Risk factors for severe postoperative complications in dogs with cranial cruciate ligament disease-A survival analysis

Objective: To analyze the effect of surgical technique and other risk factors on severe postoperative complications in dogs with cranial cruciate ligament disease (CCLD). Materials and Methods: A cohort study of 255 dogs (287 stifles) surgically treated for CCLD at two veterinary university hospitals (2011 & ndash;2016) was performed. The electronic medical records were reviewed and dog owners and referring veterinarians contacted for additional information. The complications were classified as minor, major and catastrophic, where major and catastrophic were considered severe. A multivariable Cox proportional hazards model was applied to assess risk factors for severe postoperative complications.Results: Three surgical techniques were used; lateral fabellotibial suture (LFS, 141 stifles), tibial plateau leveling osteotomy (TPLO, 77 stifles) and tibial tuberosity advancement (TTA, 69 stifles). The most common severe postoperative complications were surgical site infections or complications related to the surgical implant. Severe postoperative complications occurred in 31 % of the stifles treated with TPLO, 22 % of the stifles treated with LFS and 25 % of the stifles treated with TTA. The multivariable Cox proportional hazards model identified surgical technique (p = 0.0258) as a risk factor for severe postoperative complications; TPLO had a significantly lower hazard than LFS (hazard ratio (HR) = 0.37, p = 0.007) when controlling for body weight and age, which also were identified as risk factors (HR = 1.05, p < 0.001 and HR = 0.91, p = 0.047, respectively).Conclusion and Clinical relevance: Although TPLO procedures had the highest occurrence of severe postoperative complications, the hazard was lower than for LFS after adjusting for body weight and age. This implies that it is important to consider potential effect-modifiers when comparing postoperative complications after CCLD surgery