Vancomycin Presoaking of Hamstring Autografts in Anterior Cruciate Ligament Reconstruction Is Associated With Higher Magnetic Resonance Imaging Graft Signal Without Influencing Clinical Outcome

Vancomycin Graft Presoaking in Anterior Cruciate Ligament Reconstruction Surgery Is Associated with a Lower Risk of Graft Rerupture as Compared With No Vancomycin Presoaking: Systematic Review and Meta-analysis

BACKGROUND

To determine whether there is any difference in graft rerupture rates and clinical outcomes between cases having vancomycin graft presoaking vs. no vancomycin presoaking in anterior cruciate ligament (ACL) reconstruction (ACLR).

METHODS

Systematic review and meta-analysis. PubMed, Embase, CINAHL, and Cochrane CENTRAL were searched. Full published studies reporting on the relation between vancomycin graft presoaking and rates of graft rerupture and/or clinical outcomes in ACLR surgery vs. no vancomycin graft presoaking were included. Data extraction and quality appraisal were performed. Meta-analysis was conducted using a random effects model. The study's protocol was prospectively registered with PROSPERO (CRD42021290608).

RESULTS

The literature search identified 907 records. After removing duplicates and those not meeting inclusion criteria, 8 studies were included. Meta-analysis showed that the estimated risk of hamstring graft rerupture was lower in cases presoaked with vancomycin vs. those having no presoaking (3.2% vs. 6.2% rerupture rate, risk ratio [RR] = 0.507, 95% CI, 0.39-0.737, p < 0.001). Similarly, the estimated risk of graft rerupture was lower in cases presoaked with vancomycin vs. those having no presoaking when the analysis included various ACL graft types (2.7% vs. 3.9% rerupture rate, RR = 0.557, 95% confidence interval [CI], 0.403-0.771, p < 0.001). Meta-analysis also showed that vancomycin graft presoaking was associated with similar International Knee Documentation Committee scores as compared with no presoaking when looking at hamstring grafts (estimated mean difference 0.112, 95% CI, -2.359 to 2.582, p = 0.929) or when considering various graft types (estimated mean difference 0.933, 95% CI, -0.140 to 2.006, p = 0.088).

CONCLUSION

Vancomycin graft presoaking is a safe practice and does not compromise ACL graft rerupture rates or clinical outcomes.

LEVEL OF EVIDENCE

Level IV. See Instructions for Authors for a complete description of levels of evidence.

Vancomycin Concentrations in Synovial Fluid Do Not Reach Chondrotoxic Thresholds After Anterior Cruciate Ligament Reconstruction With Vancomycin-Soaked Autologous Soft Tissue Grafts: An In Vivo Prospective Observational Study in Humans

BACKGROUND

Studies have revealed that vancomycin soaking of the anterior cruciate ligament (ACL) graft can drastically reduce the incidence of postoperative infections after ACL reconstruction. However, it remains unknown whether the chondrotoxic threshold of vancomycin in synovial fluid is exceeded during this process. Several studies investigated the chondrotoxic properties of vancomycin in in vitro experiments and described a concentration of 1000 µg/mL as the critical threshold.

PURPOSE/HYPOTHESIS

The purpose of the study was to measure the vancomycin concentration in synovial fluid after ACL reconstruction with vancomycin-soaked autografts. It was hypothesized that intra-articular vancomycin concentrations in the synovial fluid would not reach the chondrotoxic threshold of 1000 µg/mL after vancomycin soaking of autologous semitendinosus tendon and soft tissue quadriceps tendon grafts for ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

The study enrolled 10 patients undergoing ACL reconstruction using 4-strand semitendinosus tendon autografts and 10 patients undergoing ACL reconstruction using soft tissue quadriceps tendon autografts. Before implantation, each harvested graft was intraoperatively wrapped in gauze swabs that had been soaked in a 5-mg/mL vancomycin solution. After wound closure, an aspirate of 5 mL of synovial fluid was taken from each patient. The vancomycin concentration of the aspirate was analyzed using high-performance liquid chromatography-tandem mass spectrometry. Spearman rho correlation coefficients were used to identify relationships between the parameters, and the t test was used to test for differences between graft types. A P value of <.05 was considered statistically significant.

RESULTS

The study included 20 patients (14 women and 6 men; age, 29.35 ± 11.3 years). The mean vancomycin concentration measured in the synovial fluid was 23.23 ± 21.68 µg/mL, with a minimum concentration of 2.32 µg/mL and a maximum concentration of 71.56 µg/mL. No significant difference was found between the 2 graft types (P = .911). Significant positive correlation (r = 0.644; P < .05) was observed only between the vancomycin concentration and the mean duration from initiation of vancomycin soaking of semitendinosus tendon grafts to implantation (13.4 ± 6 minutes). No correlations were observed between the vancomycin concentration and the duration from implantation to fluid aspiration or between the vancomycin concentration and the graft diameter (median, 8.5 mm; range, 6.0-10.0 mm) for both graft types.

CONCLUSION

Chondrotoxic vancomycin concentrations ≥1000 µg/mL were not reached in any aspiration of synovial fluid after ACL reconstruction using soft tissue autografts that were intraoperatively soaked in a 5-mg/mL vancomycin solution. Against the backdrop of multiple studies that showed significantly reduced infection rates after ACL reconstruction when vancomycin soaking was used, this study suggests that the chondrotoxic properties of this method are negligible because of its submarginal intra-articular concentrations.

Editorial Commentary: Soaking Anterior Cruciate Ligament Grafts in Vancomycin Solution Lowers Infection Rates Without Lowering Functional Outcomes

Soaking anterior cruciate ligament grafts in vancomycin solution is done by many surgeons. Research has indicated decreased infection rates and similar anterior cruciate ligament retear rates between grafts soaked in vancomycin solution before implantation versus those without. In addition, there has been basic science evidence for tenocyte survival and viability even when exposed to vancomycin solution. The next frontier, investigating the maturation of vancomycin-soaked grafts with advanced imaging, may cause some surgeons to reconsider the practice but should not stop it, based on the available literature.