Vancomycin Wrap for Anterior Cruciate Ligament Surgery: Molecular Insights

Presoaking hamstring autograft with vancomycin does not jeopardize its biomechanical properties, including graft elongation, after cyclic loading

PURPOSE

Presoaking the graft with vancomycin before implantation has been shown to reduce the risk of postoperative infection after anterior cruciate ligament reconstruction (ACLR). However, the effects of presoaking on the graft biomechanical properties remain unclear. This study aimed to determine whether presoaking the graft with vancomycin affects the graft biomechanical properties and length after cyclic loading.

METHODS

Ten paired (20 specimens) gracilis and semitendinous tendons were harvested from fresh-frozen human cadaveric specimens. Two tendons were folded in half to make four strands, and the grafts were randomized into the vancomycin and control groups. The graft was exposed to the antibiotic solution for 15 min (5 mg/mL) and prepared by mixing 1 g of vancomycin with 200 mL of normal saline (NaCl 0.9%). The control group was soaked in normal saline for 15 min. The prepared grafts were attached to the actuator of a dynamic tensile-testing machine. All grafts were tested with 3000 cycles of cyclic loading followed by a pull-to-failure. The cyclic loading protocol consisted of position and load control blocks to simulate the graft in vivo in the postoperative phase after ACLR.

RESULTS

Presoaking in vancomycin did not jeopardize the biomechanical properties of the graft. In addition, presoaking with vancomycin did not elongate the grafts. No significant differences were found in the mean Young's modulus and the mean total elongation of the graft of the specimen between the vancomycin group and the control group.

CONCLUSION

Presoaking the graft with vancomycin jeopardized neither its biomechanical properties nor elongation even after cyclic loading in this in vitro study. It is suggested that vancomycin presoaking could be considered a safe and effective preventive measure for postoperative infections after ACLR.

LEVEL OF EVIDENCE

Not applicable.

In Vitro Evaluation of Vancomycin-Induced Toxicity in Human Primary Knee Chondrocytes

Septic arthritis as a complication of orthopaedic joint surgery can have catastrophic outcomes for patients. To minimise infection risk associated with elective orthopaedics, topical vancomycin during surgery has become increasingly common. Evidence suggests that high concentrations of vancomycin, following direct application of the drug to the joint, are toxic towards various local cell types in the joint, including chondrocytes. However, the mechanism of this vancomycin tissue toxicity is yet to be determined. The aim of this study was to evaluate the toxicity of vancomycin on chondrocytes and the mechanisms of cell death involved. Human primary knee chondrocytes were exposed to vancomycin (1.25-10 mg/mL) for 24 h and their viability assessed using the resazurin reduction assay in vitro. Specific cell death mechanisms and their contributors, including reactive oxygen species (ROS) production and apoptosis, were measured. This study showed that high concentrations of vancomycin (5 and 10 mg/mL) were toxic towards human primary knee chondrocyte cells, while lower concentrations (1.25 and 2.5 mg/mL) were not. Cell death studies found that this occurred through an apoptotic pathway. This study provides additional support that vancomycin in high doses is toxic towards chondrocytes and preliminary evidence that this toxicity occurs via apoptotic cell death mechanisms.

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.

Wrap It! Preventive Antimicrobial Treatment Shows No Negative Effects on Tenocytes and Tendons-A Comprehensive Approach

Although the rate of infection after the reconstruction of a ruptured anterior cruciate ligament (ACL) is low, prophylactic incubation of the graft with vancomycin (Vanco-wrap or vancomycin soaking) is routinely performed. A cytotoxic effect of vancomycin is reported for several cell types, and the prophylactic treatment might prevent infection but harm the tissue and cells.

AIM

A comprehensive study was performed to investigate the effect of vancomycin on tendon tissue and isolated tenocytes using cell viability, molecular and mechanical analysis.

MATERIAL AND METHODS

Rat tendons or isolated tenocytes were incubated in increasing concentrations of vancomycin (0-10 mg/mL) for different times, and cell viability, gene expression, histology and Young's modulus were analyzed.

RESULTS

The clinically used concentration of vancomycin (5 mg/mL for 20 min) had no negative effect on cell viability in the tendons or the isolated tenocytes, while incubation with the toxic control significantly reduced cell viability. Increasing the concentration and prolonging the incubation time had no negative effect on the cells. The expression of Col1a1, Col3a1 and the tenocyte markers mohawk, scleraxis and tenomodulin was not affected by the various vancomycin concentrations. The structural integrity as measured through histological and mechanical testing was not compromised.

CONCLUSION

The results proved the safe application of the Vanco-wrap on tendon tissue.

LEVEL OF EVIDENCE

IV.

Topical vancomycin powder does not affect patella cartilage degeneration in primary total knee arthroplasty and conversion rate for secondary patella resurfacing

INTRODUCTION

Vancomycin powder (VP) is an antibiotic first introduced in pediatric spinal surgery to prevent surgical site infections (SSI). Recently its topical application was expanded to total hip and knee arthroplasty (THA, TKA) and anterior cruciate ligament reconstruction (ACLR). Toxicity to cartilage is the subject of current research. The aim of this study was to prove the hypothesis that topical application of VP in TKA does not result in a degeneration of patella cartilage. We propagate that the conversion rate for secondary patella resurfacing is not influenced by its use.

