Bilateral Stifle Arthrodesis as a Salvage Procedure for End-Stage Bilateral Grade IV Lateral Patellar Luxation in a Dog: A Case Report.

Grade IV lateral patellar luxation is an advanced orthopedic condition that may be associated with severe skeletal deformities, chronic soft-tissue contracture, and irreversible loss of normal stifle function. Although reconstructive procedures are considered the treatment of choice in most dogs, some end-stage cases may not be amenable to conventional correction. This report describes the clinical presentation, surgical management, and long-term outcome of a young dog with severe bilateral grade IV lateral patellar luxation treated with single-stage bilateral stifle arthrodesis. A 1-year-old, 42-kg intact female Romanian Shepherd Dog was presented with chronic severe hindlimb dysfunction, crouched posture, and permanent bilateral patellar luxation. Orthopedic and radiographic examination revealed severe femoral valgus, proximal tibial varus, external tibial torsion, absence of a functional trochlear groove, marked caudal thigh muscle contracture, and severely restricted stifle extension. Computed tomography was considered but not performed because of financial limitations. Based on the severity of the deformities and the limited preoperative range of motion, conventional reconstructive procedures were considered unlikely to restore functional joint motion. Bilateral stifle arthrodesis was therefore performed during a single anesthetic event using tibial tuberosity osteotomy, temporary Kirschner-wire fixation, and bilateral 3.5-mm locking compression plates. Due to severe chronic soft-tissue contracture, final arthrodesis angles of 95° and 99° were achieved. Progressive clinical improvement and radiographic bone union were observed throughout follow-up. At 12 months, complete bilateral arthrodesis and implant stability were confirmed radiographically. At 24 months, the dog remained independently ambulatory with a markedly improved quality of life despite persistent mechanical gait abnormalities, including circumduction and intermittent bunny-hopping. This case suggests that bilateral stifle arthrodesis may represent a salvage option in carefully selected dogs with end-stage bilateral grade IV lateral patellar luxation when conventional reconstructive procedures are unlikely to restore useful limb function.