Abstract

Bone healing of the ulna after osteotomy and fixation with a maxillofacial miniplate (Compact 1.0) was studied in feral pigeons (Columba livia). The ulna and radius were transected with an oscillating bone saw to produce a diaphyseal fracture. Two different procedures for fixation were compared. In procedure 1 (n = 6), the ulna was stabilized with a 6-hole maxillofacial miniplate. In procedure 2 (n = 4), the ulna was stabilized with the plate, and the radius was stabilized with an intramedullary 1.0 Kirschner wire. Plate distortion and bending occurred in all 6 birds with fractures that were immobilized with the plate only, and 1 plate failure was noted with subsequent synostosis. When both bones were immobilized, 2 cases of minimal plate deformation and 1 case of cortical fragment displacement occurred. Callus formation was significantly less pronounced after procedure 2 as compared with procedure 1; however, primary bone healing was not achieved with either procedure. From these results we conclude that dorsal single plating of the ulna with a 6-hole maxillofacial miniplate in experimentally induced ulnar and radial fractures in pigeons does not result in adequate stabilization.