Aim. Success rate of debridement, antimicrobial and implant retention (DAIR) in high suspicion of early PJI after primary arthroplasty is 70–80%. No studies have been performed focusing on outcome of DAIR after revision arthroplasty of the hip (THA) or knee (TKA). The aim of this study is to investigate the outcome of DAIR in suspected early PJI after revision THA or TKA and to identify risk factors for failure. Method. In this retrospective study, we identified early DAIRs after revision THA or TKA performed between January 2012 and August 2019. All patients received empirical antibiotics directly after the DAIR procedure. Antimicrobial treatment was adjusted to the tissue culture results. Success was defined as: 1) implant retention; 2) no repeated revision arthroplasty or supervised neglect after treatment; 3) no persistent or recurrent PJI after treatment and no administration of suppressive antimicrobial therapy; 4) survival of the patient. Infection free success was defined as: 1) no persistent or recurrent PJI after treatment; 2) no administration of suppressive antimicrobial therapy. Results. The overall success rate after one year of 100 cases with early DAIR after revision THA or TKA was 79% and infection free success rate was 85%. In PJI cases, empirical antimicrobial mismatch with causative micro-organisms was associated with lower success rate (70%) than non-mismatch (95%) (p=0.02). No patients from the non-PJI group failed after one year versus 13 failures within the PJI group. A consecutive DAIR within 90 days after the first DAIR was warranted in 24 cases. Only 4 of 20 PJI cases failed despite the consecutive DAIR. Conclusions. In high suspicion of early PJI after revision arthroplasty, DAIR is a good treatment option with comparable outcome with DAIR after primary arthroplasty. A consecutive DAIR should not be avoided when infection control fails within 90 days after the first DAIR to prevent explantation of the prosthesis. Antimicrobial mismatch is associated with failure and should be avoided

Primary arthroplasty of the hip and knee are amongst the most common elective surgical procedures carried out. Results are uniformly good with low complication rates. However, there is a subset of patients in whom a general malaise has been noted. Many of these patients have been seen to have elevated liver function tests. This study set out to examine the effects of primary arthroplasty on liver function and to establish differences between subsets of patients in a consecutive single surgeon series between June 2003 and September 2007 inclusive. In total, 374 procedures were carried out on 350 patients. There were 186 male and 164 female patients. The mean age of the patients was 64.97+/−10.02 years with no significant difference between sexes. Hip replacement accounted for 196 cases (69 cemented, 68 hybrid and 59 cementless) and there was 178 knee replacements. All 4 measurements (AST, ALT, Alk phos, Gamma GT) were significantly elevated at 1 week post-op compared to pre-op and 1 day post-op. All except Alk phos returned to normal at 6 weeks post-op. There were no differences recorded between males and females, hips and knees and the subsets of hips. It is clear from these results that liver function is affected by primary arthroplasty with no single subset providing a reason. Additional research is required to further evaluate these changes

Outsourcing elective surgery has become increasingly commonplace to meet increasing demand from a growing & aging population. There is concern that outsourcing was influencing the nature of residual workload that was unsuitable for treatment elsewhere. This led to the impression that our unit is operating on more complex patients orthopaedic problems, ASA and Body Mass Index (BMI). By losing a disproportionate number of straightforward patients our department's outcomes, productivity and training opportunities could be adversely affected. Retrospective analysis of prospectively collected data of primary hip / knee arthroplasties between July & December for 2014(pre-outsourcing), 2015 and 2016(post-outsourcing). ANOVA, Tukey Honest Significant Difference(HSD) and Pearson's correlation used. Total of 726 primary arthroplasties were performed with an almost 50 % reduction post outsourcing. Post-outsourcing, BMI and ASA were significantly worse with a ANOVA of p=0.001 and HSD p=0.003. Length of stay increased from 5.4 days in 2014 to 6.2 days in 2015 ANOVA p< 0.001 but decreased in 2016. BMI significantly affected operating time (Pearson's r =0.12, p< 0.05) and anaesthetic time (Pearson's r =0.19, p< 0.05). ASA significantly affected length of hospital stay, p< 0.01 and operation time, p=0.007 but no effect on anaesthetic time. In conclusion, we are operating on more complex patients due to current outsourcing setup. Implications for short-term were on anaesthetic and operation time, inpatient stay and training opportunity were affected, with possible long-term implications on individual surgeon and unit outcomes (complications, patient satisfaction)

