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

Introduction

A proportion of patients with hip and knee prosthetic joint infection (PJI) undergo multiple revisions with the aim of eradicating infection and improving quality of life. The aim of this study was to describe the microbiology cultured from multiply revised hip and knee replacement procedures to guide antimicrobial therapy at the time of surgery.

Periprosthetic joint infections (PJI) continue to be a diagnostic challenge for orthopedic surgeons. Chronic PJI are sometimes difficult to diagnose and occasionally present in a subclinical fashion with normal CRP/ESR and/or normal joint aspiration. Some institutions advocate for routine use of intraoperative culture swabs at the time of all revision surgeries to definitively rule out infection. The purpose of this study is to determine whether routine intraoperative cultures is an appropriate and cost effective method of diagnosing subclinical chronic PJI in revision joint replacement patients with a low clinical suspicion for infection. We performed a retrospective chart review and identified 33 patients that underwent revision hip or knee replacement from a single surgeon over a five-month period. The AAOS guidelines for preoperative PJI workup were followed. 13 patients were diagnosed preoperatively with infection and excluded from the study. 20 patients underwent revision joint replacement and three separate cultures swabs were taken for each patient to help in determining true-positive cultures. Infectious Disease was consulted for all patients with any positive culture. Culture results were reviewed. At our hospital, the cost billed to insurance for a single culture is $1,458.58. We did not calculate the cost of the consultant fee. Three (15%) of the 20 revision arthroplasty patients had a single positive culture. Infectious Disease consultants diagnosed all three of these positive cultures as contaminants. None of the patients had a true-positive intraoperative culture. The total cost billed by the hospital to obtain these cultures in all 20 patients was $87,514.80. In our study, obtaining a set of three intraoperative cultures for those patients with a negative preoperative infection workup was not only cost prohibitive but did not diagnose a single subclinical infection. Studies to find other more reliable, accurate, and cost effective alternatives to diagnose PJI are warranted. In patients undergoing revision hip or knee arthroplasty with a low preoperative clinical suspicion for infection, it does not seem that routine intraoperative culture swabs are necessary or cost effective method for diagnosing subclinical periprosthetic joint infection

Aim

”There is not a lot of data of the frequency and impact of unwanted events including glove perforation, contamination of the surgical field (drape perforation, laceration, detachment, bone bounced back from an unsterile object), unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature, and others. Mishaps occur in every surgical theatre. These events should influence the surgical site infection rate but it is not clear to what extent. We wanted to calculate the frequency and measure the impact of these events on the infection and revision rate of the relative patients.”

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. Methods. A retrospective cohort study was performed. Patients undergoing primary or revision hip or knee arthroplasty over a six-month period, from 1 July to 31 December 2020, were compared to the same period in 2019 before the COVID-19 pandemic. Demographic data, American Society of Anesthesiologists (ASA) grade, wait to surgery, COVID-19 status, and length of hospital stay were recorded. Results. A total of 1,311 patients underwent hip or knee arthroplasty in the six-month period following recommencement of elective services in 2020 compared to 1,527 patients the year before. Waiting time to surgery increased in post-COVID-19 group (137 days vs 78; p < 0.001). Length of stay also significantly increased (0.49 days; p < 0.001) despite no difference in age or ASA grade. There were no cases of postoperative COVID-19 infection. Conclusion. Time to surgery and length of hospital stay were significantly higher following recommencement of elective orthopaedic services in the latter part of 2020 in comparison to a similar patient cohort from the year before. Longer waiting times may have contributed to the clinical and radiological deterioration of arthritis and general musculoskeletal conditioning, which may in turn have affected immediate postoperative rehabilitation and mobilization, as well as increasing hospital stay. Cite this article: Bone Jt Open 2021;2(8):655–660

