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.

Malnutrition is considered a risk factor for postoperative complications in total hip and knee arthroplasty, though prospective studies investigating this assumption are lacking. The aim of this study was to prospectively analyse the 90-day postoperative complications, postoperative length of stay (LOS) and readmission rates of patients undergoing primary total hip and total kneearthroplasty using albumin, total lymphocyte count (TLC) and transferrin as serum markers of potential malnutrition. 603 primary hip and 823 primary knee arthroplasties over a 3-year period from a single centre wereprospectively analysed. BMI, demographic and comorbidity data were recorded. Complications werecategorised as surgical site infection, venous thromboembolism (deep vein thrombosis andpulmonary embolus), implant related (such as dislocation), and non-implant related (such aspneumonia). Outcomes were compared between groups, with malnutrition defined as serumalbumin <3.5g/dL, transferrin <200 mg/dL, or TLC <1,500 cells/mm³. Potential malnutrition was present in 9.3% of the study population. This group experienced a longeraverage LOS at 6.5 days compared to the normal albumin group at 5.0 days (p=0.003). Surgical siteinfection rate was higher in the malnourished group (12.5 vs 7.8%, p=0.02). There was no differencebetween the two groups in implant related complications (0.8 vs 1.0%, p=0.95) medicalcomplications (7.8 vs 13.3%, p=0.17), rate of venous thromboembolism (2.3 vs 2.7%) or 90-dayreadmission rate (14.1 vs 17.0%, p=0.56). TLC and transferrin were not predictive of any of theprimary outcomes measured (p<0.05). Pacific Island (p<0.001), Indian (p=0.02) and Asian (p=0.02) patients had lower albumin than NZ European. This study demonstrates an association between low albumin levels and increased postoperativeLOS and surgical site infection in total joint arthroplasty, providing rationale for consideration ofpreoperative nutritional screening and optimisation

Immigrated Canadians make up approximately 20% of the total population in Canada, and 30% of the population in Ontario. Despite universal health coverage and an equal prevalence of severe arthritis in immigrants relative to non-immigrants, the former may be underrepresented amongst arthroplasty recipients secondary to challenges navigating the healthcare system. The primary aim of this study was to determine if utilization of arthroplasty differs between immigrant populations and persons born in Canada. The secondary aim was to determine differences in outcomes following total hip and knee arthroplasty (THA and TKA, respectively). This is a retrospective population-based cohort study using health administrative databases. All patients aged ≥18 in Ontario who underwent their first primary elective THA or TKA between 2002 and 2016 were identified. Immigration status for each patient was identified via linkage to the ‘Immigration, Refugee and Citizenship Canada’ database. Outcomes included all-cause and septic revision surgery within 12-months, dislocation (for THA) and total post-operative case cost and were compared between groups. Cochrane-Armitage Test for Trend was utilized to determine if the uptake of arthroplasty by immigrants changed over time. There was a total of 186,528 TKA recipients and 116,472 THA recipients identified over the study period. Of these, 10,193 (5.5%) and 3,165 (2.7%) were immigrants, respectively. The largest proportion of immigrants were from the Asia and Pacific region for those undergoing TKA (54.0%) and Europe for THA recipients (53.4%). There was no difference in the rate of all-cause revision or septic revision at 12 months between groups undergoing TKA (p=0.864, p=0.585) or THA (p=0.527, p=0.397), respectively. There was also no difference in the rate of dislocations between immigrants and people born in Canada (p=0.765, respectively). Despite having similar complication rates and costs, immigrants represent a significantly smaller proportion of joint replacement recipients than they represent in the general population in Ontario. These results suggest significant underutilization of surgical management for arthritis among Canada's immigrant populations. Initiatives to improve access to total joint arthroplasty are warranted

