Prevalence, Risk Factors and Outcome of Postoperative Tibial Tuberosity Fractures in Dogs Undergoing Triple Tibial Osteotomy Surgery.

Objective The aim of this study was to report the prevalence and to identify the risk factors associated with postoperative tibial tuberosity fracture following a triple tibial osteotomy. This article also evaluates the outcome of these patients treated conservatively. Materials and Methods Medical records of 100 dogs (113 limbs) that underwent triple tibial osteotomy procedure were evaluated. Information obtained included signalment, preoperative, immediate postoperative and 6-week postoperative radiographic findings, intraoperative and postoperative complications. Long-term outcome was assessed using an owner questionnaire. Results Postoperative tibial tuberosity fracture was identified in 25/113 stifles. The only variable associated with the presence or absence of postoperative tibial tuberosity fracture within 6 weeks of surgery was postoperative cortical hinge width (CHW) or an indexed value of CHW to tibial width (TW). Using either a cut-off value of CHW of >= 5.5 mm or a cut-off value of CHW/TW of >= 0.21, only 1/27 stifle in our study developed tibial tuberosity fracture. Long-term owner evaluation of outcome was considered excellent or good in 65/70 stifles. Conclusion A narrow CHW at the distal cortical attachment of the tibial crest had a strong association with the development of postoperative tibial tuberosity fracture. No other patient or surgical variables were associated with tibial tuberosity fracture. Patients that developed tibial tuberosity fracture and were conservatively managed did not have a worse clinical outcome than patients that did not develop tibial tuberosity fracture.