Aim. The prevalence of unexpected positive cultures (UPC) in aseptic revision surgery of the joint with a prior septic revision procedure in the same joint remain unknown. The purpose of this study was to determine the prevalence of UPC in aseptic revisions performed in patients with a previous septic revision in the same joint. As secondary outcome measure, we explore possible risk factors associated with UPC and the re-revision rates. Method. This retrospective single-center study includes all patients between January 2016 and October 2018 with an aseptic revision total hip or knee arthroplasty procedure with a prior septic revision in the same joint. Patients with less than three microbiology samples, without joint aspiration or with aseptic revision surgery performed <3 weeks after a septic revision were excluded. UPC was defined as a single positive culture in a revision that the surgeon had classified as aseptic according to the 2018 International Consensus Meeting. Results. A total of 139 revision total hip/knee arthroplasties in patients with a previous septic revision were performed during the study period. After excluding 47 cases with insufficient information, a total of 92 patients were recruited for final analysis. The patient cohort consist of 52 males and 40 females with a mean age of 70 years (±10.6). There were 66 (71.7%) hips and 26 (28.3%) knees. The mean time between the septic and the aseptic revision was 83 months (±89). The two main causes for the aseptic revision were aseptic loosening (n=57, 62%) followed by instability (n=21, 22.9%). We identified 11 (12%) UPC in the entire cohort, while in 3 cases there was a concordance of the germ compared to the previous septic surgery. There were no differences for the presence of UPC between hips and knees (p=0.282), diabetes (p=0.701), immunosuppression (p= 0.252), previous one-stage or two-stages septic revision (p=0.316), or between the causes for the aseptic revision ((p=0.429). There was no correlation between the UPC and time after the septic revision (p=0.773). Conclusions. The prevalence of UPC in this specific group was similar to those reported in the literature for aseptic revisons. More studies, regarding this patient group are necessitated to better understand and more securely interprete the results in those high-risk aseptic revisions

Aim. The diagnosis of periprosthetic joint infection (PJI) remains a clinical dilemma, since presentations of PJI usually greatly overlap with aseptic failure (AF). The aim of this study is to evaluate the values of plasma fibrinogen, individually or in combination with CRP, ESR and WBC, for distinguishing PJI from AF. Method. We retrospectively enrolled 357 cases who underwent revision hip or knee arthroplasties in the Third Affiliated Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and the First Affiliated Hospital of Sun Yat-sen University from January 2013 to December 2021, including 197 AF, 116 PJI and 44 reimplantation. The diagnostic capacity of preoperative fibrinogen, CRP, ESR and WBC as well as their combinations for differentiating PJI from AF were assessed by ROC curves. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated according to the optimal cutoff value based on the Youden index. All biomarkers were further investigated for their potential ability to predict optimal timing of reimplantation as well as their diagnostic capacity in the subgroups of the knee and hip PJI. Furthermore, the correlations among fibrinogen, CRP and ESR in the patients with PJI and AF were analyzed to further evaluate the potential capacity of fibrinogen in the diagnosis of PJI. Results. The levels of fibrinogen, CRP, ESR and WBC were significantly higher in PJI group than in AF group. ROC analyses showed that the AUCs of fibrinogen, CRP, ESR and WBC were 0.879, 0.903, 0.879 and 0.685, respectively. The optimal threshold of fibrinogen is 4.04 g/L (74.1% sensitivity, 85.6% specificity, 76.1% PPV, 85.0% NPV and 81.8% accuracy). Combining fibrinogen with CRP and/or ESR (AUC: 0.903∼0.914) yielded almost equivalent diagnostic efficiency compared with the combination of CRP and ESR (AUC: 0.910). Besides, fibrinogen yielded AUCs of 0.869 (cutoff: 3.44 g/L) and 0.887 (cutoff: 4.12 g/L) in the hip and knee subgroups, with higher specificity and PPV of 93.1% and 96.1% in the knee PJI. Intriguingly, as for the cases with CRP < 10mg/L and ESR ≧ 30 mm/h, the specificity and NPV of fibrinogen for diagnosing PJI were 92.2% and 83.9%. Conclusions. Plasma fibrinogen is considered as a potential first-line screening marker for PJI detection and timing of reimplantation. As for the patients with an increased ESR but normal CRP, a low fibrinogen level (below 4.04 g/L) is more likely to rule out PJI

