Do 'Surgical Helmet Systems' or 'Body Exhaust Suits' Affect Contamination and Deep Infection Rates in Arthroplasty? A Systematic Review

Latent infections in conversion total hip arthroplasty following internal fixation of femoral neck fractures: a systematic review and meta-analysis of diagnostic methods

BACKGROUND

Accurate diagnosis of latent infections prior to conversion total hip arthroplasty (THA) following internal fixation of femoral neck fractures is crucial for successful surgical outcomes. This systematic review aimed to provide a comprehensive evaluation of the current literature regarding the diagnosis of latent infections before conversion THA.

METHODS

Systematic search of PubMed, EMBASE, and Cochrane (CENTRAL) databases was conducted, and the diagnostic accuracy of various markers and techniques was assessed. The quality of the included studies was evaluated using the QUADAS-2 instrument.

RESULTS

Five studies comprising 661 patients were included in the review. Pooled analysis using C-reactive protein (CRP) as a diagnostic marker resulted in a sensitivity and specificity of 72% and 76%, respectively, while using erythrocyte sedimentation rate (ESR) yielded a sensitivity and specificity of 75% and 78%, respectively. Fibrinogen and platelet count showed lower sensitivity and specificity compared to CRP and ESR. The best combined markers were CRP and serum platelet count, with a sensitivity of 76% and specificity of 86% based on one study.

CONCLUSION

Our review underscored the limitations and inconsistencies present in current diagnostic methods for latent infections in conversion surgery. Future research needs to focus on standardizing threshold values, exploring the potential of synovial fluid analysis, imaging techniques, and molecular methods, as well as developing tailored diagnostic algorithms.

PROSPERO

CRD42023394757.

Real time monitoring of carbon dioxide levels in surgical helmet systems worn during hip and knee arthroplasty

Background

Orthopaedic surgical helmet systems (SHS) rely on an intrinsic fan to force clean external air over the wearer. Carbon dioxide (CO2) is produced through aerobic metabolism and can potentially accumulate inside the SHS. Levels above 2500 ppm have previously been shown to affect cognitive and practical function. Maximum Health and Safety Executive (HSE) 8-h exposure limit is 5000 ppm. There is a paucity of data on real-world CO2 levels experienced during arthroplasty surgery whilst wearing a SHS.

Objectives

To determine intra-operative levels of CO2 experienced within SHS.

Methods

CO2 levels were continuously recorded during 30 elective arthroplasties, both primary and revision. Data was recorded at 0.5Hz throughout the procedure utilising a Bluetooth CO2 detector, worn inside a surgical helmet worn with a toga gown. Five surgeons contributed real time data to the study.

Results

The average CO2 level across all procedures was 3006 ppm, with 23 of the cases measured within the surgeons' helmets having a mean above 2500 ppm, but none having a mean above 5000 ppm. For each procedure, the time spent above 2500 and 5000 ppm was calculated, with the means being 72.6 % and 5.4 % respectively. Minimum fan speed was associated with only a marginally higher mean CO2 value than maximum fan speed.

Discussion

The use of surgical helmet systems for elective orthopaedic surgery, can result in CO2 levels regularly rising to a point which may affect cognitive function.

Conclusion

Further research is needed to corroborate these findings however, we recommend that future designs of SHS include active management of exhaust gases, possibly returning to Charnley's original design principles of the body exhaust system.

Preventing Infections in Reverse Shoulder Arthroplasty

PURPOSE OF REVIEW

Reverse shoulder arthroplasty (rTSA) is a commonly performed procedure to treat degenerative conditions of the shoulder. With its growing utilization, techniques to reliably diagnose and treat prosthetic joint infection (PJI) have become increasingly important. In this review we outline the current research and prevention methods of prosthetic joint infection in rTSA. This includes preoperative considerations, intraoperative, and postoperative treatment algorithms.

RECENT FINDINGS

There is currently no established standardized protocol for preoperative infection prevention or post operative management. However, recent studies have identified risk factors for infection, as well as successful prevention techniques that can be implemented to minimize infection risk. Although there is no standardized protocol currently utilized to diagnose and treat shoulder PJI, we outline a potential set of preventative measures and postoperative management strategies that clinicians can use to properly diagnose and treat patients with this difficult condition.

Main Operating Room Versus Field Sterility in Hand Surgery: A Review of the Evidence

Introduction: Many of the guidelines that are generally accepted as main operating room best practices are not evidence based. They are based on the concept that if some sterility is good, more must be better. They are not derived from evidence-based sterility. Evidence-based sterility is the study of which of our various sterility practices increase or decrease our infection rates, as opposed to guidelines based on how many bacteria are in the operating room. Methods: This article adds the most important evidence we could find that is not included in the first paper on evidence-based sterility in hand surgery published in 2019. In this review, we also balance the evidence with common sense opinion. Results: The 21st century has seen a rapid rise in the number and reports of hand surgery procedures performed with field sterility outside the main operating room. There is now an abundance of good evidence to support that the rate of infection is not higher when many hand operations are performed with field sterility in minor procedure rooms. Conclusion: Moving hand surgery out of the main operating room to minor procedure rooms should be supported by healthcare providers. The higher cost, increased solid waste, and inconvenience of main operating room surgery are not justifiable for many procedures because it does not reduce the risk of postoperative infection.

Intraoperative 'space suits' do not reduce periprosthetic joint infections in shoulder arthroplasty

Aims

Body exhaust suits or surgical helmet systems (colloquially, 'space suits') are frequently used in many forms of arthroplasty, with the aim of providing personal protection to surgeons and, perhaps, reducing periprosthetic joint infections, although this has not consistently been borne out in systematic reviews and registry studies. To date, no large-scale study has investigated whether this is applicable to shoulder arthroplasty. We used the New Zealand Joint Registry to assess whether the use of surgical helmet systems was associated with lower all-cause revision or revision for deep infection in primary shoulder arthroplasties.

Methods

We analyzed 16,000 shoulder arthroplasties (hemiarthroplasties, anatomical, and reverse geometry prostheses) recorded on the New Zealand Joint Registry from its inception in 2000 to the present day. We assessed patient factors including age, BMI, sex, and American Society of Anesthesiologists (ASA) grade, as well as whether or not the operation took place in a laminar flow operating theatre.

Results

A total of 2,728 operations (17%) took place using surgical helmet systems. Patient cohorts were broadly similar in terms of indication for surgery (osteoarthritis, rheumatoid arthritis, fractures) and medical comorbidities (age and sex). There were 842 revisions (5% of cases) with just 98 for deep infection (0.6% of all cases or 11.6% of the revisions). There were no differences in all-cause revisions or revision for deep infection between the surgical helmet systems and conventional gowns (p = 0.893 and p = 0.911, respectively).

Conclusion

We found no evidence that wearing a surgical helmet system reduces the incidence of periprosthetic joint infection in any kind of primary shoulder arthroplasty. We acknowledge the limitations of this registry study and accept that there may be other benefits in terms of personal protection, comfort, or visibility. However, given their financial and ecological footprint, they should be used judiciously in shoulder surgery.

Wearing a Surgical Vest With a Sterile Surgical Helmet System Decreases Contamination of the Surgical Field

BACKGROUND

Sterile surgical helmet systems are frequently utilized in total knee arthroplasty procedures to protect the surgeon while maintaining a comfortable working environment. However, common helmet systems pressurize the space between the surgical gown and the surgeon's skin. In gowns with a back seam, this may allow contaminated skin particles to escape into the surgical field. By measuring bacterial colony-forming units (CFUs), this study sought to determine if occlusion of the open back seam reduced the risk of potential contamination.

