Risk factors for refracture after plate removal for midshaft clavicle fracture after bone union

BACKGROUND: Open reduction and internal fixation (ORIF) with plates and screws is one of the treatment options for clavicle fractures. However, an additional operation for implant removal after union of the fracture is commonly performed due to a high incidence of hardware irritation. Despite union of the fracture, a subsequent refracture might occur after removal of the implant which requires additional surgeries for fixation. This study aims to determine the risk factors associated with refracture of the clavicle after hardware removal. METHODS: We retrospectively reviewed the medical records of 278 patients that were diagnosed with a midshaft clavicle fracture (male 190; female 88) that had (1) undergone ORIF of the clavicle with plates and (2) received a second operation for removal of hardware after solid union of the fracture between 2010 and 2017. Their mean age was 40.1 ± 15.1 years, and mean interval from fixation to plate removal was 12.5 ± 7.5 months. The patients were then divided into two groups based on the presence of refracture (n = 20) or without refracture (n = 258). We analyzed patient demographics, interval between fixation and implant removal, fracture classification (AO/OTA, Robinson), fixation device, whether wires or interfragmentary screws were used, clavicular length, and bone diameter at the fracture site. RESULTS: The overall refracture rate was 7.2%, and the mean interval between plate removal and refracture was 23.9 days. A multivariate analysis showed that female (adjusted odds ratio [aOR] 4.74; 95% CI 1.6–14.1) and body mass index [BMI] (for every 1-unit decrease, aOR 1.25; 95% CI 1.06–1.48) were risk factors for refracture. In women, BMI was the only risk factor. The optimal BMI cutoff value was 22.73. In a female patient with a lower BMI, the refracture rate was 29.8%. CONCLUSIONS: There are no significant radiographic parameters associated with refracture. Routine plate removal in a female patient with a low BMI after bony union of a midshaft clavicle fracture is not recommended because of a high refracture rate.