Presoaking ACL Grafts with a Vancomycin Solution May Significantly Decrease Infection Rates
The researchers theorized that the graft would act as a reservoir of the antibiotic, which would elute into the knee over a period of time.
Mehul R. Shah, MD
Pérez-Prieto D, Torres-Claramunt R, Gelber PE, Shehata TM, Pelfort X, Monllau JC. Autograft soaking in vancomycin reduces the risk of infection after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2014 Nov 22. [Epub ahead of print] PMID: 25416672
The authors of this article sought to determine whether the infection rate following anterior cruciate ligament (ACL) reconstruction could be decreased by soaking the graft in an antibiotic solution.
The article is a retrospective, case-control study of all ACL reconstructions performed in 2 university hospitals over an 8-year period. The study included only autograft reconstructions, and consisted of 84% quadrupled hamstrings and 16% bone-patella tendon-bone (BPTB) grafts.
They utilized historical controls from the first 4-year period of the study (Group 1). During this time, 810 ACL reconstructions were performed, and their prophylactic antibiotic protocol consisted of either 2 grams of intravenous (IV) cefazolin or 1 gram of IV vancomycin.
In the second 4-year period (Group 2), 734 patients underwent ACL reconstruction. During this time period, they added a 10- to 15-minute presoak of the autograft in a 5mg/mL vancomycin solution. They theorized that the graft would act as a reservoir of antibiotic, which would elute into the knee over a period of time.
The investigators reported an overall infection rate of 0.97% (15 cases) after ACL reconstruction, all of which were among patients in Group 1 (1.85%); there were no reported cases of infection in Group 2 (0%). All reported infections were acute infections that occurred in the first 5 weeks after surgery. Isolated organisms isolated include coagulase-negative Staphylococcus, Staphylococcus aureus, and Propionibacterium acnes.
Statistical analysis showed that presoaking the autograft in a vancomycin solution significantly decreased the infection rate in ACL reconstruction (p < 0.001).
More than 175,000 ACL reconstructions are performed in the US every year. Infection after ACL reconstruction is a disastrous complication that often requires subsequent re-operations, hospital admissions, administration of IV antibiotics, and potential revision reconstruction.
The infection rate after ACL reconstruction has been reported in the literature to be between 0.14% and 1.7%. Even with current IV prophylactic antibiotic regimens, the given rates estimate that 3,000 infections occur annually after ACL reconstruction.
The proposed regimen of presoaking the graft in a vancomycin solution has been shown in this study to significantly decrease the rate of infection.
However, this study has limitations – primarily the use of historical controls, which produces significant bias in the study. As the authors admit, both surgical technique and implants used in the study have changed over time. Additionally, one assumes that the surgeons involved in the study have improved their surgical skills over time. Improved technology in the operating room or other cofounders may also have played a role in the decreased infection rate.
Prior surgery, use of a drain, concomitant open procedures, and use of hamstring autograft have been shown to increase the risk of infection after ACL reconstruction. The surgeons involved in the study showed a preference in the utilization for hamstring autograft, which may not represent the general patient population.
Overall, the use of a vancomycin solution presoak seems to be an effective tool in reducing the infection rate after ACL reconstruction. Future prospective randomized studies of this antibiotic regimen in ACL reconstructions utilizing allograft, BPTB, and hamstring autograft will clarify its utility.
Mehul R. Shah, MD is an Assistant Professor of Orthopaedic Surgery, Division of Sports Medicine, Department of Orthopaedic Surgery, at NYU Langone Medical Center – Hospital for Joint Diseases, New York, New York.