Comparison of Two Methods of Long Bone Fracture Repair in Rabbits

Two different methods of rabbit femoral fracture repair were evaluated: (1) stainless-steel surgical plate and bone screws; and (2) placement of an intramedullary pin and an external skeletal fixator device. On average, bones repaired with the bone plate method withstood 35.1 lb/47.6 N (range, 14.4-63.0 lb/19.5-85.4 N) of compressive and bending forces before failure occurred. Bones repaired with intramedullary pin and external skeletal fixator device method withstood an average of 67.7 lb/91.8 N (range, 48.7-94.8 lb/66.0-128.5 N) of compressive and bending forces before failure, but the bone was more likely to shatter during implant application. Normal rabbit femurs placed in the control group were able to withstand an average of 148.4 lb/201.2 N (range, 100.0-192.0 lb/135.6-260.3 N). The fragility of rabbit bones made testing of any implant viability problematic. This study demonstrates advantages and disadvantages to each method of fixation in rabbits and compares important differences in application of fracture repair implants with those of other domestic species.