Fetlock varus correction in a horse using a radial osteotomy of the distal third metacarpus

Summary Angular limb deformities in horses with closed physes present a significant surgical challenge due to limited corrective options. This case report discusses a novel approach using a radial osteotomy at the centre of rotation and angulation with a crescentic saw blade and two locking compression plates (LCPs) to correct metacarpophalangeal deformity in a 10‐month‐old colt. The horse presented with right front fetlock varus, physeal closure of distal third metacarpus (MCIII), AAEP grade 4/5 lameness, and subluxation with degenerative joint disease of the metacarpophalangeal joint. A prior attempt for growth retardation using a transphyseal screw did not result in correction. A radial osteotomy was performed proximal to the distal physis of MCIII using a crescentic saw blade. Axial alignment was achieved by rotating the distal fragment of MCIII laterally in the frontal plane and fixated with two narrow 4.5 mm LCPs. Complications after surgery included surgical site infection, incisional dehiscence and progressive degenerative joint disease. Twenty weeks post‐surgery the surgical site was completely healed, and the horse was sound at the walk. Radiographs showed correction of the varus deformity from 15° to 2°. No reports exist of a radial osteotomy using a crescentic saw blade for surgical correction of a metacarpophalangeal deviation in a horse.