Venous thromboembolism (VTE) is a serious complication after total hip and knee arthroplasty. There is still no consensus regarding the best mode of thromboprophylaxis after lower limb arthroplasty. The aim of this study was to ascertain the efficacy, safety profile and rate of adverse thromboembolic events of aspirin as extended out of hospital pharmacological anticoagulation for elective primary total hip and knee arthroplasty patients and whether these rates were comparable with published data for low molecular weight heparin (LMWH). Data was extracted from a prospective hospital acquired thromboembolism (HAT) database. The period of study was from 1st Jan 2013-31st Dec 2016 and a total of 6078 patients were treated with aspirin as extended thromboprophylaxis after primary total hip and knee arthroplasty. The primary outcome measure of deep vein thrombosis and pulmonary embolism within 90 days postoperatively was 1.11%. The secondary outcome rates of wound infection, bleeding complications, readmission rate and mortality were comparable to published results after LMWH use. The results of this study clearly show that Aspirin, as part of a multimodal thromboprophylactic regime, is an effective and safe regime in preventing VTE with respect to risk of DVT or PE when compared to LMWH. It is a cheaper alternative to LMWH and has associated potential cost savings

Background. In surgeon controlled bundled payment and service models, the goal is to reduce cost but preserve quality. The surgeon not only takes on risk for the surgery, but all costs during 90 days after the procedure. If savings are achieved over a previous target price, the surgeon can receive a monetary bonus. The surgeon is placed in a position to optimize the patients preoperatively to minimize expensive postoperative readmissions in a high risk population. Traditionally, surgeons request that primary care providers medically clear the patient for surgery with cardiology consultation at their discretion, and without dictating specific testing. Our participation in the Bundled Payments for Care Improvement (BPCI) program for total hip and knee replacement surgeries since 1/1/15 has demonstrated a significant number of patients having costly readmissions for cardiac events. Objective. To determine the medical effectiveness and cost savings of instituting a new innovative cardiac screening program (Preventive Cardio-Orthopaedics) for total hip and knee replacement patients in the BPCI program and to compare result to those managed in the more traditional fashion. Methods. The new screening program was instituted on 11/1/17 directed by an advanced cardiac imaging cardiologist (EH). Testing included an electrocardiogram, echocardiogram, carotid and abdominal ultrasound, and coronary computed tomography angiography (CCTA). If needed, a 3 day cardiac rhythm monitor was also performed. Four of the ten physicians in our group performing hip and knee replacement surgeries participated. Charts of readmitted patients were reviewed to determine past medical history, method of cardiac clearance, length and cost of readmission. Results. 2,459 patients had total hip or knee replacement in the BPCI program between 1/1/15 and 10/31/17 prior to instituting the new program. All had complete 90 day postoperative readmission data supplied by the CMS, with 25 (1%) of these patients having readmissions for cardiac events for a total cost of readmissions of %149,686. 14 of 25 had a preoperative clearance by a cardiologist. In 19 of the 25 patients, the only preoperative cardiac screening tool performed was an electrocardiogram. Since instituting the new program, 842 additional surgeries were performed, 463 by the four surgeons involved. 126 patients were agreeable to be evaluated through the Preventive Cardio-Orthopaedics program. 4 patients of the four physicians still screened via the traditional cardiac program had a cardiac event readmission. The average readmission hospital stay was 3.33 days at a total cost of %42,321. 2 patients of the four physicians evaluated by the Preventive Cardio-Orthopaedics program had a cardiac related readmission, at an average hospital stay of 2 days, and at a total cost of %10,091. Conclusions. Risk sharing programs have forced surgeons to take a more active role in optimizing their patients medically; otherwise they will be penalized with a decreased reimbursement. Traditionally, we have abdicated this responsibility to primary care and cardiology physicians but have noted a high cardiac readmission risk. In response, we have begun using a unique cardiac screening model. Our preliminary experience predicts fewer cardiac readmissions thereby improving care, and at a lower cost

