Alcohol hand rubs, endorsed by WHO and NICE guidelines, are integral to modern surgical practices. Our objective was to assess how different scrubbing methods impact overall water usage by the surgical team, shedding light on variations among team members and their environmental implications. Over three consecutive arthroplasty lists spanning a week, water usage during scrubbing was observed for the operating team. Blinding all team members, including the anesthetist, consultant surgeon, orthopaedic registrar, orthopaedic SHO, and scrub nurse, during water usage calculations was implemented. Automated taps, using motion sensors, posed a challenge due to variable water quantity, necessitating water flow calculations per sensor movement. The senior surgeon, with over 20 years of experience, follows a traditional approach, starting with a morning prescrub and using an alcohol tub for each case, except when hands are soiled. We observed a total of 14 cases of lower limb primary arthroplasty. The cumulative water usage for scrubbing by the entire team was 193 liters, yielding a mean of 13.8 liters (±1.85) per case. The anaesthetist demonstrated the most conservative water usage, utilizing a total of 11.85 liters with a mean of 0.84 liters per case. Notably, alcohol rub was employed for half of the observed time, contributing to this efficient use. The senior operating surgeon used a total of 15.6 liters, averaging 1.1 liters per case. In contrast, the SHO and the registrar exhibited the highest water consumption, totaling 121.6 liters and yielding a mean of 5.7 liters per case. The nurses’ collective water usage for scrubbing amounted to 44.8 liters. Adopting alcohol rub, as endorsed by WHO, results in a remarkable 10-fold reduction in water usage, aligning with global health guidelines. This highlights significant potential for resource conservation in surgical procedures, presenting a practical and environmentally conscious approach to surgical scrubbing practices

The systemic use of steroids and habitual alcohol intake are two major causative factors in the development of idiopathic osteonecrosis of the femoral head (ONFH). To examine any interaction between oral corticosteroid use and alcohol intake on the risk of ONFH, we conducted a hospital-based case-control study of 71 cases with ONFH (mean age 45 years (20 to 79)) and 227 matched controls (mean age 47 years (18 to 79)). Alcohol intake was positively associated with ONFH among all subjects: the adjusted odds ratio (OR) of subjects with ≥ 3032 drink-years was 3.93 (95% confidence interval (CI) 1.18 to 13.1) compared with never-drinkers. When stratified by steroid use, the OR of such drinkers was 11.1 (95% CI 1.30 to 95.5) among those who had never used steroids, but 1.10 (95% CI 0.21 to 4.79) among those who had. When we assessed any interaction based on a two-by-two table of alcohol and steroid use, the OR of those non-drinkers who did use steroids was markedly elevated (OR 31.5) compared with users of neither. However, no further increase in OR was noted for the effect of using both (OR 31.6). We detected neither a multiplicative nor an additive interaction (p for multiplicative interaction 0.19; synergy index 0.95), suggesting that the added effect of alcohol may be trivial compared with the overwhelming effect of steroids in the development of ONFH. Cite this article: Bone Joint J 2013;95-B:320–5

Osteoporosis can cause significant disability and cost to health services globally. We aim to compare risk fractures for both osteoporosis and fractures at the L1-L4 vertebrae (LV) and the neck of femurs (NOFs) in patients referred for DEXA scan in the North-West of England. Data was obtained from 31546 patients referred for DEXA scan in the North-West of England between 2004 and 2011. Demographic data was retrospectively analysed using STATA, utilising chi-squared and t-tests. Logistical models were used to report odds ratios for risk factors included in the FRAX tool looking for differences between osteoporosis and fracture risk at the LV and NOFs. In a study involving 2530 cases of LV fractures and 1363 of NOF fractures, age was significantly linked to fractures and osteoporosis at both sites, with a higher risk of osteoporosis at NOFs compared to LV. Height provided protection against fractures and osteoporosis at both sites, with a more pronounced protective effect against osteoporosis at NOFs. Weight was more protective for NOF fractures, while smoking increased osteoporosis risk with no site-specific difference. Steroids were unexpectedly protective for fractures at both sites, with no significant difference, while alcohol consumption was protective against osteoporosis at both sites and associated with increased LV fracture risk. Rheumatoid arthritis increased osteoporosis risk in NOFs and implied a higher fracture risk, though not statistically significant compared to LV. Results summarised in Table 1. Our study reveals that established osteoporosis and fracture risk factors impact distinct bony sites differently. Age and rheumatoid arthritis increase osteoporosis risk more at NOFs than LV, while height and steroids provide greater protection at NOFs. Height significantly protects LV fractures, with alcohol predicting them. Further research is needed to explore risk factors’ impact on additional bony sites and understand the observed differences’ pathophysiology. For any figures or tables, please contact the authors directly

