Locking compression plate fixation of critical-sized bone defects in sheep. Development of a model for veterinary bone tissue engineering

PURPOSE: To develop a segmental tibial bone defect model for tissue engineering studies in veterinary orthopedics using single locking compression plate (LCP) fixation and cast immobilization. METHODS: A 3-cm bone defect was created in the right tibia of 18 adult Suffolk sheep. A 10-hole, 4.5-mm LCP was applied to the dorsomedial aspect of the bone. Four locking screws were inserted into the proximal and three into the distal bone fragment. Operated limbs were immobilized with casts. Animals were submitted to stall rest, but were allowed to bear weight on the operated limb. During the recovery period, animals were checked daily for physiological parameters, behavior and lameness. Follow-up radiographs were taken monthly. RESULTS: Surgical procedures and postoperative recovery were uneventful. Animals adapted quickly to casts and were able to bear weight on the operated limb with no signs of discomfort or distress. No clinical or radiographic complications were detected over a 90-day follow-up period. CONCLUSIONS: Surgical creation of tibial segmental bone defects followed by fixation with single LCP and cast immobilization was deemed a feasible and appropriate model for veterinary orthopedic research in tissue engineering.