The majority of orthopaedic surgeons routinely review their patients after six weeks, following surgery. During the first six weeks, orthopaedic surgeons are blissfully unaware of how frequently their patients seek medical attention related to problems with their arthroplasty. During this period of time, General Practitioners play a vital role in the care of the post-operative arthroplasty patient. The aim of this study was to determine how frequently patients seek medical attention following primary joint replacement in this interim six-week period. 102 patients from a single practice who had undergone a primary hip or knee replacement from 2003 to 2011 were included and the notes of all these patients were analysed retrospectively. Within this group there were 33 men and 69 women. 45 (44.1%) patients sought medical attention during the 6-week period, which accounted for 69 GP led interventions. The maximum number of interventions was four and a minimum of zero. Of these, 45 patients (29.4%) were seen once, 9 (8.8%) were seen twice, 3 (2.9%) were seen three times and 3 (2.9%) were seen four times. The interventions were for the following reasons: 1(0.9%) for post operative anaemia, 5 (4.9%) for constipation, (1.9%) for post operative nausea, 8 (7.8%) for leg pain (1 scanned for DVT), 5 (4.9%) for leg swelling (2 scanned for DVT), 12 (11.7%) were administered antibiotics, of which 1 was for a chest infection (1 scanned for DVT), 7(6.8%) for a wound review (1 scanned for DVT) (2 patients were started on antibiotic) and 19.6% (20) patients were seen for post operative analgesia. In total, there were 5 (4.9%) patients scanned for DVT and all scans were negative. GPs play a vital, often underestimated role in the post operative care of primary arthroplasty patients. The majority of interventions were required simply because of inadequate post-operative analgesia being given to patients upon discharge. This is an issue that the orthopaedic department can address, which will improve patient care and ease the burden on primary care. Patients still continue to see their GPs for suspected wound infections despite being instructed to contact the hospital. This issue needs to be addressed with further education, as any infection, even superficial, can have devastating consequences if it spreads to the prosthesis

Aim

The aim of the present work was (i) to survey the situation of healthcare regarding the use of antibiotics in orthopaedics and trauma surgery in Germany, (ii) to determine which empiric antibiotic regimens are preferred in the treatment of periprosthethic joint infections (PJI) and (iii) to evaluate the hypothetical antibiotic adequacy of the applied empirical antibiotic therapy regimens based on a patient collective of a German university hospital.

Introduction

Hip and knee device sales representatives (reps) can provide intra-operative guidance through their knowledge of the products, especially in complicated cases such as revision hip and knee arthroplasty. However, for an experienced arthroplasty surgeon in the majority of straightforward primary cases, the rep's presence may not be required for clinical decision-makings. With recent challenges in cost savings and bundle payments, hospitals and surgeons have focused on reducing the implant costs, among others, with a “repless” model. The aim of this study was to describe the process of utilizing this model, assess its efficacy, and analyze the cost savings in primary hip arthroplasty.

Aim

Prosthetic Joint Infection (PJI) remains one of the leading cause for revision arthroplasty.^1,2 Early recognition and appropriate initial treatment of early PJI with debridement, antibiotics and implant retention (DAIR) can eradicate infection on first attempt and prevent implant failure. We evaluated the outcome after one year of patients who were treated for an early PJI after primary total knee arthroplasty (TKA) or total hip arthroplasty (THA) with DAIR. Furthermore, we determined preoperative infection markers, microbiology, and treatment factors related to treatment failure after DAIR procedure.

