Higher early radiographic bone healing scores with popliteus muscle preservation during tibial plateau levelling osteotomy in dogs

OBJECTIVE: To compare early radiographic bone healing 45 days after tibial plateau levelling osteotomy performed with popliteus muscle detachment versus a modified technique preserving the muscle and to determine whether muscle preservation influences post-operative osteotomy stability through measurement of rock-back. MATERIALS AND METHODS: In this prospective, blinded, randomised clinical study (2022 to 2025), 100 client-owned dogs with unilateral cranial cruciate ligament rupture were allocated to traditional surgery (n = 50) or popliteus-sparing surgery (n = 50). Radiographic assessment was performed preoperatively, immediately post-operatively and 45 days after surgery. Bone healing was evaluated using two validated radiographic scoring systems. Osteotomy stability was assessed by measuring the change in tibial plateau angle between the immediate post-operative and 45-day radiographs. Multivariable linear regression models were used to adjust for baseline clinical variables. A P-value <.05 was considered statistically significant. RESULTS: Dogs undergoing popliteus-sparing surgery demonstrated higher bone healing scores at 45 days, with an adjusted mean difference of 1.95 (95% confidence interval 0.91 to 2.99) on the 10-point bone healing scale and 1.87 (95% confidence interval 0.88 to 2.86) on the modified radiographic union scale. There was no clinically relevant difference in post-operative tibial plateau angle change between groups, with an adjusted mean difference of 0.26 degrees (95% confidence interval -0.10 to 0.63). No major intraoperative vascular complications were recorded. CLINICAL SIGNIFICANCE: Tibial plateau levelling osteotomy performed without detachment of the popliteus muscle represents a safe and effective alternative to the traditional technique. Popliteus muscle preservation during tibial plateau levelling osteotomy was associated with higher radiographic bone healing scores at 45 days, without evidence of increased osteotomy instability. Whether this radiographic difference translates into improved clinical recovery or limb function remains unknown.