Aim. Periprosthetic joint infection (PJI) is one of the most serious and frequent complications in prosthetic surgery. Despite significant improvements in the criteria for diagnosis of PJI, the diagnostic workflow remains complex and, sometimes, inconclusive. Host immune factors hold great potential as diagnostic biomarkers in bone and joint infections. We have recently reported that the synovial concentration of the humoral pattern recognition molecule long pentraxin 3 (PTX3) is a sensitive and specific marker of PJI in total hip and knee arthroplasty patients (THA and TKA) undergoing revision surgery [1]. However, the contribution to risk and diagnosis of PJI of the genetic variation in PTX3 and inflammatory genes that are known to affect its expression (IL-1b, IL-6, IL-10, and IL-17A) has not been addressed. Therefore, we assessed these relationships in a cohort of THA and TKA patients who underwent prosthesis revision by focusing on a panel of single nucleotide polymorphisms (SNPs) in the PTX3, IL-1β, IL-6, IL-10 and IL-17A genes. Method. A case-control retrospective study was conducted on an historic cohort of patients that received THA or TKA revision and were diagnosed with PJI (cases) or aseptic complications (controls) [1]. Samples of saliva were collected from 93 subjects and used for extraction of genomic DNA to perform genotyping of the PTX3, IL-1β, IL-6, IL-10 and IL-17A polymorphisms. Moreover, whenever available, samples of synovial fluid and plasma [1] were used to measure the concentration of the IL-1β, IL-10, and IL-6 proteins by immunoassay. Uni-and multivariate analyses were performed to evaluate the relationships between genetic, biochemical, and clinical variables. Results. The rs3024491 (IL-10) and rs2853550 (IL-1b) SNPs were found to be strongly associated with the risk of PJI. The synovial levels of PTX3, IL-1β, IL-10, and IL-6 were higher in cases than in controls, and a clear correlation emerged between the synovial concentration of PTX3 and IL-1b in cases only. Also, we identified a causal relationship between rs2853550, synovial concentration of IL-1b and that of PTX3 (that is induced by IL-1b). Conclusions. Our findings suggest that SNPs in the IL-10 and IL-1b genes could be used for early identification of THA and TKA patients with high risk of PJI. It is therefore conceivable that integrating genetic data into current diagnostic criteria would improve diagnosis of PJI

Background. The Bundled Payments for Care Improvement (BPCI) was developed by the US Center for Medicare and Medicaid (CMS) to evaluate a payment and service delivery model to reduce cost but preserve quality. 90 day postoperative expenditures are reconciled against a target price, allowing for a monetary bonus to the provider if savings were achieved. The surgeon is placed in a position to optimize the patients preoperatively to minimize expensive postoperative cardiovascular readmissions in a high risk population. Traditionally, surgeons request that primary care providers medically clear the patient for surgery with or without additional cardiology consultation, without dictating specific testing. Typical screening includes an EKG, occasionally an echocardiogram and nuclear stress test, and rarely a cardiac catheterization. Our participation in the BPCI program for total hip and knee replacement surgeries since 1/1/15 has demonstrated a significant number of patients having readmissions for cardiac events. Objective. To determine the medical effectiveness and cost savings of instituting a new innovative cardiac screening program (Preventive Cardio-Orthopaedics) for total hip and knee replacement patients in the BPCI program and to compare result to those managed in the more traditional fashion. Methods. The new screening program was instituted on 11/1/17 directed by an advanced cardiac imaging cardiologist (EH). Testing included an electrocardiogram, echocardiogram, carotid and abdominal ultrasound, and coronary computed tomography angiography (CCTA). If needed, a 3 day cardiac rhythm monitor was also performed. Four of the ten physicians in our group performing hip and knee replacement surgeries participated. Charts of readmitted patients were reviewed to determine past medical history, method of cardiac clearance, length and cost of readmission. Results. 1,361 patients had total hip or knee replacement in the BPCI program between 1/1/15 and 1/28/18 and all had complete 90 day postoperative readmission data supplied by the CMS, with 25 of these patients evaluated through the Preventive Cardio- Orthopaedics program. 12 (0.90%) screened via the traditional cardiac program had a cardiac event readmission. The average readmission hospital stay was 3.67 days at a total cost of $69,378. 7 of 12 had a preoperative clearance by a cardiologist. In 9 of the 12 patients, the only preoperative cardiac screening tool performed was an electrocardiogram. None of these 25 patients evaluated through the new program has been readmitted. 84 more patients have been evaluated in this program since 1/28/18, but 90 day readmission data is still incomplete. Preliminary data suggests that the highest risk in these patients is not severe coronary artery disease, but atrial fibrillation, hypertension with left ventricular hypertrophy, and cardiac plaques with ulceration. Conclusions. Risk sharing programs have forced joint replacement surgeons to take a more active role in optimizing their patients medically; otherwise they will be penalized with a decreased reimbursement. Traditionally, we have abdicated this responsibility to primary care and cardiology physicians but have noted a high readmission risk with a cardiac event. In response, we have begun using a unique cardiac screening model. Our preliminary experience predicts fewer cardiac readmissions thereby improving care, and at a lower cost

