Aims

This study aimed to assess the carbon footprint associated with total hip arthroplasty (THA) in a UK hospital setting, considering various components within the operating theatre. The primary objective was to identify actionable areas for reducing carbon emissions and promoting sustainable orthopaedic practices.

Aim. Whether laminar airflow (LAF) in the operating room (OR) is effective for decreasing periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) remains a clinically significant yet controversial issue. This study investigated the association between operating room ventilation systems and the risk of PJI in TJA patients. Method. We performed a retrospective observational study on consecutive patients undergoing primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) from January 2013-September 2017 in two surgical facilities within a single institution, with a minimum 1-year follow-up. All procedures were performed by five board-certified arthroplasty surgeons. The operating rooms at the facilities were equipped with LAF and turbulent ventilation systems, respectively. Patient characteristics were extracted from clinical records. PJI was defined according to Musculoskeletal Infection Society criteria within 1-year of the index arthroplasty. A multivariate logistic regression model was performed to explore the association between LAF and risk of 1-year PJI, and then a sensitivity analysis using propensity score matching (PSM) was performed to further validate the findings. Results. A total of 6,972 patients (2,797 TKA, 4,175 THA) were included. The incidence of PJI within 1 year for patients from the facility without laminar flow was similar at 0·4% to that of patients from the facility with laminar flow at 0·5%. In the multivariate logistic regression analysis, after all confounding factors were taken into account, the use of LAF was not significantly associated with reduction of the risk of PJI. After propensity score matching, there was no significant difference in the incidence of PJI within 1 year for patients between the two sites. Conclusions. The use of LAF in the operating room was not associated with a reduced incidence of PJI following primary TJA. With an appropriate perioperative protocol for infection prevention, LAF does not seem to play a protective role in PJI prevention

Literature debates whether fluid aspirates for suspected PJI should undergo prolonged incubation for cultures. We looked at sensitivity and specificity of 14-day cultures, compared to 7-days, for aspirates from prosthetic hips and knees. Design and methods. Conducted at a quaternary referral centre for PJIs from Jan 2017 to July 2019. Suspected PJIs who underwent aspiration, incubated 14 days and later surgical intervention with minimum three tissue samples were included. Results. 176 aspirates were included. This is an increased number compared to our historic figures (average 88 Vs 48 pts/yr). 47 patients had fluid and tissue positive (true positive), 20 fluid +ive but tissue -ive (false positive), 98 fluid and tissue -ive (true negative) and 15 fluid negative but tissue +ive (False negative). Thus, sensitivity 76%, specificity 83%, positive predictive value70% and negative predictive value 87%. Of 88 positive aspirates, only 75% were within 7-day cultures. Low virulence organisms as Propionibacterium acnes and coagulase negative staph were grown later. Of 48 with only one tissue sample positive, 38 were culture-negative on aspiration and 6 grew different organisms on aspirate and tissues. Also, as many were cultured later, it suggests contamination. Conclusion. Increased numbers reflect quaternary referral nature of institution and increasing PJI load. Modest drop in sensitivity and specificity of 14-day cultures compared to 7-day(84 and 85% respectively) is due to higher false negatives. Contamination contributes to false-ive as more tissue samples become positive (there were 1076 tissue samples due to multiple sampling Vs 176 aspirates). Higher tissue yield may also be because they are more representative. Effect of antibiotic use between samples cannot be determined. Organism profile suggest14-day culture produces more contaminant growth despite a well-equipped microbiology lab with laminar airflow for subcultures. Caution in interpreting 14-day results in diagnosis of PJI of Hip and Knee is advised

Aims

We report the long-term clinical and radiological outcomes of a consecutive series of 200 total ankle arthroplasties (TAAs, 184 patients) at a single centre using the Scandinavian Total Ankle Replacement (STAR) implants.

Aims

Total ankle arthroplasty (TAA) surgery is complex and attracts a wide variety of complications. The literature lacks consistency in reporting adverse events and complications. The aim of this article is to provide a comprehensive analysis of each of these complications from a literature review, and to compare them with rates from our Unit, to aid clinicians with the process of informed consent.

Deep infection was identified as a serious complication in the earliest days of total hip arthroplasty. It was identified that airborne contamination in conventional operating theatres was the major contributing factor. As progress was made in improving the engineering of operating theatres, airborne contamination was reduced. Detailed studies were carried out relating airborne contamination to deep infection rates.

