Risk factors for tibial tuberosity fracture after tibial tuberosity advancement in dogs

Objective: To retrospectively identify factors that predispose to tibial tuberosity (TT) fracture after tibial tuberosity advancement (TTA) in dogs. Methods: The medical records and radiographs of a group of control dogs (n = 212) that had TTA surgery (n = 241 procedures) and did not sustain a fracture between 2008 and 2013, and those of 12 dogs that did sustain a fracture (n = 13 procedures) between 2008 and 2013 at two veterinary teaching hospitals were evaluated to determine the effect of signalment, body weight and surgical inaccuracies on TT fracture. Multivariable logistic regression was performed with the occurrence of TT fracture as the outcome variable of interest. Results: Signalment and body weight were not found to be associated with TT fracture. Of the surgical inaccuracies, osteotomy shape (p = 0.003), plate position (p = 0.009), and cage position (p = 0.039) were factors significantly associated with TT fracture. Clinical significance: This study provides data to support the hypothesis that poor plate position, poor cage position, and narrow distal osteotomy width are associated with TT fracture after TTA. We conclude that it is of paramount importance to pay careful attention to surgical technique in order to reduce this risk.