METHODS

First, qualitative analysis depicting airflow variations between gown configurations was performed using the Schlieren Spherical Mirror imaging system. Each gown configuration consisted of a sterile surgical helmet and one of 3 gown configurations: a standard gown with rear-tied closure, a standard gown with a surgical vest, and a zippered Toga-style gown. Next, a surgeon then performed simulated surgical activities for 60 minutes within a 1.4 m3 isolation chamber with work surfaces and controllable filtered air exchanges. During each procedure, contaminated particles were collected on sets of agar settle plates positioned directly behind the surgeon. Upon completion, the agar plates were incubated in a biolab, and the number of bacterial and fungal CFUs was counted. The experimental procedure was repeated 12 times for each gown configuration, with sterilization of the chamber between runs. Contamination rates were expressed as CFUs/m2/h.

RESULTS

The mean contamination rate measured with the standard gown was 331.7 ± 52.0 CFU/m2/h. After the addition of a surgical vest, this rate decreased by 45% to 182.2 ± 30.8 CFU/m2/h (P = .02). Similarly, with the Toga-style gown, contamination rates dropped by 49% to 170.5 ± 41.9 CFU/m2/h (P = .01).

CONCLUSIONS

When used in conjunction with surgical helmet systems, conventional surgical gowns do not prevent potential contamination of the surgical field. We recommend that staff within the surgical field cover the back seam of standard gowns with a vest or don a zippered Toga-style gown.

Comprehensive Guidance for the Prevention of Periprosthetic Joint Infection After Total Joint Arthroplasty and Pitfalls in the Prevention

Total joint arthroplasty (TJA) is a surgical procedure, in which parts of damaged joints are removed and replaced with a prosthesis. The main indication of TJA is osteoarthritis, and the volume of TJA is rising annually along with the increase of aged population. Hip and knee are the most common joints, in which TJAs are performed. The TJA prosthesis is composed of metal, plastic, or ceramic device. Even though TJA is the most successful treatment for end-stage osteoarthritis, it is associated with various complications, and periprosthetic joint infection (PJI) is the most serious complication after TJA. With the increasing volume of TJAs, there is a simultaneous rise in the incidence of PJI. Contamination of the surgical wound and the adherence of bacteria to the surface of prosthetic component represent the initial step in the pathogenesis of PJI. The main sources of the contamination are 1) patient's own flora, 2) droplets in the operation room air, and 3) surgical gloves and instruments. Even though modern techniques have markedly reduced the degree of contamination, TJAs cannot be done in completely germ-free conditions and some degree of contamination is inevitable in all surgical procedures. However, not all contamination leads to PJI. It develops when the burden of contamination exceeds the immune threshold or the colony forming units (CFUs) and various factors contribute to a decrease in the CFU level. Surgeons should be aware of the germ burden/CFU concept and should monitor sources of contamination to maintain the germ burden below the CFU to prevent PJI.

Variation of Practice in Prophylactic Protocol to Reduce Prosthetic Joint Infection in Primary Hip and Knee Arthroplasty: A National Survey in the United Kingdom

Purpose

Prosthetic joint infection (PJI) has an enormous physiological and psychological burden on patients. Surgeons rightly wish to minimise this risk. It has been shown that a standardised, evidence-based approach to perioperative care leads to better patient outcomes. A review of current practice was conducted using a cross-sectional survey among surgeons at multiple centers nationwide.

Materials and Methods

An 11-question electronic survey was circulated to hip and knee arthroplasty consultants nationally via the BOA (British Orthopaedic Association) e-newsletter.

Results

The respondents included 56 consultants working across 19 different trusts. Thirty-four (60.7%) screen patients for asymptomatic bacteriuria (ASB) preoperatively, with 19 (55.9%) would treating with antibiotics. Fifty-six (100%) screen for methicillin-resistant Staphylococcus aureus and treat if positive. Only 15 (26.8%) screen for methicillin-sensitive S. aureus (MSSA) or empirically eradicate. Zero (0%) routinely catheterise patients perioperatively. Forty-one (73.2%) would give intramuscular or intravenous gentamicin for a perioperative catheterisation. All surgeons use laminar flow theatres. Twenty-six (46.4%) use only an impervious gown, 6 (10.7%) exhaust pipes, and 24 (42.3%) surgical helmet system. Five different antimicrobial prophylaxis regimens are used 9 (16.1%) cefuroxime, 2 (3.6%) flucloxacillin, 19 (33.9%) flucloxacillin and gentamicin, 10 (17.9%) teicoplanin, 16 (28.6%) teicoplanin and gentamicin. Twenty-two (39.3%) routinely give further doses.

Conclusion

ASB screening, treatment and intramuscular gentamicin for perioperative catheterisation is routinely practiced despite no supporting evidence base. MSSA screening and treatment is underutilised. Multiple antibiotic regimens exist despite little variation in organisms in PJI. Practice varies between surgeons and centers, we should all be practicing evidence-based medicine.

Surgical helmet systems in total joint arthroplasty: assessment of hood sterility and donning technique

BACKGROUND

The incidence of prosthetic joint infection (PJI) is increasing, coincident with the rising volume of joint arthroplasty being performed. With recent controversy regarding the efficacy of surgical helmet systems (SHS) in preventing infection, the focus has turned to the correct donning techniques and usage of surgical hoods. The aim of this study was to compare the bacterial contamination of the operating surgeon's gloves after two common donning techniques of SHS hoods. We also evaluated the baseline sterility of the SHS hoods at the beginning of the procedure.

METHODS

The bacterial contamination rate was quantified using colony-forming units (CFUs), with 50 trials performed per donning technique. Samples were cultured on 5% Columbia blood agar in ambient air at 37 °C for 48 h and all subsequent bacterial growth was identified using a MALDI-TOF mass spectrometer. In Group 1, the operating surgeon donned their colleague's hood. In Group 2, the operating surgeon had their hood applied by a non-scrubbed colleague. After each trial, the operating surgeon immediately inoculated their gloves onto an agar plate. The immediate sterility of 50 SHS hoods was assessed at two separate zones-the screen (Zone 1) and the neckline (Zone 2).

RESULTS

There was no significant difference in contamination rates between the two techniques (3% vs. 2%, P = 0.99) or between right and left glove contamination rates. Immediately after donning, 6/50 (12%) of SHS hoods cultured an organism. Contamination rates at both the face shield and neckline zones were equivalent. The majority of bacteria cultured were Bacillus species.

DISCUSSION

We found no significant difference in the operating surgeon's glove contamination using two common SHS hood-donning techniques when they were performed under laminar airflow with late fan activation. We suggest the SHS hood should not be assumed to be completely sterile and that gloves are changed if it is touched intraoperatively.

The effect of the surgical helmet system on intraoperative contamination in arthroplasty surgery

Aims

The surgical helmet system (SHS) was developed to reduce the risk of periprosthetic joint infection (PJI), but the evidence is contradictory, with some studies suggesting an increased risk of PJI due to potential leakage through the glove-gown interface (GGI) caused by its positive pressure. We assumed that SHS and glove exchange had an impact on the leakage via GGI.

Methods

There were 404 arthroplasty simulations with fluorescent gel, in which SHS was used (H+) or not (H-), and GGI was sealed (S+) or not (S-), divided into four groups: H+S+, H+S-, H-S+, and H-S-, varying by exposure duration (15 to 60 minutes) and frequency of glove exchanges (0 to 6 times). The intensity of fluorescent leakage through GGI was quantified automatically with an image analysis software. The effect of the above factors on fluorescent leakage via GGI were compared and analyzed.

