Extended patient waiting lists for assessment and treatment are widely reported for planned elective joint replacement surgery. The development of regionally based Elective Orthopaedic Centres, separate from units that provide acute, urgent or trauma care has been suggested as one solution to provide protected capacity and patient pathways. These centres will adopt protocolised care to allow high volume activity and increased day-case care. We report the plan to establish a new elective orthopaedic centre serving a population of 2.4 million people. A census conducted in 2022 identified that 15000 patients were awaiting joint replacement surgery with predictions for further increases in waiting times. The principle of care will be to offer routine primary arthroplasty surgery for low risk (ASA 1 and 2) patients at a new regional centre. Pre-operative assessment and preparation will be undertaken digitally, virtually and/or in person at local centres close to the where patients live. This requires new and integrated pathways and ways of working. Predicting which patients will require perioperative transfusion of blood products is an important safety and quality consideration for new pathways. We reviewed all cases of hip and knee arthroplasty surgery conducted at our centre over a 12-month period and identified pre-operative patient related predictive factors to allow us to predict the need for the perioperative transfusion of blood products. We examined patient sex, age, pre-operative haemaglobin and platelet count, use of anti-coagulants, weight and body mass index to allow us to construct the Imperial blood transfusion tool. We have used the results of our study and the transfusion tool to propose the patient pathway for the new regional elective orthopaedic centre which we present

Introduction. Oral factor Xa inhibitors have recently been licensed for use as thromboprophylaxis in arthroplasty surgery. Phase IV trials have proven there efficacy in DVT/PE prevention with comparable rates in major adverse events, including major bleeding. We examined whether the introduction of rivaroxoban, an oral factor Xa inhibitor, increased total blood loss in patients undergoing primary arthroplasty surgery. Methods. Two groups were studied. The intervention group were prescribed rivaroxoban thrombophrophylaxis 6–10 hours post-surgery, and the control group were prescribed low molecular weight heparin (daltaparin 5,000u) 6–10 hours post-surgery. All other factors were kept constant. Pre- and post-operative haemoglobin levels (post-operative day 2) were recorded. Any requirement for transfusion was also documented. Actual drop in haemoglobin levels was compared between the two groups. Results. 91 patients were prescribed rivaroxoban (48 THR and 43 TKR), and 71 were included in the control group (34 THR and 37 TKR). Baseline pre-operative haemoglobin were comparable (p=0.43; 13.0 vs 13.2g/dL), however, post-operative blood loss was significantly increased in the rivaroxoban group (p=< 0.0001; 3.6 vs 2.8g/dL). Total knee replacements had a significant increase in post-operative blood loss in the rivaroxoban group (p=< 0.0001; 3.4 vs 2.6g/dL). Total hip replacement surgery had an increase in total blood loss in the rivaroxoban group, but this did not reach statistical significance (p=0.33; 3.8 vs 3.3g/dL). More patients undergoing TKR required transfusion in the rivaroxoban group (0.07% vs 0.03%). Conclusions. Oral factor Xa inhibitors significantly increase post-operative blood loss in total knee arthroplasty surgery when compared with LMWH. There is a subsequent increased requirement for blood transfusion and the potential complications related to bleeding and transfusion. These factors must be considered and balanced with the ease of oral anticoagulation when introducing these newer agents in arthroplasty patients

Aims

Our primary aim was to establish the proportion of female orthopaedic consultants who perform arthroplasty via cases submitted to the National Joint Registry (NJR), which covers England, Wales, Northern Ireland, the Isle of Man, and Guernsey. Secondary aims included comparing time since specialist registration, private practice participation, and number of hospitals worked in between male and female surgeons.

Aims

Elective orthopaedic services have had to adapt to significant system-wide pressures since the emergence of COVID-19 in December 2019. Length of stay is often recognized as a key marker of quality of care in patients undergoing arthroplasty. Expeditious discharge is key in establishing early rehabilitation and in reducing infection risk, both procedure-related and from COVID-19. The primary aim was to determine the effects of the COVID-19 pandemic length of stay following hip and knee arthroplasty at a high-volume, elective orthopaedic centre.