MATERIALS AND METHODS

Between 2014 and 2021, 4292 joints were included in this monocentric retrospective cohort study. All patients underwent TKA without primary patella resurfacing. After a change of the procedure in the hospital, one group (VPG) was administered VP intraoperatively. The other group (nVPG) received no VP during surgery (nVPG). The remaining perioperative procedure was constant over the investigation period. Conversion rates for secondary patella resurfacing for both groups were determined without making distinctions in the indication. A second cohort was composed of patients presenting for follow-up examination 12 months after TKA and included 210 joints. Retrospective radiographic evaluations were performed preoperatively, before discharge and at follow-up examination. Patella axial radiographs were analyzed for patella tracking (lateral patellar tilt, patellar displacement) and patella degeneration (Sperner classification, patellofemoral joint space).

RESULTS

There was no significant difference in the conversion rate for secondary patella resurfacing (4.24% VPG, 4.97% nVPG). Patella tracking and patella degeneration did not differ significantly between both groups.

CONCLUSIONS

The topical application of VP does not influence the conversion rate for secondary patella resurfacing. Moreover, it does not result in a degeneration of patella cartilage in TK.

LEVEL OF EVIDENCE

Retrospective case series, Level III.

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

PURPOSE

To present the clinical and imaging results of a series of patients undergoing anterior cruciate ligament reconstruction with vancomycin presoaking of the hamstring autograft compared with patients in the immediate period prior, when no vancomycin was used.

METHODS

This was a retrospective sequential series of patients with anterior cruciate ligament reconstruction using either a graft protocol with no vancomycin presoaking (group 1, January 2013 to October 2015) or a graft protocol with vancomycin presoaking (group 2, November 2015 to December 2018). Lysholm and International Knee Documentation Committee scores were obtained at a minimum 24-month follow-up. Graft ruptures were recorded. Between 6 and 12 months' follow-up, magnetic resonance imaging (MRI) was obtained to evaluate graft healing and integration.

RESULTS

There were 102 patients (72% male patients), with 40 in group 1 (mean age, 32.2 years) and 62 in group 2 (mean age, 32.3 years). A graft rupture occurred in 5 patients (13%) in group 1 and 6 patients (10%) in group 2 (P = .65). The median Lysholm score was 95 points (interquartile range [IQR], 86-100 points) in group 1 and 95 points (IQR, 90-100 points) in group 2 (P = .37). The median International Knee Documentation Committee score was 93 points (IQR, 82-99 points) in group 1 and 94 points (IQR, 86-99 points) in group 2 (P = .22). MRI evaluation of integration showed that 87 patients (90%) had no synovial fluid at the tunnel-graft interface, without a difference between groups (P = .24). On the basis of graft signal appearance, hyperintense grafts were found in 45 patients (46%); isointense, 45 (46%); and hypointense, 7 (7%). Group 1 had a higher prevalence of hypointense grafts, whereas group 2 had a higher prevalence of hyperintense and isointense grafts (P = .003).

CONCLUSIONS

Vancomycin presoaking of hamstring grafts increased the number of hyperintense and isointense grafts on MRI. Additionally, more hypointense grafts were noted when vancomycin was not used, suggesting the presence of more mature grafts in the non-vancomycin group.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

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.

Evaluation of the Efficacy of Vancomycin-Soaked Autograft to Eliminate Staphylococcus aureus Contamination After Anterior Cruciate Ligament Reconstruction: Based on an Infected Rat Model

BACKGROUND

Vancomycin-soaked autograft application in anterior cruciate ligament reconstruction (ACLR) significantly reduces postoperative infection rates. However, the optimal vancomycin concentrations and time of vancomycin presoaking of autografts for preventing infection are still unknown.

PURPOSE

To evaluate the efficacy of vancomycin-soaked autografts in preventing infection in rats with ACLR.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 102 tendons of Wistar rats were harvested under sterile conditions from fresh cadaveric legs. Contamination with 2.0 × 10⁴ colony forming units per milliliter of Staphylococcus aureus and soaking in different vancomycin concentrations for different soaking times was performed in vitro. In vivo, after being contaminated with S. aureus and soaked with optimal vancomycin solution treatment and sterile saline, the grafts were implanted in rat knees to finish ACLR surgery. At 2, 4, and 12 weeks after surgery, samples were harvested to observe signs of infection and tendon-bone incorporation via general postoperative conditions, serum inflammatory markers, microbiological counting, knee radiographs, micro-computed tomography, histologic staining, scanning electron microscopy, and biomechanical testing.

RESULTS

Bacterial contamination was eliminated when at least 5 or 10 mg/mL of vancomycin was applied for 30 minutes in vitro. Rats in the vancomycin-soaked graft group (5 mg/mL of vancomycin for 30 minutes) showed no significant signs of infection and fewer positive cultures than did those without presoaking. The vancomycin-soaked graft group had reduced serum inflammatory markers, tissue scores, inflammatory reactions in the joint tissue, and radiographic evidence of periarticular osseous destruction compared with the control group. At postoperative week 12, the vancomycin-soaked graft group showed good outcomes in tendon-bone incorporation via micro-computed tomography, histologic staining, and biomechanical testing.

