NM Fitzpatrick ¹, R Yeadon1, MP Kowaleski ².
¹ Fitzpatrick Referrals, Farnham, United Kingdom, ² The Ohio State University, Ohio, United States

ACVS Abstract 2007 

Concurrent medial patellar luxation (MPL) and cranial cruciate ligament disease (CCLD) is recognised. We hypothesised that simultaneous transposition and advancement of the tibial tuberosity would unify treatment for both conditions and improve reliability of outcome by three-dimensional tibial tuberosity manipulation. 

Historic, clinical, surgical and post-operative records for 22 dogs (26 stifles) operated by Tibial Tuberosity Transposition-Advancement (TTTA) were reviewed. Lateral arthrotomy, recession sulcoplasty and soft tissue release/imbrication were performed for all cases. TTA technique was modified allowing lateral tibial tuberosity transposition and distalisation.

Anatomical axes, patellar ligament: patellar length (L:P) ratio and sagittal vector of tuberosity translation were determined from pre- and post-operative radiographs.  Six joints had cranial cruciate ligament (CCL) rupture and 20 had partial CCL rupture.MPL grade was 2/4 or 3/4.  Vector analysis of sagittal tuberosity translocation was used to calculate a post-operative patellar height ratio (using equivalent measurement parameters to pre-op L:P) of 1.47 for dogs 420 kg, and 1.14 for dogs o20 kg. True tuberosity advancement was noticeably reduced compared to cage size used. Mean resolution of lameness was 8.1weeks.

Complications included recurrent MPL and infection.  TTTA is a valid treatment for concomitant MPL and CCLD. Versatility of tibial tuberosity manipulation is greater than other reported techniques. Short term outcome and morbidity are promising. Pre-operative planning protocols require refinement to optimise biomechanical outcome. Optimal post-operative vertical patellar height has yet to be elucidated. Potential for alleviation of retro-patellar pain using TTTA requires further investigation.