Arthroplasty procedures in low-income countries are mostly performed at tertiary centers, with waiting lists exceeding 12 to 24 months. Providing arthroplasty services at other levels of healthcare aims to offset this burden, however there is a marked paucity of literature regarding surgical outcomes. This study aims to provide evidence on the safety of arthroplasty at district level. Retrospective review of consecutive arthroplasty cases performed at a District Hospital (DH), and a Tertiary Hospital (TH) in Cape Town, between January 2015 and December 2018. Patient demographics, hospital length of stay, surgery related readmissions, reoperations, post-operative complications, and mortality rates were compared between cohorts. Seven hundred and ninety-five primary arthroplasty surgeries were performed at TH level and 228 at DH level. The average hospital stay was 5.2±2.0 days at DH level and 7.6±7.1 days for TH (p<0.05). Readmissions within 3 months post-surgery of 1.75% (4 patients) for district and 4.40% (35) for TH (p<0.05). Reoperation rate of 1 in every 100 patients at the DH and 8.3 in every 100 patients at the TH (p<0.05). Death rate was 0.4% vs 0.6% at district and TH respectively (p>0.05). Periprosthetic joint infection rate was 0.43% at DH and 2.26% at TH. The percentage of hip dislocation requiring revision was 0% at district and 0.37% at TH. During the study period, 228 patients received arthroplasty surgery at the DH; these patients would otherwise have remained on the TH waiting list. Hip and Knee Arthroplasty at District health care level is safe and may help ease the burden on arthroplasty services at tertiary care facilities in a Southern African context. Adequately trained surgeons should be encouraged to perform these procedures in district hospitals provided there is appropriate patient selection and adherence to strict theatre operating procedures

Abstract. Aim. To identify the difference in infection rates in ankle fracture surgery in Laminar and Non Laminar flow theatres. Background. The infection rates in ankle fracture surgery range between 1–8%. The risk factors include diabetes, alcoholism, smoking, open fractures, osteoporotic fractures in the elderly, and high BMI. Laminar flow has been shown to reduce infections in Arthroplasty surgeries. Therefore, it has become mandatory to use in those procedures. However, it's not the same with ankle fracture surgery. Materials and Methods. It was a retrospective study. The data was collected over a 5 year period between 2015 and 2020. It was collected from Blue spier, Panda, and theatre register. There were 536 cases in each group i.e. Laminar flow (LF) and Non-Laminar flow (NLF). The variables looked at were: 1. Superficial and deep infection rates in LF and NLF theatres, 2. The number of open fractures, 3. Type of ankle fractures (Bimalleolar, Trimalleolar), 4. The number of infected cases who had external fixation prior to ORIF, 5. The number of cases that had Plastics reconstructive procedures, and 6. The grade of the operating surgeon. Conclusions. Superficial infection rate between NLF and LF was not significantly different 11.5% vs 10.3%. The deep infection rate was statistically significant against NLF theatres at 6.34% vs 4.29%. The open fracture was a major contributing factor for deep SSI (14.7% vs 26%). The application of an external fixator in LF and NLF theatres did not alter the infection. rates. Bimalleolar fractures were associated with a higher infection rate

In 2020, the COVID-19 pandemic meant that proceeding with elective surgery was restricted to minimise exposure on the wards. In order to maintain throughput of elective cases, our hospital was forced to convert as many cases as possible to same day procedures rather than overnight admission. In this retrospective analysis we review the cases performed as same day arthroplasty surgeries compared to the same period 12 months previous. We conducted a retrospective analysis of patients undergoing total hip and knee arthroplasties in a three month period between October and December in 2019 and again in 2020, in the middle of the SARS-CoV-2 pandemic. Patient demographics, number of out-patient primary arthroplasty cases, length of stay for admissions, 30-day readmission and complications were collated. In total, 428 patient charts were reviewed for the months of October-December of 2019 (n=195) and 2020 (n=233). Of those, total hip arthroplasties comprised 60% and 58.8% for 2019 and 2020, respectively. Demographic data was comparable with no statistical difference for age, gender contralateral joint replacement or BMI. ASA grade I was more highly prevalent in the 2020 cohort (5.1x increase, n=13 vs n=1). Degenerative disc disease and fibromyalgia were less significantly prevalent in the 2020 cohort. There was a significant increase in same day discharges for non-DAA THAs (2x increase) and TKA (10x increase), with a reciprocal decrease in next day discharges. There were significantly fewer reported superficial wound infections in 2020 (5.6% vs 1.7%) and no significant differences in readmissions or emergency department visits (3.1% vs 3.0%). The SARS-CoV-2 pandemic meant that hospitals and patients were hopeful to minimise the exposure to the wards and to not put strain on the already taxed in-patient beds. With few positives during the Coronavirus crisis, the pandemic was the catalyst to speed up the outpatient arthroplasty program that has resulted in our institution being more efficient and with no increase in readmissions or early complications

