Implant contamination as a cause of surgical site infection in spinal surgery: are single-use implants a reasonable solution? - a systematic review

Does Reusable Instrumentation for Four-Anchor Rotator Cuff Repair Offer Decreased Waste Disposal Costs and Lower Waste-Related Carbon Emissions?

INTRODUCTION

Orthopaedic surgery is culpable, in part, for the excessive carbon emissions in health care partly due to the utilization of disposable instrumentation in most procedures, such as rotator cuff repair (RCR). To address growing concerns about hospital waste, some have considered replacing disposable instrumentation with reusable instrumentation. The purpose of this study was to estimate the cost and carbon footprint of waste disposal of RCR kits that use disposable instrumentation compared with reusable instrumentation.

METHODS

The mass of the necessary materials and their packaging to complete a four-anchor RCR from four medical device companies that use disposable instrumentation and one that uses reusable instrumentation were recorded. Using the cost of medical waste disposal at our institution ($0.14 per kilogram) and reported values from the literature for carbon emissions produced from the low-temperature incineration of noninfectious waste (249 kgCO2e/t) and infectious waste (569 kgCO2e/t), we estimated the waste management cost and carbon footprint of waste disposal produced per RCR kit.

RESULTS

The disposable systems of four commercial medical device companies had 783%, 570%, 1,051%, and 478%, respectively, greater mass and waste costs when compared with the reusable system. The cost of waste disposal for the reusable instrumentation system costs on average $0.14 less than the disposable instrumentation systems. The estimated contribution to the overall carbon footprint produced from the disposal of a RCR kit that uses reusable instrumentation was on average 0.37 kg CO2e less than the disposable instrumentation systems.

CONCLUSION

According to our analysis, reusable instrumentation in four-anchor RCR leads to decreased waste and waste disposal costs and lower carbon emissions from waste disposal. Additional research should be done to assess the net benefit reusable systems may have on hospitals and the effect this may have on a long-term decrease in carbon footprint.

LEVEL OF EVIDENCE

Level II.

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

The incidence of microbial infections in orthopedic prosthetic surgeries is a perennial problem that increases morbidity and mortality, representing one of the major complications of such medical interventions. The emergence of novel technologies, especially 3D printing, represents a promising avenue of development for reducing the risk of such eventualities. There are already a host of biomaterials, suitable for 3D printing, that are being tested for antimicrobial properties when they are coated with bioactive compounds, such as antibiotics, or combined with hydrogels with antimicrobial and antioxidant properties, such as chitosan and metal nanoparticles, among others. The materials discussed in the context of this paper comprise beta-tricalcium phosphate (β-TCP), biphasic calcium phosphate (BCP), hydroxyapatite, lithium disilicate glass, polyetheretherketone (PEEK), poly(propylene fumarate) (PPF), poly(trimethylene carbonate) (PTMC), and zirconia. While the recent research results are promising, further development is required to address the increasing antibiotic resistance exhibited by several common pathogens, the potential for fungal infections, and the potential toxicity of some metal nanoparticles. Other solutions, like the incorporation of phytochemicals, should also be explored. Incorporating artificial intelligence (AI) in the development of certain orthopedic implants and the potential use of AI against bacterial infections might represent viable solutions to these problems. Finally, there are some legal considerations associated with the use of biomaterials and the widespread use of 3D printing, which must be taken into account.

Nanostructured Coatings Based on Graphene Oxide for the Management of Periprosthetic Infections

To modulate the bioactivity and boost the therapeutic outcome of implantable metallic devices, biodegradable coatings based on polylactide (PLA) and graphene oxide nanosheets (nGOs) loaded with Zinforo™ (Zin) have been proposed in this study as innovative alternatives for the local management of biofilm-associated periprosthetic infections. Using a modified Hummers protocol, high-purity and ultra-thin nGOs have been obtained, as evidenced by X-ray diffraction (XRD) and transmission electron microscopy (TEM) investigations. The matrix-assisted pulsed laser evaporation (MAPLE) technique has been successfully employed to obtain the PLA-nGO-Zin coatings. The stoichiometric and uniform transfer was revealed by infrared microscopy (IRM) and scanning electron microscopy (SEM) studies. In vitro evaluation, performed on fresh blood samples, has shown the excellent hemocompatibility of PLA-nGO-Zin-coated samples (with a hemolytic index of 1.15%), together with their anti-inflammatory ability. Moreover, the PLA-nGO-Zin coatings significantly inhibited the development of mature bacterial biofilms, inducing important anti-biofilm efficiency in the as-coated samples. The herein-reported results evidence the promising potential of PLA-nGO-Zin coatings to be used for the biocompatible and antimicrobial surface modification of metallic implants.

