Nonunion After Clavicle Osteosynthesis: High Incidence of Propionibacterium acnes

Objective: The objective of this study was to review the etiology of clavicle nonunions after osteosynthesis and investigate the outcomes of a treatment with a single-stage revision. Design: Retrospective case series. Setting: Orthopaedic specialty hospital. Patients: Twenty cases of nonunion after osteosynthesis of the clavicle were identified. The average age was 44 years (±13 years). In 9 cases, there was catastrophic implant failure that prompted the revision surgery. In the 18 cases in which cultures were taken, 15 of the 18 (83%) were treated as infections with a course of antibiotics. In 14 cases, the cultures were positive for Propionibacterium acnes. Results: Fifteen patients were treated with a prolonged course of antibiotics. Eighteen patients had follow-up, and the average time to radiographic union was 22 weeks. There were no cases of nonunion after revision surgery. Conclusions: There is a high rate of positive cultures in cases of nonunion after osteosynthesis of the clavicle. This suggests the etiology of midshaft clavicle nonunions may result from a combination of suboptimal mechanical fixation and latent infection. Our treatment protocol of superior and anterior plating, interfragmentary fixation, bone grafting, and appropriate antimicrobial treatment of latent infections has resulted in 100% union rate. Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.