Results

The leakage intensity increased with exposure duration and frequency of glove exchanges in all groups. When SHS was used and GGI was not sealed (H+S-), the leakage intensity via GGI had the fastest increase, consistently higher than other groups (H+S+, H-S+ and H-S-) after 30 minutes (p < 0.05) and when there were more than four instances of glove exchange (p < 0.05). Additionally, the leakage was strongly correlated with the duration of exposure (rs = 0.8379; p < 0.050) and the frequency of glove exchange (rs = 0.8198; p < 0.050) in H+S-. The correlations with duration and frequency turned weak when SHS was not used (H-) or GGI was sealed off (S+).

Conclusion

Due to personal protection, SHS is recommended in arthroplasties. Meanwhile, it is strongly recommended to seal the GGI of the inner gloves and exchange the outer gloves hourly to reduce the risk of contamination from SHS.

Prosthetic joint infections of the shoulder: A review of the recent literature

Introduction

Shoulder arthroplasty is a common treatment for shoulder arthritis. Prosthetic joint infection of the shoulder (PJIS) is a debilitating complication to the patient and the healthcare system. Incidence of infection is 0.98-5% for primary arthroplasty. The mean hospital cost for two-stage revision was approximately $35,824. The aim of this paper is to review the recent literature and collate the latest evidence to aid diagnosis and treatment of this serious complication.

Methods

A literature review was performed using PubMed and Google Scholar databases. A search strategy was adopted using the keywords: 'infection' AND 'shoulder arthroplasty' OR 'total shoulder arthroplasty'OR 'TSA' OR 'reverse shoulder arthroplasty' OR 'RSA' OR 'rTSA'. This initial search resulted in 349 articles. A PRISMA flowchart process was followed. Duplicates were removed, screening was performed and the resulting full texts were analysed and further excluded, leaving 46 articles suitable for inclusion. A PICO search strategy was also used.

Results and interpretation

Risk factors for PJIS include procedure type, trauma indications and patient factors.The organism commonly isolated is Cutebacterium acnes, which makes diagnosis challenging due to its indolent nature. Investigations include biochemical tests, synovial aspirate, tissue cultures and radiological examinations.Treatment depends on the depth of the infection and the patient requirements. Medical treatment with antibiotics to local debridement, cement spacer and revision arthroplasty have all been described in the literature. A multidisciplinary decision is made on the microbiological evidence and patient factors.

Conclusion

PJIS is a rare but potentially devastating complication of shoulder arthroplasty and diagnosis is often challenging. There has been much research performed recently, providing more evidence on how to optimise management.

Periprosthetic Joint Infection With Actinomyces radingae May Lead to the Identification of a Neglected Source of Intraoperative Contamination

Periprosthetic joint infection remains a major complication in arthroplasty. We present the first description of a case of periprosthetic joint infection with Actinomyces radingae, microorganism that is mostly found on the skin of the upper body and might cause particular challenges as it is difficult to culture and specify. Furthermore, a thorough microbiologic workup may indicate the source of infection. In this case, it is possible that perspiration from the surgeon was the source of intraoperative contamination. Intraoperative contamination through perspiration may be important and should be avoided by all means.

Current and potential approaches on assessing airflow and particle dispersion in healthcare facilities: a systematic review

An indoor environment in a hospital building requires a high indoor air quality (IAQ) to overcome patients' risks of getting wound infections without interrupting the recovery process. However, several problems arose in obtaining a satisfactory IAQ, such as poor ventilation design strategies, insufficient air exchange, improper medical equipment placement and high door opening frequency. This paper presents an overview of various methods used for assessing the IAQ in hospital facilities, especially in an operating room, isolation room, anteroom, postoperative room, inpatient room and dentistry room. This review shows that both experimental and numerical methods demonstrated their advantages in the IAQ assessment. It was revealed that both airflow and particle tracking models could result in different particle dispersion predictions. The model selection should depend on the compatibility of the simulated result with the experimental measurement data. The primary and secondary forces affecting the characteristics of particle dispersion were also discussed in detail. The main contributing forces to the trajectory characteristics of a particle could be attributed to the gravitational force and drag force regardless of particle size. Meanwhile, the additional forces could be considered when there involves temperature gradient, intense light source, submicron particle, etc. The particle size concerned in a healthcare facility should be less than 20 μm as this particle size range showed a closer relationship with the virus load and a higher tendency to remain airborne. Also, further research opportunities that reflect a more realistic approach and improvement in the current assessment approach were proposed.

Technical Considerations and Avoiding Complications in Total Hip Arthroplasty

Total hip arthroplasty (THA) is considered to be the surgical procedure of the 20th century. Current projections show that by 2030, primary THA is expected to grow by 171%, with revision THA expected to increase by 142% in the same time frame. Although complications are not common, when they occur, they can cause notable morbidity to the patient. Understanding the unique anatomy and needs of each patient will prepare the surgeon to avoid soft-tissue or bony injury, optimize prosthesis placement, and decrease the risk of infection. This article aims to highlight common causes of early revision THA and provide specific technical strategies to avoid these complications. Following a systematic approach to the primary THA and using these techniques will assist the surgeon in avoiding complications to revision hip arthroplasty.

Effectiveness of Manual Terminal Cleaning Varies on High-Touch Surfaces Near the Operative Field

Background

Periprosthetic joint infection may result from pathogen to patient transmission within the environment. The purpose of this study is to evaluate the contamination level of selected high-touch surfaces in the operating room (OR) using a blacklight fluorescent marking system after a manual terminal clean.

Methods

Prior to the manual terminal clean, 16 high-touch surfaces were marked using a blacklight fluorescent gel. The marked areas were assessed the next morning for thoroughness of cleaning. Surfaces were categorized based on the average percent of the marks removed as “clean” (>75%), “partially clean” (26%-74%), or poorly cleaned (<25%). This process was repeated randomly 12 times. Terminal cleaning was done in the standard fashion, and the perioperative team was unaware of the initiation of this study.

Results

A total of 936 marks were analyzed. There was a significant difference in the number of marks completely clean (29.1%, 272/936) vs marks that were not touched (40.8%, 382/936), P < .001. Only the OR back table (75%) had a rating of clean. Partially clean areas included Mayfield table (72%), overhead lights (70.1%), infusion pump (61.1%), clock reset button (58.3%), table remote control (50%), tourniquet machine (50%), and the OR table (33.3%). Poorly cleaned surfaces included anesthesia medication cart (21.8%), door handles (20.8%), phone (16.7%), electrocautery unit (16.7%), foot pedal (16.7%), anesthesia cart (16.2%), nurses’ station (14.1%), and supply cabinet doors (6%).

Conclusions

Effectiveness of manual terminal cleaning varied greatly across surfaces. In general, surfaces further from the operative field were less likely to have markings removed.

Prevention of Orthopedic Prosthetic Infections Using Evidence-Based Surgical Site Infection Care Bundles: A Narrative Review

Background: The number of primary/revision total joint replacements (TJR) are expected to increase substantially with an aging population and increasing prevalence of comorbid conditions. The 30-day re-admission rate, in all orthopedic specialties, is 5.4% (range, 4.8%-6.0%). A recent publication has documented that the surgical site infection (SSI) infection rate associated with revision total knee (rTKR, 15.6%) and revision total hip (rTHR, 8.6%) arthroplasties are four to seven times the rate of the primary procedures (2.1%-2.2%). These orthopedic infections prolong hospital stays, double re-admissions, and increase healthcare costs by a factor of 300%. Methods: A search of PubMed/MEDLINE, EMBASE and the Cochrane Library publications, which reported the infection risk after TKR and THR, was undertaken (January 1, 1995 to December 31, 2021). The search also included documentation of evidence-based practices that lead to improved post-operative outcomes. Results: The evidence-based approach to reducing the risk of SSI was grouped into pre-operative, peri-operative, and post-operative periods. Surgical care bundles have existed within other surgical disciplines for more than 20 years, although their use is relatively new in peri-operative orthopedic surgical care. Pre-admission chlorhexidine gluconate (CHG) showers/cleansing, staphylococcal decolonization, maintenance of normothermia, wound irrigation, antimicrobial suture wound closure, and post-operative wound care has been shown to improve clinical outcome in randomized controlled studies and meta-analyses. Conclusions: Evidence-based infection prevention care bundles have improved clinical outcomes in all surgical disciplines. The significant post-operative morbidity, mortality, and healthcare cost, associated with SSIs after TJR can be reduced by introduction of evidence-based pre-operative, intra-operative, and post-operative interventions.