The New Zealand Joint Registry (NZJR) was established in 1999. However, ethnicity data was not recorded by prioritisation in line with Ministry of Health (MoH) recommendations. Recently, cross-referencing with MoH updated ethnicity data for all 326,150 entries in the NZJR database. The objective of this national level, population study was to identify any ethnic disparities in access and outcome for Māori for primary total hip (THA) and knee arthroplasty (TKA) for Osteoarthritis. The utilisation rate for THA and TKAs were calculated for the Māori and NZ European population from all data in the NZJR and Census data in 2001, 2006, 2013 and 2018. Utilisation rate was reported separately for four age groups (<55, 55-64, 65-74, >75) over four time periods (1999-2004, 2005-2009, 2010-2014, 2015-2020). Revision rate, 6 months and 5-year Oxford scores were adjusted for age, sex and BMI, then compared between groups. In every age group and at all but one time point, significant under-utilisation of TKA was observed in Māori. For THAs, Māori had similar utilisation rates in the <55 and 55-64 age groups, but significantly lower utilisation rates in all other age groups. When adjusted for age, sex and BMI, no significant differences in revision rates were observed between Māori and NZ Europeans for THAs (HR 0.939, P 0.417) or TKAs (HR 1.129, P 0.149). Adjusted 6 months and 5-year Oxford scores were significantly higher in NZ Europeans, however, the maximum difference was less than 3 points and is unlikely to be clinically significant. Despite the same risk of being diagnosed with osteoarthritis, Māori are less likely to undergo THA and TKA. There are no clinically significant differences in outcomes post arthroplasty between Māori and NZ Europeans. Further research is required to investigate causes for lower utilisation in Māori

Introduction. It is thought that socioeconomic status and cultural upbringing influence the patient based outcomes of total joint arthroplasty. Previous studies have shown that patients in a lower socioeconomic class had surgery at an earlier age, increased comorbidities, increased severity of symptoms at presentation, and less satisfaction with the outcome. The purpose of this study was to compare the 1) reasons for undergoing total joint replacement and 2) satisfaction with the outcome among patients in different cultures and socioeconomic categories. We hypothesized that the overall reasons for undergoing surgery would be similar among all groups. Method. Patients undergoing total hip or knee arthroplasty were divided into groups based on their country of residence and socioeconomic status. The patients were asked to rank their reasons for undergoing surgery preoperatively from 1 to 4 according to importance. They were also asked to state how much relief of pain or improvement in function they expected to obtain. They were then asked to complete a questionnaire assessing their satisfaction with surgery 6 months post-operatively. These results were then compared across the three groups. Results. Thirty Nepalese patients and 10 American patients who received total hip or knee arthroplasty as part of a charitable outreach program were compared with 20 age and sex matched American patients who electively underwent total hip or knee arthroplasty. In both the Nepalese and outreach American patients, pain relief followed by improvement in performing everyday actions were listed as the most important reasons for undergoing surgery. The control group of American patients who sought surgery electively listed pain relief followed by improvement in performing individual activities as the main reasons for undergoing surgery. As compared to the other groups, the elective patients ranked athletic improvement higher as a reason for undergoing surgery. A review of the post-operative questionnaires completed by the Nepalese and American outreach patients showed that all were satisfied with the outcome of surgery and reported improvement in pain and the ability to perform individual as well as everyday activities. The postoperative questionnaires completed by the elective American patients showed satisfaction with the surgery, however, they reported less improvement in all functional categories. Conclusion. We found that, despite socioeconomic status, the reasons for undergoing total joint arthroplasty were similar among all groups. Pain relief was the most important reason for having surgery. There was a tendency for elective patients to rank participation in athletic activities higher than those in the lower socioeconomic groups. All patients were satisfied with their outcomes. However, the degree of subjective improvement among elective patients was less than that in lower socioeconomic groups. This may be due to the fact that, due to their lack of access to care, patients in lower socioeconomic groups had more severe disease prior to surgery