Aims. Cemented hemiarthroplasty is an effective form of treatment for most patients with an intracapsular fracture of the hip. However, it remains unclear whether there are subgroups of patients who may benefit from the alternative operation of a modern uncemented hemiarthroplasty – the aim of this study was to investigate this issue. Knowledge about the heterogeneity of treatment effects is important for surgeons in order to target operations towards specific subgroups who would benefit the most. Methods. We used causal forest analysis to compare subgroup- and individual-level treatment effects between cemented and modern uncemented hemiarthroplasty in patients aged > 60 years with an intracapsular fracture of the hip, using data from the World Hip Trauma Evaluation 5 (WHiTE 5) multicentre randomized clinical trial. EuroQol five-dimension index scores were used to measure health-related quality of life at one, four, and 12 months postoperatively. Results. Our analysis revealed a complex landscape of responses to the use of a cemented hemiarthroplasty in the 12 months after surgery. There was heterogeneity of effects with regard to baseline characteristics, including age, pre-injury health status, and lifestyle factors such as alcohol consumption. This heterogeneity was greater at the one-month mark than at subsequent follow-up timepoints, with particular regard to subgroups based on age. However, for all subgroups, the effect estimates for quality of life lay within the confidence intervals derived from the analysis of all patients. Conclusion. The use of a cemented hemiarthroplasty is expected to increase health-related quality of life compared with modern uncemented hemiarthroplasty for all subgroups of patients aged > 60 years with a displaced intracapsular fracture of the hip. Cite this article: Bone Joint J 2024;106-B(7):656–661

Aims. This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy. Methods. Literature reporting on preoperative patient-related risk factors and outcomes following hip arthroscopy were systematically identified from a computer-assisted literature search of Pubmed (Medline), Embase, and Cochrane Library using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and a scoping review. Results. Assessment of these texts yielded 101 final articles involving 90,315 hips for qualitative analysis. The most frequently reported risk factor related to a less favourable outcome after hip arthroscopy was older age and preoperative osteoarthritis of the hip. This was followed by female sex and patients who have low preoperative clinical scores, severe hip dysplasia, altered hip morphology (excess acetabular retroversion or excess femoral anteversion or retroversion), or a large cam deformity. Patients receiving workers’ compensation or with rheumatoid arthritis were also more likely to have a less favourable outcome after hip arthroscopy. There is evidence that obesity, smoking, drinking alcohol, and a history of mental illness may be associated with marginally less favourable outcomes after hip arthroscopy. Athletes (except for ice hockey players) enjoy a more rapid recovery after hip arthroscopy than non-athletes. Finally, patients who have a favourable response to local anaesthetic are more likely to have a favourable outcome after hip arthroscopy. Conclusion. Certain patient-related risk factors are associated with less favourable outcomes following hip arthroscopy. Understanding these risk factors will allow the appropriate surgical indications for hip arthroscopy to be further refined and help patients to comprehend their individual risk profile. Cite this article: Bone Joint J 2020;102-B(7):822–831

Aims. Of growing concern in arthroplasty is the emergence of atypical infections, particularly Cutibacterium (formerly Propionibacterium) sp. infections. Currently, the dermal colonization rate of Cutibacterium about the hip is unknown. Therefore, the aim of this study was to investigate colonization rates of Cutibacterium sp. at locations approximating anterior and posterolateral approaches to the hip joint. Methods. For this non-randomized non-blinded study, 101 adult patients scheduled for hip or knee surgery were recruited. For each, four 3 mm dermal punch biopsies were collected after administration of anaesthesia, but prior to antibiotics. Prebiopsy skin preparation consisted of a standardized preoperative 2% chlorhexidine skin cleansing protocol and an additional 70% isopropyl alcohol mechanical skin scrub immediately prior to biopsy collection. Two skin samples 10 cm apart were collected from a location approximating a standard direct anterior skin incision, and two samples 10 cm apart were collected from a lateral skin incision (suitable for posterior, direct-lateral, or anterolateral approaches). Samples were cultured for two weeks using a protocol optimized for Cutibacterium. Results. A total of 23 out of 404 cultures (collected from 101 patients) were positive for a microorganism, with a total of 22 patients having a positive culture (22%). Overall, 15 of the cultures in 14 patients were positive for Cutibacterium sp. (65%), of which Cutibacterium acnes comprised the majority (n = 13; 87%). Other isolated microorganisms include coagulase-negative Staphylococcus (n = 6), Clostridium (n = 1), and Corynebacterium (n = 1). Of all positive cultures, 15 were obtained from the anterior location (65%), of which seven (60%) were from the most proximal biopsy location. However, these findings were not statistically significant (anterior vs lateral, p = 0.076; proximal vs distal, p =0.238). Conclusion. Approximately 14% (14/101) of the patients demonstrated a positive Cutibacterium colonization about the hip, the majority anteriorly. Given the high colonization rate of Cutibacterium, alternative skin preparations for total hip arthroplasty should be considered. Cite this article: Bone Joint J 2020;102-B(7 Supple B):52–56

