Benefits of pre- and intraoperative planning for tibial plateau leveling osteotomy.

Objective: To determine (1) if preoperative and intraoperative osteotomy planning increases the likelihood that a surgeon will achieve a centered osteotomy during tibial plateau leveling osteotomy (TPLO) and (2) if that centered osteotomy reduces the risk of tibial tuberosity (TT) fractures.

Study Design: Retrospective case series.

Animals: Dogs (n = 406) with cranial cruciate ligament that had TPLO (n = 468).

Methods: Medical records (2007-2010) and radiographs of dogs that had TPLO were reviewed. Osteotomies from Group A (pre and intra-operative planning) were compared to Group B (free-hand osteotomy only) investigating the influence of osteotomy planning as well as 21 other variables, looking for any other confounding variables that may also contribute to TT fractures. Data were analyzed with logistic regression and χ(2) analysis.

Results: Actual osteotomies were closer to the centered-osteotomy position in Group A than in Group B (P ≤ .01). TT fractures occurred in 20 cases (4.3% overall). Group A had 0 fractures out of 172 surgeries and Group B had 20 fractures out of 296 surgeries (6.8%). Five variables were found to increase the risk of TT fractures: lack of osteotomy planning, bilateral same-session surgeries, osteotomy gap, anti-rotational pin location, and decreased tibial crest width at the insertion of the patellar ligament (P ≤ .05).

Conclusions: Dogs that had osteotomy planning had a more centered osteotomy position and a reduced risk of developing TT factures.