Aim. Perioperative myocardial infarction/injury (PMI) is a common complication in noncardiac surgery, contributing to postoperative morbidity and mortality. We aimed to identify the risk for PMI in periprosthetic joint infection (PJI) in comparison to primary hip (THA) and knee arthroplasty (TKA) and to non-PJI revision surgery. Methods. Patients undergoing primary/revision THA/TKA at a University Hospital who were eligible for the institutional PMI screening and response program were prospectively included. Revision arthroplasties were divided into 2 groups (PJI revision and non-PJI revision). PJI was defined according to the EBJIS criteria, and included DAIR, one-stage and two-stage revisions. Non-PJI revisions included partial and/or complete exchange of components. The primary endpoint was PMI, secondary endpoints were major adverse cardiovascular events (MACE) and all-cause mortality within 120 days. Results. The study population included 673 patients (443 primary THA/TKA, 119 PJI revision, 111 Non-PJI revision) enrolled from 05/2014 to 06/2018. The median age in all groups was 75 years. In primary, non-PJI and PJI revision surgery, 39%, 41% and 50%, respectively were male. PMI occurred in 12% of patients with primary arthroplasty compared to 20% and 35% in non-PJI and PJI revision, respectively (p<0.001 overall), with PJI having a significantly elevated risk over non-PJI revisions (p=0.014). Conversely, in MACE (4% primary vs 9% non-PJI vs 12% PJI, p=0.002) an all-cause mortality (2% primary vs 4% non-PJI vs 9% PJI, p<0.001) no significant difference between PJI and non-PJI revisions was observed. We found no difference for the risk of PMI comparing DAIR vs one-/two-stage PJI revision (p=0.88). In multivariable analysis (primary arthroplasty as reference), significant odds ratios for PMI included PJI (3, 1.7–5.3), coronary artery disease (2.9, 1.9–4.4), chronic heart faiure (1.3, 1.1–1.7) and age (1.1, 1.0–1.1 per each year age). Urgency of surgery, duration of surgery, to the presence of Staphylococcus aureus were not significant. impact on PMI. Conclusion. In PJI, PMI and MACE were 3-times, and death 4.5 times, respectively, more frequently observed than in primary arthroplasty. Also, PJI had the highest odds for PMI (3.0). Orthopaedic surgeons should be aware of the high PMI risk when performing revision surgery. This work confirms the importance of a peri-/postpoperative PMI screening and response program in the field of septic surgery

Aim. Debridement, antibiotics and implant retention (DAIR) are considered as an optimal curative treatment option for prosthetic joint infection (PJI) when the biofilm is still immature and radical debridement is achievable. There are two main groups of patients suitable for DAIR. Those with an early acute PJI and patients with acute hematogenous PJI. However, there is also a third group of early PJI resulting from a wound healing problem or leaking hematoma. These may be either high or low grade depending on the microorganisms that infected the artificial joint “per continuitatem”. Methods. We retrospectively analysed 100 successive DAIR procedures on prosthetic hip and knee joints performed between January 2010 and January 2022, from total of 21000 primary arthroplasties implanted within the same time period. We only included PJI in primary total replacements with no previous surgeries on the affected joint. Patients data (demographics, biochemical, microbiological, histopathological results, and outcomes) were collected from hospital bone and joint infection registry. The aim of surgery was radical debridement and the mobile parts exchange. The standardized antibiotic regime based on antibiofilm antibiotics. Results. The mean age of patients was 70 years (60% women, 43 hips, 57 knees) with a mean follow-up of 3 years. 45 cases were early acute or related to wound healing problems, 55 were hematogenous PJI. 25 patients received preoperative antibiotics. 6 of these were culture negative. The mean symptom duration was 7 days. Mean age of the prosthesis was 30 days for early, and 1064 days for the hematogenous group. Conclusions. In our cohort the success rate of DAIR is 94% which indicates that the protocol is highly successful in PJI with short-lasting symptoms and “debridable” joints. Antibiotic protocol violation and duration of symptoms may have a role in failures

