Original Full Length ArticleThe effect of Amifostine prophylaxis on bone densitometry, biomechanical strength and union in mandibular pathologic fracture repair

•Amifostine's effect on quality and strength of mandible pathologic fracture•Radiated samples differ from fracture control and Amifostine‐treated samples.•No difference between Amifostine‐treated specimens and fracture in all metrics•Amifostine prophylaxis protects bone quality and strength in the setting of radiation.

BackgroundPathologic fractures (Fx) of the mandibles are severely debilitating consequences of radiation (XRT) in the treatment of craniofacial malignancy. We have previously demonstrated Amifostine's effect (AMF) in the remediation of radiation‐induced cellular damage. We posit that AMF prophylaxis will preserve bone strength and drastically reverse radiotherapy‐induced non‐union in a murine mandibular model of pathologic fracture repair.Materials and methodsTwenty-nine rats were randomized into 3 groups: Fx, XRT/Fx, and AMF/XRT/Fx. A fractionated human equivalent dose of radiation was delivered to the left hemimandibles of XRT/Fx and AMF/XRT/Fx. AMF/XRT/Fx was pre‐treated with AMF. All groups underwent left mandibular osteotomy with external fixation and setting of a 2.1 mm fracture gap post-operatively. Utilizing micro-computed tomography and biomechanical testing, the healed fracture was evaluated for strength.ResultsAll radiomorphometrics and biomechanical properties were significantly diminished in XRT/Fx compared to both Fx and AMF/XRT/Fx. No difference was demonstrated between Fx and AMF/XRT/Fx in both outcomes.ConclusionOur investigation establishes the significant and substantial capability of AMF prophylaxis to preserve and enhance bone union, quality and strength in the setting of human equivalent radiotherapy. Such novel discoveries establish the true potential to utilize pharmacotherapy to prevent and improve the treatment outcomes of radiation‐induced late pathologic fractures.