Introduction. Prosthetic joint infection (PJI) is the leading cause of failure of primary and revision hip and knee arthroplasty. It is challenging condition which represents a growing burden on hospital resources. In-patient hospital stay for antibiotic therapy post-operatively is costly and access to out-patient IV therapy (OPAT) varies between regions. In a tertiary referral centre for revision and infection, the suitability and cost-effectiveness of Dalbavancin was reviewed as a “single-shot” therapy following DAIR or revision lower limb arthroplasty for PJI. Methods & Materials. A prospective service evaluation was carried out for consecutive patients treated for PJI of the hip or knee who received Dalbavancin. Treatment was indicated by Consultant Microbiologist advice within an MDT setting where clinical or patient factors made alternative therapies eg. OPAT inappropriate. Service-level data was collected to allow calculation of bed-day savings compared to a traditional 14-day course of IV treatment. Readmission rates to the trust within 30 days were reviewed as a marker of clinical efficacy and safety. Results. 12 patients received dalbavancin for PJI. Mean bed-day saving was 6.9 (SD 3.7) per patient. A total of 83 bed days were saved compared to traditional treatment and there was a modest cost-benefit. There were no adverse reactions noted and no readmissions within 30 days. Discussion. The safety and efficacy of dalbavancin has been demonstrated in recent literature, but the impact that it can have on health-care costs and in-patient burden has not been explored. In addition, the success of out-patient therapy relies on patient engagement. In patients with co-existing cognitive difficulty or alcohol/substance use Dalbavancin offers an attractive alternative. Conclusions. The results of our pilot suggest that IV Dalbavancin is cost-effective as part of the treatment strategy for PJI and can lead to significant bed-day savings, which can assist in patient flow and departmental efficiency

Introduction. Cutibacterium acnes (C. acnes) is now recognized as a clinical entity in periprosthetic joint infections (PJI) of the shoulder and spine. However, the colonization rate of C. acnes in the adult hip is currently unknown. Therefore, the purpose of this study was to investigate the rate of C. acnes colonization from the skin of healthy subjects from various anatomic locations corresponding to direct anterior and lateral/posterolateral surgical approaches. Methods. 90 patients scheduled for hip or knee surgery were recruited for cultured biopsies. Four 3-mm dermal punch biopsies were collected after administration of anesthesia, but prior to delivery of perioperative antibiotics. Pre-biopsy skin prep consisted of a standardized pre-operative 2% chlorhexidine skin cleanse and an additional 70% isopropyl alcohol mechanical skin scrub immediately prior to biopsy collection. Two culture samples 10-cm apart were collected from a location approximating a standard direct anterior skin incision, and two samples 10-cm apart were collected from a location approximating a lateral skin incision (suitable for a posterior, direct-lateral or anterolateral surgical approach). Samples were cultured for two weeks. Results. 22 of the 90 (24%) patients had a positive culture biopsy, fourteen of which (16% of all patients) were positive for C. acnes. Ten (71%) of the culture positive biopsies for C. acnes were obtained from the anterior location with 50% of those obtained from the most proximal sample site. Conclusions. Approximately 16% of the patients in the study demonstrated positive C. acnes colonization about the hip, the majority of which occurred from an anterior location. C. acnes should be considered in the diagnosis of PJI after THA. Given the high rate of skin colonization, particularly as regards the direct anterior approach to the hip, these results have stimulated consideration for different skin preparations for the THA patient. For any tables or figures, please contact the authors directly