In a trial conducted by the United Kingdom Medical Research Council (MRC), it was found that the use of ultra-clean air (UCA) operating theatres was associated with a significant reduction in deep infection rates. Deep infection rates were further reduced by the use of a body exhaust system. The MRC trial also included a detailed microbiology study, which confirmed the relationship between airborne contamination and deep infection rates.

Recent observational evidence from joint registries has shown that in contemporary practice, infection rates remain a problem, and may be getting worse. Registry observations have also called into question the value of “laminar flow” operating theatres.

Observational evidence from joint registries provides very limited evidence on the efficacy of UCA operating theatres. Although there have been some changes in surgical practice in recent years, the conclusions of the MRC trial remain valid, and the use of UCA is essential in preventing deep infection.

There is evidence that if UCA operating theatres are not used correctly, they may have poor microbiological performance. Current UCA operating theatres have limitations, and further research is required to update them and improve their microbiological performance in contemporary practice.

Cite this article: Bone Joint J 2018;100-B:1264–9.

Laminar airflow systems are universal in current orthopaedic operating theatres and are assumed to be associated with a lower risk of contamination of the surgical wound and subsequent early infection. Evidence to support their use is limited and sometimes conflicting. We investigated whether there were any differences in infection rates (deep and superficial) between knee and hip arthroplasty cases performed in non-laminar and laminar flow theatres at 10 year follow-up. Between 2002 and 2006, 318 patients underwent knee and hip arthroplasty in a non-laminar flow theatre. Prospectively collected local arthroplasty audit data was collected including superficial and deep infection, revision for infection and functional outcomes. A cohort of patients from the same time period, who underwent knee and hip arthroplasty in a laminar flow theatre, were matched for age, sex, body mass index (BMI), operative approach, implant and experience of surgeon. Superficial infection rates were lower overall in the non-laminar flow theatre (2.2percnt; versus 4.7percnt;), with a significantly lower superficial infection rate for knee arthroplasty performed in the non-laminar flow theatre (2percnt; versus 6.9percnt;). The deep infection rates were similar (1.3percnt; vs 1.9percnt;) for both laminar and non-laminar flow theatre respectively. Revision rates for infection were similar between both groups (0.9percnt; in non-laminar flow theatre vs 0.3percnt; in laminar flow). Whilst the causes of post-operative surgical site infection are multifactorial, our results demonstrate that at long –term follow-up, there was no increased risk of infection without laminar flow use in our theatre

Aims. The interaction between surgical lighting and laminar airflow is poorly understood. We undertook an experiment to identify any effect contemporary surgical lights have on laminar flow and recommend practical strategies to limit any negative effects. Materials and Methods. Neutrally buoyant bubbles were introduced into the surgical field of a simulated setup for a routine total knee arthroplasty in a laminar flow theatre. Patterns of airflow were observed and the number of bubbles remaining above the surgical field over time identified. Five different lighting configurations were assessed. Data were analysed using simple linear regression after logarithmic transformation. Results. In the absence of surgical lights, laminar airflow was observed, bubbles were cleared rapidly and did not accumulate. If lights were placed above the surgical field laminar airflow was abolished and bubbles rose from the surgical field to the lights then circulated back to the surgical field. The value of the decay parameter (slope) of the two setups differed significantly; no light (b = -1.589) versus one light (b = -0.1273, p < 0.001). Two lights touching (b = -0.1191) above the surgical field had a similar effect to that of a single light (p = 0. 2719). Two lights positioned by arms outstretched had a similar effect (b = -0.1204) to two lights touching (p = 0.998) and one light (p = 0.444). When lights were separated widely (160 cm), laminar airflow was observed but the rate of clearance of the bubbles remained slower (b = -1.1165) than with no lights present (p = 0.004). . Conclusion. Surgical lights have a significantly negative effect on laminar airflow. Lights should be positioned as far away as practicable from the surgical field to limit this effect. Cite this article: Bone Joint J 2017;99-B:1061–6