In Vivo Prevention of Implant-Associated Infections Caused by Antibiotic-Resistant Bacteria through Biofunctionalization of Additively Manufactured Porous Titanium

Additively manufactured (AM) porous titanium implants may have an increased risk of implant-associated infection (IAI) due to their huge internal surfaces. However, the same surface, when biofunctionalized, can be used to prevent IAI. Here, we used a rat implant infection model to evaluate the biocompatibility and infection prevention performance of AM porous titanium against bioluminescent methicillin-resistant Staphylococcus aureus (MRSA). The specimens were biofunctionalized with Ag nanoparticles (NPs) using plasma electrolytic oxidation (PEO). Infection was initiated using either intramedullary injection in vivo or with in vitro inoculation of the implant prior to implantation. Nontreated (NT) implants were compared with PEO-treated implants with Ag NPs (PT-Ag), without Ag NPs (PT) and infection without an implant. After 7 days, the bacterial load and bone morphological changes were evaluated. When infection was initiated through in vivo injection, the presence of the implant did not enhance the infection, indicating that this technique may not assess the prevention but rather the treatment of IAIs. Following in vitro inoculation, the bacterial load on the implant and in the peri-implant bony tissue was reduced by over 90% for the PT-Ag implants compared to the PT and NT implants. All infected groups had enhanced osteomyelitis scores compared to the noninfected controls.

Sustainable surgical practices: A comprehensive approach to reducing environmental impact

This paper presents a comprehensive overview of the environmental impact of surgical procedures and highlights potential strategies to reduce the associated greenhouse gas emissions. We discuss procurement, waste management, and energy consumption, providing examples of successful interventions in each area. We also emphasize the importance of adopting the Green Theatre Checklist as a useful tool for clinicians aiming to implement sustainable surgical practices.

Guidelines for improvement of the procedural aspects of devices and surgical instruments in the operating theatre

Surgical site infections are a major complication for patients undergoing surgical treatment and a significant cause of mortality and morbidity. Many international guidelines suggest measures for the prevention of surgical site infections (SSI) in perioperative processes and the decontamination of surgical devices and instruments. This document proposes guidelines for improving the perioperative setting in view of the devices and instrumentation required for surgical procedures, aiming to reduce contamination rates and improve clinical performance and management for patients undergoing surgical treatment. This document is intended for doctors, nurses and other practitioners involved in operating theatre procedures, resource management and clinical risk assessment processes, and the procurement, organisation, sterilisation and reprocessing of surgical instruments.

The Environmental Impact of Spine Surgery and the Path to Sustainability

STUDY DESIGN

Narrative literature review.

OBJECTIVE

The aim of this study was to review published literature discussing sustainable health care and to identify aspects that pertain to spine surgery.

SUMMARY OF BACKGROUND DATA

In recent years, research has investigated the contribution of surgical specialties to climate change. To our knowledge, no article has yet been published discussing the impact specific to spinal procedures and possible mitigation strategies.

METHODS

A literature search was performed for the present study on relevant terms across four electronic databases. References of included studies were also investigated.

RESULTS

Spine surgery has a growing environmental impact. Investigations of analogous specialties find that procurement is the single largest source of emissions. Carbon-conscious procurement strategies will be needed to mitigate this fully, but clinicians can best reduce their impact by adopting a minimalist approach when using surgical items. Reduced wastage of disposable goods and increased recycling are beneficial. Technology can aid remote access to clinicians, and also enable patient education.

