Use of Intrawound Antibiotics in Orthopaedic Surgery

[Translated article] Vancomycin powder in the prevention of infection in primary knee and hip arthroplasty: Case-control study with 1151 arthroplasties

BACKGROUND AND OBJECTIVE

Vancomycin powder (VP) has been positively used in spinal surgery to reduce the rate of infections. Hardly any data have been published on hip and knee joint replacement surgery, and its usefulness is questioned. Our objective was to investigate the effectiveness of VP in reducing prosthetic infection and its possible complications.

METHODS

Primary hip (THA) and knee (TKA) arthroplasties were reviewed, performed by five surgeons in one hospital centre, between 2017 and 2018. One gram of VP was used on the implant prior to surgical closure based on the surgeon's preferences. With a 5-year follow-up in which the infection rate and local complications were analysed.

RESULTS

One thousand one hundred and fifty-one arthroplasties were performed, 748 were TKA and 403 were THA. Nine patients were diagnosed with prosthetic infection, of which five received VP and four did not (p=0.555). Likewise, another 15 patients suffered wound complications, of which 11 received VP and 4 did not (p=0.412). There were no differences, either, in the rest of the complications depending on the use or not of VP (p=0.101). Likewise, the number of patients who needed reintervention was similar (p=0.999). No systemic complications were detected due to the use of VP.

CONCLUSIONS

It has not been possible to demonstrate that the use of VP reduces the rates of prosthetic infection in the hip and knee, so we cannot recommend its use.

Antibiotic-Coated Intramedullary Nailing Managing Long Bone Infected Non-Unions: A Meta-Analysis of Comparative Studies

Long bone infected non-unions are such an orthopedic challenge that antibiotic-coated intramedullary nailing (ACIN) has become a viable therapeutic option for their management. This study aims to provide a comprehensive assessment of the available data about the use of antibiotic-coated nailing in the treatment of long bone infected non-unions. Following the PRISMA guideline in this meta-analysis, a systematic literature search was conducted across major databases for studies evaluating ACIN in long bone infected non-unions. The primary outcome measures included union rates, infection control, complications and functional status. Five eligible studies encompassing 183 patients in total met the inclusion criteria. The meta-analysis revealed no difference in the union rate in the antibiotic-coated intramedullary nailing group compared to that of the control group (OR = 1.73 [0.75-4.02]). Antibiotic-coated intramedullary nailing demonstrated no association with higher infection eradication (OR = 2.10 [0.97-4.54]). Also, functional outcome measure was mostly not significantly different between ACIN and control interventions. According to this meta-analysis, compared to the management of controls, ACIN is neither linked to increased union rates nor decreased infection rates. The paucity of research on this topic emphasizes the continuous need for additional well-designed randomized controlled trials for the application of antibiotics-coated intramedullary nailing in long bone non-unions.

Vancomycin powder in the prevention of infection in primary knee and hip arthroplasty: Case-control study with 1151 arthroplasties

BACKGROUND AND OBJECTIVE

Vancomycin powder (VP) has been positively used in spinal surgery to reduce the rate of infections. Hardly any data have been published on hip and knee joint replacement surgery, and its usefulness is questioned. Our objective was to investigate the effectiveness of VP in reducing prosthetic infection and its possible complications.

METHODS

Primary hip (THA) and knee (TKA) arthroplasties were reviewed, performed by five surgeons in one hospital center, between 2017 and 2018. 1g of VP was used on the implant prior to surgical closure based on the surgeon's preferences. With a 5-year follow-up in which the infection rate and local complications were analyzed.

RESULTS

One thousand one hundred and fifty one arthroplasties were performed, 748 were TKA and 403 were THA. Nine patients were diagnosed with prosthetic infection, of which five received VP and four did not (P=.555). Likewise, another 15 patients suffered wound complications, of which 11 received VP and 4 did not (P=.412). There were no differences, either, in the rest of the complications depending on the use or not of VP (P=.101). Likewise, the number of patients who needed reintervention was similar (P=.999). No systemic complications were detected due to the use of VP.

CONCLUSIONS

It has not been possible to demonstrate that the use of VP reduces the rates of prosthetic infection in the hip and knee, so we cannot recommend its use.