Osteonecrosis of the femoral head (ONFH) is an ischemic disorder that causes bone and bone marrow necrosis. In spite of many studies, the primary cause of ischemia is still unknown. The purpose of this study is to identify the susceptibility genes in ONFH. We performed a genome-wide association study (GWAS) in 1,602 ONFH cases and 60,000 controls. Stratified GWASs based on the 3 subgroups of ONFH (corticosteroids, alcohol, idiopathic) were also performed. We then evaluated the candidate gene in silico using public databases. Two loci in 12q24.11–12 and 20q12 showed significant association with ONFH. A stratified analysis suggested that the 12q24 locus was associated with ONFH through the drinking capacity. In the 20q12 locus, LINC01370 was the only gene, which functions were related to the plausible biological pathway for the development of ONFH. A novel ONFH locus was identified at chromosome 20q12, and LINC01370 was the best candidate gene in this locus

Aims. Instability continues to be a troublesome complication after total hip arthroplasty (THA). Patient-related risk factors associated with a higher dislocation risk include the preoperative diagnosis, an age of 75 years or older, high body mass index (BMI), a history of alcohol abuse, and neurodegenerative diseases. The goal of this study was to assess the dislocation rate, radiographic outcomes, and complications of patients stratified as high-risk for dislocation who received a dual mobility (DM) bearing in a primary THA at a minimum follow-up of two years. Materials and Methods. We performed a retrospective review of a consecutive series of DM THA performed between 2010 and 2014 at our institution (Hospital for Special Surgery, New York, New York) by a single, high-volume orthopaedic surgeon employing a single prosthesis design (Anatomic Dual Mobility (ADM) Stryker, Mahwah, New Jersey). Patient medical records and radiographs were reviewed to confirm the type of implant used, to identify any preoperative risk factors for dislocation, and any complications. Radiographic analysis was performed to assess for signs of osteolysis or remodelling of the acetabulum. Results. There were 151 patients who met the classification of high-risk according to the inclusion criteria and received DM THA during the study period. Mean age was 82 years old (73 to 95) and 114 patients (77.5%) were female. Mean follow-up was 3.6 years (1.9 to 6.1), with five patients lost to follow-up and one patient who died (for a reason unrelated to the index procedure). One patient (0.66%) sustained an intraprosthetic dislocation; there were no other dislocations. Conclusion. At mid-term follow-up, the use of a DM bearing for primary THA in patients at high risk of dislocation provided a stable reconstruction option with excellent radiographic results. Longer follow-up is needed to confirm the durability of these reconstructions

We investigated the preliminary results of femoral head necrosis treated by modified femoral neck osteotomy through surgical hip dislocation in young adults. 33 patients with femoral head osteonecrosis received modified femoral neck osteotomy through surgical hip dislocation from March 2015. 14 patients who had minimal 12 months of follow-up were reviewed radiographically and clinically (mean follow-up:16 months, 12–36 months). The mean age of the patients 32 years at the time of surgery (ranged from 16 to 42years). There were 6 women and 8 men. The cause of the osteonecrosis was steroid administration in 6, alcohol abuse in 4, trauma in 3, and no apparent risk factor in 1. According to the Ficat staging system, 1 hips was stage II, 9 hips III, and 4 hips stage IV. The posterior or anterior rotational angle was 90–180° with a mean of 143°. Clinical evaluation was performed in terms of pain, walk and range of motion on the basis of Merle d'Aubigné hip scores: 17–18 points are excellent, 15–16 are good, 13–14 are fair, 12 or less are poor. Recollapse of the final follow-up anteroposterior radiograph was prevented in 13 hips. One patient got 1 mm recollapse 18 months after surgery. No patient got progressive joint space narrowing. The Merle d'Aubigné score was excellent in 7 hips, good in 5, fair in 2. The preliminary results suggest that modified femoral neck osteotomy through surgical hip dislocation is in favor of young patients. But longer term follow-up is necessary

