Predictors of plate extrusion in oromandibular free flap reconstruction

OBJECTIVES: Plate extrusions after free tissue transfer for mandibular reconstruction can be problematic and generally require revision surgery. Our objective was to assess the predictors of plate extrusion and compare outcomes between fibular free flaps (FFF), lateral border scapular flaps (LBSF), and scapular tip free flaps (STFF). METHODS: Retrospective review of consecutive patients who underwent osseous free tissue reconstruction of the mandible (2008-2014) at Victoria Hospital, London, Ontario. Patient demographics and treatment-related information were collected. RESULTS: We identified 134 procedures and 27 (20.2%) plate extrusions (21/61 FFF, 3/49 STFF, and 3/24 LBSF). Freedom from extrusion after 2 years was significantly associated with the use of FFF (P = .003, HR 6.09 1.82-20.44), performing 1 osteotomy (P = .03, HR 2.61 1.08-6.31), and anterior mandibular defects (P = .01, HR 2.66 1.25-5.66) in the univariate model. FFF's were employed more frequently in younger patients, with 2.4 mm plates, more anterior defects, and with a greater number of osteotomies (P < .001). However, after controlling for these variables in multivariate analyses the use of a FFF was the only significant predictor of extrusion at 2 years (P = .006, HR 3.68 1.46-9.28). CONCLUSIONS: At our institution, use of the STFF predicts mandibular defects that are less prone to developing plate extrusion and FFF tended to be used more frequently in anterior defects with osteotomies. However, after controlling for these factors use of the FFF appeared to have higher rates of extrusion than scapular flaps. Further prospective studies controlling for defect variables are needed to elucidate the risk factors for plate extrusion.