Evaluation of three miniplate systems for fracture stabilization in pigeons (Columba livia).

Bone plates are rarely used in avian fracture management for several reasons, and until recently, there was no plating system considered appropriate for use in birds with a body mass less than 500 g. To evaluate 3 different miniplate systems in avian fracture repair, 3 groups (A, B, and C) of 6 pigeons (Columba livia) each were used. The left ulna and radius of the pigeons were transected, and the ulna was stabilized. In group A, a 1.3-mm adaption plate was used. In group B, a limited contact system was created with washers that were placed between a 1.3-mm adaption plate and the bone. The intention was to reduce the compression of the periosteum and vascular damage to the bone. In group C, a 1.0-mm maxillofacial miniplate was used. Healing was evaluated with radiographs after 14 and 28 days. A flight test was conducted on day 28; the birds were then euthanatized, and the wing was dissected. Birds in group A with the adaptation plate achieved the best flight results (100%). In group B birds, no effect of the limited contact concept was visible at necropsy, and a high percentage of the screws had loosened, leading to failure (33%). The maxillofacial miniplates of group C birds were too weak and bent (100%). These results indicate that the adaption plate 1.3 met the desired requirements. To improve the system, further trials, with smaller drill bits and with screws having a smaller thread pitch, are recommended.