EXPRESS: Surgical management of proximal tibial caudal angulation deformity in a cat with cranial cruciate ligament rupture

Case summary: A 5-year-old neutered male Bengal cat presented with right hindlimb lameness after being accidentally stepped on by the owner. Orthopaedic and radiographic examination revealed right cranial cruciate ligament rupture. Furthermore, bilateral proximal tibial caudal angulation deformity resulted in a right and left tibial plateau angle (TPA) of 59.4° and 59.3°, respectively, and a right and left anatomical–mechanical axis (AMA) angle of 10.9° and 10.6°, which exceeded normal values (mean TPA: 23.4°; mean AMA angle: 6.5°). The abnormal right angles and tibial caudal angulation deformity were subsequently corrected via modified cranial closing wedge osteotomy. Because the planned postoperative TPA was high (29.7°), a lateral fabellotibial suture was concurrently performed to further stabilise the stifle joint. Lameness improved immediately within the postoperative period, and limb function normalised at 3 months. Relevance and novel information: This case report describes a novel surgical strategy, guided by TPA and AMA assessment, for the management of a rare case of proximal tibial caudal angulation deformity concurrent with cranial cruciate ligament rupture in a cat.