Aboriginal and Torres Strait Islander (ATSI) people have higher elective wait times compared to non-ATSI population in Australia. The Murrumbidgee Local Health District (MLHD) in southern New South Wales services 125,242km. 2. and a population of 287,000 people, with 5.8% identifying as ATSI. The aim of this study is to investigate the arthroplasty waitlist time of ATSI, and the impact of rurality on joint replacement, within the MLHD and compared to the Australian national data. 1435 consecutive patients who underwent elective hip or knee arthroplasty from July 2018 to June 2021 were collated. Demographics, ATSI status, total wait time, readiness for care, and rurality were collected. Rurality was measured by distance from the arthroplasty hospital within MLHD. 1,151 patients were included after excluding patients with missing data or underwent emergent surgery. Within this cohort, 72 of 1,151 patients (6.2%) identified as ATSI. ATSI were younger than non-ATSI population (60.7y v 66.4y). There was no difference between Aboriginal status and ready for care wait time (368.0 v 349.9 days; p=0.116). The rurality of the groups was similar and increasing rurality did not affect total wait time (ATSI 103.1km v 98.6km; p=0.309). There was no difference in total or not-ready-for-care time between the groups (p: 0.68). Findings suggest equitable access to joint arthroplasty in the MLHD between ATSI and non-ATSI populations, which differs from the national experience. There is no significant difference between rurality and accessibility in the MLHD. This may be a result of the increased focus to ATSI and rural health within the district. A state or national study would be beneficial in identifying high performing regions and reviewing processes that enable equitable and accessible care. MLHD provides equitable access to arthroplasty surgery between ATSI and non-ATSI, as well as patients from rural areas within the LHD

Aim. Deadspace is the tissue and bony defect in a surgical wound after closure. This space is presumably poorly perfused favouring bacterial proliferation and biofilm formation. In arthroplasty surgery, an obligate deadspace surrounding the prosthesis is introduced and deadspace management, in combination with obtaining therapeutic prophylactic antibiotic concentrations, is important for limiting the risk of acquiring a periprosthetic joint infection (PJI). This study aimed to investigate cefuroxime distribution to an orthopaedic surgical deadspace in comparison with plasma and bone concentrations during two dosing intervals (8 h × 2). Method. In a setup imitating shoulder arthroplasty surgery, but without insertion of a prosthesis, microdialysis catheters were placed for cefuroxime sampling in a deadspace in the glenohumeral joint and in cancellous bone of the scapular neck in eighteen pigs. Blood samples were collected from a central venous catheter as a reference. Cefuroxime was administered according to weight (20 mg/kg). The primary endpoint was time above the cefuroxime minimal inhibitory concentration of the free fraction of cefuroxime for Staphylococcus aureus (fT > MIC (4 µg/mL)). Results. During the two dosing intervals, mean fT > MIC (4 µg/mL) was significantly longer in deadspace (605 min) compared with plasma (284 min) and bone (334 min). For deadspace, the mean time to reach 4 µg/mL was prolonged from the first dosing interval (8 min) to the second dosing interval (21 min), while the peak drug concentration was lower and half-life was longer in the second dosing interval. Conclusions. In conclusion, weight-adjusted cefuroxime fT > MIC (4 µg/mL) and elimination from the deadspace was longer in comparison to plasma and bone. Our results suggest a deadspace consolidation and a longer diffusions distance, resulting in a low cefuroxime turn-over. Based on theoretical targets, cefuroxime appears to be an appropriate prophylactic drug for the prevention of PJI. Acknowledgments. We would like to thank Department of Clinical Medicine, the surgical research laboratories, Aarhus University Hospital and Department of Clinical Biochemistry, Lillebaelt Hospital, Vejle, Denmark, for supporting this study. This research was funded by Novo Nordisk Foundation, grant number [NNF20OC0062032, 2020]