Aim. The aim of this study was to validate the information on operating room ventilation reported to the Norwegian Arthroplasty Register (NAR) and to assess the influence of this ventilation on the risk of revision due to infection after primary total hip arthroplasty (THA). Method. Current and previous ventilation systems were evaluated together with the hospitals head engineer in 40 orthopaedic hospitals. The ventilation system of each operating room was assessed and confirmed as either conventional ventilation, vertical laminar airflow (LAF) or horizontal LAF. We then identified cases of first revision due to deep infection after primary THA and the type of ventilation system reported to the NAR in the period 1987–2014. The association between revision due to infection and operating room ventilation was estimated by relative risks (RR) in a Cox regression model. Results. 103370 primary THAs and 971 (0.9%) first revisions due to deep infection were reported. 51% of the primary THAs were performed in a room with vertical LAF, 44% in a room with conventional ventilation and 5% in a room with horizontal LAF. There was a mean misreporting rate of approximately 12%. There was similar risk of revision due to infection after THA performed in operating rooms with vertical laminar air flow compared to conventional ventilation (RR=0.95, 95 % CI: 0.8–1.1) and an increased risk of revision due to infection after THA performed in horizontal LAF conditions compared to conventionally ventilated conditions (RR=1.3, 95 % CI: 1.0–1.7). Conclusions. Surgeons are not fully aware of what kind of ventilation there is in the operating room. This study may indicate that vertical LAF is not superior to conventional ventilation concerning reduction of THA infection, and therefore does not justify any increased installation costs. Also, horizontal LAF systems appear to be inferior to other ventilation systems

Objectives. During open orthopaedic surgery, joints may be exposed to air, potentially leading to cartilage drying and chondrocyte death, however, the long-term effects of joint drying in vivo are poorly understood. We used an animal model to investigate the subsequent effects of joint drying on cartilage and chondrocytes. Methods. The patellar groove of anaesthetised rats was exposed (sham-operated), or exposed and then subjected to laminar airflow (0.25m/s; 60 minutes) before wounds were sutured and animals recovered. Animals were monitored for up to eight weeks and then sacrificed. Cartilage and chondrocyte properties were studied by histology and confocal microscopy, respectively. Results. Joint drying caused extensive chondrocyte death within the superficial regions of cartilage. Histology of dried cartilage demonstrated a loss of surface integrity at four weeks, fibrillations at eight weeks, and an increased modified Mankin score (p < 0.001). Cartilage thickness increased (p < 0.001), whereas chondrocyte density decreased at four weeks (p < 0.001), but then increased towards sham-operated levels (p < 0.01) at eight weeks. By week eight, chondrocyte pairing/clustering and cell volume increased (p < 0.05; p < 0.001, respectively). Conclusions. These in vivo results demonstrated for the first time that as a result of laminar airflow, cartilage degeneration occurred which has characteristics similar to those seen in early osteoarthritis. Maintenance of adequate cartilage hydration during open orthopaedic surgery is therefore of paramount importance. Cite this article: Dr A. Hall. Drying of open animal joints in vivo subsequently causes cartilage degeneration. Bone Joint Res 2016;5:137–144. DOI: 10.1302/2046-3758.54.2000594

Periprosthetic joint infection (PJI) complicates between 0.5% and 1.2% primary total hip arthroplasties (THAs) and may have devastating consequences. The traditional assessment of patients suffering from PJI has involved the serological study of inflammatory markers and microbiological analysis of samples obtained from the joint space. Treatment has involved debridement and revision arthroplasty performed in either one or two stages.

We present an update on the burden of PJI, strategies for its diagnosis and treatment, the challenge of resistant organisms and the need for definitive evidence to guide the treatment of PJI after THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):27–30.

We conducted a randomized controlled trial (RCT) to investigate if iodine impregnated incision drapes (IIID) increases bacterial recolonization rates compared to no drape use under conditions of simulated total knee arthroplasty (TKA) surgery. Background: To prevent surgical site infection (SSI), one of the important issues is managing the patient´s own skin flora. Many prophylactic initiatives have been suggested, including the use of IIID. IIID has been debated for many years and was deemed ineffective in preventing SSI in a recent systematic review [1], while some evidence suggests a potential increase in postoperative infection risk, as a result of IIID use [2]. IIID is sparsely investigated in orthopaedic surgery. An increase in the number of viable bacteria in the surgical field of an arthroplasty operation has a potential to increase the risk of SSI in an otherwise elective and clean procedure [3]. 20 patients scheduled for TKA were recruited. Each patient had one knee randomized for draping with IIID [4] while the contralateral knee was left bare, thus the patients acted as their own controls. Operating theater settings with laminar airflow and standard perioperative procedures were simulated. Sampling was performed with the cup-scrup technique [5] using appropriate neutralizers. Samples were collected from the skin of each knee prior to disinfection and on 2 occasions after skin-preparation, 75 minutes apart. Bacterial quantities were estimated by spread plating with 48-hour aerobic incubation. Outcome was measured as colony forming units per square centimeter of skin. We used Wilcoxon signed-rank test for comparative analysis within and between knees. Following skin-disinfection we found no significant difference in bacterial quantities between the intervention and the control knee (p = 0.388). Neither did we see any difference in bacterial quantities between the two groups after 75 minutes of simulated surgery (p = 0.367). When analyzed within the intervention and control group, bacterial quantities had not significantly increased at the end of surgery when compared to baseline, thus no recolonization was detected (p = 0.665 and 0.609, respectively). Iodine impregnated incision drapes did not increase bacterial recolonization rates in simulated TKA surgery. Thus, the results of this RCT study does not support the hypothesis that iodine impregnated incision drapes promotes bacterial recolonization and postoperative infection risk

