Radiation dose modulates plate complications in patients undergoing maxillo-mandibular reconstruction

BACKGROUND: Despite carrying significant complication risk, titanium plates remain the standard-of-care in the reconstruction of segmental mandibulectomy defects. Radiation therapy (RT) is known to impair wound healing and cause dose perturbation at the metal-tissue interface. In this study, we sought to investigate the relationship between RT dosimetry and hardware-related complications. METHODS: A retrospective review of 99 patients who underwent segmental mandibulectomy with osseous free flap and titanium plate reconstruction between 2013 and 2022 was performed. Multivariable logistic and linear regression were performed to evaluate hardware-related complications, including plate exposure, fracture, screw loosening, and fistula/infection, adjusting for age, tumor stage, diabetes, and tobacco history. RESULTS: Overall, 60 patients (60.6 %) experienced at least one plate-related complication at a median of 11.2 months (range 0.33-93.1 months) and mean of 22.1 ± 15.8 months from surgery. Plate removal was required in 28.3 % of the cohort. Each 1 Gy of radiation conferred a 6.8 % increase in the odds of any plate complication (OR 1.07, 95 % CI 1.00-1.14, P = 0.037), with > 60 Gy predicting any plate complication (OR 3.07, 95 % CI 1.12-8.41, P = 0.03), plate removal (OR 3.13, 95 % CI 1.15-8.53, P = 0.026) and fistula or soft tissue infection (OR 2.99, 95 % CI 1.13-7.87, P = 0.027) after controlling for age, tumor stage, diabetes, and tobacco use. CONCLUSIONS: Titanium reconstruction plates carry a high complication rate, with a threshold of > 60 Gy associated with a three-fold increase in complication risk. These findings suggest a need for alternative plating strategies or materials to reduce patient morbidity.