Management of concurrent patellar luxation and cranial cruciate ligament rupture using modified tibial plateau levelling

OBJECTIVES: To evaluate a novel surgery aimed at managing concurrent medial patellar luxation (MPL) and cranial cruciate ligament (CCL) ruptures in dogs weighing more than 30 kg. METHODS: Tibial plateau levelling osteotomy (TPLO) and femoral trochleopasty were performed. The principal tibial fragment was laterally translated by 3 to 6 mm and was externally and abaxially rotated to create a wedge measuring 1.5 to 2.5 mm at the medial and cranial aspect and 1 to 3 mm at the medial and distal aspect of the tibial plateau fragment. The fragments were stabilised with a narrow TPLO plate. RESULTS: Thirteen surgeries were performed in 12 dogs with a mean weight of 39.8 kg. The mean postoperative tibial plateau slope was 8.1 degrees. Additional surgery was required in two cases, one due to failure of fixation and another due to screw breakage. The mean lameness score was 3.5 (out of 5) before surgery, 0.7 after 8 to 12 weeks, and 0.3 at final follow-up. Median follow-up was 1115 days (range, 270 to 2040 days). No patella luxated after surgery. CLINICAL SIGNIFICANCE: MPL and CCL ruptures may be successfully managed by performing a TPLO and simultaneously altering the relationship of the principal and tibial plateau fragments during surgery.