UC Davis

Objectives The aim of this study was to describe a screw fixation method of the tibial tuberosity after transposition during surgical treatment of patellar luxation and to report complications and outcome of the procedure. Materials and Methods Medical records (2010–2016) of dogs treated for patellar luxation with tibial tuberosity transposition stabilization using a cortical bone screw placed adjacent to the tuberosity were retrospectively reviewed. Radiographs acquired immediately after surgery were evaluated for fissures. Proximal tibial dimensions and tibial tuberosity segments were measured. Intraoperative and postoperative complications were recorded. Results One-hundred and six dogs and 131 stifle surgeries were included. Implant complications associated with the screw occurred in 2/106 dogs (1.9%). Two dogs developed tibial tuberosity fracture and proximal displacement within 1 week of surgery and required stabilization with pin and tension band. Patellar reluxation rate following surgery was 6.9% (9/131 procedures). Presence of a fissure on postoperative radiographs increased the odds of tibial tuberosity fracture development (p < 0.001), while greater tibial tuberosity size (p = 0.023) and larger distal cortical attachment (p = 0.018) decreased the odds of fissure formation. Clinical significance Tibial tuberosity transposition can be achieved with a cortical screw placed lateral or medial to the tibial tuberosity.