Aim. Aim was to compare revision rates when using single versus dual antibiotic loaded cement (ABLC) in hip fracture arthroplasty and aseptic revision hip or knee arthroplasty using data from the Dutch national joint registry (LROI). Methods. All primary cemented (hemi-)arthroplasties for acute hip fractures and cemented aseptic hip or knee revision arthroplasties, were incorporated in 3 datasets. All registered implants between 2007 and 2018 were included (minimum 2 years follow-up). Primary end-point was subsequent revision rates for infection and for any reason in the single and dual ABLC groups. Cumulative crude incidence of revision was calculated using competing risk analysis. Results. A total of 22,308 hip fracture arthroplasties, 2,529 hip revision and 7,124 knee revision arthroplasties were registered and analyzed in the study period. The majority of hip fracture patients (97.1%) was treated with single ABLC. For hip and knee revision arthroplasties dual ABLC was used in 33.8% and 25.7%. The revision rate for infection in the fracture arthroplasty group was not different between groups (0.5% versus 0.8%, p=0.27). The re-revision rate following hip or knee revision based on single versus dual ABLC was not different between groups (3.2% versus 2.8%, p=0.82 for hip revision and 1.8% versus 2.5%, p=0.36 for knee revision). In addition, the re-revision rate for any reason was not different in all three datasets. The crude cumulative revision and re-revision rates for any reason based on single ABLC versus dual ABLC showed no differences in all three datasets. The crude cumulative 7-year re-revision rate for any reason following revision THA with Gentamicin ABLC use was 11.8%, with Gentamicin + Clindamycin ABLC use 13.1% and with Erythromycin + Colistin ABLC use 14.8% (ns). The crude cumulative 9-year re-revision rate for any reason following revision TKA with Gentamicin ABLC use was 17.7% and with Gentamicin + Clindamycin ABLC use 16.5% (ns). Conclusions. In conclusion, we could not show a difference in revision rate for hip fracture arthroplasty or re-revision rates for revision hip- or knee arthroplasty with the use of dual ABLC compared to single ABLC bone cement, with 7and 9 year follow up. The low percentage of dual ABLC in hip fracture arthroplasties in our registry do not enable us to make a reliable estimation of the added value in this patient category. The results of this study do not confirm the potential benefit of dual ABLC use in revision cases

Aims. As the peak of the COVID-19 pandemic passes, the challenge shifts to safe resumption of routine medical services, including elective orthopaedic surgery. Protocols including pre-operative self-isolation, COVID-19 testing, and surgery at a non-COVID-19 site have been developed to minimize risk of transmission. Despite this, it is likely that many patients will want to delay surgery for fear of contracting COVID-19. The aim of this study is to identify the number of patients who still want to proceed with planned elective orthopaedic surgery in this current environment. Methods. This is a prospective, single surgeon study of 102 patients who were on the waiting list for an elective hip or knee procedure during the COVID-19 pandemic. Baseline characteristics including age, ASA grade, COVID-19 risk, procedure type, surgical priority, and admission type were recorded. The primary outcome was patient consent to continue with planned surgical care after resumption of elective orthopaedic services. Subgroup analysis was also performed to determine if any specific patient factors influenced the decision to proceed with surgery. Results. Overall, 58 patients (56.8%) wanted to continue with planned surgical care at the earliest possibility. Patients classified as ASA I and ASA II were more likely to agree to surgery (60.5% and 60.0%, respectively) compared to ASA III and ASA IV patients (44.4% and 0.0%, respectively) (p = 0.01). In addition, patients undergoing soft tissue knee surgery were more likely to consent to surgery (90.0%) compared to patients undergoing primary hip arthroplasty (68.6%), primary knee arthroplasty (48.7%), revision hip or knee arthroplasty (0.0%), or hip and knee injections (43.8%) (p = 0.03). Conclusion. Restarting elective orthopaedic services during the COVID-19 pandemic remains a significant challenge. Given the uncertain environment, it is unsurprising that only 56% of patients were prepared to continue with their planned surgical care upon resumption of elective services. Cite this article: Bone Joint Open 2020;1-6:267–271