Laminar flow theatres were first introduced in the United Kingdom in the 1960s and 1970s and have become standard in orthopaedic surgery involving implants. A study from 1982 showed a 50% reduction in infections with joint arthroplasties when compared to conventional theatres and laminar flow became standard in the following decades. Recent evidence including a meta-analysis from 2017 questions the effectiveness of these theatre systems. Most of the evidence for Laminar flow use is based on arthroplasty surgery. We aimed to determine the effect of using non-laminar flow theatres on our trauma patients. A total of 1809 patients who had trauma surgery were identified from 2019 to 2021. 917 patients were operated on in a laminar theatre and 892 in a non-laminar theatre across two operating sites. We identified the surgical site infections as reported through our surveillance program within the first 90 days of infection. Patient co-morbidities were noted through patient records and procedure length was also noted. Of the 1809 trauma patients identified between the years of 2019 and 2021, 917 patients had operations in a laminar flow theatre and 892 in a non-laminar theatre. Of the 892 operated in non-laminar flow theatres, 543 were operated in the University Hospital of Wales (UHW) and 349 at the University Hospital of Llandough (UHL). An analysis of soft tissue infections and hospital acquired infections post-operatively demonstrated 15/543 and 71/543 respectively for non-laminar UHW infections and 4/349 and 21/349 for non-laminar UHL infections. A look at laminar flow patients showed 25/917 with soft tissue infections and 86/917 hospital acquired infections. There was no difference between laminar and non-laminar flow theatre infection rates showing rates of 12.1% and 12.2% respectively. In our trauma patients we noticed no significant advantage of using laminar flow theatres when compared to non-laminar flow theatres. This is in keeping with some recently published literature. Laminar flow theatres have been shown to decrease airborne pathogen counts under controlled conditions, but we conclude in the day to day environment of trauma theatres these conditions are either not met or that the theoretical advantage of laminar flow does not translate to a direct advantage of reduction of infections which may be achieved by standard prophylactic antibiotics

Introduction. Total knee and hip arthroplasty were the main arthroplasty surgery performed in Brazil. In Brazil, around 50% of arthroplasty surgeries are performed by the public health system, knowing as SUS . 1. SUS is the biggest public and universal health system in the world, attending 100% of the Brazilian population (220 million), with 2020's expected budget of US$ 31 billion . 2,3. . The National Institute of Clinical Excellence utilizes the QALY system (Quality adjustment year life)to calculate the best cost-benefit between medical interventions . 4. In compliance with the study, an operated person has a QALY index of £5000 while a non-operated person has an index of £7182. In March 2020, due to the COVID-19 pandemics, the Brazilian Health Ministry oriented for the postponing of elective surgery, to prioritize combating the virus . 5. This postponing, it was important but will cause an impact in the economy at the public health system from Brazil this year and in the next years. Therefore, this study aims to present the economic impact caused by COVID-19 pandemics in the public heal system, SUS, of Brazil. Methods. Data about total hip arthroplasty (THA) and total knee arthroplasty (TKA) in Brazil were collected from the TABNET portal of the Brazilian Health Ministry/Datasus . 6. It was collected information per month about hospitalization authorization (AIH), and total cost per AIH. The information regards the period of January to June from years 2015 to 2020. Results and Discussion. After the orientation in march 2020 to postpone elective surgery, there was a reduction of up to 91% in total knee arthroplasty (TKA) and 76% in total hip arthroplasty (THA), compared to the same period in the previous years (see Figure 1). This represents a reduction of more than 5000 surgeries in the first semester. According to Brazilian doctors, the retention of surgeries will result in excessive demand for the sector in the upcoming months . 7. . Due to the reduction of the AIH, which occurs a reduction US$3,881,494 of the budget destined for arthroplasty surgeries in the first semester of 2020 (see Figure 2), being used to the combat of COVID-19. Consequently, the purchase of new hip and knee prostheses decreases, harming the implant sales sector in Brazil. Furthermore, by the QALY system, the cost of a non-operated patient is up to 43% bigger than that of an operated patient. Thus, this will generate an increase in the expenses of the SUS in the upcoming months or years. Conclusion. The COVID-19 pandemics generate the need of postponing elective surgery of the SUS, such as total hip and knee arthroplasty. Because of this, there was a reduction of 67% of the number and expense of knee and hip arthroplasties in the first semester of 2020. This generates an economic loss for the implants companies and it will increase overly the demand for new surgeries in the upcoming months or years. For any figures or tables, please contact the authors directly