Introduction. Recent advances in algorithms developed with passively collected sensor data from smart phones and watches demonstrate new, objective, metrics with the capacity to show qualitative gait characteristics. The purpose of this feasibility study was to assess the recovery of gait quality following primary total hip and knee arthroplasty collected using a smartphone-based care platform. Methods. A secondary data analysis of an IRB approved multicenter prospective trial evaluating the use of a smartphone-based care platform for primary total knee arthroplasty (TKA, n=88), unicondylar knee arthroplasty (UKA, n=28), and total hip arthroplasty (THA, n=82). Subjects were followed from 6 weeks preoperative to 24 weeks postoperative. The group was comprised of 117 females and 81 males with a mean age of 61.4 and BMI of 30.7. Signals were collected from the participants' smartphones. These signals were used to estimate gait quality according to walking speed, step length, and timing asymmetry. Post-operative measures were compared to preoperative baseline levels using a Signed-Rank test (p<0.05). Results. Mean walking speeds were lowest at postoperative week 2 for all three procedures (p<.001). The TKA population stabilized to preoperative speeds by week 17. For UKA cases, mean walking speeds rebounded to preoperative speed consistently by week 9 (p>.05). THA cases returned to preoperative walking speeds with a stable rebound starting at week 6 (p>.05), and improvement was seen at week 14 (p=.025). The average weekly step length was lowest in postoperative week 2 for both TKA and UKA (p<.001), and at week 3 for THA (p<.001). The TKA population rebounded to preoperative step lengths at week 9 (p=0.109), UKA cases at week 7 (p=.123), and THA cases by week 6 (p=.946). For TKA subjects, the change in average weekly gait asymmetry peaked at week 2 postoperatively (p <0.001), returning to baseline symmetry by week 13 (p=.161). For UKA cases, mean gait asymmetry also reached its maximum at week 2 (p =.006), returning to baseline beginning at week 7 (p=0.057). For THA cases mean asymmetry reached its maximum in week 2 (p <0.001) and was returned to baseline values at week 6 (p=.150). Discussion and Conclusion. Monitoring gait quality in real-world patient care following hip and knee arthroplasty using smart phone technology demonstrated recovery curves similar to previously reported curves captured by traditional gait analysis methods and patient reported outcome scores. Capturing such real-world gait quality metrics passively through the phone may also provide the advantage of removing the Hawthorne effect related to typical gait assessments and in-clinic observations, leading to a more accurate picture of patient function

We aimed to measure cerebral microemboli load during total hip [THA] and knee arthroplasty (TKA) using transcranial Doppler ultrasound (TCD) and to investigate whether cerebral embolic load influences neuropsychiatric outcome. The timing of the microemboli was also related to certain surgical activities to determine if a specific relationship exists and the presence of a patent foramen ovale was investigated. Patients undergoing primary THA and TKA underwent a battery of ten neuropsychiatric tests pre-operatively and at 6 weeks and 6 months post-operatively. Microembolic load was recorded using TCD onto VHS tape for subsequent analysis. Patent foramen ovale detection was performed using bolus intravenous injection of agitated saline followed by valsalva manoeuvre. The timing of specific surgical steps was recorded for each operation and embolic load calculated for that period. All patients were assessed for quality of life and orthopaedic outcome measures. Results. 45 THA patients and 50 TKA patients were studied. Cerebral microembolisation occurred in 35% of all patients (10 THA patients and 19 TKA patients). Mean microembolic load was 2.8 per patient for THA and 3.76 per patient for TKA patients. PFO was detected in 29 patients overall. Insertion of the femoral component and deflation of the tourniquet were associated with a larger microembolic loads. Neuropsychiatric outcome was not affected by the low embolic loads. Quality of life and Orthopaedic outcome at 6 months was good. Conclusion. Cerebral microembolisation occurs in a significant proportion of patients during total hip and knee arthroplasty. The presence of a patent foramen ovale does not appear to influence the incidence of microembolisation or load. Specific surgical activities are associated with generating greater embolic loads and methods of avoiding these emboli such as venting the femur may minimise complications and optimise outcomes. Neuropsychiatric outcomes do not seem to be affected by microembolisation of the brain during total joint arthroplasty