The aim of this study was to validate the information on operating room ventilation reported to the Norwegian Arthroplasty Register (NAR). We then wanted to assess the influence of operating room ventilation on the rate of revision due to infection after primary THA performed in operating rooms with conventional ventilation, “greenhouse”–ventilation and Laminar Airflow ventilation (LAF). We identified cases of THA revisions due to deep infection and the type of ventilation system reported to the NAR from the primary THA. We included 5 orthopaedic units reporting 17947 primary THAs and 136 (0.8%) revisions due to infection during the 28 year inclusion period from 1987 to 2014. The hospitals were visited and the current and previous ventilation systems were evaluated together with the hospitals head engineer, and the factual ventilation on the specific operating rooms was thereby assessed. The association between revision due to infection and operating room ventilation was estimated by calculating relative risks (RR) in a Cox regression model. 73% of the primary THAs were performed in a room with LAF, in contrast to the reported 80 % of LAF. There was similar risk of revision due to infection after THA performed in operating rooms with laminar air flow compared to conventional ventilation (RR=0.7, 95 % CI: 0.2–2.3) and after THA performed in operating rooms with “greenhouse”-ventilation compared to conventional ventilation (RR=1.2, 0.1–11). Surgeons are not fully aware of what kind of ventilation there is in the operating room. This study may indicate that, concerning reduction in incidence of THA infection, LAF does not justify the substantial installation cost. The numbers in the present study are too small to conclude strongly. Therefore, the study will be expanded to include all hospitals reporting to the NAR

To compare the number of airborne bacteria and particles under laminar airflow (LAF) versus turbulent airflow (TAF) with 100% and 50% reduced fresh air exchange during simulated total hip arthroplasty (THA). Two equally dimensioned operating rooms (OR) build in 2009 with modern ventilation systems of LAF and TAF respectively were used during 32 simulated THA-operations under four different ventilation conditions: LAF or TAF with either full (n=8+8) or 50% reduced (n=8+8) fresh air exchange volume. We followed a protocol controlling the complete perioperative setup including interior cleaning, sterile materials, OR-personnel procedures, surgical clothing, instruments and 50-minute surgical procedure on a full-sized dummy at 37°C. Microbial contamination was determined intra-operatively by ISO-validated Microbiological Active Sampler (MAS-100, Merck, 100 L/min) at two 10-minute intervals in 30 cm distance of the operating field. Blood-agar plates from each operation were incubated for 2 days at 35°C and the microbial concentration was determined by viable counting of colony-forming units (CFU) per m3 air. Furthermore airborne particulate (0,5–10 µm) was sampled with ISO-validated light scattering particle analyzer (MET-one, Beckman Coulter, 28,3 L/min) during the 50-minute surgical procedure (1,42 m3/operation). Large particle sizes (>5 µm) are correlated with microbial contamination (Stocks, 2010). According to standards large-sized particle number must not exceed a 2.900/m3-threshold for cleanroom operations. Microbial air concentration (mean CFU/m3 ±standard deviation) under LAF conditions with full and 50% reduced fresh air exchange were 0,4±0,8 and 0,4±0,4 respectively, whereas air contamination under TAF conditions were significantly higher with 7,6±2,0 and 10,3±8,1 (p<0,05). Large (>5 µm) airborne particulate (mean no./m3 ±standard deviation) under LAF conditions with full and 50% reduced fresh air exchange were 1.581±2.841 and 1.018±1.084 respectively, whereas particulate under TAF conditions were 7.923±5.151 and 6.157±2.439 respectively. Microbial air contamination was significantly lower under LAF ventilation compared to TAF during simulated THA under both full and 50% reduced fresh air exchange in modern operating theatres used in daily clinic. The number of particles measured under TAF conditions exceeded the threshold for cleanroom operations in 12/16 simulated operations. These findings indicate that LAF reduces the airborne microbial risk factor of surgical site infection in comparison to TAF

The number of arthroplasties being undertaken is expected to grow year on year, and periprosthetic joint infections will be an increasing socioeconomic burden. The challenge to prevent and eradicate these infections has resulted in the emergence of several new strategies, which are discussed in this review.