Dual mobility is a French concept that appeared in the 1970s and was initially intended to reduce dislocation rates. In recent years, this concept has evolved with new HA titanium spray coatings, new external macrostructures, and better-quality polyethylene. This has allowed to extend the indications to younger and therefore active populations. The objective of our work is to analyze at least 10 years a homogeneous and continuous series of 170 primary total hip replacements associating a latest generation Novae Sunfit. ®. dual mobility cup with a straight femoral stem. Only primary arthroplasties for osteoarthritis or necrosis were included. Total hip arthroplasty was always performed through a posterolateral approach. All patients had regular clinical and radiological follow-up. The average follow-up in our series was 11.5 years. The average age of the population is 71 years. At the last follow-up, there were 17 deaths, 6 losses to follow up and 9 adverse events, including 1 cup change for psoas impingement and 1 dislocation. The low rate of dislocation at 11 years confirms the high stability of the dual mobility, which should be recommended for primary procedure for patients at high risk of postoperative instability. The lack of intraprosthetic dislocation due to wear at 11 years of follow-up highlights the good quality of the latest generation of polyethylene, and the need to combine high-polished surfaces and a refined femoral neck with a dual mobility cup. Finally, the lack of aseptic loosening confirms the quality of the secondary fixation of these implants and justifies their wider use in all patients

Direct anterior approach (DAA) arthroplasty has generated great interest because of its minimally invasive and muscle sparing nature. Obese patients are reported to be associated with greater incidence of complications in primary joint replacement. The purpose of this study was to compare patient outcomes and complication rates between obese and non-obese patients undergoing primary total hip arthroplasty (THA) through a Bikini direct anterior incision. This retrospective, single surgeon study compared the outcome of 258 obese patients and 200 non-obese patients undergoing DAA THA using a Bikini incision, over a 7-year period. The average follow-up was 4.2 years (range 2.6-7.6 years). There were no statistically significant differences in the complication rate between the two groups. The obese group recorded 2 major (venous thromboembolism and peri-prosthetic fracture) and 2 minor complications (superficial wound infection), compared with the non-obese group, which recorded 2 major (deep-wound infection and peri-prosthetic fracture) and 1 minor complication (superficial wound infection). Patient-reported outcomes (WOMAC and Harris Hip Scores) showed significant post-operative improvements (p < 0.001) and did not differ between the two groups. Bikini DDA THA does not increase the complication rate in obese patients and offers similar clinical improvements compared to non-obese patients. (200 words)

Novel oral anticoagulant (NOAC) use in Australia has increased significantly since their introduction to the Pharmaceutical Benefits Scheme (PBS). Currently, there are no specific guidelines regarding recommencement of NOAC therapy post-operatively for patients concurrently on a NOAC and undergoing arthroplasty. To address this gap in the literature, the aim of this study was to compare the clinical and patient-reported outcomes in a patient cohort recommencing a therapeutic dose of NOAC within 24 hours of total hip or knee arthroplasty. Data was retrieved from a prospective registry (ACTRN1262000079698) containing hip and knee arthroplasties. Cases were labelled based on whether they presented on a therapeutic dose of NOAC prior to surgery or not. Descriptive statistics were used to summarise patient outcomes. Of 291 patients undergoing 331 primary arthroplasties, 9.3% were undertaking NOAC therapy prior to their surgery. In the NOAC cohort, there was a 34.5% adverse event rate, however on closer analysis of each event, it was found that none of these events were complications in relation to NOAC use. This was compared to 15.6% of the comparison cohort who experienced a range of complications, some involving bleeding events. PROMs improved to a similar degree amongst both groups. This study showed that recommencing therapeutic doses of NOACs in patients post hip and knee arthroplasty within 24 hours was safe. These findings will help guide larger scale analysis to better inform clinical guidelines pertaining to hip and knee arthroplasty