Introduction. The intra-operative diagnosis of Prosthetic Joint Infection (PJI) is a dilemma requiring intra-operative sampling of suspicious tissues for frozen section, deep tissue culture and histopathology to secure a diagnosis. Alfa defensin-1 testing has been introduced as a quick and reliable test for confirming or ruling out PJI. This study aims to assess its intra-operative reliability compared to the standard tests. Methods. Twenty patients who underwent revision hip and knee arthroplasty surgery were included. Patients joint aspirate was tested intra-operatively with the Synovasure kit, which takes approximately ten minutes for a result. Our standard protocol of collecting 5 deep tissue samples for culture and one sample for histopathology was followed. Results for Alfa defensin-1 test were then compared with final culture and histopathology results in all these patients. Results. Our results show an excellent correlation with the final deep tissue cultures and histopathology outcomes. Literature reports frozen section to have low (58–73%) sensitivity but high (96%) specificity. Conclusions. Alfa defensin-1 test is easy, quick and efficient; results were available immediately intra-operatively. Cryosection is time consuming with samples shipped to the reference laboratory at times resulting in intra-operative delays. In our practice Alfa defensin-1 test certainly will replace frozen section for intra-operative testing

DAIR procedure is well established for Prosthetic Joint Infection (PJI) in acute setting after total hip and knee replacements. We present our experience of DAIR following hip and knee replacements in a District General Hospital (DGH), where we delivered comparable results to leading tertiary centres in short to mid-term followup. We undertook a retrospective study involving 14 patients, who underwent DAIR in our DGH between August 2012 and December 2015. Patient cohort included primary, complex primary and revision hip and knee replacements. Microbiological support was provided by a Microbiologist with interest in musculoskeletal infections. 14 patients [9 males, 5 females; age 62 to 78 years (Mean 70.7); BMI 22 to 44.2 (Mean 33.8)] with multiple comorbidities underwent DAIR procedure within 3 weeks of onset of symptoms. 12 out of 14 grew positive cultures with two growing Vancomycin resistant Enterococci. Intravenous antibiotics were started after multiple samples intraoperatively and continued in six patients after discharge, while 8 were discharged with oral antibiotics. One patient died of overwhelming intraoperative septic shock in postoperative period. Another patient died of myocardial infarction subsequently. 12 (85.7%) patients were doing well with regular followup (Mean 20 months). With good patient selection, DAIR is a far simpler solution and a safe and reproducible surgical option for early PJI following hip and knee replacements compared to one or two stage revisions. But published data in contemporary literature is predominantly from specialised centres. Our small series provides a perspective of comparable early to mid-term results of DAIR from DGH

Aim. Synovial fluid investigation is the best alternative to diagnose prosthetic joint infection (PJI) before adequate microbiological/histology sampling during revision surgery. Although accurate preoperative diagnosis is certainly recommended, puncturing every patient before revision arthroplasty raises concerns about safety and feasibility issues especially in difficult to access joint (e.g., hip), that often require OR time and fluoroscopy/ultrasound guidance. Currently there is no clear guidelines regarding optimal indications to perform preoperative joint aspiration to diagnose PJI before revision surgery. The main goal of this study is to determine the accuracy of our institutional criteria using the new European Bone and Joint Infection Society (EBJIS) PJI definition. Method. We retrospectively evaluated every single- or first-stage for presumed aseptic or known infected revision total hip/knee arthroplasty procedures between 2013–2020. Preoperative clinical and laboratory features were systematically scrutinized. Cases with insufficient information for accurate final PJI diagnosis (i.e., no perioperative synovial fluid examination or no multiple cultures including sonication of removed implant) were excluded. Preoperative joint aspiration is recommended in our institution if any of the following criteria are met: 1) elevated CRP and/or ESR; 2) early failure (<2 years) or repeat failure; 3) high clinical suspicion/risk factors are present. Performance of such criteria were compared against final postoperative EBJIS definition PJI diagnosis. Results. A total of 364 revision THAs or TKAs were performed during the study period. After excluding 258 cases with insufficient information, a total of 106 patients were ultimately included. 38 (35,8 %) were classified as confirmed infections, 10 (9.4 %) as likely infected and 58 (54.7%) as infection unlikely. Of those, 37 confirmed infection cases, 9 likely infected cases and 32 infection unlikely cases did have indication for preoperative synovial fluid collection before revision surgery. Institutional criteria showed 95.8 % Sensitivity, 44.83 % Specificity, 92.9 % Negative Predictive Value (NPV) and 59 % Positive Predictive Value (PPV). Conclusions. Sensitivity and NPV of the aforementioned institutional criteria are very high even with the use of the more sensitive EBJIS PJI definition. As such they seem to be a valid alternative in selecting patients that should be punctured before revision arthroplasty. They identify the vast majority of infected patients while saving a significant number of patients from unnecessary procedures

