Teaching Associate Azabu University Sagamihara-shi, Japan
Although tibial cranial drawer signs (TCDS) do not disappear with tibial plateau leveling osteotomy (TPLO), in some cases, this may occur and is presumed to be due to periarticular fibrosis; however to our knowledge, no reports have confirmed the disappearance of TCDS after TPLO. Here, we aimed to identify factors influencing the presence/absence of TCDS after TPLO. Thirty-five canine stifle joints performed TPLO for cranial cruciate ligament rupture were assessed preoperatively, immediately postoperatively, and each month for 3 months following surgery. The cases were classified as those in which TCDS disappeared (13 stifles, disappeared group) and those in which TCDS remained (22 stifles, residual group). Age, body weight, breed, preoperative and postoperative tibial plateau angle (TPA), differences between preoperative and postoperative TPA, and duration of clinical symptoms were recorded. The osteoarthritis (OA) score at each postoperative time point was subtracted from the preoperative OA score (variation in OA score). There were no differences between the two groups, except in the preoperative OA scores (which were higher in the disappeared group). Significant increases in the variations in OA score were observed over time in both groups; these variations were significantly higher in the disappeared than in the residual group at 1, 2, and 3 months postoperatively. The study limitations include a small sample size and no long-term follow-up. Synovial fibrosis occurs in the late OA stages, and disappearance of TCDS after TPLO is associated with a higher degree of OA progression, suggesting involvement of OA progression factors and periarticular fibrosis.