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

Periprosthetic joint infection (PJI) in geriatric and/or multimorbid patients is an enormous challenge for orthopaedic surgeons. Revision procedures have also been demonstrated to expose patients to higher infection risks. Prior patient stratification according to presumed infection risks, followed by a more potent local antibiotic prophylaxis protocol with selective use of DALBC, is an interesting strategy to decrease the burden of PJI in high risk patients. The PubMed & EMBASE databases were screened for publications pertaining to the utilization of DALBC in cement for infection prophylaxis & prosthesis fixation. 6 preclinical & 7 clinical studies were identified which met the inclusion criteria and were stratified by level of clinical evidence. Only those studies were considered which compared the PJI outcome in the DALBC vs the SALBC group. (1). DALBC have been shown to exert a much stronger and longer lasting inhibition of biofilm formation on many PJI relevant bacteria (gram-positive and gram-negative pathogens) than single gentamicin-only containing cements. (2). DALBC use (COPAL G+C) in the intervention arm of 7 clinical studies has led to a significant reduction of PJI cases in a) cemented hemiarthroplasty procedures (3 studies, evidence level I and III), in b) cemented septic revision surgeries (2 studies, evidence level III), in c) cemented aseptic knee revisions (1 study, evidence level III) and in d) cemented primary arthroplasties in multi-morbid patients (1 study, evidence level III-IV). These benefits were not associated with more systemic side effects or a higher prevalence of broad antimicrobial resistancies. Use of DALBC is likely to be more effective in preventing PJI in high risk patients. The preliminar findings so far may encourage clinicians to consolidate this hypothesis on a wider clinical range

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

Acetabulum fractures caused by civilian firearms represent a unique challenge for orthopaedic surgeons. Treatment strategies should include the assessment of infection risk due to frequently associated abdominal injuries and maintenance of joint function. Still, internationally accepted treatment algorithms are not available. The aim of the study was to increase knowledge about civilian gunshot fractures of the acetabulum by describing their characteristics and management at a high-volume tertiary hospital. All adult patients admitted to our hospital between January 2009 and December 2022 with civilian gunshot fractures of the acetabulum were included in this descriptive retrospective study. In total our institution treated 301 patients with civilian gunshot fractures of the hip joint and pelvis during the observation period, of which 54 involved the acetabulum. Most patients were young males (88,9%) with a mean age of 29 years. Thirty patients (55,6%) had associated intraabdominal or urological injuries. Fracture patterns were mostly stable fractures with minor joint destruction amenable to conservative fracture treatment (n=48, 88,9%). Orthopaedic surgical interventions were performed in 21 patients (38,9%) with removal of bullets in contact with the hip joint via arthrotomy or surgical hip dislocation as most frequent procedures. Most patients received antibiotics on admission (n=49, 90,7%). Fracture related infections of the acetabulum were noted in six patients (11,1%) while the mortality in the study population was low with one demised patient (1,9%) due to the trauma burden. Most civilian acetabulum gunshot fractures are associated with intraabdominal or urological injuries. In comparison to the literature on extremity gunshot fractures, there is an increased risk of infection in our study population. The decision for surgical wash-out and bullet removal should be based on contamination and anticipated joint destruction, while osteosynthesis or primary arthroplasty are rarely necessary for these injuries

The optimum indications for debridement, antibiotics and implant retention (DAIR) are unclear. Previous studies have demonstrated higher success rate of DAIR within one year of the primary arthroplasty. This study aimed to compare the success rate of DAIR vs revision in “early” and “late” infections to provide guidance for clinical decision making. The Prosthetic Joint Infection in Australia and New Zealand Observational (PIANO) cohort prospectively recorded PJIs between July 2014 and December 2017 in 27 hospitals. This study included PIANO patients with first time PJIs occurring after primary TKA. Treatment success was defined as the patient being alive, free from further revision and without clinical or microbiological evidence of reinfection at two years follow-up. “Early” and “late” infections were analyzed separately. Univariate analysis compared demographic and disease specific factors between the DAIR and Revision groups. Multivariate binary logistic regression identified whether treatment strategy and other risk factors were associated with treatment success in “early” and “late” infections. In 117 “early” (<1 year) infections, treatment success rate was 56% in the DAIR group and 54% in the revision group (p=0.878). No independent risk factors were associated with treatment outcome on multivariate analysis. In 134 “late” (>1 year) infections, treatment success rate was 34.4% in the DAIR group and 60.5% in the revision group (OR 3.07 p=0.006). On multivariate analysis, revision was associated with 2.47x higher odds of success (p=0.041) when compared to DAIR, patients with at least one significant co-morbidity (OR 2.27, p=0.045) or with Staphylococcus aureus PJIs (OR 2.5, p=0.042) had higher odds of failure. In “late” PJIs occurring >1 year following primary TKA, treatment strategy with revision rather than DAIR was associated with greater success. Patients with significant comorbidities and Staphylococcus aureus PJIs were at higher risk of failure regardless of treatment strategy