It is estimated that a quarter to half of all hospital waste is produced in the operating room. Recycling of surgical waste in the perioperative setting is largely underutilized, despite the fact that many of the materials being discarded can be potentially recycled safely and easily. Given this mounting waste production, recycling programs have become increasingly popular. Therefore, the primary objective of this study is assess the effect of these recent eco-friendly polices by determining the amount of waste and recycling produced in the pre-operative and operative time period for several orthopaedic subspecialties. Surgical cases were prospectively chosen and assigned to an orthopaedic subspecialty category, which included trauma, arthroplasty, sports, foot and ankle, upper extremity, and paediatrics. The preoperative phase began with the opening of the surgical case carts and concluded with the end of skin preparation. The intraoperative period began after skin preparation was complete, and concluded after the operating room was cleaned. At the end of the preoperative period all surgical waste was weighed and divided into recyclables and non-recyclables. Following the intraoperative period, surgical waste was divided into recyclables, non-recyclables, linens, and biohazardous waste streams. All bags were weighed in a standardized fashion using a portable hand held scale. The primary outcome of interest was the amount of recyclable waste produced per case. Secondary outcomes included the amount of nonrecyclable, biohazardous and total waste produced during the same time intervals. Statistical analysis was then completed using (ANOVA) to detect differences between specialties. This study included 55 procedures collected over a 1-month period at two hospitals from October 2017 to November 2017. A total of 341 kg of waste was collected with a mean mass of 6.2 kg per case. In terms of primary outcomes, arthroplasty surgery produced a significantly greater amount of recyclable waste per case in the preoperative (2327.9 g)and intraoperative (938.6 g)period. It also produced the greatest amount of total recyclable waste per case, resulting in a significantly greater ratio of waste recycling per case then nearly all other specialties in the preoperative (86.2%) and intraoperative period (14.5%). In terms of secondary outcomes, arthroplasty surgery similarly produced a significantly greater amount of nonrecyclable waste per case then all other specialties (5823.6 g), the majority of which was produced during the intraoperative period (5512.9 g). Arthroplasty surgery also produced a significantly greater amount of biohazardous waste then all other specialties (409.3 g). The majority of surgical waste was produced in the intraoperative period compared to the preoperative period. In the preoperative period an average of 74.4% of waste was recyclable, compared to 7.6% of waste produced during the intraoperative period. In total, the average amount of waste recycled per case was 25.6%. Biohazardous waste only constituted 1.8% of the total waste mass. Orthopaedic surgery is a significant source of waste production in our hospital system. Among orthopaedic subspecialties, arthroplasty is one of the largest waste producers, but also has the highest potential for recycling of materials. Effective OR recycling programs can significantly reduce our ecological footprint by diverting waste from landfills. In particular, the preoperative period has significant potential for landfill diversion as our study showed that nearly three quarters of all waste in this period can be effectively recycled

The pain of arthritic disorders occurs in a social and environmental context. Thus, the pain of arthritis not only can affect the patient, but also the spouse. Numerous investigations have shown that the spouses of individuals with persistent pain report lower levels of marital satisfaction, higher rates of depression and lower quality of life. For the vast majority of patients with osteoarthritis, total hip (THA) or total knee (TKA) arthroplasty results in a significant reduction in pain, emotional distress, disability and a significant improvement in their quality of life and function. Little is currently known about how these recovery-related changes impact on the spouse or the marital relationship. Patients and their spouses were recruited within one-year following the arthroplasty surgery. Couples participated in a semi-structured interview and were each asked to recall their level of pain on a numerical rating scale from 1 to 10 before and after recovering from surgery, and provide a numerical rating score (10 points) for a set of seven questions pertaining to their level of disability in seven different activities of daily living. In addition, the spouses were asked to list in order of importance the ways in which the surgery of their spouse affected their overall quality of life. In total, 33 couples (66 respondents) answered the survey questionnaire. There were 17 male patients, 16 female patients who underwent 29 THAs and 4 TKAs. With regard to pain, the spouses estimated their partner's pain, both preoperatively and at the time of the survey, to be at a significantly higher level than the patient's perception (p=0.05). The spouses perceived a greater improvement in family/home responsibilities, recreation and social activities, and in their occupation than that noted by the partner. After the arthroplasty, the spouses indicated that their lives had improved with respect to doing more activities/leisure (70%), because there partner had less suffering (61%), they had more independence/less caregiving (54%), it improved their marital relationship (54%), they had a better social/family life (27%) and they were able to travel (27%). In addition to the patient, THA and TKA result in a significant improvement in quality of life and marital functioning of the spouse. This should not continue to be unrecognized as a significant benefit of the procedure

Aim. The primary aim of this study was to examine whether the use of iodine impregnated incision drape (IIID) decreased the risk of periprosthetic joint infections (PJIs). The secondary aim was to investigate whether intraoperative contamination could predict postoperative infection. PJI is a devastating incident for the patients and in a population that is getting older and the incidence of arthroplasty surgery is rising it is vital to keep the infection rate as low as possible. Despite prophylactic measures as pre-operative decontamination, antisepsis and prophylactic antibiotics the infection rate has been constant at 1–2%. Method. We performed a transregional, prospective, randomized two arm study (IIID vs control group) of 1187 patients undergoing primary knee arthroplasty surgery. A database with patient demographics and surgical observations was established with the purpose of following the patients for ten years. Patients, who developed an infection within the first year of surgery were analyzed for correlation with the intraoperative bacterial findings and the use of IIID. Results. 31/1187 (3.6%) patients were re-operated during the follow-up period. 18/1187 (1.5%) patients were deemed infected and received antibiotic treatment. 9/18 patients deemed infected were male. Of the 18 infected patients 2 were contaminated at the primary surgery. Chi square test showed no correlation between contamination and infection (OR 0.97, 95% CI 0.38–2.46, p=0.95). 9 of the 18 infected patients were operated with IIID at the primary surgery. No correlation was found between the use of IIID at primary surgery and subsequent infection (OR 0.86, 95% CI 0.20–3.79, p=1). Conclusions. We found no effect of the use of IIID and subsequent development of PJI. Nor did we find a correlation between the intraoperative contamination and development of PJI within the first year of follow-up. Acknowledgements. University of Copenhagen and 3M Health Care (St. Paul, Minnesota) funded the study. 3M did not participate in the design of the study, data collection, data analysis or data interpretation

