Avaliação biomecânica das técnicas de TPLO e CBLO para ruptura do ligamento cruzado cranial em cães – estudo ex-vivo

Abstract

Cranial cruciate ligament (CCL) disease represents one of the most frequent causes of lameness and stifle joint instability in dogs. Surgical intervention aimed at restoring joint stability and eliminating cranial tibial translation remains the treatment of choice. Among tibial osteotomy techniques, the tibial plateau levelling osteotomy (TPLO) is the most widely performed. More recently, alternative techniques such as the CORA-based levelling osteotomy (CBLO) have been developed. The mechanical properties of these newer stabilization methods require assessment using ex vivo canine stifle joint models. The objective of this study was to biomechanically evaluate and compare joint stability and resistance in ex vivo canine stifles with experimentally transected CCL stabilized using TPLO and CBLO techniques. A total of 24 pelvic limbs from 12 dogs of varying breeds, sexes, and ages, all weighing over 21 kg, were included. Following disarticulation at the hip and tibiotarsal joints and subsequent radiographic evaluation, the limbs were mounted on a biomechanical testing machine, with the femur and tibia secured to mobile platforms and the stifle joint positioned at a 135° angle. A compressive vertical load corresponding to 50% of body weight was applied. The CCL was then transected via craniomedial mini-arthrotomy, followed by reapplication of the same load. The stifles were stabilized using either TPLO technique, with a target postoperative tibial plateau angle (TPA) of 5°, or CBLO technique, with a target postoperative TPA of 10°. The limbs were remounted on the biomechanical testing machine, with a reapplication of compressive vertical load. Joint stability was assessed by horizontal displacement, which represents the cranial tibial thrust. Finally, with the stifle joint maintained at 135° and both the femur and tibia connected on fixed platforms, the limbs underwent destructive axial compression test with increasing load, observing the vertical displacement and the maximum load supported by the test specimens, as well as the failure characteristics of the structure. The results showed no significant difference between TPLO and CBLO techniques in terms of horizontal displacement (tibial thrust), vertical displacement, or maximum load to failure. However, neither technique restored biomechanics equivalent to those of the intact stifle. In conclusion, no differences in joint stability or resistance were found between TPLO and CBLO techniques in biomechanical testing. These findings support CBLO as a viable surgical option for the treatment of CCL disease in dogs.