A back table ultraviolet light decreases environmental contamination during operative cases

BACKGROUND

The purpose of this study is to assess the impact of a germicidal ultraviolet light-emitting diode (LED) on the contamination level of a back table in the operating room (OR) during total joint arthroplasty procedures.

METHODS

Eight Tryptic Soy Agar petri plates were placed on a table located near the operative field and exposed to air. One plate was removed on the hour over an 8-hour time span. The back table had either an UV-LED for disinfection or a sham UV-LED. This process was repeated in 12 different ORs (6 with UV light, 6 with sham device). The plates were then incubated for 48 hours at 36°C ± 1°C . Colony forming units (CFU) were recorded 24 and 48 hours after incubation.

RESULTS

There was a statistically significant difference in total CFUs between the intervention vs sham at 24-hours (27 vs 95, P = .0001) and 48-hours (38 vs 122, P < .0001). The multivariate analysis revealed that the 24-hour and 48-hour count, the predictors UV light (P = .002) and hour of plate removal (P = .050) were statistically significantly associated with CFU counts. Together, the predictor variables explained 15.8% and 23.0% of the variance in CFU counts at 24- and 48-hours, respectively.

CONCLUSIONS

A back table UV-LED may decrease environmental contamination near the operative field. This has potential to lead to a decrease in joint infection.

Surgical Helmet Systems Are Associated With a Lower Rate of Prosthetic Joint Infection After Total Knee Arthroplasty: Combined Results From the New Zealand Joint Registry and Surgical Site Infection Improvement Programme

BACKGROUND

This study aimed to identify the risk factors, in particular the use of surgical helmet systems (SHSs), for prosthetic joint infection (PJI) after total knee arthroplasty (TKA). Data recorded by the New Zealand Surgical Site Infection Improvement Programme (SSIIP) and the New Zealand Joint Registry (NZJR) were combined and analyzed.

METHODS

Primary TKA procedures performed between July 2013 and June 2018 that were recorded by both the SSIIP and NZJR were analyzed. Two primary outcomes were measured: (1) PJI within 90 days as recorded by the SSIIP and (2) revision TKA for deep infection within 6 months as recorded by the NZJR. Univariate and multivariate analyses were performed to identify risk factors for both outcomes with results considered significant at P < .05.

RESULTS

A total of 19,322 primary TKAs were recorded by both databases in which 97 patients had a PJI within 90 days as recorded by the SSIIP (0.50%), and 90 patients had a revision TKA for deep infection within 6 months (0.47%) as recorded by the NZJR. An SHS was associated with a lower rate of PJI (adjusted odds ratio [OR] = 0.50, P = .008) and revision for deep infection (adjusted OR = 0.55, P = .022) than conventional gowning. Male sex (adjusted OR = 2.6, P < .001) and an American Society of Anesthesiologists score >2 were patient risk factors for infection (OR = 2.63, P < .001 for PJI and OR = 1.75, P = .017 for revision for deep infection).

CONCLUSION

Using contemporary data from the SSIIP and NZJR, the use of the SHS was associated with a lower rate of PJI after primary TKA than conventional surgical gowning. Male sex and a higher American Society of Anesthesiologists score continue to be risk factors for infection.

The use of a surgical helmet system with a high-efficiency particulate air filter as possible protection equipment during the coronavirus disease 2019 pandemic: a double-blinded randomized control study

PURPOSE

The rapid spread of coronavirus disease 2019 (COVID-19) has increased the use of personal protective equipment. The purpose of this study was to investigate whether a commercially available sterile surgical helmet system (SSHS) can be considered protective against COVID-19 and therefore safe for use.

METHODS

A double-blinded randomized controlled study was performed to investigate the efficacy of the ViVi® SSHS with a high-efficiency particulate air filter called HFD Hood (THI, Total Healthcare Innovation GmbH, Feistritz im Rosental, Austria) to protect against respiratory droplets. Forty recruited participants were divided into two different groups. The SSHS was tested using a validated qualitative test for respirator masks through saccharin or placebo solutions based on random allocation into two cohorts. Saccharin droplets are a validated surrogated marker for any elements of viral size, such as coronaviruses. A positive report of sweet taste after saccharin exposure was suggestive of ViVi® SSHS inefficacy in protection against droplets.

RESULTS

One participant out of 21 (4.8%) reported positive for taste within the placebo cohort, while five out of 19 (26.3%) reported positive for taste within the saccharin cohort upon testing. Two out of 21 (9.5%) participants reported positive for taste within the placebo cohort, and two out of 19 (10.5%) reported positive for taste within the saccharin cohort upon retesting. There were no statistically significant differences between the saccharin and placebo groups in either the test or retest measurements (p = 0.085 and p = 1.000, respectively).

CONCLUSIONS

This study demonstrates that the ViVi® SSHS equipped with HFD Hood protects against respiratory droplets, increasing protection against several microorganisms, including the virus that causes COVID-19, allowing surgeons to carry out procedures on COVID-positive patients in a more comfortable and safer way.

The Relationship between Bacterial Load and Initial Run Time of a Surgical Helmet

Background

Periprosthetic joint infection (PJI) is a complication of arthroplasty surgery with significant morbidity and mortality. Surgical helmets are a possible source of infection. Pre-existing dust and microorganisms on its surface may be blown into the surgical field by the helmet ventilation system.

Methods

Twenty surgical helmets at our institution were assessed through microscopy and polymerase chain reaction testing. Helmets were arranged with agar plates under the front and rear outflow vents. Helmets ran while plates were exchanged at different time points. Bacterial growth was assessed via colony counts and correlated with fan operating time. Gram staining and 16S sequencing were performed to identify bacterial species.

Results

The primary microbiological contaminate identified was Burkholderia. There was an inverse relationship between colony formation and fan operating time. The highest number of colonies was found within the first minute of fan operating time. There was a significant decrease in the number of colonies formed from the zero-minute to the three (27 vs 5; P = <.01), four (27 vs 3; P = <.01), and five-minute (27 vs 4; P = <.01) time points for the front outflow plates. A significant difference was also observed between the one-minute and four-minute time points ( P = .046).

Conclusion

We observed an inverse relationship between bacterial spread helmet fan operation time, which may correlate with dispersion of pre-existing contaminates. To decrease contamination risk, we recommend that helmets are run for at least 3 min prior to entering the operating room.

Systematic study on the relationship between particulate matter and microbial counts in hospital operating rooms

In this study, a systematic procedure for establishing the relationship between particulate matter (PM) and microbial counts in four operating rooms (ORs) was developed. The ORs are located in a private hospital on the western coast of Peninsular Malaysia. The objective of developing the systematic procedure is to ensure that the correlation between the PMs and microbial counts are valid. Each of the procedures is conducted based on the ISO, IEST, and NEBB standards. The procedures involved verifying the operating parameters are air change rate, room differential pressure, relative humidity, and air temperature. Upon verifying that the OR parameters are in the recommended operating range, the measurements of the PMs and sampling of the microbes were conducted. The TSI 9510-02 particle counter was used to measure three different sizes of PMs: PM 0.5, PM 5, and PM 10. The MAS-100ECO air sampler was used to quantify the microbial counts. The present study confirms that PM 0.5 does not have an apparent positive correlation with the microbial count. However, the evident correlation of 7% and 15% were identified for both PM 5 and PM 10, respectively. Therefore, it is suggested that frequent monitoring of both PM 5 and PM 10 should be practised in an OR before each surgical procedure. This correlation approach could provide an instantaneous estimation of the microbial counts present in the OR.