Image guided surgery (IGS), or “Navigation,” is now widely used in many areas of surgery including arthroplasty. However, the options for establishing, in real time, the veracity of the navigation information are limited. Manufacturers recommend registering with a “prominent anatomical feature” to confirm accurate navigation is being presented. In their fine print, they warrant the accuracy proximate to the navigation array attached to the body. In multi-level spine surgery where it is most sorely needed, this limits the warrants to the vertebra of reference array attachment. In arthroplasty surgery, the accuracy of the system can be erroneous through technical errors and a delay may occur prior to verification of such innacuracy. In response to this situation surgeons have taken to using K-wires, FaxMax screws and a variety of other “Fiducial Markers”, but these were not specifically designed for this purpose and in many ways are inadequate for the task of verification of navigation accuracy. We have developed a fiducial marker that is designed to address these unmet needs. The Precision Screw is clearly visible on imaging modalities and the central registration point is identifiable at any angle of viewing, with accuracy of fractions of a millimeter. It does not interfere with surgery, being low profile and securely fixed to bone. Finally, in use, it is secure in capturing the navigation probe so that the surgeon does not need to focus on keeping the probe located while reviewing the navigation data. We believe these features make this a useful and worthwhile addition to IGS

Aim. Reveal the rate of surgical site infection (SSI) after primary hip and knee arthroplasty in patients with inflammatory joint disease and analyse if the infection rate was correlated to the given anti-rheumatic treatment. The background is that since 2006 patients operated at the orthopaedic department at Skåne University hospital, Lund, Sweden, have continued treatment with TNF-alpha inhibitors during the perioperative period. Method. During 2006 to 2015 494 planned primary hip and knee arthroplasties were performed on 395 patients (236 hip arthroplasties and 239 knee arthroplasties). Data on age, sex, diagnosis, BMI, operation time, ASA-classification, treatment with cDMARDs (conventional disease modifying anti-rheumatic drugs) and bDMARDs (biological disease modifying antirheumatic drugs) and use of prednisolone was collected. The primary outcome variable was prosthetic joint infection (PJI) within 1 year from surgery with a secondary outcome variable being superficial SSI. Results. In 32% (n=159) of the cases the patient was treated with a TNF-alpha inhibitor. The rate of PJI was 1.4% (n=7). The overall rate of infection, including superficial infections, was 2.4% (n=12). All the PJIs occurred after a knee arthroplasty and only 1 patient was treated with a TNF-alpha inhibitor (etanercept). Conclusions. We could not find that continuing treatment with TNF-inhibitors perioperatively led to a higher incidence of PJI or SSI than generally would be expected in a group of patients with an inflammatory joint disease. Based on these results there is no need to discontinue treatment with TNF-inhibitors when performing arthroplasty surgery