Aim. Alpha-defensin was recently introduced as a new biomarker having a very high accuracy to rule out periprosthetic joint infection (PJI). A new rapid lateral flow version of the Alpha-defensin test was developed and introduced to detect high levels of Alpha-defensin in synovial fluid quickly and with ease. We conducted a single-centre prospective clinical study to compare the results of the Alpha-defensin rapid test* against the conventional diagnostics according to MSIS criteria. Method. A total of 223 consecutive patients with painful total hip or knee arthroplasty were enrolled into the study. In all patients, blood C-reactive protein was measured and joint aspirations were performed. From the synovial fluid a leukocyte cell count with granulocyte percentage, microbiology cultures and Leukocyte Esterase tests were carried out according to the recommendation of MSIS for diagnosing PJI. At the same time, the Lateral Flow Test* was performed from the aspirate. 191 subjects with 195 joint aspirations (96 hips, 99 knees) were included in final clinical and statistical evaluation. We had 119 joints with an aseptic revision and 76 joints with PJI. Results. After statistical analysis the overall sensitivity of the Lateral Flow Test* was 92.1% (95% confidence interval [CI], 83.6% to 97.1%), the specificity was 100% (95% CI, 97.0% to 100%), the positive predictive value was 100% (95% CI, 94.9% to 100%), and the negative predictive value was 95.2% (95% CI, 89.9% to 98.2%). The overall accuracy of the Lateral Flow Test* was 96.9% (189 of 195, 95% CI, 93.4% to 98.9%). Conclusions. Our results suggest that the PJI test* has a very high accuracy in diagnosing infected THA and TKA. Though the Lateral Flow Test* does not provide information on the identity of the infectious pathogen, the test does have an important role in recognizing PJI early and enables surgeons to start proper therapy without delay. *Synovasure®

Introduction. Perioperative dexamethasone has been shown to effectively reduce post-operative nausea and vomiting and aide in analgesia after total joint arthroplasty (TJA), however systemic glucocorticoid therapy is carries the theoretical risk of increased susceptibility to prosthetic joint infection (PJI), increased white blood cell (WBC) counts, and increased blood glucose levels. The purpose of this study is to determine the effect of dexamethasone on PJI, WBC count, and blood glucose levels in diabetic and non-diabetic patients undergoing TJA. Methods. A retrospective chart review of all patients receiving primary total joint (hip or knee) arthroplasty between January 1, 2013 and December 31, 2015 (n = 1818) was conducted. The patients were divided into two main cohorts: those receiving dexamethasone (n = 1426) and those not receiving dexamethasone (n = 392); these groups were further subdivided into diabetic (n = 428 dexamethasone; n = 129 no dexamethasone) and non-diabetic patients (n = 998 dexamethasone, n = 263 no dexamethasone). The primary outcome was PJI; secondary measures included in (WBC) count, glucose levels, and days to infection. Statistics were carried out using chi-squared or ANOVA tests. Results. Of the 1818 joints, 1.05% (19) developed PJI; there was no significant difference between the dexamethasone and no dexamethasone groups (p = 0.1023): 12 (0.84%) in the dexamethasone group and 7 (1.79%) in the no-dexamethasone group. Additionally there was no significant effect on the increase in WBC count (p = 0.1784) or on the increase in blood glucose (p = 0.3120). Further subdividing the patients, there was a significantly higher rate of infection in those who received dexamethasone with diabetes (2.1%) compared to those without diabetes (0.30%) (p = 0.0016). Further, diabetics who received dexamethasone had a significantly greater elevation in blood glucose (p < 0.0001) compared to non-diabetics, but no significant change in WBC count (p = 0.6993). Conclusion. Perioperative intravenous dexamethasone had no statistically significant effect on the overall rate of prosthetic joint infections in primary total hip or knee arthroplasty; however diabetic patients had a significantly higher rate of infection compared to non-diabetics when given dexamethasone. WBC counts were not affected overall by administration of dexamethasone, or with stratification into diabetics and non-diabetics. Glucose levels were not effected by administration of dexamethasone