Immunomodulatory biomaterials for implant-associated infections: from conventional to advanced therapeutic strategies

Implant-associated infection (IAI) is increasingly emerging as a serious threat with the massive application of biomaterials. Bacteria attached to the surface of implants are often difficult to remove and exhibit high resistance to bactericides. In the quest for novel antimicrobial strategies, conventional antimicrobial materials often fail to exert their function because they tend to focus on direct bactericidal activity while neglecting the modulation of immune systems. The inflammatory response induced by host immune cells was thought to be a detrimental force impeding wound healing. However, the immune system has recently received increasing attention as a vital player in the host's defense against infection. Anti-infective strategies based on the modulation of host immune defenses are emerging as a field of interest. This review explains the importance of the immune system in combating infections and describes current advanced immune-enhanced anti-infection strategies. First, the characteristics of traditional/conventional implant biomaterials and the reasons for the difficulty of bacterial clearance in IAI were reviewed. Second, the importance of immune cells in the battle against bacteria is elucidated. Then, we discuss how to design biomaterials that activate the defense function of immune cells to enhance the antimicrobial potential. Based on the key premise of restoring proper host-protective immunity, varying advanced immune-enhanced antimicrobial strategies were discussed. Finally, current issues and perspectives in this field were offered. This review will provide scientific guidance to enhance the development of advanced anti-infective biomaterials.

Strategies to improve bioactive and antibacterial properties of polyetheretherketone (PEEK) for use as orthopedic implants

Polyetheretherketone (PEEK) has gradually become the mainstream material for preparing orthopedic implants due to its similar elastic modulus to human bone, high strength, excellent wear resistance, radiolucency, and biocompatibility. Since the 1990s, PEEK has increasingly been used in orthopedics. Yet, the widespread application of PEEK is limited by its bio-inertness, hydrophobicity, and susceptibility to microbial infections. Further enhancing the osteogenic properties of PEEK-based implants remains a difficult task. This article reviews some modification methods of PEEK in the last five years, including surface modification of PEEK or incorporating materials into the PEEK matrix. For surface modification, PEEK can be modified by chemical treatment, physical treatment, or surface coating with bioactive substances. For PEEK composite material, adding bioactive filler into PEEK through the melting blending method or 3D printing technology can increase the biological activity of PEEK. In addition, some modification methods such as sulfonation treatment of PEEK or grafting antibacterial substances on PEEK can enhance the antibacterial performance of PEEK. These strategies aim to improve the bioactive and antibacterial properties of the modified PEEK. The researchers believe that these modifications could provide valuable guidance on the future design of PEEK orthopedic implants.

Do Intrawound Antibiotics Reduce the Incidence of Surgical Site Infections in Pelvic and Lower-Limb Trauma Surgery? A Systematic Review and Meta-analysis

OBJECTIVES

To analyze the efficacy of intraoperative topical antibiotics in reducing the incidence of postoperative surgical site infections in pelvic and lower-limb trauma orthopaedic surgery.

DATA SOURCES

A search of Ovid MEDLINE, PubMed, and Embase was conducted for English language studies published from 1946 through September 3, 2021, using relevant keywords.

STUDY SELECTION

Included studies were randomized controlled trials, cohort studies, or case-control studies reporting on the rate of surgical site infections in adult patients (age 16 and older) who underwent surgical fixation of lower-limb or pelvic traumatic fractures, including both open and closed fractures, with topical intraoperative antibiotics applied to the surgical site before wound closure.

DATA EXTRACTION

Studies were evaluated using the Joanna Briggs Institute Critical Appraisal Checklist for analytical cross-sectional studies. The risk of bias was assessed using the ROBINS-I and Cochrane risk-of-bias tools.

DATA SYNTHESIS

A meta-analysis was conducted using the inverse variance method and random-effects model to assess effect significance and study heterogeneity.