Many hospitals and orthopaedic surgery teams across Canada have instituted quality improvement (QI) programs for hip and knee arthroplasty. One of the common goals is to reduce hospital length of stay (LOS) in order to improve operational efficiency, patient flow and, by achieving this, provide improved access for patients to arthroplasty surgery. A common concern among surgeons and care providers is that hospital readmission rates will increase if LOS is significantly reduced. This study assesses the relationship between LOS and readmission rates in Alberta over a six year period during a focused QI initiative targeting LOS. Data from all patients undergoing primary elective total hip or knee arthroplasty in Alberta between 2010 and 2015 was captured through a provincial QI program. Patient characteristics captured included age, gender, joint replaced, and pre-surgical co-morbidities. Patient LOS and all-cause hospital readmissions within thirty days from the initial discharge were captured through provincial data repositories, including the Discharge Abstract Database (DAD), operating room information systems, electronic medical records, and comorbidity risk grouper (CRG) data. Three longitudinal analyses were performed: 1) the crude and risk adjusted length of stay and 30-day readmission rates were calculated, 2) the population was grouped into two 3-year subsets and compared using t-test (acute LOS) and chi-square (30-day readmission), and 3) a multivariable regression analyses was performed to determine the rate of change and statistical significance in acute LOS and 30-day readmission between the two time periods. The number of patients undergoing elective lower extremity arthroplasty in the province during the six-year study period (2010–2015) was 48,760 patients. Fifty-nine percent were female and forty-one percent were male. Mean age of the cohort was 66.9 years. Thirty-nine percent of patients had a total hip arthroplasty and 61% had a total knee arthroplasty. Forty-five percent of patients had no pre-surgical risk factors, 27% had one risk factor, and 28% of the patients had 2 or more risk factors. During the quality improvement program risk-adjusted length of stay improved from a mean of 4.82 days (in 2010–2012) to 3.90 days (in 2013–2015) (p<0.01). Controlling for differences in age, sex, joint replaced, and pre-surgery risk factors, the acute LOS declined by 0.32 days between the two time periods (p<0.001). Quality improvement programs that target reduced LOS can avoid increasing 30-day hospital readmission rates. This has significant implications for inpatient resource utilisation for lower extremity arthroplasty surgery and for improving patient flow

The number of shoulder arthroplasty procedures performed in the United States continues to rise. Currently, the number of procedures performed per year ranges from 55,000–80,000 and is expected to increase more than 300% in the coming years. Periprosthetic joint infection (PJI) is one of the most serious complications associated with arthroplasty surgery, leading to poor outcomes, increased cost, and technically difficult revision surgery. The incidence of infection following primary shoulder arthroplasty has been reported between 0.7% and 4%, representing 2.9–4.6% of all complications. Prosthetic shoulder joint infections are unlike prosthetic joint infections of the hip and knee. Shoulder PJIs are primarily indolent in nature and difficult to diagnose using traditional methods that have been shown to be accurate for periprosthetic infections of the hip and knee. The majority of infected revision shoulder arthroplasties are associated with growth of Propionibacterium acnes (P. Acnes). This slow-growing, anaerobic organism requires longer than normal incubation times for culture (7–21 days), and typically demonstrates a subtle, non-specific clinical presentation that can make the presence of infection difficult to identify. In the reported literature, P. Acnes accounts for about 70% of cases with positive cultures associated with revision for treatment of a painful shoulder arthroplasty and due to the bacteria's slow growing nature and virulence profile, the rate of infection following shoulder arthroplasty may often be underestimated. A more recent and promising tool for evaluation of periprosthetic infection has been analysis of synovial fluid. Synovial fluid biomarkers have been identified as part of the innate response to pathogens, and include pro-inflammatory cytokines and anti-microbial peptides, and marker levels have shown promise for improved diagnostic efficacy in hip and knee PJI. Currently, no highly predictive clinical test for diagnosis of PJI in the shoulder exists, however, several of these synovial biomarkers have recently been analyzed for their diagnostic capacity in the setting of periprosthetic shoulder infection. Synovial fluid cytokine analysis shows the potential to improve diagnosis of infection in revision shoulder arthroplasty. This information can help to guide decision-making in the management of PJI of the shoulder, including the decision to perform a single- vs. two-stage revision surgery, and the need for post-operative antibiotics following an unexpected positive culture result after revision surgery. However, there are still challenges to broader use of these synovial biomarkers. Synovial α-defensin (Synovsure, CD Diagnostic) is the only marker currently available as a commercial test, and no point-of-care test is currently available for any of the biomarkers to allow for intraoperative decision-making. While a preoperative synovial aspirate is possible to send for α-defensin analysis currently, with results back in approximately 24 hours, dry fluid aspirations are frequent in the shoulder because of the predominance of indolent pathogens and may limit utility of the test. In summary, indolent infection associated with P. acnes is a common cause for the painful total shoulder arthroplasty. Pre-operative diagnosis of infection is difficult as a result of the poor diagnostic accuracy of traditional methods of testing. Synovial biomarker testing may ultimately improve our ability to more accurately diagnosis and treat prosthetic shoulder joint infections