Instability continues to be a troublesome complication after THA and has been reported to be the main indication for revision in the United States, accounting for 22.5% of revisions. Risk factors associated with dislocation include: age of 75 years or older, body mass index (BMI) of 30 kg/m2 or greater, alcohol abuse, and neuro-degenerative diseases such as multiple sclerosis or Parkinson's disease. Dual-mobility articulations have become an increasingly popular option for these “at risk” primary THAs. Few studies have assessed their use in this complex patient population. The purpose of this study was to assess dislocation rate, radiographic outcomes and complications of the dual-mobility articulation in the setting of primary THA for patients at high risk for dislocation at a minimum follow up of 2 years. We retrospectively reviewed 151 dual mobility acetabular components, that had been performed using a single design (ADM Stryker, Mahwah, NJ) between 2010 and 2014 at a single institution by a single surgeon. The mean age at time of index surgery was 82 years (range, 73–95), 114 patients were female, and mean BMI was 26.2 kg/m2 (range, 16.1–60.9). Dislocation rate and complications associated with dual mobility cups were reviewed, along with the radiographic outcomes after an average follow-up period of 3.6 years (range, 1.9–6.1 years). The indication for hip replacement was osteoarthritis in all cases. We had one traumatic dislocation which required component revision after intraprosthetic dislocation following an attempt of closed reduction. There were no further dislocations in this cohort. No progressive radiolucencies or component positional changes were seen on radiographic assessment. At short-term follow-up dual mobility provides a stable reconstruction in patients at high risk of dislocation with excellent radiographic results. Longer follow-up is needed to confirm the durability of these reconstructions

Aims

Our primary aim was to assess reoperation-free survival at one year after the index injury in patients aged ≥ 75 years treated with internal fixation (IF) or arthroplasty for undisplaced femoral neck fractures (uFNFs). Secondary outcomes were reoperations and mortality analyzed separately.

Aims

This study was designed to develop a model for predicting bone mineral density (BMD) loss of the femur after total hip arthroplasty (THA) using artificial intelligence (AI), and to identify factors that influence the prediction. Additionally, we virtually examined the efficacy of administration of bisphosphonate for cases with severe BMD loss based on the predictive model.

Aims

The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems.

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It is not known whether preservation of the capsule of the hip positively affects patient-reported outcome measures (PROMs) in total hip arthroplasty using the direct anterior approach (DAA-THA). A recent randomized controlled trial found no clinically significant difference at one year postoperatively. This study aimed to determine whether preservation of the anterolateral capsule and anatomical closure improve the outcome and revision rate, when compared with resection of the anterolateral capsule, at two years postoperatively.

Bone ingrowth is desired with uncemented hip implants. Infection is clearly undesirable. We have worked on developing a nanofiber coating for implants that would enhance bone formation while inhibiting infection. Few studies have focused on developing an implant surface nanofiber (NF) coating to prevent infection and enhance osseointegration by local drug release. In this study, coaxial doxycycline (Doxy)-doped polycaprolactone/polyvinyl alcohol (PCL/PVA) Nanofibers were directly deposited on the titanium (Ti) implant surface during electrospinning. The interaction of loaded Doxy with both PVA and PCL NFs was characterized by Raman spectroscopy. The bonding strength of Doxy-doped NF coating on Ti implants was confirmed by a stand single-pass scratch test. The improved implant osseointegration by PCL/PVA NF coatings in vivo was confirmed by scanning electron microscopy, histomorphometry and micro computed tomography at 2, 4 and 8 weeks after implantation. The bone contact surface (%) changes of NF coating group (80%) is significantly higher than that of no NF group (< 5%, p<0.05). Finally, we demonstrated that Doxy-doped NF coating effectively inhibited bacterial infection and enhanced osseointegration in an infected (Staphylococcus aureus) tibia implantation rat model. Doxy released from NF coating inhibited bacterial growth up to 8 weeks in vivo. The maximal push-in force of Doxy-NF coating (38 N) is much higher than that of NF coating group (6.5 N) 8 weeks after implantation (p<0.05), which was further confirmed by quantitative histological analysis and micro computed tomography. These findings indicate that coaxial PCL/PVA NF coating doped with Doxy and/or other drugs have great potential in enhancing implant osseointegration and preventing infection

Aims

The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England.

