Effect of Stabilisation Method on Postoperative Complication Rates and Outcome After Treatment of Concomitant Cranial Cruciate Ligament Disease and Medial Patellar Luxation

Introduction:
To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA).

Material and methods:
Medical records were reviewed for dogs that had treatment of concomitant CrCL pathology and MPL using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete tear, MPL grade, occurrence of postoperative complications and final outcome based on a subjective grading scale. Associations were investigated using univariable logistic regression. Multiple logistic regression was used to explore confounding factors.

Results:
Thirty-seven stifles were evaluated; ECS+TTT (14) and TTTA (23). Before taking into account confounders, TTTA cases were less likely to develop complications (26.1%) than ECS+TTT cases (64.3%) (OR=0.20, 95% CI: 0.40; 0.79, p=0.03). After adjusting for confounding there was weak evidence to suggest that the TTTA group had lower odds of any complication (OR=0.23, 95% CI 0.04; 1.05, p=0.07). Before taking into account confounders, TTTA cases were more likely to have a better outcome (OR=0.17, 95% CI: 0.03; 0.82, p=0.03) but after adjusting for confounders, there was very weak evidence to suggest that TTTA cases had lower odds of a poorer clinical outcome (OR 0.21, 95% CI: 0.02; 1.71, p=0.15).

Discussion/Conclusion:
There may be associations between surgical procedure, complication rate and outcome however, after adjusting for the effect of confounders this evidence was weak. This may be the result of a type two statistical error and larger studies are warranted to investigate this.