Evaluation of Three Miniplate Systems for Fracture Stabilization in Pigeons (Columba livia)

Abstract

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.

Evaluation of Two Miniplate Systems and Figure-of-eight Bandages for Stabilization of Experimentally Induced Ulnar and Radial Fractures in Pigeons (Columba livia)

“…In the study performed by Gull et al, 2 1 group of 6 pigeons was treated with an 8-hole 1.3-mm adaption plate, using 4 screws of 6-mm length. In that study, 1 of 6 pigeons was euthanatized due to screw loosening, and 3 of 6 pigeons had screws that were not bicortical.…”

“…The general aspects of surgical procedure were according to the studies of Christen et al 7 and Gull et al 2 A dorsal approach to the radius and ulna was used. The skin incision was made just cranial to the insertion point of the secondary flight feathers of the left ulna.…”

“…Recently a 1.0-mm steel compression plate system has been marketed that includes screws with a thread pitch as proposed by Gull et al 2 The aim of the present study was to evaluate this new plate in comparison with the 1.3-mm adaptation plate used by Gull et al 2 to stabilize experimentally induced ulnar and radial fractures in pigeons. Additionally, the effect of a figure-of-eight bandage was tested.…”

“…2 Reported examples include a locking compression plate system used to treat a comminuted tarsometatarsal fracture with delayed union after 1 month of external coaptation in a bald eagle (Haliaeetus leucocephalus), 3 a 2.0-mm titanium miniplate successfully used in a blue-and-yellow macaw (Ara ararauna) with an old middiaphyseal fracture of the left tibiotarsus, 4 and a miniplate used in a goose (Anser anser) to stabilize a simple, complete, spiral-third fractured right tibia. 5 In birds that weigh less than 1000 g, exceptionally small plating systems (ie, miniplate systems ,2 mm) are required, which are relatively expensive and more challenging to insert.…”

“…So far, none of the tested implants have proven entirely satisfactory for the use in small avian species. 1,2,6 In a study in pigeons (Columba livia), Christen et al 7 used a maxillofacial titanium adaptation 1.0-mm miniplate to treat induced ulnar and radial fractures; all implants bent, and callus formation was exuberant. The authors recommended the use of stronger and longer plates because an increase in plate size and length (plate : span ratio) may increase the strength of an implant and reduce the risk of fatigue failure.…”