Introduction. Rivaroxaban has been recommended for routine use as a thromboprophylactic agent in patients undergoing lower limb arthroplasty. Trials supporting its use have not fully evaluated the risks of wound complications related to rivaroxaban. Method. A retrospective cohort analysis of 1558 consecutive patients who underwent total hip or knee replacements within the same hospital during a 19 month period (2009–2010) was performed. The first 489 patients (Group 1) were given tinzaparin postoperatively as per NICE guidance. The following 559 patients (Group 2) were given rivaroxaban. Concerns regarding wound complications prompted a change back to tinzaparin for the next 510 patients (Group 3.) Other than the thromboprophylactic agent used there were no other differences in the pre and postoperative treatments of all these patients. Results. Nine of the 489 patients in Group 1 (tinzaparin) (1.8%, 95% CI 0.9–3.5%) returned to theatre with wound complications within 30 days compared with 22 out of 559 patients in Group 2 (rivaroxaban) (3.94%, 95% CI 2.6–5.9%.) This increase in RTT rate was statistically significant (p=0.046.) After reverting back to tinzaparin 8 out of 510 patients in Group 3 (tinzaparin) (1.6% 95% CI 0.74–3.1%) returned to theatre. This reduction in RTT rate was statistically significant (p=0.02.) Combining the tinzaparin groups (1 and 3) and comparing with the rivaroxaban group (2) further increases the significance of our observations. Tinzaparin RTT was 1.7% (95% CI 1.0–2.7%) compared with rivaroxaban RTT of 3.94% (95% CI 2.6–5.9%) (p=0.01.). Discussion. We observed a significant rise in wound complication necessitating further surgery after a change in thromboprophylactic agent from tinzaparin to rivaroxaban, followed by a significant reduction after reverting back to tinzaparin. We call for further independent randomised controlled clinical trials examining wound related complications with respect to new pharmacological treatments

This study aimed to evaluate the month-to-month prevalence of antibiotic dispensation in the 12 months before and after total knee arthroplasty (TKA) and total hip arthroplasty (THA) and to identify factors associated with antibiotic dispensation in the month immediately following the surgical procedure.

In total, 4,115 THAs and TKAs performed between April 2013 and June 2019 from a state-wide arthroplasty referral centre were analysed. A cross-sectional study used data from an institutional arthroplasty registry, which was linked probabilistically to administrative dispensing data from the Australian Pharmaceutical Benefits Scheme. Multivariable logistic regression was carried out to identify patient and surgical risk factors for oral antibiotic dispensation.

Oral antibiotics were dispensed in 18.3% of patients following primary TKA and 12.0% of patients following THA in the 30 days following discharge. During the year after discharge, 66.7% of TKA patients and 58.2% of THA patients were dispensed an antibiotic at some point. Patients with poor preoperative health status were more likely to have antibiotics dispensed in the month following THA or TKA. Older age, undergoing TKA rather than THA, obesity, inflammatory arthritis, and experiencing an in-hospital wound-related or other infectious complications were associated with increased antibiotic dispensation in the 30 days following discharge.

A high rate of antibiotic dispensation in the 30 days following THA and TKA has been observed. Although resource constraints may limit routine wound review for all patients by a surgeon, a select cohort may benefit from timely specialist review postoperatively. Several risk factors identified in this study may aid in identifying appropriate candidates for such changes to follow-up care.

Aim

There is limited data on the frequency and impact of untoward events such as glove perforation, contamination of the surgical field (drape perforation, laceration, detachment), the unsterile object in the surgical field (hair, sweat droplet…), defecation, elevated air temperature…that may happen in the operating 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 general revision rate.

Background. The optimal strategy for postoperative deep venous thrombosis (DVT) prophylaxis remains among the most controversial topics in hip and knee arthroplasty. Warfarin, the most commonly used chemical anticoagulant, initially causes transient hypercoagulability; however the optimal timing of treatment with respect to surgery remains unclear. Our purpose was to evaluate the effects of pre- versus postoperative initiation of warfarin therapy with a primary endpoint of perioperative change in hemoglobin (pre- minus post-operative level), with secondary endpoints of postoperative International Normalized Ratio (INR), drain output, and bleeding/thrombotic events. Methods. A quasi-experimental study design was employed, under which patients were assigned to begin taking warfarin the night prior to surgery or the night following surgery based on day of the week seen in clinic. An a priori power analysis was conducted in order to ensure appropriate enrollment to detect a 0.5 g/dL difference in perioperative change in hemoglobin between groups, given an alpha level of 0.05 and beta of 0.80. Based on the results, the study included all primary, elective total hip and knee arthroplasties performed by a single surgeon over a 12 month period. Fifteen patients were excluded (7 chronic anticoagulation, 3 hip fractures, 2 medical contraindications, 3 simultaneous procedures), leaving 165 cases (108 hips, 57 knees) available for study. Of these, 73 received warfarin preoperatively (49 hips, 24 knees) and 92 postoperatively (59 hips, 33 knees). Warfarin was dosed according to a standard nomogram in both groups. INR (on postoperative days 1 and 2), perioperative decrease in hemoglobin (difference between level preoperatively and on postoperative days 1 and 2), and drain outputs were compared between groups using a student t test. Adverse events (transfusions, hematomas, epidural complications, and pulmonary embolus) were compared using two-tailed Fischer's exact test. Results. No statistically significant difference in perioperative hemoglobin change was observed between treatment groups on either postoperative day 1 (mean 3.279 versus 3.377, p=0.6824) or 2 (mean 4.0 versus 4.12, p=0.6831). As expected, the preoperative warfarin group demonstrated higher INRs on both postoperative days 1 (mean 1.18 versus 1.12, p=0.0023) and 2 (mean 1.46 versus 1.31, p=0.0006). Of note, preoperative warfarin dosing was also associated with significantly lower drain outputs (mean 185.4 versus 268.7, p=0.0025). 9 transfusions (4 preoperative dosing, 5 postoperative dosing), 3 hematomas (1 preoperative dosing, 2 postoperative dosing), and 1 pulmonary embolus (preoperative dosing) occurred, but no significant difference could be detected given the numbers available for study. Conclusions. Initiation of warfarin pre- rather than postoperatively was not associated with a significant difference in perioperative hemoglobin change, although a significant reduction in drain output was observed. Larger studies are needed to determine whether the risk of adverse events is increased with either dosing strategy