CONCLUSIONS

Seven studies were included in the systematic review. Results of the meta-analysis suggested a potential 23% reduction in the odds of developing a deep surgical site infection in patients treated with intraoperative antibiotic powder compared with those managed with intravenous antibiotics alone (odds ratio 0.77, 95% confidence interval 0.52-1.13), although the results did not reach statistical significance. Further powered studies including randomized controlled trials would be of great value to validate the results suggested in this study and inform best practice intraoperative antibiotic prophylaxis in pelvic and lower-limb trauma surgery.

LEVEL OF EVIDENCE

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

Antibiotic-loaded Bone Cement Combined with Vacuum-assisted Closure Facilitating Wound Healing in Wagner 3-4 Diabetic Foot Ulcers

This study explored the clinical effectiveness of antibiotic-loaded bone cement (ALBC) combined with vacuum-assisted closure (VAC) on the treatment of Wagner 3-4 diabetic foot ulcers (DFUs). This is a retrospective study, including 32 patients with Wagner 3-4 DFUs who had undergone treatment between August 2019 and June 2021. Patient age, sex, Hemoglobin A1c (HbA1c), body mass index (BMI), ankle brachial index (ABI), white blood cells (WBC), C-reactive protein (CRP) levels, comorbidities and wound closure methods were recorded. Patients were divided into the study group and control group according to the treatment modality. Patients in the study group received the combination treatment of ALBC and VAC, while patients in the control group received single VAC treatment. Clinical endpoints were assessed and compared between the two groups, including wound complete healing time and complications after operation. All patients were followed-up 6 months postoperation. Results showed that the mean healing time of the study group (44.20 ± 16.72 days) was shorter than that of the control group (64.00 ± 29.85 days) (P < .05). The infection rate of the study group on the 10th day postoperation was lower than that of the control group (6.67%, 47.06%, P < .05). And there were no significant statistical differences between the two groups in terms of bleeding and necrosis complications postoperation (P = .603, P = .603). Based on the findings, we conclude that the application of ALBC combined with VAC can facilitate wound healing in Wagner 3-4 DFUs patients. It can help to control wound infections and shorten wound healing time.

Connections between Orthopedic Conditions and Oxidative Stress: Current Perspective and the Possible Relevance of Other Factors, Such as Metabolic Implications, Antibiotic Resistance, and COVID-19

The general opinion in the literature is that these topics remain clearly understudied and underrated, with many unknown aspects and with controversial results in the respective areas of research. Based on the previous experience of our groups regarding such matters investigated separately, here we attempt a short overview upon their links. Thus, we summarize here the current state of knowledge regarding the connections between oxidative stress and: (a) orthopedic conditions; (b) COVID-19. We also present the reciprocal interferences among them. Oxidative stress is, of course, an interesting and continuously growing area, but what exactly is the impact of COVID-19 in orthopedic patients? In the current paper we also approached some theories on how oxidative stress, metabolism involvement, and even antibiotic resistance might be influenced by either orthopedic conditions or COVID-19. These manifestations could be relevant and of great interest in the context of this current global health threat; therefore, we summarize the current knowledge and/or the lack of sufficient evidence to support the interactions between these conditions.

An Additively Manufactured Sample Holder to Measure the Controlled Release of Vancomycin from Collagen Laminates

The controlled release of antibiotics prevents the spread of pathogens and thereby improves healing processes in regenerative medicine. However, high concentrations may interfere with healing processes. It is therefore advantageous to use biodegradable materials for a controlled release. In particular, multilayer materials enable differential release at different surfaces. For this purpose, collagen sheets of different properties can be bonded by photochemical crosslinking. Here, we present the development and application of an easily accessible, additively manufactured sample holder to study the controlled release of vancomycin from modularly assembled collagen laminates in two directions. As proof-of-concept, we show that laminates of collagen sheets covalently linked by rose bengal and green light crosslinking (RGX) can be tightly inserted into the device without leakage from the upper to lower cavity. We used this sample holder to detect the release of vancomycin from symmetrically and asymmetrically loaded two-layer and three-layer collagen laminates into the upper and lower cavity of the sample holder. We show that these collagen laminates are characterized by a collagen type-dependent vancomycin release, enabling the control of antibiotic release profiles as well as the direction of antibiotic release.

