Lateral suture repair (a type of extracapsular repair [ECR]), and tibial plateau-leveling osteotomy (TPLO) are used to repair rupture of cranial cruciate ligament (CCL). Both prevent cranial tibial thrust, thereby controlling cranial drawer, but TPLO does not simulate CCL function. To compare long-term functional outcome of TPLO versus ECR for canine unilateral CCL rupture, ground reaction forces (GRFs) were measured and symmetrical indices (SI) calculated between operated and unoperated pelvic limbs. Data were compared with that for clinically normal dogs using force plate gait analysis and SI of GRFs.

Seventy-nine clinically normal dogs and 38 dogs with unilateral CCL injury were enrolled; all weighed >15 kg. The SI in the TPLO group (n = 15) were not significantly different from the control group at a walk or trot by 6–12 months, indicating that these dogs were clinically normal at that point. SIs for the ECR group (n = 23) were less symmetrical than for the control group for all GRFs consistently at all postoperative times. The TPLO group showed higher acceleration to normal function at a trot, although no difference in function was observed at a walk. Dogs may return to normal limb loading faster after TPLO than after ECR, and the data may provide prognostic indicators for surgical intervention.

This study lends credence to the idea that dogs recover faster and have greater potential to return to normal function following TPLO, contradicting previous studies using force plate to compare TPLO with ECR. The main detraction is the low number of operated dogs that completed the study.—Jonathan Miller, DVM, MS, DACVS

Long-term functional outcome of tibial plateau leveling osteotomy versus extracapsular repair in a heterogeneous population of dogs. Nelson SA, Krotscheck U, Rawlinson J, et al. VET SURG 42:38-50, 2013.