Hypothesis. Pre-specified pooling of data from the four phase III RECORD studies was conducted to determine whether rivaroxaban significantly reduced the less-frequent clinical endpoint of symptomatic venous thromboembolism (VTE) and all-cause mortality after total hip or knee arthroplasty (THA or TKA, respectively), compared with standard North American and European enoxaparin regimens. Methods and analysis. Patients (n=12,729) received rivaroxaban 10 mg once daily or enoxaparin 40 mg once daily (RECORD1-3) or 30 mg 12-hourly (RECORD4). Thromboprophylaxis was administered for 31-39 days (RECORD1; THA) or 10-14 days (RECORD3 and 4; TKA). RECORD2 (THA) compared 31-39 days' rivaroxaban with 10-14 days' enoxaparin followed by placebo. The pre-specified primary efficacy endpoint in the pooled analysis (composite of symptomatic VTE and all-cause mortality) and adjudicated bleeding events were analysed in the day 12±2 active treatment pool, when all patients had received active drug, and total treatment duration pool, where subgroup analyses were performed. Results. In the day 12±2 active treatment pool, the primary efficacy endpoint occurred in 0.5% of patients receiving rivaroxaban versus 1.0% of patients receiving enoxaparin (p=0.001). Major bleeding occurred in 0.3% versus 0.2% patients respectively (p=0.18) and major plus clinically relevant non-major bleeding occurred in 2.9% versus 2.5% patients respectively (p=0.19). In the total treatment duration pool, rivaroxaban significantly reduced the primary efficacy endpoint compared with enoxaparin regimens 0.6% versus 1.3% patients (p< 0.001) with similar rates of major bleeding. Over the total treatment period, rivaroxaban consistently reduced the primary efficacy endpoint across the pre-specified subgroups (age, gender, body weight, creatinine clearance). Conclusion. Rivaroxaban significantly reduced the composite of clinically important symptomatic VTE and all-cause mortality after THA or TKA compared with subcutaneous enoxaparin regimens in the direct comparison day 12±2 active treatment pool, with no significant differences in bleeding events. These results suggest a positive benefit-risk profile for oral, once-daily rivaroxaban

We analysed the clinical data of 858 consecutive primary total hip and knee replacement patients to establish how age, ASA grade, body mass index and a simplified cognitive score correlate with the length of hospital stay and early complication rates. We further used statistical regression analysis to study how hospital stay and complication rates correlate with different pre-operative grading systems based on combinations of age, ASA grade, body mass index and a cognitive score. The results indicate that age and ASA grade correlate significantly with both length of hospital stay and complication rates, while body mass index correlated poorly with both. A grading system based on a combination of age and ASA grade (the AA Grade) correlated significantly with both length of hospital stay and complication rates. Adding body mass index or a cognitive score did not significantly add to the correlation. We discuss the relevance of this simple grading system and how it might contribute to pre-operative risk assessment and peri-operative planning

Abstract