Orthopedic Surgical Helmet Systems Significantly Impair Speech Intelligibility

Surgical suits provide protection to orthopedic surgeons, but the suits and fan noise may interfere with communication between operative team members. The goal of this study was to quantify the fan sound and effect of the suit, fan, and N95 mask. Sound levels were measured using a specialized manikin and evaluated using preferred speech interference levels (PSILs), noise criterion (NC) ratings, and comparison with speech sound levels from the literature. Additionally, sound blocking due to the surgical suit was measured and combined effects of the fan and suit were described using a signal to noise ratio (SNR). The noise with the fan at medium and high speed was louder than average speech and the PSILs at these speeds were significantly higher than with the fan off. The fan NC rating of 50 to 60 exceeded the recommended range of 25 to 30 for operating rooms. The N95 mask, space suit, and distance between speaker and receiver all reduced the sound signal at the receiver's ear, with the worst case being full personal protective equipment on both and speaker distanced from receiver. The estimated SNR for the suit and fan system was negative for many frequency bands used in speech, indicating more noise than signal. Multiple measures indicated that the fan noises were at levels associated with speech interference. This noise combined with sound blocking provided by the suit produced SNRs commonly associated with noisy to very noisy environments. This study suggests the combined effects of the suit, fan, and distance may negatively impact operating room communication. [Orthopedics. 2021;44(4):208-214.].

The rise of 3D Printing entangled with smart computer aided design during COVID-19 era

During the current Pandemic, seven and a half million flights worldwide were canceled which disrupted the supply chain of all types of goods such as, personal protective gears, medical health devices, raw materials, food, and other essential equipments. The demand for health and medical related goods increased during this period globally, while the production using classical manufacturing techniques were effected because of the lockdowns and disruption in the transporation system. This created the need of geo scattered, small, and rapid manufacturing units along with a smart computer aided design (CAD) facility. The availability of 3D printing technologies and open source CAD design made it possible to overcome this need. In this article, we present an extensive review on the utilization of 3D printing technology in the days of pandamic. We observe that 3D printing together with smart CAD design show promise to overcome the disruption caused by the lockdown of classical manufacturing units specially for medical and testing equipment, and protective gears. We observe that there are several short communications, commentaries, correspondences, editorials and mini reviews compiled and published; however, a systematic state-of-the-art review is required to identify the significance of 3D printing, design for additive manufacturing (AM), and digital supply chain for handling emergency situations and in the post-COVID era. We present a review of various benefits of 3DP particularly in emergency situations such as a pandemic. Furthermore, some relevant iterative design and 3DP case studies are discussed systematically. Finally, this article highlights the areas that can help to control the emergency situation such as a pandemic, and critically discusses the research gaps that need further research in order to exploit the full potential of 3DP in pandemic and post-pandemic future era.

Ventilation design conditions associated with airborne bacteria levels within the wound area during surgical procedures: a systematic review

BACKGROUND

Without confirmation of the ventilation design conditions (typology and airflow rate), the common practice of identifying unidirectional airflow (UDAF) systems as equivalent to ultra-clean air ventilation systems may be misleading, but also any claims about the ineffectiveness of UDAF systems should be doubted. The aim of this review was to assess and compare ventilation system design conditions for which ultra-clean air (mean <10 cfu/m³) within 50 cm from the wound has been reported. Six medical databases were systematically searched to identify and select studies reporting intraoperative airborne levels expressed as cfu/m³ close to the wound site, and ventilation system design conditions. Available data on confounding factors such as the number of persons present in the operating room, number of door openings, and clothing material were also included. Predictors for achieving mean airborne bacteria levels within <10 cfu/m³ were identified using a penalized multivariate logistic regression model. Twelve studies met the eligibility criteria and were included for analysis. UDAF systems considered had significantly higher air volume flows compared with turbulent ventilation (TV) systems considered. Ultra-clean environments were reported in all UDAF-ventilated (N = 7) rooms compared with four of 11 operating rooms equipped with TV. On multivariate analysis, the total number of air exchange rates (P=0.019; odds ratio (OR) 95% confidence interval (CI): 0.66-0.96) and type of clothing material (P=0.031; OR 95% CI: 0.01-0.71) were significantly associated with achieving mean levels of airborne bacteria <10 cfu/m³. High-volume UDAF systems complying with DIN 1946-4:2008 standards for the airflow rate and ceiling diffuser size unconditionally achieve ultra-clean air close to the wound site. In conclusion, the studied articles demonstrate that high-volume UDAF systems perform as ultra-clean air systems and are superior to TV systems in reducing airborne bacteria levels close to the wound site.

Examination of Surgical Helmet and Surgical Hood Application Methods in Reducing Contamination in Arthroplasty Surgery

Background

Contamination of the surgeon during gowning is a possible risk factor for prosthetic joint infection in arthroplasty surgery. Surgical helmets are a common form of personal protective equipment used during this type of surgery. Increasingly, there is a focus on the methods of application of the surgical hood and gown while wearing these helmets.

Methods

Ultraviolet fluorescent powder was used to represent air-borne contaminant and applied through the airflow inlet of the surgical helmet. Seven methods of helmet and surgical gown application methods were examined. A ultraviolet torch was used to determine the level of contamination across 11 body regions. A single body region with less than 10 particles was classified as minor contamination, and over 10 particles as major contamination.

Results

Early activation of the surgical helmet resulted in significant level of contamination across the majority of body regions. Major contamination also affected the scrub nurse when applying the surgical hood to the surgeon’s helmet. Late activation of helmet system resulted in only minor level of contamination to the surgeon’s shoulders and forearms. Adhesive wrist wraps over the inner gloves did not decrease contamination when added to late activation of the helmet.

Conclusion

It is our recommendation that the surgical hood should be applied by an unsterile theater assistant and that the surgical helmet system should be activated after the surgeon has applied inner gloves to minimize the level of contamination to the surgeon’s gown.

Improvising the surgical helmet system for aerosol-generating procedures in the OR: Surgeon designed 3D printed mould for augmented filtration system

1 BACKGROUND

The aim of this paper is to describe the process of designing and developing a mould for filter placement via 3D printing on top of the surgical helmet. This mould was designed to affix a filter material on top of the helmet system for use during the COVID - 19 pandemic.

2 METHOD

The authors performed 3D scanning of the Stryker Surgical helmet (Stryker T5, REF 400-610, US patents 6,973,677:7,753,682) and created a negative template of the top of the helmet. A mould for filter placement was printed and fitted onto the top of the surgical helmet. This construct was tested to evaluate the surgeon's comfort, aerosol filtration efficiency etc.

3 RESULT

The helmet provided adequate comfort, showed no evidence of staining on spill test and the filter passed the industry filtration efficiency standards.

4 CONCLUSION

The 3D printed mould is an inexpensive, efficient, and comfortable design to augment personal protection ability of the Stryker helmet system. This process can be extrapolated to 3D print templates for other surgical helmets.

Prevention of infection in primary THA and TKA

Rates of peri-prosthetic joint infection (PJI) in primary total hip and total knee arthroplasty range between 0.3% and 1.9%, and up to 10% in revision cases. Significant morbidity is associated with this devastating complication, the economic burden on our healthcare system is considerable, and the personal cost to the affected patient is immeasurable.