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

Aim. Debridement, antibiotics, and implant retention (DAIR) is a viable treatment option for acute periprosthetic joint infections (PJI). The landmark DATIPO trial of Bernard et al. concluded that six weeks is not non-inferior to 12-week antibiotic therapy for DAIR. However, it is unknown if suppressive antibiotic treatment (SAT) would improve patient outcomes. Therefore, our study aims to evaluate the utility of SAT after 12 weeks of therapy. Method. We performed a retrospective study of patients with acute hip or knee PJI managed with DAIR at five institutions; in the U.S. (n=1), Netherlands (n=3), and Spain (n=1) from 2005–2020. We analyzed the effect of SAT using a Cox model among patients after 12 weeks of antibiotic treatment. The primary covariate of interest was whether the patient was on antibiotics after week 12, which was coded as a time-varying covariate. We decided a-priori to control for the clinically important risk factors such as age, sex, type of infection, modular exchange, joint, and presence of bacteremia and Staphylococcus aureus. We excluded patients who died, had treatment failure, or were lost to follow-up before 12 weeks. We defined treatment failure as infection recurrence (same or different organism), unexpected reoperation, or death due to infection. Results. There were 504 patients included in the study. The majority were female (58%, n=292), with a mean age of 70 years ago (SD 11). Hips and knees were equally proportioned. Primary arthroplasties represented 69% of the total cohort (n=349). Treatment failure was 11.9% in the total cohort (n=60). There was no statistically significant association between SAT after 12 weeks and treatment failure (HR 1.25, p=0.45, 95% CI 0.70–2.24). This finding was consistent across different subgroups, including hip or knee joints, early or late acute infections, cohort, and a subgroup of knee joints after 180 days. Conclusions. SAT after 12 weeks of antibiotic treatment for acute PJI managed with DAIR does not appear to improve patient outcomes

With an ageing population and an increasing number of primary arthroplasties performed, the revision burden is predicted to increase. The aims of this study were to 1. Determine the revision burden in an academic hospital over a 11-year period; 2. identify the direct hospital cost associated with the delivery of revision service and 3. ascertain factors associated with increased cost. This is an IRB-approved, retrospective, single tertiary referral center, consecutive case series. Using the hospital data warehouse, all patients that underwent revision hip or knee arthroplasty surgery between 2008-2018 were identified. 1632 revisions were identified (1304 patients), consisting of 1061 hip and 571 knee revisions. The majority of revisions were performed for mechanical-related problems and aseptic loosening (n=903; 55.3%); followed by periprosthetic joint infection (n=553; 33.9%) and periprosthetic fractures (176; 10.8%). Cost and length of stay was determined for all patient. The direct in-hospital costs were converted to 2020 inflation-adjusted Canadian dollars. Several patients- (age; gender; HOMR- and ASA-scores; Hemoglobin level) and surgical- (indication for surgery; surgical site) factors were tested for possible associations. The number of revisions increased by 210% in the study period (2008 vs. 2018: 83 vs. 174). Revision indications changed over study period; with prevalence of fracture increasing by 460% (5 in 2008 vs. 23 in 2018) with an accompanying reduction in mechanical-related reasons, whilst revisions for infection remained constant. The mean annual cost over the entire study period was 3.9 MMCAD (range:2.4–5.1 MMCAD). The cost raised 150% over the study period from 2.4 MMCAD in 2008 to 3.6 MMCAD. Revisions for fractured had the greatest length of stay, the highest mean age, HOMR-score, ASA and cost associated with treatment compared to other revision indications (p < 0 .001). Patient factors associated with cost and length of stay included ASA- and HOMR-scores, Charlson-Comorbidity score and age. The revision burden increased 1.5-fold over the years and so has the direct cost of care delivery. The increased cost is primarily related to the prolonged hospital stay and increased surgical cost. For tertiary care units, these findings indicate a need to identify strategies on improving efficiencies whilst improving the quality of patient care (e.g. efficient ways of reducing acute hospital stay) and reducing the raise of the economic burden on a publicly funded health system