Cite this article: Bone Joint J 2015;97-B:1162–9.

We compared the clinical and radiographic results of total ankle replacement (TAR) performed in non-diabetic and diabetic patients. We identified 173 patients who underwent unilateral TAR between 2004 and 2011 with a minimum of two years’ follow-up. There were 88 male (50.9%) and 85 female (49.1%) patients with a mean age of 66 years (sd 7.9, 43 to 84). There were 43 diabetic patients, including 25 with controlled diabetes and 18 with uncontrolled diabetes, and 130 non-diabetic patients. The clinical data which were analysed included the Ankle Osteoarthritis Scale (AOS) and the American Orthopaedic Foot and Ankle Society (AOFAS) scores, as well the incidence of peri-operative complications.

The mean AOS and AOFAS scores were significantly better in the non-diabetic group (p = 0.018 and p = 0.038, respectively). In all, nine TARs (21%) in the diabetic group had clinical failure at a mean follow-up of five years (24 to 109), which was significantly higher than the rate of failure of 15 (11.6%) in the non-diabetic group (p = 0.004). The uncontrolled diabetic subgroup had a significantly poorer outcome than the non-diabetic group (p = 0.02), and a higher rate of delayed wound healing.

The incidence of early-onset osteolysis was higher in the diabetic group than in the non-diabetic group (p = 0.02). These results suggest that diabetes mellitus, especially with poor glycaemic control, negatively affects the short- to mid-term outcome after TAR.

Cite this article: Bone Joint J 2014;96-B:1674–80.

The aim of this study was to evaluate whether coating titanium discs with selenium in the form of sodium selenite decreased bacterial adhesion of Staphylococcus aureus and Staph. epidermidis and impeded osteoblastic cell growth.

In order to evaluate bacterial adhesion, sterile titanium discs were coated with increasing concentrations of selenium and incubated with bacterial solutions of Staph. aureus (ATCC 29213) and Staph. epidermidis (DSM 3269) and stained with Safranin-O. The effect of selenium on osteoblastic cell growth was also observed. The adherence of MG-63 cells on the coated discs was detected by staining with Safranin-O. The proportion of covered area was calculated with imaging software.

The tested Staph. aureus strain showed a significantly reduced attachment on titanium discs with 0.5% (p = 0.011) and 0.2% (p = 0.02) selenium coating. Our test strain from Staph. epidermidis showed a highly significant reduction in bacterial adherence on discs coated with 0.5% (p = 0.0099) and 0.2% (p = 0.002) selenium solution. There was no inhibitory effect of the selenium coating on the osteoblastic cell growth.

Selenium coating is a promising method to reduce bacterial attachment on prosthetic material.

Cite this article: Bone Joint J 2013;95-B:678–82.

We have recently shown that waste heat from forced-air warming blankets can increase the temperature and concentration of airborne particles over the surgical site. The mechanism for the increased concentration of particles and their site of origin remained unclear. We therefore attempted to visualise the airflow in theatre over a simulated total knee replacement using neutral-buoyancy helium bubbles. Particles were created using a Rocket PS23 smoke machine positioned below the operating table, a potential area of contamination. The same theatre set-up, warming devices and controls were used as in our previous study. This demonstrated that waste heat from the poorly insulated forced-air warming blanket increased the air temperature on the surgical side of the drape by > 5°C. This created convection currents that rose against the downward unidirectional airflow, causing turbulence over the patient. The convection currents increased the particle concentration 1000-fold (2 174 000 particles/m³ for forced-air warming vs 1000 particles/m³ for radiant warming and 2000 particles/m³ for the control) by drawing potentially contaminated particles from below the operating table into the surgical site.

Cite this article: Bone Joint J 2013;95-B:407–10.

Periprosthetic joint infection (PJI) is a devastating complication which can follow a total joint arthroplasty (TJA). Although rare, this ongoing threat undermines the success of TJA, a historically reputable procedure. It has haunted the orthopedic community for decades and several ongoing studies have provided insights and new approaches to effectively battle this multilayered problem.