Tibial plateau leveling osteotomy (TPLO) is a procedure used to repair cranial cruciate ligament ruptures. This in vitro study was designed to compare TPLO with the osteotomy centered on the intercondylar tubercles of the tibia (TPLO-C) or with the osteotomy as distal as possible on the tibial long axis (TPLO-D). Six pairs of hindlimbs from canine cadavers were used. One limb from each pair was randomly assigned to the TPLO-C or the TPLO-D group. Cranial tibial subluxation (CTS) was quantified sequentially under 3 conditions: intact, after cranial cruciate ligament transaction, and after TPLO. With the limb positioned under a load of 30% body weight, radiographs were taken both before and after transection of the cranial cruciate ligament. The CTS under load was measured again, and a corrected CTS value was calculated. Postoperative tibial plateau angle and tibial long axis shift were also measured. The results confirmed that TPLO-C is geometrically more precise and biomechanically more effective than using the distal position.

COMMENTARY: Cruciate tears are a common injury of dogs and when they occur surgery is usually the best treatment option in all but toy breed dogs. Some surgeons prefer TPLO method for large dogs. This article is an important reminder of the importance of proper surgical technique in order for TPLO to be most successful.

The effect of tibial plateau leveling osteotomy position on cranial tibial subluxation: An in vitro study. Kowaleski MP, Apelt D, Mattoon JS, et al. VET SURG 34:332-336, 2005.