Infection after primary total knee arthroplasty: a randomized controlled prospective study of the addition of antibiotics to bone cement

Objective  The present prospective, randomized and controlled study was conducted with 286 patients submitted to primary total knee arthroplasty (TKA) with the objective of evaluating the efficacy of the addition of antibiotics to bone cement as a way to prevent post arthroplasty infection (PAI).

Methods  The patients were randomized into two groups: bone cement without antibiotic (No ATB, n  = 158) or cement with antibiotic (ATB, n  = 128), in which 2 g of vancomycin was added to 40 g of cement. The patients were followed up for 24 months after surgery.

Results  Regarding preoperative demographic data, the distribution of patients between groups was homogeneous ( p  < 0.05). In the 24-month period, the overall infection rate was of 2.09% (6/286), with no difference (odds ratio [OR] = 1.636; 95% confidence interval [CI]: 0.294–9.080; p  = 0.694) between the ATB group (1.56%; 2/128) and the No ATB group (2.53%; 4/158). In the No ATB group, the infection was caused by methicillin-resistant Staphylococcus aureus (MRSA) ( n  = 2), methicillin-sensitive S. aureus (MSSA) ( n  = 1) and Eschirichia coli ( n  = 1). Proteus mirabilis and MSSA were isolated from patients in the ATB group. Among the comorbidities, all patients with PAI were hypertensive and nondiabetic. Two rheumatoid arthritis patients who developed PAI were from the ATB group.

Conclusion  The use of cement with ATB reduced the absolute number of infections, but without statistical difference between the groups; thus, routine use should not be encouraged.

Effect of Vancomycin Soaking on Anterior Cruciate Ligament Graft Biomechanics

PURPOSE

To evaluate the effect of soaking of anterior cruciate ligament (ACL) grafts in vancomycin solution on graft biomechanical properties at the time of implantation.

METHODS

The central third of patellar tendons was harvested from mature bovine knees and prepared as a tendon-only graft or a bone-tendon-bone (BTB) graft. Tendons were wrapped in gauze soaked in vancomycin solution (VS) (5 mg/mL) or normal saline (NS) and left to stand for 30 minutes at room temperature, simulating graft exposure times in the operating room during ACL reconstruction. Tensile testing was carried out on a materials testing system with (1) low-magnitude loading (60 N at 3 mm/s) with repeated testing of tendon-only grafts; and (2) high-magnitude loading (600 N at 10 mm/min) of BTB grafts. For tendon-only grafts, specimens were first wrapped in NS-soaked gauze and underwent testing, with repeated testing performed after wrapping in gauze soaked in VS or buffered VS (pH 7.0). For BTB grafts, specimens were randomly assigned to treatment with VS or NS.

RESULTS

For tendon-only grafts, there was no difference in Young's modulus (YM) after soaking with VS soaking (baseline, 12.69 MPa; treatment, 16.07 ± 4.44 MPa; P = .99) or buffered VS (baseline, 12.45 ± 4.55 MPa; treatment, 15.56 ± 2.83 MPa; P = .99). For BTB grafts, there were no differences in elongation strain (VS, 46.8% ± 7.0%; NS, 31.5% ± 13.5%, P = .19) or YM (VS, 158.4 ± 15.8 MPa; NS, 158.5 ± 23.3 MPa, P = .99).

CONCLUSIONS

According to controlled biomechanical tests, vancomycin soaking of patellar tendon grafts does not adversely affect time-zero material properties.

CLINICAL RELEVANCE

This study suggests that vancomycin wrapping has no immediate adverse effects on the biomechanical properties of ACL grafts. Randomized controlled trials are warranted to validate the widespread use of vancomycin soaking of tendon grafts for infection prophylaxis during ACL reconstruction.

Efficacy and safety of intrawound vancomycin in primary hip and knee arthroplasty

Aims

The efficacy and safety of intrawound vancomycin for preventing surgical site infection in primary hip and knee arthroplasty is uncertain.

