2025 ISAKOS Biennial Congress ePoster
Could Low-Grade Infections Be The Cause Of Graft Failure In Acl Reconstruction? A Microbiological Comparison Of Native Acl And Graft Ruptures.
Christoph Offerhaus, MD, Köln GERMANY
Vera Jaecker, MD, Cologne, NRW GERMANY
Sven T. Shafizadeh, Prof. Dr. , Cologne, NRW GERMANY
Sebastian Leutheuser, MD, Köln GERMANY
University of Witten-Herdecke, Sana Medical Center Cologne, Cologne, GERMANY
FDA Status Cleared
Summary
Tissue samples of ACL grafts and synovial fluid aspirations revealed the occurrence of low-grade infections and cultivable bacterial presence in revision ACLR.
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Abstract
Background
Numerous studies have shown that presoaking the graft in vancomycin decreases the rate of postoperative septic arthritis in anterior cruciate ligament reconstruction (ACLR). Some of these studies additionally observed a decrease of graft failure after ACLR with the use of topical vancomycin. Consequently, low-grade infections of the graft are discussed as a possible cause of graft failure. The purpose of the present study was to investigate whether the bacterial presence in a ruptured native anterior cruciate ligament (ACL) differs from that in a ruptured hamstrings ACL graft and whether low-grade infections cumulatively can be detected in the case of graft failure.
Methods
A total of 112 consecutive patients undergoing primary (n=59) and revision (n=53) ACLR were recruited from one center. No patient had history or showed clinical signs of infection. Synovial fluid aspirates and tissue samples of failed ACL grafts were examined for evidence of bacterial colonization and compared to samples of the native ACL in primary ACLR using microbiological culture, 16S rRNA-PCR and histopathological examination. Furthermore, synovial fluid aspiration was investigated for possible future biomarkers for a low-grade infection.
Results
A total of 389 samples were analyzed by culture. Bacteria were detected more frequently in patients with a graft rupture (9.4%, n=5/53) compared to patients with a primary ACL rupture (3.4%, n=2/59; p=0.192). One patient with a “true” low-grade infection was found in our study population, resulting in an incidence of 1.9% (1/53) in the graft group. Remarkably the percentage of polymorphonuclear leukocytes (PMN%) as a highly sensitive marker for joint infections was significantly higher in aspirated synovial fluid of graft ruptures (27% ± 3% vs. 20% ± 4%, p=0.032), as well as glucose levels were significantly lower (83 mg/dl ± 2 mg/dl vs. 88 mg/dl ± 2 mg/dl, p=0.042).
Conclusion
Tissue samples of ACL grafts and synovial fluid aspirations revealed the occurrence of low-grade infections and cultivable bacterial presence in revision ACLR. In particular, synovial fluid obtained before revision ACLR showed evidence of bacterial metabolism, demonstrating that the intra-articular milieu changes significantly after ACLR. Furthermore, limitations of current routine diagnostic tools in distinguishing between clinically inapparent bacterial colonization and contamination during and/or after surgery were highlighted in this study.