Long-Term Changes in Tibial Plateau Angle (TPA) Following Tibial Plateau Leveling Osteotomy (TPLO) in Dogs—A Retrospective Study

Abstract

Background: Cranial cruciate ligament rupture is a common orthopedic condition in dogs. Tibial plateau leveling osteotomy (TPLO) is a widely accepted method due to its success in stabilizing the stifle joint. This study aims to investigate the changes in the TPA over a 12-month follow-up period in dogs undergoing TPLO. Methods: An analysis of medical records from 60 dogs, aged 2 to 8 years and weighing between 7 and 59 kg, who underwent the TPLO procedure was conducted. TPA measurements were recorded before surgery, immediately after surgery, and during follow-up periods at 8 weeks, 6 months, and 12 months post-operation. Results: Results showed a consistent increase in TPA over time, with the mean TPA rising from 4.98 degrees immediately post-surgery to 9.02 degrees at the 12-month follow-up. No patients exhibited a decrease in TPA during the study period. The mean difference between the final and initial TPA was 4.045 degrees, with patients exhibiting smaller initial TPAs showing less variation over time; Conclusions: This is the first report on long-term TPA changes following TPLO, offering essential insights into tibial remodeling and the potential for optimizing surgical outcomes. Based on the results, achieving a lower initial TPA (1–2 degrees) may reduce postoperative TPA changes, supporting more stable stifle function.