Methods

A systematic review of the literature was conducted, indexed from inception to March 2020 in PubMed, Web of Science, Cochrane Library, Embase, and Google Scholar databases. All studies evaluating the efficacy and/or safety of intrawound vancomycin in patients who underwent primary hip and knee arthroplasty were included. Incidence of periprosthetic joint infection (PJI), superficial infection, aseptic wound complications, acute kidney injury, anaphylactic reaction, and ototoxicity were meta-analyzed. Results were reported as odds ratios (ORs) and 95% confidence intervals (CIs). The quality of included studies was assessed using the risk of bias in non-randomized studies of interventions (ROBINS-I) assessment tool.

Results

Nine studies involving 4,607 patients were included. Intrawound vancomycin was associated with lower incidence of PJI (30 patients (1.20%) vs 58 control patients (2.75%); OR 0.44, 95% CI 0.28 to 0.69) and simultaneous acute kidney injury (four patients (0.28%) vs four control patients (0.35%), OR 0.71, 95% CI 0.19 to 2.55). However, it did not reduce risk of superficial infection (four patients (0.67%) vs six control patients (1.60%), OR 0.60, 95% CI 0.17 to 2.12) and was associated with higher incidence of aseptic wound complications (23 patients (2.15%) vs eight in control patients (0.96%), OR 2.39, 95% CI 1.09 to 5.23). Four studies reported no anaphylactic reactions and three studies reported no ototoxicity in any patient group.

Conclusion

The current literature suggests that intrawound vancomycin used in primary hip and knee arthroplasty may reduce incidence of PJI, but it may also increase risk of aseptic wound complications.

Cite this article: Bone Joint Res 2020;9(11):778–788.

The application of ceragenins to orthopedic surgery and medicine

Osteomyelitis and infections associated with orthopedic implants represent a significant burden of disease worldwide. Ceragenins (CSAs) are a relatively new class of small-molecule antimicrobials that target a broad range of Gram-positive and Gram-negative bacteria as well as fungi, viruses, and parasites. This review sets the context of the need for new antimicrobial strategies by cataloging the common pathogens associated with orthopedic infection and highlighting the increasing challenges of managing antibiotic-resistant bacterial strains. It then comparatively describes the antimicrobial properties of CSAs with a focus on the CSA-13 family. More recently developed members of this family such as CSA-90 and CSA-131 may have a particular advantage in an orthopedic setting as they possess secondary pro-osteogenic properties. In this context, we consider several new preclinical studies that demonstrate the utility of CSAs in orthopedic models. Emerging evidence suggests that CSAs are effective against antibiotic-resistant Staphylococcus aureus strains and can prevent the formation of biofilms. There remains considerable scope for developing CSA-based treatments, either as coatings for orthopedic implants or as local or systemic antibiotics to prevent bone infection.

Antimicrobial activity of mesenchymal stem cells against Staphylococcus aureus

Introduction

There have been limited advances in the treatment of bone and joint infections, which currently involves a combination of surgery and antibiotic administration. There is a timely need in orthopedics to develop more effective and less invasive forms of antimicrobial prophylaxis and treatment. The antibacterial effect of adult tissue-derived mesenchymal stem cells (MSCs) has recently been investigated against Escherichia coli and Staphylococcus aureus. The main mechanism of action is postulated to be via MSC production of the cationic antimicrobial peptide, LL-37.

Methods

This study examines the antimicrobial activity of adipose-derived human MSCs (ASCs) on S. aureus, specifically examining the role of LL-37 and regulation of its expression. Bacteria colony-forming unit (CFU) assay was used to assess antimicrobial activity.

Results

Our results showed that the ASC-conditioned medium significantly inhibited the growth of S. aureus under standard culture conditions with or without the continued presence of ASCs. Also, the treatment of ASCs with 1,25-dihydroxy vitamin D₃ elevated LL-37 expression and enhanced their antimicrobial activity. In support, treatment with the vitamin D receptor inhibitor, GW0742, blocked the antimicrobial activity of ASCs.

Conclusion

Our findings clearly demonstrate the antimicrobial activity of adult ASCs against S. aureus and implicate a key regulatory role for vitamin D. Further testing in in vivo models is being pursued to assess the potential application of ASCs as a biocompatible, adjunct treatment for musculoskeletal infections.