CONCLUSION

In a rat model of infection after ACLR, presoaking grafts in a 5-mg/mL vancomycin solution for 30 minutes could effectively prevent S. aureus contamination without affecting tendon-bone incorporation and knee function.

CLINICAL RELEVANCE

The present study could provide a specific solution for the use of vancomycin in the prevention of infection after ACLR clinically.

Vancomycin Soaking Is Highly Cost-Effective in Primary ACLR Infection Prevention: A Cost-Effectiveness Study

BACKGROUND

Although presoaking grafts in vancomycin has been demonstrated to be effective in observational studies for anterior cruciate ligament reconstruction (ACLR) infection prevention, the economic benefit of the technique is uncertain.

PURPOSE

To 1) determine the cost-effectiveness of vancomycin presoaking during primary ACLR to prevent postoperative joint infections and 2) to establish the break-even cost-effectiveness threshold of the technique and determine its cost-effectiveness across various international health care settings.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

A Markov model was used to determine cost-effectiveness and the incremental cost-effectiveness ratio of additional vancomycin presoaking compared with intravenous antibiotic prophylaxis alone. A repeated search of the PubMed, SCOPUS, and Cochrane Central Register of Controlled Trials databases, using the same criteria as a recent meta-analysis, was completed. A repeated meta-analysis of 9 cohort studies (level 3 evidence) was completed to determine the odds ratio of infection with vancomycin presoaking compared with intravenous antibiotics alone. Estimated costs of the vancomycin technique, treatment of infection, and further surgery were sourced from local hospitals and literature. Transitional probabilities for further surgery, including revision reconstruction and primary arthroplasty, were obtained from the literature. Probabilistic sensitivity analyses and a 1-way sensitivity analysis were performed to evaluate the ACLR infection rate break-even threshold for which the vancomycin technique would be no longer cost-effective.

RESULTS

The vancomycin soaking technique provides expected cost savings of $660 (USA), A$581 (Australia), and €226 (Spain) per patient. There was an improvement in the quality-adjusted life-years of 0.007 compared with intravenous antibiotic prophylaxis alone (4.297 vs 4.290). If the infection rate is below 0.014% with intravenous antibiotics alone, the vancomycin wrap would no longer be cost-effective.

CONCLUSION

The vancomycin presoaking technique is a highly cost-effective method to prevent postoperative septic arthritis after primary ACLR.

Anterior Cruciate Ligament Reconstruction: Is Biological Augmentation Beneficial?

Surgical reconstruction in anterior cruciate ligament (ACL) ruptures has proven to be a highly effective technique that usually provides satisfactory results. However, despite the majority of patients recovering their function after this procedure, ACL reconstruction (ACLR) is still imperfect. To improve these results, various biological augmentation (BA) techniques have been employed mostly in animal models. They include: (1) growth factors (bone morphogenetic protein, epidermal growth factor, granulocyte colony-stimulating factor, basic fibroblast growth factor, transforming growth factor-β, hepatocyte growth factor, vascular endothelial growth factor, and platelet concentrates such as platelet-rich plasma, fibrin clot, and autologous conditioned serum), (2) mesenchymal stem cells, (3) autologous tissue, (4) various pharmaceuticals (matrix metalloproteinase-inhibitor alpha-2-macroglobulin bisphosphonates), (5) biophysical/environmental methods (hyperbaric oxygen, low-intensity pulsed ultrasound, extracorporeal shockwave therapy), (6) biomaterials (fixation methods, biological coatings, biosynthetic bone substitutes, osteoconductive materials), and (7) gene therapy. All of them have shown good results in experimental studies; however, the clinical studies on BA published so far are highly heterogeneous and have a low degree of evidence. The most widely used technique to date is platelet-rich plasma. My position is that orthopedic surgeons must be very cautious when considering using PRP or other BA methods in ACLR.

Editorial Commentary: Is It Time for the Vancomycin Wrap to Become a Universal Recommendation for the Prevention of Septic Arthritis Following Anterior Cruciate Ligament Reconstruction?

Septic arthritis is a devastating complication of anterior cruciate ligament (ACL) reconstruction, which can still occur in approximately 1% of patients despite appropriate intravenous antibiotic prophylaxis and other recommended preventative measures being undertaken. The infection is most likely secondary to the autograft becoming contaminated during harvest and preparation, introducing bacteria into the joint on insertion. Presoaking ACL grafts in 5 mg/mL vancomycin is a novel method developed to eradicate this bacterial contamination and is supported by compelling Level III evidence from multiple observational trials showing a dramatic reduction in infection rates without any evidence of increased graft failure. As such, it is time for this technique to become a universal recommendation? That said, as observational studies using a historical cohort as a comparator are at risk of various biases, Level I evidence is ultimately required for infection prophylaxis methods to be recognized as a universal recommendation in infection control guidelines. Consequently, future research endeavors on the "vancomycin wrap" should focus on randomized controlled trials, possibly nested within ACL registries.