The risk of surgical site infection (SSI) and PJI is related to surgical factors and patient factors such as age, body mass index (BMI), co-morbidities, and lifestyle. Reducing the risk of SSI in primary hip and knee arthroplasty requires a multi-faceted strategy including pre-operative patient bacterial decolonization, screening and avoidance of anaemia, peri-operative patient warming, skin antisepsis, povidone-iodine wound lavage, and anti-bacterial coated sutures.

This article also considers newer concepts such as the influence of bearing surfaces on infection risk, as well as current controversies such as the potential effects of blood transfusion, laminar flow, and protective hoods and suits, on infection risk.

Cite this article: EFORT Open Rev 2020;5:604-613. DOI: 10.1302/2058-5241.5.200004

Efficacy of surgical helmet systems for protection against COVID-19: a double-blinded randomised control study

Purpose

This study assesses whether sterile surgical helmet systems (SSHS) provide surgeons with additional protection from aerosol pathogens alongside their traditional role protecting against splash. There has been debate on whether to use such systems in reopening elective orthopaedic surgery during the current COVID-19 pandemic environment.

Methods

Thirty-five participants were enrolled in a double-blinded randomised controlled study investigating efficacy of the Stryker Flyte Surgical Helmet (Stryker Corporation, Kalamazoo, MI, USA) as protection against respiratory droplets. Wearing the SSHS in a fit testing hood, subjects were randomised to nebulised saccharin solution or placebo. Twenty were allocated to the saccharin group with 15 to placebo. Positive sweet taste represented a failure of the test. Taste tests were performed with the helmet fan turned on and off.

Results

SSHS did not prevent saccharin taste (p < 0.0001). Within the saccharin cohort, 40% recorded a positive taste with the fan on and 100% with the fan off. There was a statistically significant difference in mean time-to-taste saccharin (p = 0.049) comparing fan on (123.5 s) vs. off (62.6 s).

Conclusions

SSHS do not protect against aerosol particulate and therefore are not efficacious in protection against COVID-19. The fan system employed may even increase risk to the surgeon by drawing in particulates as well as delay recognition of intraoperative cues, such as exhaust from diathermy, that point to respirator mask leak.

Bacterial contamination of protective lead garments in an operating room setting

Background

Protective lead garments (PLG) worn in the operating room are a potential source for bacterial colonisation and thus may increase the risk of intraoperative infection. The clinical significance of such bacterial contamination has yet been established. Although disinfection protocols have been employed, their effectiveness is also unknown.

Objective

We sought to describe and compare the bacterial profile of PLGs with a focus on common pathogens involved in surgical site infections (SSI) and prosthetic joint infections (PJI).

Methods

We studied body aprons and neck-thyroid protective shields. We sampled 20 body aprons and 21 neck PLGs, swabbing the inside and outside of the PLGs. Swabs were cultured on different media and the results were assessed and compared.

Results

Of PLGs, 87.8% were contaminated. The neck-thyroid shield PLGs was generally more contaminated than body apron PLGs and exhibited significantly higher loads of Staphylococcus epidermidis (P = 0.048). Other pathogen cultured were Micrococcus spp., Acinetobacter lwoffii (A. lwoffii), Bacillus species (Bacillus spp.), Moraxella osloensis (M. osloensis) and Pseudomonas stutzeri (P. stutzeri). No other common pathogens associated with SSI or PJI were detected.

Conclusions

PLGs are heavily contaminated despite regular cleaning protocols. Neck PLGs are highly contaminated with potentially infectious agents. As neck PLGs are often directly exposed above the surgical sterile gown and the surgical field, measures should be undertaken to reduce their exposure and bacterial load, perhaps by suggesting users consider avoiding the use of intraoperative fluoroscopy when possible or alternatively supporting the use of body exhaust suits when PLGs are needed.

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.

Helmet Modification to PPE With 3D Printing During the COVID-19 Pandemic at Duke University Medical Center: A Novel Technique

Care for patients during COVID-19 poses challenges that require the protection of staff with recommendations that health care workers wear at minimum, an N95 mask or equivalent while performing an aerosol-generating procedure with a face shield. The United States faces shortages of personal protective equipment (PPE), and surgeons who use loupes and headlights have difficulty using these in conjunction with face shields. Most arthroplasty surgeons use surgical helmet systems, but in the current pandemic, many hospitals have delayed elective arthroplasty surgeries and the helmet systems are going unused. As a result, the authors have begun retrofitting these arthroplasty helmets to serve as PPE. The purpose of this article is to outline the conception, design, donning technique, and safety testing of these arthroplasty helmets being repurposed as PPE.

Contemporary Strategies to Prevent Infection in Hip and Knee Arthroplasty

PURPOSE OF REVIEW

Prosthetic joint infection (PJI) remains a serious concern in lower limb arthroplasty. Despite the significant consequences of PJI, the assessment of the safety and efficacy of preventative measures is challenging due to a low event rate. Notwithstanding, enormous efforts have been made in this arena, and prevention strategies continue to evolve. This review provides an update on contemporary literature (published within the last 5 years) pertaining to infection prevention in primary hip and knee arthroplasty.

RECENT FINDINGS

Patient optimization has been highlighted as a critical preoperative factor in mitigating PJI risk. Recent evidence emphasizes the importance of preoperative glycaemic control, nutritional status, weight optimization and smoking cessation prior to hip and knee arthroplasty. Perioperatively, attention to detail in terms of surgical skin preparation agent and technique as well as prophylactic antibiotic agent, spectrum, dose and timing is important with statistically and clinically significant differences seen between differing strategies. Intraosseous regional antibiotic administration is an emerging technique with promising preclinical data. Dilute betadine lavage also shows promise. Data supporting bundled interventions continues to grow. A multimodal approach is required in PJI prevention, and attention to detail is important with each element. Patient optimization is critical, as is the execution of the planned perioperative infection prevention strategy.

Do Double-fan Surgical Helmet Systems Result in Less Gown-particle Contamination Than Single-fan Designs?

BACKGROUND

Surgical helmet systems commonly are stand-alone systems with a single fan blowing air into the suit, creating positive pressure that blows particles out through areas of low resistance, possibly contaminating surgical attire and the surgical field. Two-fan systems were developed more recently to release spent air, also theoretically lowering pressure in the suit and decreasing the aforementioned risk of particle contamination. To our knowledge no study to date has measured the potential differences in gown particle contamination to support this hypothesis.

QUESTIONS/PURPOSES

We compared a commonly used single-fan system versus a two-fan system and asked: (1) Which fan system results in less gown particle contamination? (2) Are there differences between the systems in the location of contamination?

METHODS

Using an existing experimental study model, two surgeons performed five 30-minute TKA simulations comparing a single-fan to a double-fan helmet system after applying fluorescent powder to the hands, axillae, and chest. Both are two-piece hood and gown systems. The single-fan sits on top of the helmet blowing air into the suit; the double-fan system has a second fan positioned at the rear blowing out spent air. Ultraviolet light-enhanced photographs were subsequently obtained of the flexor and extensor surfaces of the arms, axillary areas, and front and back of the chest. We chose these locations because they all contain either a seam or an overlap between gown and hood or gloves through which particles can escape. The images were scored for contamination on a scale of 1 (zero specks) to 4 (> 100 specks) by three independent observers. Interobserver correlation was assessed through Spearman's test yielding 0.91 (95% CI 0.86 to 0.94; p < 0.0001), 0.81 (95% CI 0.73 to 0.87; p < 0.0001) and 0.87 (95% CI 0.80 to 0.91; p < 0.0001) between observers 1 and 2, observers 1 and 3, and observers 2 and 3, rendering the used scale reliable. Results of the observers were averaged and compared using the Mann-Whitney U test.

