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

Simple Summary: This retrospective study examines how the tibial plateau angle (TPA) changes over time in dogs following a tibial plateau leveling osteotomy (TPLO), a common surgery for treating cranial cruciate ligament (CCL) ruptures. The TPLO procedure stabilizes the stifle joint by rotating the tibial plateau to reduce stress on the ligament and improve joint function. While short-term outcomes of this surgery are well-documented, this study focuses on how the TPA evolves over a longer period, up to 12 months after surgery. We studied 60 dogs of various ages and weights, measuring the TPA before surgery, immediately after, and at 8 weeks, 6 months, and 12 months post-surgery. Our findings showed a steady increase in TPA over time, indicating that the tibia continues to remodel long after the initial healing period. No dog showed a decrease in the TPA, with the average TPA increasing from 4.98 degrees post-surgery to 9.02 degrees at 12 months. These results highlight the importance of long-term monitoring and suggest that aiming for a lower TPA immediately after surgery may result in better long-term outcomes for dogs undergoing TPLO. 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. [ABSTRACT FROM AUTHOR]