Objective: Vascularized bone flaps are currently indicated for reconstructing mandibular defects 6 cm or larger. This technique can result in donor-site morbidity and requires microsurgery. To explore alternative methods of mandibular reconstruction, we sought to compare bone graft obtained with the reamer-irrigator-aspirator (RIA) device with the free fibula (FF) flap for the reconstruction of a critical-sized mandibular defect.
Methods: Sixteen 3-month-old Yorkshire pigs underwent 6-cm full-thickness resection of the left mandible. For the FF group (n = 8), an osseous FF flap was raised from the left leg and placed into the defect. For the RIA group (n = 8), a RIA Instrument Set was used on the ipsilateral femur to ream the femoral canal and harvest RIA putty. This putty containing medullary bone marrow contents and cortical bone was packed into the defect. At the study end point, volumetric, biomechanical, and histologic analyses were performed.
Results: Operative times were significantly shorter in the RIA group (RIA,126 [30] min; FF, 346 [50] min; P < 0.05). Biomechanical testing of reconstructed sites showed no significant difference in maximum fracture loads between both groups (RIA, 468 [97] N; FF, 689 [262] N; P = 0.11). Mean (SD) volume ratio of bone growth at the reconstructed sites was comparable between both groups (RIA, 71% [4.5%]; FF, 72% [3.3%]; P = 0.60). Equal bone quality was confirmed histologically.
Conclusions: The RIA technique significantly reduces operative time and provides bone of equal strength and histologic quality to FF flap reconstruction in a large animal model. The RIA method may represent an efficient technique for the reconstruction of craniomaxillofacial defects.