Soaking of Autologous Tendon Grafts in Vancomycin Before Implantation Does Not Lead to Tenocyte Cytotoxicity

Abstract

Background: Surgical site infections (SSIs) after anterior cruciate ligament (ACL) reconstruction procedures are an unfortunate complication. Soaking grafts in vancomycin before implantation has been reported to reduce the incidence of postoperative SSI after ACL reconstruction. There is potential for vancomycin to compromise graft integrity because of tenocyte toxicity. Purpose: To examine the in vitro toxicity of varying doses of vancomycin on human tenocytes. Study Design: Controlled laboratory study. Methods: Human patellar tenocytes were isolated and expanded in vitro. Tenocytes in culture were exposed to vancomycin at 5 different concentrations (400, 1600, 3200, 6400, and 12,800 μg/mL) and 3 time intervals (2, 6, and 24 hours). The control for all series was tenocyte exposure to only culture medium for each time interval. After treatment, a 10% Cell Counting Kit-8 solution in cellular growth medium was applied to the cells to examine cytotoxicity. A live/dead assay was used to assess tenocyte viability through fluorescence microscopy and flow cytometry. Results were analyzed statistically using multivariable logistic regression models with Tukey honest significant difference post hoc tests. Results: Vancomycin did not cause significant changes in tenocyte viability after 2 and 6 hours of incubation at any concentration between 0 and 12,800 µg/mL. Incubation with vancomycin for 24 hours led to a significant decrease in cell viability at higher concentrations. Conclusion: Tenocytes derived from human patellar tendons exposed to relatively high concentrations of vancomycin for short periods of time do not demonstrate significant cell death and toxicity. Clinical Relevance: Exposing tendons to vancomycin for a short period of time, such as before ACL reconstruction, is not likely to cause tenocyte toxicity because of vancomycin administration.

The role of vancomycin-soaking of the graft in anterior cruciate ligament reconstruction

“…There were no significant changes in tenocyte viability after 2 and 6 hours of incubation at any vancomycin concentration between 0 and 12,800 µg/mL. Incubation with vancomycin for 24 hours led to a significant decrease in cell viability at higher concentrations 13 .…”

Editorial Commentary: Vancomycin Soaking of the Graft in Anterior Cruciate Ligament Reconstruction: A Concept on the Way to Becoming the New Gold Standard

“…Comparable results have been shown for porcine flexor digitorum profundus tendons and human semitendinosus grafts, and even relatively high concentrations of vancomycin did not show significant cell death and toxicity in human tenocytes derived from human patellar tendons. [7][8][9] Evaluating this data, it can be stated with high confidence that at the time of implantation, vancomycin soaking does not affect the biomechanical properties of the various ACL grafts.…”

Local Application of Vancomycin in Orthopaedic Surgery—A Review

“…Statistically significant fewer infections (0.013% vs. 0.77%, p , 0.001) were observed in patients who had graft treatment with vancomycin (7,507 subjects) compared with the controls (13,861 subjects) 35 . Two of these studies analyzed patient-reported outcome measures, and IKDC scores showed no difference for patients in the vancomycin group and control group at 1 year postoperatively 35 . Overall, the vancomycin wrap has been effective in ACLR procedures because of its safety profile, low allergenicity, heat stability, and large volume of distribution 36 .…”