OBJECTIVE. Debridement, Antibiotics and Implant Retention (DAIR) procedure is well established for Prosthetic Joint Infection (PJI) in acute setting after total hip and knee replacements. We present our perspective of DAIR in a relatively a small cohort following hip and knee replacements in a District General Hospital (DGH) in United Kingdom, where we delivered comparable results to leading tertiary centers in short to mid-term followup. METHODS. We undertook a retrospective study involving 14 patients, who underwent DAIR in our DGH between August 2012 and December 2015. Patient cohort included primary, complex primary and revision hip and knee replacements. Multiple samples were taken intraoperatively for cultures and histology. mMicrobiological support was provided by a microbiologist with interest in musculoskeletal infections. RESULTS. 14 patients [9 males, 5 females; age 62–78 years (Mean 70.7); BMI 22–44.2 (Mean 33.8)] with multiple comorbidities underwent DAIR procedure within 3 weeks of onset of symptoms, (although the time from index surgery ranged from 15 days to 58 months). Patient selection was made by two Hip surgeons. 12 out of 14 grew positive cultures with two growing Vancomycin resistant Enterococcus. IV antibiotics were stated after samples intraoperatively and continued in six patients after discharge using (OPAT), while 8 were discharged with oral antibiotics. One patient died in immediate post operative period due to generalised sepsis. Another patient died of myocardial infarction 2 years after DAIR. 12 (85.7%) patients are doing well with regular followup (Mean 20 months) in clinics. CONCLUSIONS. With good patient selection, DAIR is a far simpler solution and a safe and reproducible surgical option in PJI in hip and knee replacements compared to one or two stage revisions with the implications. But published Data in contemporary literature is predominantly from specialized centers. Our small series provides a perspective of early to mid term results of DAIR from a DGH

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

Debridement Antibiotics Implant Retention (DAIR) is a recognised procedure in the management of acute prosthetic joint infection (PJI). We present an experience of DAIR following hip and knee replacements in a District General Hospital. A retrospective review of 14 patients who underwent DAIR procedures between August 2012 and December 1015 were collated. The cohort included primary, complex primary and revision hip and knee replacements. All patients received multidisciplinary care with surgery performed by one of two arthroplasty surgeons. 9 males and 5 females with age 62 − 78 years (Mean 70.7) and BMI 22–44.2 (Mean 33.8) with various co-morbidities underwent DAIR. Surgical criteria required DAIR to be performed within 3 weeks of the onset of symptoms of infection. The time from index surgery however ranged from 15 days to 58 months. 12 of 14 grew positive cultures including two growing Vancomycin Resistant Enterococcus. Intravenous antibiotics were commenced after intraoperative samples and tailored OPAT. Antibiotic schedule varied from six weeks to eight months. 12 (85.7%) patients remain under follow up. Mean follow is 20 months (RANGE 6months-3years10months) with no recurrence of infection or reoperation. With appropriate patient selection, DAIR is safe and reproducible surgical option in PJI in hip and knee replacements, avoiding the implications of a one or two stage revision. Published Data in contemporary literature is predominantly from specialised centres. Our small series provides a perspective of early to mid term results of DAIR to DGH. Interestingly each procedure is categorised as a failed implant on the National Joint Register

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. Methods. During the month of January 2016, 20 cases of primary, straightforward total hip arthroplasties were performed with the repless model by 2 experienced arthroplasty trained surgeons. All patients were followed prospectively for minimum 3 months. Prior to initiating the repless model, we focused on process management of the operating room with staff training and re-engineering of the trays to obtain a setup that included one hospital tray and one device company tray for each operation. The responsibilities of the rep were divided into 2 categories for better management:. Familiarity of the instruments, implant, and techniques; trays set up and assurance of availability of the implants. These responsibilities were covered by a trained OR technician and the surgeon. Final verification of the accurate implants prior to opening the packaging. This was done by a trained OR nurse and the surgeon. Results. We did not have any intra-operative complications. We also did not encounted any issued with the trays or errors in opening of the implants. There were no re-admissions, fracture, dislocation, or infection. The mean length of stay was 2.2 ± 0.5 days (range 1–3 days) with 68% home discharges. The cost of the implant was reduced from $4,800 to $1,895 with $2,905 cost saving per case and total savings of $58,100. The projected savings only for uncomplicated primary total hip arthroplasty (minimum 120 cases/year between 2 surgeons) is $384,600. Further cost saving from the process management changes were seen in central sterile processing time. Prior to the one tray system, the hospital had 3 in-house trays and there were 4 device company trays. We also noticed an approximate 27% improvement in turnover time. Conclusion. Repless model has significant cost saving potential. Preparation for the transition, proper patient selection, standardization of the trays and implants, and distribution of the responsibilities between OR nurses, technicians and the surgeon are essential

