the initial operative management between 1998 and 2019.

Outcome Measures And Comparisons: Success rate of nonunion surgery.

Results: Ninety patients were included (56% female; median age 50 years; mean follow-up 21.2 months). Of 90 aseptic humerus nonunions, 71 (78.9%) united following nonunion surgery. Thirty patients (33.3%) experienced 1 or more postoperative complications, including infection, failure of fixation, and readmission. Multivariate analysis found that not performing revision internal fixation during nonunion surgery (n = 8; P = 0.002) and postoperative de novo infection (n = 9; P = 0.005) were associated with an increased risk of recalcitrant nonunion. Patient smoking status and the use of bone graft were not associated with differences in the nonunion repair success rate.

Conclusions: This series of previously operated aseptic humerus nonunions found that more than 1 in 5 patients failed nonunion repair. De novo postoperative infection and failure to perform revision internal fixation during nonunion surgery were associated with recalcitrant nonunion. Smoking and use of bone graft did not influence the success rate of nonunion surgery. These findings can be used to give patients a realistic expectation of results and complications following humerus nonunion surgery.

Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.