Tibial tuberosity transposition-advancement for treatment of medial patellar luxation and concomitant cranial cruciate ligament disease in the dog

OBJECTIVE: To report surgical technique, morphometric effects and clinical outcomes for tibial tuberosity transposition-advancement (TTTA), sulcoplasty and para-patellar fascial imbrication for management of concomitant medial patellar luxation (MPL) and cranial cruciate ligament (CCL) disease in 32 dogs. STUDY DESIGN: Case series. METHODS: A previous technique for tibial tuberosity advancement was modified to incorporate lateral and distal tibial tuberosity transposition. Preoperative, immediate, and six to eight week postoperative radiographs were reviewed with morphometry of a range of tibial and stifle anatomic parameters. Findings of sequential clinical examinations to six to 20 months postoperatively were recorded. RESULTS: Thirty-nine stifles were treated by surgery. Medial patellar luxation grade ranged from II to IV/IV. The CCL rupture was complete in 17/39 stifles, and incomplete in 22/39. Complications occurred in 11/39 stifles including MPL recurrence (n=4). Resolution of subjectively-assessed lameness occurred in 29/39 stifles at the six to eight week assessment. Resolution of lameness was eventually documented in 35/39 stifles (4/39 lost to follow-up), and was maintained at the six to 20 month reassessment where available. The TTTA induced relative patella baja in 31/39 stifles. Magnitude of actual tibial tuberosity advancement was lower than that predicted by cage size. CLINICAL SIGNIFICANCE: Tibial tuberosity transposition-advancement is a potential treatment modality for concomitant CCL disease and MPL in the dog, but refinement of planning is required, while biomechanical and kinematic effects remain unknown.