Introduction & Aims. Patient recovery after total knee arthroplasty remains highly variable. Despite the growing interest in and implementation of patient reported outcome measures (e.g. Knee Society Score, Oxford Knee Score), the recovery process of the individual patient is poorly monitored. Unfortunately, patient reported outcomes represent a complex interaction of multiple physiological and psychological aspects, they are also limited by the discrete time intervals at which they are administered. The use of wearable sensors presents a potential alternative by continuously monitoring a patient's physical activity. These sensors however present their own challenges. This paper deals with the interpretation of the high frequency time signals acquired when using accelerometer-based wearable sensors. Method. During a preliminary validation, five healthy subjects were equipped with two wireless inertial measurement units (IMUs). Using adhesive tape, these IMU sensors were attached to the thigh and shank respectively. All subjects performed a series of supervised activities of daily living (ADL) in their everyday environment (1: walking, 2: stair ascent, 3: stair descent, 4: sitting, 5: laying, 6: standing). The supervisor timestamped the performed activities, such that the raw IMU signals could be uniquely linked to the performed activities. Subsequently, the acquired signals were reduced in Python. Each five second time window was characterized by the minimum, maximum and mean acceleration per sensor node. In addition, the frequency response was analyzed per sensor node as well as the correlation between both sensor nodes. Various machine learning approaches were subsequently implemented to predict the performed activities. Thereby, 60% of the acquired signals were used to train the mathematical models. These models were than used to predict the activity associated with the remaining 40% of the experimentally obtained data. Results. An overview of the obtained prediction accuracy per model stratified by ADL is provided in Table 1. The Nearest Neighbor and Random Forest algorithms performed worse compared to the Support Vector Machine and Decision Tree approaches. Even for the latter, differentiating between walking and stair ascent/descent remains challenging as well as differentiating between sitting, standing and laying. The prediction accuracies are however exceeding 90% for all activities when using the Support Vector Machine approach. This is further illustrated in Figure 1, indicating the actual versus predicted activity for the validation set. Conclusions. In conclusion, this paper presents an evaluation of different machine learning algorithms for the classification of activities of daily living from accelerometer-based wearable sensors. This facilitates evaluating a patient's ability to walk, climb or descend stairs, stand, lay or sit on a daily basis, understanding how active the patient is overall and which activities are routinely performed following arthroplasty surgery. Currently, effort is undertaken to understand how participation in these activities progresses with recovery following total knee arthroplasty

Aim. Dexamethasone is often used as part of multimodal analgesia to prevent postoperative nausea and vomiting (PONV) and also to reduce postoperative pain. Because glucocorticoids have immunosuppressive and glucose-rising effects, the aim of current study was to examine if dexamethasone may be used safely in arthroplasty surgery. Methods. All consecutive total primary and revision hip and knee arthroplasties performed in the Hospital District of Helsinki and Uusimaa, Peijas Hospital were analyzed (n=18 872). Emergency operations, for example total hip arthroplasties for femur fractures, were also included. Prospective surveillance for postoperative infections was performed. All infections meeting the Musculoskeletal Infection Society definition for prosthetic joint infection (PJI) were included. Results. A total of 189 (1.0%) PJIs occurred: 0.8% after all primary arthroplasties and 1.9% after revision arthroplasties. The PJI rate after the emergency operations was 2.3 % (19/796). The PJI rate in the dexamethasone group was 1.0% (30/2 922) and in the non-dexamethasone group 1.0% (159/15 950), with no significant difference in the PJI incidence (P=0.849). The median time from the index operation to the infection was 16.0 (Q1–Q3 13.0–23.0) days. Total of 35 causative bacteria were cultured from the 30 PJI in dexamethasone group and 169 bacteria from the 159 PJI in non-dexamethasone group with no significant difference: Staphylococcus aureus (40.0% and 45.0%, respectively, P=1.000), Staphylococcus epidermidis (14.3% and 10.7%, P=0.375), other coagulase-negative staphylococci (11.4% and 11.8%, P=0.200), Streptococcus agalactiae (11.4% and 11.8%, P=0.695), Streptococcus betahemolyticus G (8.6% and 2.4%, P=0.081), other streptococci (0.0% and 4.1%, P=0.599), Enterococcus faecalis (2.9% and 5.3%, P=1.000), Enterobacter cloacae (2.9% and 3.6%, P=1.000), Pseudomonas aeruginosa (2.9% and 1.8%, P=0.502), and other bacteria (14.3% and 8.8%, P=0.544). Only one methicillin-resistant Staphylococcus aureus (MRSA) was detected in dexamethasone group. The proportion of polymicrobial PJIs was similar in both groups: 13.3% and 8.8%, respectively (p=0.495). Conclusions. In our study material, the use of 5–10mg dose of dexamethasone did not increase the incidence of postoperative PJI. The single 5–10 dose of dexamethasone may be safely used to prevent PONV and as part of multimodal analgesia on patients undergoing arthroplasty operation