Introduction. Several surgical approaches are available for elective total hip arthroplasty (THA) for osteoarthritis. While posterior surgical approaches are the most common, interest in a direct anterior (Hueter) approach is increasing because of alleged advantages in convalescence. However, no studies have examined differences in patient-reported global and condition-specific measures of health across multiple institutions. The ongoing Pulmonary Embolism Prevention after Hip and Knee Replacement (PEPPER) study is a PCORI-funded multicenter pragmatic clinical trial randomizing patients to three different antithrombotic regimens. We analyzed operative data from PEPPER to compare pre-post changes in validated patient-reported outcome measures after THA based on surgical approach. Methods. Participants (age 21 or older) were recruited from 27 academic medical centers for the PEPPER trial. Eligibility screening, baseline measures, and operative detail were entered into a central database with standardized blinded post-operative data collection protocol. We included participants undergoing elective primary total hip arthroplasty, excluding those undergoing revision, resurfacing, bilateral procedures, on chronic preoperative anticoagulation, with a recent history of gastrointestinal, cerebral, or other hemorrhage, defective hemostasis, or uncontrolled hypertension. Participating centers reported the operative approach as “Posterior”, “Transgluteal”, or “Anterior”. The brief version of the Hip Dysfunction and Osteoarthritis Outcome Score (HOOS Jr.) and the Patient Reported Outcome Measurement Information System Global Survey (PROMIS10) were ascertained pre-operatively, and at 1, 3 and 6 months post-operatively. Mixed-effects linear regression was used to compare difference in patient-reported outcomes over time based on surgical approach, adjusting for baseline measures of health outcome, patient age, sex, race, ethnicity, BMI, comorbidity, education, work status, alcohol use, and smoking status. Results. As of 5/15/2018, a total of 1,238 patients had undergone primary THA as part of the PEPPER trial and were being monitored postoperatively, including 51.6% involving posterior, 18.1% transgluteal, and 30.3% anterior surgical approaches. Mean preoperative HOOS Jr. scores for posterior approach (47.6; 95%CI 46.4 – 48.7) were similar to transgluteal (47.4, 95%CI 45.4 – 49.5, p=0.654) and anterior (48.9, 95%CI 47.4 – 50.4, p=0.461) approaches. At 6-month follow-up, adjusted mean HOOS Jr. Scores significantly improved for all groups, but were not statistically different between groups. The adjusted mean HOOS Jr. score at 6 months was 85.6 for those undergoing a posterior (95%CI 83.7 – 87.5), 83.6 for transgluteal (95%CI 79.0 – 88.2, p=.474) and 85.0 for anterior approaches (95%CI 82.6 – 87.5, p=0.255). Baseline PROMIS-10 Physical Function scores were similar between posterior (40.1; 95%CI 40.2 – 41.3), transgluteal (40.6, 95%CI 39.6 – 41.6, p=0.716), and anterior approaches (41.5, 95%CI 40.8 – 42.3, p=0.390), with similar postoperative improvement through 6 months (posterior=52.1, 95%CI 51.2 – 53.0; transgluteal=52.4, 95%CI 50.2 – 54.5, p=0.734; anterior=52.8, 95%CI 51.6 – 53.9, p=0.414). These findings were robust utilizing a variety of methods to account for missing responses. Conclusion. We found similar short-term improvements in patient-reported global measures of health between posterior, transgluteal, and anterior surgical approaches for elective THA, and a trend suggesting inferior early patient-reported measures of function with a trans-gluteal surgical approach

Deep infection occurs in 2–4% of lower limb arthroplasty resulting in increasing cost, co-morbidity and challenging revision arthroplasty surgery. Identifying the potential sources of infection helps reduce infection rates. The aim of our study is to identify the impact and potential for contamination of our hands and gowns whilst scrubbing using SSHS. A colony-forming unit (CFU) is a pathogenic particle of 0.5 micrometers to 5 micrometers. Concurrent particle counts and blood agar exposure settle plates for 3 subjects and 1 alcohol cleaned mannequin; testing a standard arthroplasty hood, a SSHS with and without the fan on for a 2 minute exposure to represent scrubbing time. Microbiological plates were incubated using a standard protocol by our local microbiology department. All SSHS were positive for gram-positive cocci with a mean colony count of 410cfu/m. 2. Comparing background counts for laminar flow (mean 0.7 particle/m. 3. ; 95% CI 0–1.4) versus scrub areas (mean 131.5 particle/m3; 95% CI 123.5–137.9; p=0.0003), however neither grew any CFU's with a 2-minute exposure. For the mannequin, the only significant result was with the fan on with a 1.5× increase in the particle count (p=0.042) and a correlating positive organism (13CFU/m. 2. ). With human subjects, however, the particle count increased by 3.75× the background count with the fan on (total p=0.004, CFU p=0.047) and all had positive cultures, mean 36 CFU/m. 2. There were no positive cultures with the standard arthroplasty hood or the SSHS with no fan on. If repeated in laminar flow, there was only a statistically significant increase with the fan on (p=0.049), but with negative cultures following a 2-minute exposure. Sterile gloves and gowns can be contaminated when scrubbing with the SSHS fan on. We recommend having the fan switched off when scrubbing until the hood and gown is in place, ideally in a laminar flow environment