CONCLUSIONS

Spine-surgery-specific research is warranted to evaluate its carbon footprint. A broad range of measures is recommended from preventative medicine to preoperative, intraoperative, and postoperative spine care.

LEVEL OF EVIDENCE

5.

Prevention of surgical site infection: a ten-step approach

Surgical site infection (SSI) is a common cause of morbidity and mortality in patients undergoing surgery. Similarly, periprosthetic joint infection (PJI), is a major cause of failure after total joint arthroplasty (TJA). As the annual volume of TJA procedures is projected to rise, so will the rate of subsequent SSI and PJI. Currently, prevention has been identified as the single most important strategy for combating SSI/PJI. Hence, the present article will serve as a summary of an evidence-based ten-step approach for SSI/PJI prevention that may help orthopedic surgeons with their infection prevention strategies.

Can Steam Sterilization Affect the Accuracy of Point-of-Care 3D Printed Polyetheretherketone (PEEK) Customized Cranial Implants? An Investigative Analysis

Polyetheretherketone (PEEK) has become the biomaterial of choice for repairing craniofacial defects over time. Prospects for the point-of-care (POC) fabrication of PEEK customized implants have surfaced thanks to the developments in three-dimensional (3D) printing systems. Consequently, it has become essential to investigate the characteristics of these in-house fabricated implants so that they meet the necessary standards and eventually provide the intended clinical benefits. This study aimed to investigate the effects of the steam sterilization method on the dimensional accuracy of POC 3D-printed PEEK customized cranial implants. The objective was to assess the influence of standard sterilization procedures on material extrusion-based 3D-printed PEEK customized implants with non-destructive material testing. Fifteen PEEK customized cranial implants were fabricated using an in-house material extrusion-based 3D printer. After fabrication, the cranial implants were digitalized with a professional-grade optical scanner before and after sterilization. The dimensional changes for the 3D-printed PEEK cranial implants were analyzed using medically certified 3D image-based engineering software. The material extrusion 3D-printed PEEK customized cranial implants displayed no statistically significant dimensional difference with steam sterilization (p > 0.05). Evaluation of the cranial implants’ accuracy revealed that the dimensions were within the clinically acceptable accuracy level with deviations under 1.00 mm. Steam sterilization does not significantly alter the dimensional accuracy of the in-house 3D-printed PEEK customized cranial implants.

Optimisation of perioperative procedural factors to reduce the risk of surgical site infection in patients undergoing surgery: a systematic review

Surgical site infections (SSI) are the leading cause of hospital readmission after surgical procedures with significant impact on post-operative morbidity and mortality. Modifiable risk factors for SSI include procedural aspects, which include the possibility of instrument contamination, the duration of the operation, the number of people present and the traffic in the room and the ventilation system of the operating theatre.The aim of this systematic review was to provide literature evidence on the relationship between features of surgical procedure sets and the frequency of SSI in patients undergoing surgical treatment, and to analyse how time frames of perioperative processes and operating theatre traffic vary in relation to the features of the procedure sets use, in order tooptimise infection control in OT. The results of the systematic review brought to light observational studies that can be divided into two categories: evidence of purely clinical significance and evidence of mainly organisational, managerial and financial significance. These two systems are largely interconnected, and reciprocally influence each other. The decision to use disposable devices and instruments has been accompanied by a lower incidence in surgical site infections and surgical revisions for remediation. A concomitant reduction in post-operative functional recovery time has also been observed. Also, the rationalisation of traditional surgical sets has also been observed in conjunction with outcomes of clinical significance.

Prevalence of Bacterial Burden on Macroscopic Contaminants of Orthopaedic Surgical Instruments Following Sterilization

BACKGROUND

Macroscopic contamination of orthopaedic instruments with particulates, including cortical bone and polymethyl methacrylate (PMMA) cement, having previously undergone preoperative sterilization, is frequently encountered peri- or intraoperatively, calling into question the sterility of such instruments.

AIM

The purpose of this study is to determine if macroscopic contaminants of orthopaedic surgical instrumentation maintain a bacterial burden following sterile processing. Additionally, this manuscript looks to determine the most commonly contaminated instruments and what the most common contaminants are.