RESULTS

There was no difference in overall gown particle contamination between the systems (overall single-fan median contamination score 2.5 of 4 [interquartile range Q1-Q3 0-3.42] versus double fan 1 out of 4 (Q1-Q3 0-3); p = 0.082), but all tests showed there was contamination at the gown-glove interface. In general, there were few differences between the two systems in terms of location of the contamination; however, when comparing only the axillary regions, we found that the single-fan group (median score 3.67 [Q1-Q3 3-4]) showed more contamination than the double-fan group (2.33 [Q1-Q3 0-3.08]); p = 0.01.

CONCLUSION

We found no difference in gown particle contamination between a single-fan and a double-fan helmet design. However, we note that contamination was present in all tests with both systems, so surgeons should not assume that these systems provide a contamination-free environment.

CLINICAL RELEVANCE

When using such helmets, the surgeon should not place items close to the axillary region because the seam of the gown may have low resistance to particle contamination. Gown designs could be improved by creating better seals, especially at the arm-body seam.

Intraoperative and Postoperative Infection Prevention

Implementation of strategies for prevention of surgical site infection and periprosthetic joint infection is gaining further attention. We provide an overview of the pertinent evidence-based guidelines for infection prevention from the World Health Organization, the Centers for Disease Control and Prevention, and the second International Consensus Meeting on Musculoskeletal Infection. Future work is needed to ascertain clinical efficacy, optimal combinations, and the cost-effectiveness of certain measures.

The Impact of Supplemental Intraoperative Air Decontamination on the Outcome of Total Joint Arthroplasty: A Pilot Analysis

BACKGROUND

During the early era of arthroplasty, the concept of ultraclean operating room (OR) was introduced based on the principle that the number of airborne particles in the OR directly influences incidence of device-related infections. The hypothesis of this pilot study was that use of an innovative UV-C air decontamination technology would lead to a reduction in the incidence of periprosthetic joint infection (PJI) following total joint arthroplasty.

METHODS

A retrospective, observational, surveillance study was conducted with a consecutive series of patients who underwent total joint arthroplasty (n = 496) between January 2016 and August 2017. All perioperative and postoperative care protocols were identical for both groups, only study variable was that in 231 arthroplasty patients (OR B), an innovative supplemental UV-C air decontamination technology was used, whereas in the remaining 265 patients, arthroplasty was performed with standard turbulent HVAC (OR A).

RESULTS

There was no significant difference between patient groups regarding age, body mass index, diabetes diagnosis, smoking status, length of surgery, or revision status. The rate of PJI was documented to be 1.9% in the turbulent air group, and no infections were documented in the cohorts operated under UV-C air decontamination, which was statistically significant (P < .044).

CONCLUSION

While PJI is multifactorial in nature, the present retrospective pilot study suggests that use of an intraoperative supplemental air decontamination significantly reduced the overall risk of PJI. The findings of this study are encouraging and should be examined in a larger-scale, prospective, multicenter study.

Effectiveness of architectural separation of septic and aseptic operating theatres for improving process quality and patient outcomes: a systematic review

BACKGROUND

Architectural division of aseptic and septic operating theatres is a distinct structural feature of surgical departments in Germany. Internationally, hygienists and microbiologists mainly recommend functional separation (i.e. aseptic procedures first) without calling for separate operating floors and rooms. However, patients with severe musculoskeletal infections (e.g. joint empyema, spondylodiscitis, deep implant-associated infections) may benefit from the permanent availability of septic operating capacities without delay caused by an ongoing aseptic surgical program. A systematic literature review on the influence of a structural separation of septic and aseptic operating theatres on process and/or outcome quality has not yet been conducted.

METHODS

Systematic literature search in PubMed MEDLINE, Ovid Embase, CINAHL and the Cochrane Library, screening of referenced citations, and assessment of grey literature.

RESULTS

A total of 572 articles were found through the systematic literature search. No head-to-head studies (neither randomised, quasi-randomised nor observational) were identified which examined the impact of structural separation of septic and aseptic operating theatres on process and/or outcome quality.

CONCLUSIONS

This review did not identify evidence in favour nor against architectural separation of septic or aseptic operating theatre. Specifically, there is no evidence of a harmful effect of architectural separation. Unless prospective studies, ideally randomised trials, will be available, it is unjustified to call for abolishing established hospital structures. Future investigations must address patient-centered endpoints, surgical site infections, process quality and hospital economy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (International prospective register of systematic reviews): CRD42018086568.

A Clinical Test to Measure Airborne Microbial Contamination on the Sterile Field During Total Joint Replacement: Method, Reference Values, and Pilot Study

Background

Airborne microbe-carrying particles in the operating-room environment during total joint replacement are a risk factor for periprosthetic joint infection. The present study focuses on a simple environmental test, based on practices used in aseptic cleanrooms, to quantify the deposition of microbe-carrying particles onto the sterile field.

Methods

Settle plates are exposed Petri dishes. A settle plate test system and sampling plan were developed from current practices used in aseptic manufacturing. A pilot study evaluated this system in an orthopaedic operating room during 22 total knee and hip arthroplasties. The microbial deposition total (MDT), expressed in colonies/m², is proposed as an outcome variable to report airborne sterile-field contamination as measured with settle plates. Two reference MDT levels were developed: (1) an upper limit of 450, corresponding with the ultraclean air definition of 10 colonies/m³, and (2) a target level of 100, corresponding with 1 colony/m³. These levels also correspond with widely used limits in aseptic cleanrooms and controlled environments.

Results

High MDT standard deviations were noted. Ninety-one percent (95% confidence interval, 71.0% to 98.7%) of wound zone MDT levels were within the upper limit. Twenty-seven percent (95% confidence interval, 12.9% to 48.4%) of wound zone levels were within the target level.

Conclusions

Settle plates are a feasible technique to test environmental levels of microbe-carrying particles on sterile fields during total joint replacement for scientific and environmental quality studies.

Clinical Relevance

This settle plate operating-room environmental test can be used in future research to validate the presence of actual ultraclean-air conditions during periprosthetic joint infection outcome studies. Surgeons also can use this test to measure intraoperative airborne microbe-carrying-particle sterile-field contamination and compare it with ultraclean-air reference levels for environmental quality-control programs.

Preventing infection in shoulder surgery

Although rare, infection after shoulder surgery can represent a devastating complication. Infection can negatively affect clinical outcomes, and eradication often requires a protracted treatment course. Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes are among the most frequently isolated pathogens. Perioperative measures can be implemented to reduce infection risk. Here we review various perioperative practices and their efficacy at reducing infection after shoulder surgery.

The Impact of Patient and Surgical Factors on the Rate of Postoperative Infection After Total Hip Arthroplasty-A New Zealand Joint Registry Study

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty (THA). The potential to define and modify risk factors for infection represents an important opportunity to reduce the incidence of PJI. This study uses New Zealand Joint Registry data to identify independent risk factors associated with PJI after primary THA.

METHODS

Data on 91,585 THAs performed between 2000 and 2014 were analyzed. Factors associated with revision for PJI within 12 months were identified using univariate and multivariate analyses.

RESULTS

Revision rates for PJI were 0.15% and 0.21% at 6 and 12 months, respectively. Multivariate analysis showed significant associations with the American Society of Anesthesiologists grade (odds ratio [OR] 6.13, 95% confidence interval [CI] 1.28-29.39), severe or morbid obesity (OR 2.15, CI 1.01-4.60 and OR 3.73, CI 1.49-9.39), laminar flow ventilation (OR 1.98, CI 1.38-2.85), consultant-supervised trainee operations (OR 1.94, CI 1.22-3.08), male gender (OR 1.68, CI 1.23-2.30) and anterolateral approach (OR 1.62, CI 1.11-2.37). Procedures performed in the private sector were protective for revision for infection (OR 0.68, CI 0.48-0.96).