In spite of its incidence decreasing to 1% nowadays, prosthesis-related infections remain a research, diagnostic, therapeutic and cost-related problem. Early diagnosis, selection of an appropriate surgical strategy, accurate identification of the responsible microorganisms and construction of an appropriate antibiotic regimen are essential elements of any management strategy. Our study aim was firstly to compare the diagnostic accuracy of conventional periprosthetic tissue culture and culture of fluid derived from vortexing and bath sonication of the explanted hardware and secondly to investigate the role of possible metabolic factors affecting the sensitivity of the sonication method. We investigated 70 patients undergoing revision hip or knee arthroplasty because of loosening of the prostheses, at our institution, between October 2011 and November 2013. Patients’ medical history and demographic characteristics were recorded. We compared the culture of samples obtained by sonication of explanted hip and knee prostheses with conventional culture of periprosthetic tissue for the microbiological diagnosis of prosthetic-joint infection. Infectious Diseases Society of America (IDSA) Guidelines were used for the definition of prosthetic-joint infection. Thirty-two patients had septic loosening and 38 aseptic loosening (48 hip prostheses and 22 knee prostheses). The sensitivity of sonication fluid culture was 81.25% and the sensitivity of conventional tissue cultures was 56.25% (p-value = 0.043). The sensitivity of the sonication method was statistically higher in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis (p-values < 0.05). The sonication method represents a reliable test for the diagnosis of prosthetic – joint infections with a greater sensitivity than the conventional periprosthetic tissue cultures, especially in obese, diabetic patients, with age above 60, in uncemented arthroplasties and in arthroplasties because of primary osteoarthritis

Aim. Compare clinical outcomes following staged revision arthroplasty for periprosthetic joint infection (PJI) secondary to either multidrug resistant (MDR) bacteria or non-MDR (NMDR) bacteria. Method. Retrospective analysis of a prospectively collected bone infection database. Adult patients diagnosed and treated for hip or knee PJI, between January 2011 and December 2014, with minimum one-year follow-up, were included in the study. Patients were divided into two groups: MDR group (defined as resistance to 3 or more classes) and N-MDR group (defined as acquired resistance to two classes of antibiotic or less). The Charlson Comorbidity Index was used to stratify patients into low, medium and high risk. The diagnosis of PJI, and any recurrence following treatment, was made in accordance with the Musculoskeletal Infection Society criteria. Failure was defined as recurrence of infection necessitating implant removal, excision arthroplasty, arthrodesis or amputation. Results. The study population comprised 240 patients. 74 (31%) had an MDR infection. 14 patients were deceased at the time of data capture. All infections were treated by staged revision with interval antibiotic space and targeted systemic antibiotics under the supervision of a multidisciplinary team. Total number of failures in both groups was 39 (16%), 15 hips (12%) and 24 knees (21%). There were significantly more failures in the MDR group (n=24, 32%) than the non-MDR group (n=15, 9%)(p<0.0001). Using the Charlson Comorbidity Index within the N-MDR group there was no significant difference in outcomes between the low and medium groups (p=0.352), the low and high risk groups (p=1.000) and the high and medium risk groups (p=1.000). There was no statistically significant association discerned within the MDR group based on co-morbidity also. (p values = 0.1702, 0.665 and 0.1096 respectively). When comparing all cases, there was a statistically significantly higher rate of failure in patients with polymicrobial infection versus single organism infection (P<0.0001). When stratifying by the presence of an MDR organism versus an N-MDR organism, both polymicrobial sub groups showed a greater rate of failure than their single organism counterparts, however this was only significant in the MDR group and not the N-MDR group (p=0.0007 vs p=0.123). Furthermore the polymicrobial MDR group showed a statistically significant higher rate of failure versus the polymicrobial N-MDR group (p=0.002). Conclusions. The study suggests that the presence of an MDR organism may be a predictor of failure, independent of patient co-morbidity, in staged revision hip and knee arthroplasty for PJI

