Bilateral fractures of the horizontal mandibular ramus in a Mediterranean Buffalo: surgical management

Fractures of the mandible are the most common fractures of the cranium in cattle usually involving the interdental space and the molar part of the horizontal ramus (1). In literature only a report about the surgical repair of a mandibular fractures in a new-born buffalo calf is reported (2) and no reports describe the management of mandibular fractures in adult Mediterranean Buffaloes (MB). This report describes clinical presentation, surgical treatment and follow-up of a bilateral fracture of the molar part of the horizontal mandibular ramus in a Mediterranean Buffalo (MB), stabilized by external skeletal fixation (ESF). A 6 months pregnant, primiparous MB (32 months old) was refereed to Clinical Mobile Service of Veterinary Teaching Hospital of the University of Naples Federico II, following its head knocked by the mixer-wagon. The buffalo showed severe salivation nasal discharge and an opened mouth. Instability and crepitus were elicited on mandibular palpation. X-ray showed complete bilateral mandibular fractures involving, on the left side, the molar part of the horizontal mandibular ramus between second (P2) and third (P3) premolar tooth indeed on the right side, just in front of P2. The MB was premedicated with Xylazine cloridrate (0.03 mg/kg i.v.) (Rompun®-Bayer) and a mandibuloalveolar nerve block was performed. After the routine aseptic preparation of the surgical field, a first rostral smooth Kirschner pin was placed caudal to the IV incisive, inserted as a full-pin, through mandible symphysis involving both mandiboular ramous. One positive threaded pin (4mm ø x 150mm) was placed caudal to the incisura vasorum and other two pins were placed rostrally and caudally to the fracture gap. All pins were placed in both side of mandibular ramous and connected to the connecting bars (6mm ø x 500mm) through ESF clamps (4/6 size) and Polymethyl-Methacrylate (PMMA). The reduction was considered good in order to correct anatomical occlusion of the mouth. Five days after surgery a traumatic partial pull out of left side ESF implant occurred and the latter was removed, leaving in place only the rostral full pin. Thus a telescoping unilateral dynamic External Skeletal Fixator (dESF) (Monotube® TriaxTM Stryker®) was applied to stabilize the left side of fracture. The dESF was placed using the rostral full-pin and 3 positive threaded half-pins (4mm ø x 16cm) placed through the dedicated clamps. Forty days after the second surgery, the good general clinical conditions and the radiological findings set the timing for the implants removal. The MB was able to eat and drink normally and calved according to the estimated delivery time The main goal of the surgical treatment of mandible fractures is to achieve stability at the fracture site and a sufficient mouth occlusion to allow a comfortable eating until complete bone healing (1). To our knowledge, in MB repair of fractured bones is not commonly reported (2) and no reports about mandibular fracture in adults exist. Economic constraints, lack of ad-hoc implants and difficult follow-up make the use of ESFs in ruminants usually limited. In this case the use of ESF seems to have been adequate to provide strength and stability to the mandibular fracture. Moreover the use of ESFs recycled by human medicine have been a valid and cheap solution for the present case.