Study Title: Vancomycin Soaking of ACL Reconstructions Does Not Alter the Mechanical Strength
DOI: 10.52628/90.3.12980
Authors: V. Jahier, J. Maximen, P. Guillemont, Q. Bidard, M. Ropars, H. Common
Affiliations: Orthopaedic and Trauma Surgery, Rennes University Hospital Pontchaillou, Rennes, France
Introduction
Anterior cruciate ligament (ACL) reconstruction is a widely performed procedure, but the risk of post-operative infection remains a concern. One technique to reduce infection rates is soaking autografts in vancomycin, which has been shown to significantly decrease bacterial contamination. However, concerns persist regarding its potential impact on graft integrity and long-term mechanical strength. This study aimed to objectively assess whether vancomycin soaking affects ACL graft strength and joint stability at 6 months post-operatively using the GNRB® robotic knee arthrometer.
Study Objectives
The primary objective was to evaluate the laximetric qualities of vancomycin-soaked hamstring autografts at 6 months post-operatively after ACL reconstruction by comparing them with the joint laxity of the contralateral healthy knee on the GNRB® at 134N. This evaluation was performed to determine whether the soaking process affects graft integrity and post-operative stability. By using precise robotic arthrometry, the study aimed to provide an objective measurement of knee laxity and assess any potential differences between the treated and untreated knees.
The secondary objective was to assess the rate of rupture at 1 year, evaluating potential factors contributing to graft failure and ensuring that vancomycin application does not increase structural weakness or lead to early failures.
Methods
This retrospective study included 53 patients who underwent ACL reconstruction using vancomycin-soaked hamstring autografts at Rennes University Hospital between December 2018 and February 2021. The GNRB® arthrometer was used to objectively measure anterior knee laxity at 134N of applied force at 6 months post-operatively. Additionally, subjective functional outcomes were evaluated using the Lysholm and IKDC questionnairesat 1 year.
Inclusion & Exclusion Criteria
Inclusion: Patients who underwent primary ACL reconstruction using hamstring autografts, with a minimum follow-up of 1 year.
Exclusion: Multi-ligament injuries, revision ACL surgeries, contralateral ACL injury preventing comparative assessment, vancomycin allergy.
Results
GNRB® Arthrometric Findings
The mean GNRB® laxity at 6 months was 4.50 ± 1.43 mm in the operated knee, compared to 3.49 ± 0.91 mm in the healthy knee.
Despite a statistically significant difference, the post-operative laxity remained within the expected range for successful ACL reconstructions.
The difference in anterior knee laxity between the two knees was below the threshold of 3 mm, indicating no cases of complete graft failure.
Functional Outcomes
At 1 year, patients reported a mean Lysholm score of 87 ± 13 and an IKDC subjective score of 85.7 ± 4.3%, suggesting a good to excellent recovery.
No cases of post-operative infection were recorded.
The early graft rupture rate was 3.8%, with failures attributed to surgical technical errors rather than graft integrity.
Discussion
This study provides strong evidence that vancomycin soaking does not compromise ACL graft mechanical integrity. The findings align with previous in vitro and animal studies that have demonstrated the safety of vancomycin on tenocyte viability and tendon remodeling. Importantly, GNRB® arthrometric data confirm that joint stability remains within clinically acceptable limits.
Clinical Relevance
The use of vancomycin soaking as a prophylactic measure against post-operative infections is validated by this study, with no observed adverse effects on graft function. The results reinforce the recommendation for vancomycin soaking as a safe and effective protocol in ACL surgery.
Conclusion
Vancomycin soaking of ACL grafts significantly reduces infection risk without compromising mechanical strength or post-operative knee stability. The study further supports the use of objective robotic arthrometers like GNRB® in evaluating ACL reconstruction outcomes.
Medical Reference (Link in DOI)
- Jahier V, Maximen J, Guillemont P, Bidard Q, Ropars M, Common H. Vancomycin soaking of ACL reconstructions does not alter the mechanical strength. Acta Orthop Belg. 2024;90(3):415-420. DOI: 10.52628/90.3.12980.