Background. Post-operative deep venous thrombosis (DVT) and subsequent pulmonary embolism (PE) remain a serious complication after total joint replacement. Although with modern chemical and mechanical prophylaxis and rapid rehabilitation the rate of symptomatic DVT and PE has reduced, isolation of pre-operative DVT, specially in patients with prior history of DVT remains a challenge. The aim of this study was to assess the use of pre-operative dopplers as a tool to detect and identify prior DVT in patients undergoing total joint replacement. Methods. Between January 2014 and December 2014, 211 elective primary and revision hip and knee arthroplasty were identified from our prospective institutional database. All cases were performed by two adult reconstruction specialists. All primary total hip arthroplasties (THA) were non-cemented and all primary total knee arthroplasties (TKA) were cemented with similar implant and technique. Prior to July 2014, only patients with prior history of DVT or PE underwent pre-operative dopplers. From July 2014, all cases underwent routine pre-operative doppler screening. All patients with clinical symptoms of calf pain underwent post-operative dopplers. Patients were followed for a minimum of 3 month post-operatively. All emergency room (ER) visits for role out DVT were identified. No patient was lost to follow. Results. 115 patients patient underwent pre-operative dopplers. Three patients had a history of prior popliteal DVT, none of which had post-operative DVT or PE. In the remaining 112 patients, none of the pre-operative dopplers were positive for DVT. 34 patients in this group (29%) underwent post-operative dopplers, either during the hospital stay or in the ER within 3 month after index surgery. Only one patient developed symptomatic PE (0.8%) after total knee arthroplasty. 96 patients did not have pre-operative dopplers, 3 of which (3%) had symptomatic DVT and PE during hospital stay, all after total knee arthroplasty. There was no statistical difference for rate of symptomatic DVT/PE between the two groups (p=0.3). There was no correlation between DVT and obesity, age, or revision versus primary cases. Discussion and Conclusions. Routine pre-operative dopplers do not significantly lower rate of symptomatic DVT/PE and are not helpful in early detection and prevention in asymptomatic patients prior to routine total joint replacement

Introduction. Periprosthetic joint infection (PJI) is a significant challenge to the orthopedic surgeon, patient, hospital, and insurance provider. As the number of total hip and knee replacements has increased, the number of revision procedures has also increased. Revisions for infection require a greater amount of hospital and surgeon resources than noninfectious revisions. Our study compares the financial information for all two-stage revision surgeries performed at our tertiary referral center for hip or knee PJI over the last four years, separating them into two groups: referral versus self-originating cases. Methods. We performed a review of all patients who underwent two-stage revision hip or knee arthroplasty for infection between 2008 and 2013 at our facility. We collected detailed financial information for patients and separated them into referral versus self-originating cases, indicating whether index surgery was performed at an outside facility or at our facility, respectively. Only those patients who underwent full two-stage procedure at our facility were included. Results. We found an increasing number of referrals over the study period. There was a non-statistical increased cost of treating hips over knees (p=0.24). We found a continued financial incentive, with no statistical difference between referral and self-originating groups, in treating hip (p=0.89) and knee (p=0.84) PJIs (Figure 1). Despite no difference in payer status, there was a non-statistical trend for a much lower reimbursement (p=0.15) in the referral hip group. We found that referral knee PJIs overall reimbursement (p=0.65), and in turn revenue (p=0.55), was non-statistically higher than that of self-originating knee PJIs. There is a significant financial disincentive in treating hip PJI referrals if the antibiotic spacer has already been placed (p=0.036) (Figure 2). We found a non-significant decreased reimbursement for treating referral knee PJIs if the antibiotic spacer has been placed prior to referral (p=0.81). Conclusion. To our knowledge, our study is the first to extensively compare the financial implications of treating an institution's own PJIs of the knee and hip versus treating referred infections. In the modern era of referral centers accepting more of the burden of PJIs, we show there is continued financial incentive to treating one's own PJIs and referral PJIs, given the antibiotic spacer was not placed at an outside facility