Teaching Associate Azabu University Sagamihara-shi, Japan
Modified Tibial Plateau Leveling Osteotomy Using a Fixin-Micro System in Small Breed Dogs Affected by Cranial Cruciate Ligament Rupture with Concurrent Medial Patellar Luxation. Ichinohe T1;2, Fujita Y2;1. 1Azabu University Veterinary Teaching Hospital, Sagamihara-shi, Japan; 2Azabu University, Laboratory of Small Animal Surgery, Sagamihara-shi, Japan.
Modified tibial plateau leveling osteotomy (TPLO) can be used to treat cranial cruciate ligament rupture with concurrent medial patellar luxation (CCLRw/MPL) in dogs. However, in Japan, this method is used for dogs with very low body weight. The appropriate amount of medial displacement of the proximal tibial fragment is also unknown. We hypothesized that the outcomes of modified TPLO with a Fixin-micro system and TPLO for CCLRw/MPL would be similar and the incidence of patellar reluxation would depend on the amount of medial displacement. Dogs ( < 5 kg) with CCLRw/MPL treated with standard or modified TPLO were evaluated (23 stifle joints). Dogs were assessed preoperatively and immediately and until four months postoperatively. The width of the tibia at the osteotomy site and the tibial medialization ratio (M/TW), tibial width and tibial tuberosity height ratio, and the tibial width and tibial tuberosity width ratio (TTW/TW) were calculated and compared between the standard and modified TPLO groups. There were no differences between the standard and modified TPLO groups, except for in TTW/TW, which was higher in the modified TPLO than in the standard TPLO group. M/TW was significantly lower in dogs with patellar reluxation in the modified TPLO group. Modified TLPO was as effective as standard TPLO for the treatment of small breed dogs with CCLRw/MPL in the short-term, and dogs did not require another osteotomy or an implant; however, the sample size was small. Patellar reluxation after modified TPLO could result from insufficient medialization of the proximal tibial segment.