Prevention of Prosthetic Joint Infection: From Traditional Approaches towards Quality Improvement and Data Mining

A projected increased use of total joint arthroplasties will naturally result in a related increase in the number of prosthetic joint infections (PJIs). Suppression of the local peri-implant immune response counters efforts to eradicate bacteria, allowing the formation of biofilms and compromising preventive measures taken in the operating room. For these reasons, the prevention of PJI should focus concurrently on the following targets: (i) identifying at-risk patients; (ii) reducing “bacterial load” perioperatively; (iii) creating an antibacterial/antibiofilm environment at the site of surgery; and (iv) stimulating the local immune response. Despite considerable recent progress made in experimental and clinical research, a large discrepancy persists between proposed and clinically implemented preventative strategies. The ultimate anti-infective strategy lies in an optimal combination of all preventative approaches into a single “clinical pack”, applied rigorously in all settings involving prosthetic joint implantation. In addition, “anti-infective” implants might be a choice in patients who have an increased risk for PJI. However, further progress in the prevention of PJI is not imaginable without a close commitment to using quality improvement tools in combination with continual data mining, reflecting the efficacy of the preventative strategy in a particular clinical setting.

Topical rifampicin for prevention of deep sternal wound infections in patients undergoing coronary artery bypass grafting

Deep sternal wound infections (DSWI), although an infrequent complication, significantly impair postoperative outcomes after coronary artery bypass grafting (CABG) surgery. Among several preventive strategies, topical antibiotic therapy immediately before sternal closure has been strongly advocated. In this retrospective analysis, the incidence of DSWI in 517 patients undergoing isolated CABG and receiving rifampicin irrigation of mediastinum, sternum and suprasternal tissues was compared to an historical consecutive cohort of 448 patients. To account for the inherent selection bias, a 1:1 propensity matched analysis was performed. Patients receiving topical rifampicin experienced significantly less occurrence of postoperative DSWI (0.2% vs 2.5%, p = 0.0016 in the unmatched analysis; 0.3% vs 2.1%, p = 0.0391 in the matched analysis). Intensive care unit stay, hospital stay, and operative mortality were similar between groups. This study shows that topical rifampicin in combination with commonly prescribed preventative strategies significantly reduces the incidence of DSWI to less than 0.3% in unselected patients undergoing a full median sternotomy for CABG. Further studies, including a larger number of patients and with a randomization design, would establish the potential preventative role of topical rifampicin in reducing the occurrence of DSWI.

Systematic Review and Meta-Analysis of Intrawound Vancomycin in Total Hip and Total Knee Arthroplasty: A Call for a Prospective Randomized Trial

BACKGROUND

Topical intrawound vancomycin has been used extensively in spine surgery to decrease surgical site infections. However, the efficacy of intrawound vancomycin in total hip (THA) and total knee arthroplasty (TKA) to prevent periprosthetic joint infection (PJI) has not been established.

METHODS

The PubMed and MEDLINE databases were searched to identify studies utilizing intrawound vancomycin in primary and revision THA and TKA. Data for postoperative infection were pooled using random effect models with results reported as odds ratios (ORs) and 95% confidence intervals. Studies were weighted by the inverse variance of their effect estimates.

RESULTS

Of the 91 studies identified, 6 low-quality retrospective studies (level III) were pooled for further analysis. A total of 3298 patients were assessed, 1801 of which were treated with intrawound vancomycin. Overall, patients who received vancomycin had a decreased rate of PJI (OR 0.2530, P < .0001). When analyzed separately, TKA patients and THA patients who received intrawound vancomycin had lower rates of PJI (OR 0.3467, P = .0005 and OR 0.3672, P = .0072, respectively). Pooled primary TKA and THA patients receiving vancomycin saw the rate of PJI decrease (OR 0.4435, P = .0046). Pooled revision TKA and THA patients saw a similar decrease in infection rates (OR 0.2818, P = .0013). No apparent publication bias was observed; however, the results from this analysis are limited by the low quality of evidence and inherent potential for bias.

CONCLUSION

Intrawound vancomycin may reduce the risk of PJI in primary and revision TKA and THA. However, only low-quality evidence exists, highlighting the need for randomized controlled trials before broad adoption of this practice can be recommended given the potential implications of widespread use of vancomycin in hip and knee arthroplasty.