METHODS

At a single tertiary referral centre, we prospectively collected available macroscopic contaminants in orthopaedic instrument trays over a six month period from August 2021 to May 2022. When identified, these specimens were swabbed and plated on sheep blood agar. All specimens were incubated at 37°C for 14 days, and visually inspected for colony formation. When bacterial colony formation was identified, samples were sent for species identification.

RESULTS

A total of 33 contaminants were tested, with only one contaminant growing bacterial colonies which was found to be Corynebacterium. The items most commonly found to have macroscopic contamination were surgical trays (9) and cannulated drills. The identifiable contaminants were bone (10), PMMA bone cement (4), and hair (4). There were 11 macroscopic contaminants that were not identifiable.

CONCLUSION

This study found that 97% of macroscopic orthopaedic surgical instrument contaminants that underwent sterile processing did not possess a bacterial burden. Contaminants discovered during a procedure are likely to be sterile and do not pose a substantially increased risk of infection to a patient.

Is Iatrogenic Implant Contamination Preventable Using a 16-Step No-Touch Protocol?

BACKGROUND

Intraoperative contamination of the surgical field during aesthetic breast augmentation may lead to implant infection with devastating consequences. This study covers a period of 30 years and is divided into 2 phases: a retrospective phase from 1992-2004 when a standard approach was used and a prospective phase from 2004-2022 when a no-touch approach was implemented to avoid contamination.

METHODS

Patients in the standard and no-touch groups underwent aesthetic breast augmentation by the same senior surgeon (FDP) in the same outpatient surgical facility during the 30-year period of the study. Patients are divided into 2 groups: from 1992-2004 and from the implementation of the no-touch protocol in 2004-2022.

RESULTS

Patients who underwent breast augmentation using the no-touch approach developed no infections, whereas the standard group had an infection rate of 3.54% (P = .017). The validity of this finding is discussed.

CONCLUSIONS

The no-touch approach as described in this article was effective in reducing implant infection rate when performing aesthetic breast augmentation by 1 surgeon at 1 surgical center during an 18-year observation period. Multicenter prospective cooperative studies are necessary to validate perioperative iatrogenic contamination as the cause of implant infection and to explore optimal approaches that could eliminate implant contamination.

Postoperative Spinal Implant Infections (PSII)-A Systematic Review: What Do We Know So Far and What is Critical About It?

STUDY DESIGN

Systematic review.

OBJECTIVES

Postoperative spinal implant infections (PSII) are an increasing challenge in the daily clinical routine. This review summarizes existing knowledge in the field of PSII, including definitions, epidemiology, classifications, risk factors, pathogenesis, symptoms, diagnosis, and treatment.

METHODS

A systematic review was performed using a structured PubMed analysis, based on the PRISMA criteria. The search terminology was set as: "spinal implant associated infection OR spinal implant infection OR spinal instrumentation infection OR peri spinal implant infection." PubMed search was limited to the categories randomized controlled trials (RCT), clinical trials, meta-analysis and (systematic) reviews, whereas case reports were excluded. Studies from January 2000 to December 2020 were considered eligible. A total of 572 studies were identified, 82 references included for qualitative synthesis, and 19 for detailed sub analysis (12 meta-analysis, 7 prospective RCT).

RESULTS

Structural problems in the field of PSII were revealed, including (1) limited level of evidence in clinical studies (missing prospective RCT, metanalyzes), (2) small patient numbers, (3) missing standardized definitions, (4) heterogeneity in patient groups, and (5) redundancy in cited literature.

CONCLUSION

Evidence-based knowledge about spinal implant-associated infections is lacking. All involved medical fields should come together to define the term PSII and to combine their approaches toward research, training, and patient care.

Instrument tables equipped with local unidirectional airflow units reduce bacterial contamination during orthopedic implant surgery in an operating room with a displacement ventilation system

Background

Airborne bacteria present in the operating room may be a cause of surgical site infection, either contaminating the surgical wound directly, or indirectly via e.g. surgical instruments. The aim of this study was to evaluate if instrument and assistant tables equipped with local unidirectional airflow reduce bacterial contamination of the instrument area to ultra clean levels, during orthopedic implant surgery in an operating room with displacement ventilation.

