Contributing factors to surgical site infection after tibial plateau leveling osteotomy: A follow-up retrospective study.

OBJECTIVE: To identify factors associated with surgical site infection (SSI) after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 541) that underwent TPLO (n = 659). METHODS: Medical records of dogs that underwent TPLO from 2011-2018 were reviewed. Data collected included perioperative and postoperative antimicrobial administration, stifle inspection, duration of surgery and anesthesia, comorbidities, and development of SSI including timing, microbiological investigation, and implant removal. Referring veterinarians were contacted for all dogs without a recorded return visit. Risk factors for SSI were assessed by using a multivariable logistic regression model built by using a stepwise approach. RESULTS: Surgical site infection was documented in 71 of 659 (11%) TPLO, with methicillin-resistant Staphylococcus pseudintermedius accounting for 20 of 71 (28%) infections. Protective factors against SSI included administration of postoperative antimicrobials (odds ratio [OR] 0.263; 95% CI = 0.157, 0.442) and timing of preoperative antimicrobial administration. Preoperative antimicrobial timing was protective against SSI when it was administered more than 60 minutes before the first incision compared with administration within 30 minutes (OR 0.275; 95% CI = 0.112, 0.676) or within 60 minutes (OR 0.419; 95% CI = 0.189, 0.929) of the first incision. CONCLUSION: Early administration of perioperative antimicrobials and postoperative antimicrobial administration were protective against SSI after TPLO. CLINICAL SIGNIFICANCE: Antimicrobials can influence the risk of SSI after TPLO. Perioperative and postoperative antimicrobial administration timing should be considered to reduce SSI.

In vitro elution of amikacin and Dispersin B from a polymer hydrogel.

OBJECTIVE: To characterize the in vitro elution of amikacin and Dispersin B (ß-N-acetylglucosaminidase) in a degradable hydrogel. STUDY DESIGN: In vitro, prospective study. METHODS: Amikacin (group A; 40 mg/mL), Dispersin B (group D; 70 µg/mL), or combined amikacin and Dispersin B (group AD; 40 mg/mL and 70 µg/mL, respectively) were added to a hydrogel. Ten aliquots per group were incubated in phosphate-buffered saline that was exchanged at 1, 4, 8, 12, and 24 hours and then once daily for 10 days. Eluted amikacin and Dispersin B were quantitated by using an amikacin reagent kit and a Dispersin B enzyme-linked immunosorbent assay kit, respectively. Time point drug concentrations were compared between groups by using repeated-measures analysis of variance, and total drug elution was compared by using an area under the curve calculation. RESULTS: Amikacin alone, Dispersin B alone, and amikacin and Dispersin B combined together underwent rapid elution in the first 24 hours, followed by a gradual decrease over 10 days. The concentration of Dispersin B eluted in group D was higher at 1 day and lower from day 5 to day 10 compared with that in group AD. The concentration of amikacin eluted in group A was higher at 1, 4, and 8 hours and on day 10 and lower on day 1 compared with that in group AD. The total elution of amikacin was greater from group AD compared with that from group A (P = .02). CONCLUSION: Combining amikacin and Dispersin B had an affect on the total elution of amikacin but not Dispersin B. CLINICAL SIGNIFICANCE: The combination of amikacin and Dispersin B in a degradable hydrogel could allow local treatment of complex infections without the requirement for multiple invasive procedures.