Tibial plateau levelling osteotomy implant removal: a retrospective analysis of 129 cases.

OBJECTIVE To evaluate a cohort of dogs undergoing tibial plateau levelling osteotomy (TPLO) implant removal to determine key clinical features, prevalence, and indications for implant removal. METHODS Medical records of dogs undergoing TPLO implant removal at a private referral practice (Dallas Veterinary Surgical Center) between 2004-2008 were reviewed. Patient signalment, implant type, presence of concurrent medical disease, surgeon, antibiotic use, aerobic bacterial culture result, and operative findings were recorded. Data were analyzed using paired t-test, Fisher's exact test, and Wilcoxon-rank sum test. Statistical significance was set at p <0.05. RESULTS The TPLO implants were removed from 126 dogs (n = 129, 4.8% of TPLO procedures) during the study period. Average time interval from TPLO to implant removal was 16.0 ± 17.8 months. The most common clinical signs were the presence of an open wound (n = 80), draining tract (n = 64), and lameness (n = 59). Culture of tissue or fluid from the implant bed or implants was positive for bacterial growth in 95/115 cases. A significantly greater proportion of the implants removed were Slocum TPLO plates (n = 109; 6.1%) when compared to other TPLO plate types (n = 20; 2.3%) (p <0.0001). No association was identified between a positive bacterial culture and measured variables. CLINICAL SIGNIFICANCE Local bacterial infection and clinical signs of inflammation were the most common reasons for TPLO implant removal. There may be an increased implant-associated complication rate for Slocum TPLO plates in the study population.