Methods

Local airflow units of instrument and assistant tables were either active or inactive. Colony forming units were sampled intraoperatively from the air above the instruments and from instrument dummies. A minimum of three air samples and two-three samples from instrument dummies were taken during each surgery. Samples were incubated on agar for total aerobic bacterial count. The mean air and instrument contamination during each surgery was calculated and used to analyze the difference in contamination depending on use of local airflow or not. All procedures were performed in the same OR.

Results

188 air and 124 instrument samples were collected during 48 orthopedic implant procedures. Analysis showed that local unidirectional airflow above the surgical instruments significantly reduced the bacterial count in the air above assistant table (P<0.001) and instrument table (P=0.002), as well as on the instrument dummies from the assistant table (P=0.001).

Conclusions

Instrumentation tables equipped with local unidirectional airflow protect the surgical instruments from bacterial contamination during orthopedic implant surgery and may therefore reduce the risk of indirect wound contamination.

Long-term antibacterial properties of a nanostructured titanium alloy surface: An in vitro study

The demand for joint replacement and other orthopedic surgeries involving titanium implants is continuously increasing; however, 1%-2% of surgeries result in costly and devastating implant associated infections (IAIs). Pseudomonas aeruginosa and Staphylococcus aureus are two common pathogens known to colonise implants, leading to serious complications. Bioinspired surfaces with spike-like nanotopography have previously been shown to kill bacteria upon contact; however, the longer-term potential of such surfaces to prevent or delay biofilm formation is unclear. Hence, we monitored biofilm formation on control and nanostructured titanium disc surfaces over 21 days following inoculation with Pseudomonas aeruginosa and Staphylococcus aureus. We found a consistent 2-log or higher reduction in live bacteria throughout the time course for both bacteria. The biovolume on nanostructured discs was also significantly lower than control discs at all time points for both bacteria. Analysis of the biovolume revealed that for the nanostructured surface, bacteria was killed not just on the surface, but at locations above the surface. Interestingly, pockets of bacterial regrowth on top of the biomass occurred in both bacterial species, however this was more pronounced for S. aureus cultures after 21 days. We found that the nanostructured surface showed antibacterial properties throughout this longitudinal study. To our knowledge this is the first in vitro study to show reduction in the viability of bacterial colonisation on a nanostructured surface over a clinically relevant time frame, providing potential to reduce the likelihood of implant associated infections.

In Vitro Bactericidal Efficacy of Nanostructured Ti6Al4V Surfaces is Bacterial Load Dependent

The demand for medical implants globally has increased significantly due to an aging population amongst other reasons. Despite the overall increase in the survivorship of Ti6Al4V implants, implant infection rates are increasing due to factors such as diabetes, obesity, and bacterial resistance to antibiotics. Two commonly found bacteria implicated in implant infections are Staphylococcus aureus and Pseudomonas aeruginosa. Based on prior work that showed nanostructured surfaces might have potential in passively killing these bacterial species, we developed a hierarchical, hydrothermally etched, nanostructured titanium surface. To evaluate the antibacterial efficacy of this surface, etched and as-received surfaces were inoculated with S. aureus or P. aeruginosa at concentrations ranging from 10² to 10⁹ colony-forming units per disc. Live/dead staining revealed there was a 60% decrease in viability for S. aureus and greater than a 98% decrease for P. aeruginosa on etched surfaces at the lowest inoculum of 10² CFU/disc, when compared to the control surface. Bactericidal efficiency decreased with increasing bacterial concentrations in a stepwise manner, with decreases in bacterial viability noted for S. aureus above 10⁵ CFU/disc and above 10⁶ CFU/disc for P. aeruginosa. Surprisingly, biofilm depth analysis revealed a decrease in bacterial viability in the 2 μm layer furthest from the nanostructured surface. The nanostructured Ti6Al4V surface developed here holds the potential to reduce the rate of implant infections.