Effect of jig on the precision of tibial plateau leveling osteotomy in toy-breed dogs

Abstract

Because of plate development, it is now possible to perform tibial plateau leveling osteotomy (TPLO) in small-breed dogs with cranial cruciate ligament rupture. Compared with conventional treatment, faster walking and better function are reported post-TPLO. However, TPLO can be more difficult in toy-breed dogs than large-breed dogs. Because of the smaller bones, it is difficult to manipulate the bone fragments during surgery, and small movements of bones can cause major differences in limb alignment. In TPLO, a jig is conventionally recommended to increase the accuracy of alignment; however, installation of the jig can be difficult in small-breed dogs, and it may cause problems such as iatrogenic fracture. The present study thus aimed to evaluate the accuracy of TPLO without a jig in toy-breed dogs. Paired stifles (n=22) obtained from 11 toy-breed dogs cadavers (body weight range, 2.0-7.4 kg) were randomly assigned to a jig or non-jig group. Radiographic images were obtained preoperative and postoperative TPLO. Tibias were dissected from the hindlimb and measured for evaluation of accuracy. The following postoperative parameters were compared: tibial plateau angle, mechanical medial proximal tibial angle, osteotomy location, tibia crest thickness, gap between segments, and orientation line angles. There were no significant differences between the two groups, demonstrating that jig usage does not affect precision of TPLO in toy-breed dogs. Therefore, it is better not to use a jig in toy-breed dogs with relatively small bones, considering the risk of iatrogenic injury, cost and operation time.