Fibula free flap in maxillomandibular reconstruction. Factors related to osteosynthesis plates' complications.

The aim of this paper is to identify risk factors associated with the development of osteosynthesis plates' related complications in fibula free flap reconstructions. This is a case series study of consecutive fibula free flaps. Clinical and radiological variables were recorded. Patient outcomes were evaluated with special attention to osteosynthesis plates' related complications; these included plate exposure, plate fracture, loosening of screws, non-union, bone resorption, oro-cutaneous fistulas, and bone exposure. We have done a descriptive analysis, univariate analysis, and multivariate logistic regression model to explore possible risk factors for osteosynthesis plates' related complications. Data analysis was performed using R software (version 3.5.0). 111 fibula free flaps were studied. 29 patients (26.1%) developed osteosynthesis plates' related complications. The mean time to osteosynthesis plates' related complications was 22 months; range (1-120); the median and mode were 12 months. Patients with preoperative radiotherapy (34% vs 14%, p = 0.021), and secondary reconstruction (31% vs 15%, p = 0.053) had a higher incidence of osteosynthesis plates' related complications. In the univariate analysis, "preoperative radiotherapy" (OR 3.07, 95%CI = 1.139-8.242, p = 0.025) and "extraoral soft-tissue defect" (OR 2.907, 95%CI = 1.032-8.088, p = 0.042) were risk factors for osteosynthesis plates' related complications. We have observed an interaction effect: patients with mandibular Brown's classes III + IV and "secondary reconstruction" have a higher risk for osteosynthesis plates' related complications; more than 47.30 times compared to Brown's class I and "primary reconstruction" (p = 0.026). Different factors may contribute to the development of osteosynthesis plates' related complications. Our study adds important information about these. Patients with higher risk of developing complications should be informed that a second intervention to remove the plates might be necessary.