CONCLUSIONS

The PJI risk profile for patients undergoing THA is constituted of a complex of patient and surgical factors. Several patient factors had strong independent associations with revision rates for PJI. Although surgical factors were less important, these may be more readily modifiable in practice.

Surgeon Personal Protection: An Underappreciated Benefit of Positive-pressure Exhaust Suits

BACKGROUND

Positive-pressure exhaust suits cost more than standard surgical gowns, and recent evidence suggests that they do not decrease infection risk. As a result, some hospitals and surgeons have abandoned positive-pressure exhaust suits in favor of less expensive alternatives. We propose that in addition to their original purpose of decreasing infection rates, positive-pressure exhaust suits may also improve personal protection for the surgeon and assistants, perhaps justifying their added costs.

QUESTIONS/PURPOSES

(1) Do positive-pressure exhaust suits decrease exposure to particulate matter during TKA? (2) What areas covered by gowning systems are at risk of exposure to particulate matter?

METHODS

Three surgical gowning systems were tested: (1) surgical gown, face mask, surgical skull cap, protective eyewear; (2) surgical gown, face mask, surgical protective hood, protective eyewear; and (3) positive-pressure exhaust suit. For each procedure, a cadaver knee was injected intraarticularly and intraosseously with a 5-µm fluorescent powder mixed with water (1 g/10 mL). After gowning in the standard sterile fashion, the primary surgeon and two assistants performed two TKAs with each gowning system for a total of six TKAs. After each procedure, three independent observers graded skin exposure of each surgical participant under ultraviolet light using a standardized scale from 0 (no exposure) to 4 (gross exposure). Statistical analysis was performed using Friedman's and Nemenyi tests. The interrater reliability for the independent observers was also calculated.

RESULTS

The positive-pressure exhaust suits had less surgeon and assistant exposure compared with other systems (p < 0.001). The median overall exposure grade for each gowning system was 4 for System 1 (range, 3-4), 2.5 for System 2 (range, 2-3), and 0 for System 3 (range, 0-0). In pairwise comparisons between gowning systems, the positive-pressure exhaust suits had less exposure than gowning System 1 (difference of medians: 4, p < 0.001) and gowning System 2 (difference of medians: 2.5, p = 0.038). There was no difference found in exposure between Systems 1 and 2 (difference of medians: 1.5, p = 0.330). When gowning Systems 1 and 2 were removed, particulate matter was found in places that were covered such as the surgeon's beard, lips, inside the nostrils, behind the protective eyewear around the surgeon's eye, and in both eyebrows and eyelashes.

CONCLUSIONS

The positive-pressure exhaust suits provided greater personal protection with each procedure than the other two gowning systems.

CLINICAL RELEVANCE

With conventional gowns, particulate matter was found in the surgeon's eyelashes, under the face mask around the mouth, and inside the nostrils. Despite recent evidence that certain types of positive-pressure exhaust suits may not decrease infection, there is a clear benefit of surgeon protection from potentially infectious and harmful patient substances. Despite their added costs, hospitals and surgeons should weigh this protective benefit when considering the use of positive-pressure exhaust suits.

Surgical Space Suits Increase Particle and Microbiological Emission Rates in a Simulated Surgical Environment

BACKGROUND

The role of space suits in the prevention of orthopedic prosthetic joint infection remains unclear. Recent evidence suggests that space suits may in fact contribute to increased infection rates, with bioaerosol emissions from space suits identified as a potential cause. This study aimed to compare the particle and microbiological emission rates (PER and MER) of space suits and standard surgical clothing.

METHODS

A comparison of emission rates between space suits and standard surgical clothing was performed in a simulated surgical environment during 5 separate experiments. Particle counts were analyzed with 2 separate particle counters capable of detecting particles between 0.1 and 20 μm. An Andersen impactor was used to sample bacteria, with culture counts performed at 24 and 48 hours.

RESULTS

Four experiments consistently showed statistically significant increases in both PER and MER when space suits are used compared with standard surgical clothing. One experiment showed inconsistent results, with a trend toward increases in both PER and MER when space suits are used compared with standard surgical clothing.

CONCLUSION

Space suits cause increased PER and MER compared with standard surgical clothing. This finding provides mechanistic evidence to support the increased prosthetic joint infection rates observed in clinical studies.

Assessment of theatre shoe contamination in an orthopaedic theatre

Prosthetic joint infection (PJI) is a devastating complication of arthroplasty. Numerous protocols reduce potential risk for PJI peri-operatively, but none exist for the management of theatre shoes. Our aim was to assess for bacteria known to cause prosthetic infection on theatre shoes. Forty theatre shoes were analysed; there were coagulase-negative staphylococci on 65% (N = 25), meticillin-susceptible Staphylococcus aureus on 40% (N = 16), and meticillin-resistant S. aureus on 25% (N = 10). Amount of blood spatter correlated poorly with microbial contamination. Shoes harbouring Gram-positive bacteria, including antibiotic-resistant strains, provide a potential route of transmission to the theatre environment.

Do surgical helmet systems affect intraoperative wound contamination? A randomised controlled trial

BACKGROUND

Deep infection following arthroplasty remains a devastating complication. Some registry data suggests that modern positive-pressure surgical helmet systems (SHS) are associated with a paradoxical increase in infection rates, and as such their role in arthroplasty remains unclear. The aim of this study was to investigate whether SHS increase wound contamination in total knee arthroplasty (TKA) and if this contamination can be reduced by placing tape around the gown/glove interface.

METHODS

Seventy-five patients were randomised into three groups: scrubbed theatre staff wore standard surgical gowns (SG), SHS without tape at the gown/glove interface, or SHS with tape. All TKA operations were carried out by the same surgeon. Wound contamination was assessed using a wound culture technique. Blinded laboratory analysis was performed.

RESULTS

There were 5/50 culture positive cases when a SHS was used compared to 0/25 when a SG was used; but this difference was not statistically significant (p = 0.16). There were 4/24 culture positive cases when SHS with tape was used compared to 1/26 when SHS without tape was used; but this difference was not statistical significant p = 0.18.

CONCLUSION

We found no difference in wound contamination between SG and SHS. Addition of tape at the gown/glove interface did not alter the contamination rate. The choice of surgical gown should take into account cost, comfort and personal protection; as this study found no evidence that wound contamination rates will be altered.

Environment of care: Is it time to reassess microbial contamination of the operating room air as a risk factor for surgical site infection in total joint arthroplasty?

In the modern operating room (OR), traditional surgical mask, frequent air exchanges, and architectural barriers are viewed as effective in reducing airborne microbial populations. Intraoperative sampling of airborne particulates is rarely performed in the OR because of technical difficulties associated with sampling methodologies and a common belief that airborne contamination is infrequently associated with surgical site infections (SSIs). Recent studies suggest that viable airborne particulates are readily disseminated throughout the OR, placing patients at risk for postoperative SSI. In 2017, virtually all surgical disciplines are engaged in the implantation of selective biomedical devices, and these implants have been documented to be at high risk for intraoperative contamination. Approximately 1.2 million arthroplasties are performed annually in the United States, and that number is expected to increase to 3.8 million by the year 2030. The incidence of periprosthetic joint infection is perceived to be low (<2.5%); however, the personal and fiscal morbidity is significant. Although the pharmaceutic and computer industries enforce stringent air quality standards on their manufacturing processes, there is currently no U.S. standard for acceptable air quality within the OR environment. This review documents the contribution of air contamination to the etiology of periprosthetic joint infection, and evidence for selective innovative strategies to reduce the risk of intraoperative microbial aerosols.