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

The proportion of very elderly people within the general population is steadily increasing. These people, who often have coexisting medical problems and a limited life expectancy, may pose a dilemma for Orthopaedic Surgeons when referred for elective Orthopaedic procedures. The purpose of this study is to review the outcome of primary hip and knee arthroplasty in patients aged 90, and over, who are registered with the Trent Regional Arthroplasty Database. Between 1990 and 2000, prospective data was collected on patients aged 90, and over, undergoing primary total hip and knee arthroplasty. Data collection was carried out on behalf of the Trent Regional Arthroplasty Audit Group. The present living status of these patients was confirmed using patient administrations systems of the hospitals involved. Missing data was obtained from the Office for National Statistics. Those patients alive at one year were sent a simple satisfaction questionnaire regarding their operation. 144 patients underwent 149 hip or knee arthroplasty procedures over this eleven year period. The group comprised 122 (85%) females and 27 (15%) males. There were 93 (62%) total hip replacements and 56 (38%) total knee replacements. Ostcoarthritis was the predominant reason for surgery. There was only one intra-operative complication, comprising a fractured femur during a total hip replacement. 78 patients have died since their surgery. The crude mortality rate at one year was 11. 5%. The median survival was 34 months. 51% of the patients returned satisfaction questionnaires one year after the operation. From this group the satisfaction rates for hip and knee arthroplasty were 93. 6% and 92. 6% retrospectively. With suitable pre-operative assessment, primary total hip and knee arthroplasty can be a successful operation with a high satisfaction rate. This is an age group with a high mortality regardless of surgery, and age alone should not be a determining factor in deciding whether a patient will benefit from primary hip or knee arthroplasty

Two of the major complications of total hip and knee arthroplasty is periprosthetic infection and aseptic loosening. The serum marker Procalcitonin (PCT) has been shown to be a sensitive indicator of bacterial infection, but very little is known of its behaviour in Orthopaedic practice. The diagnosis of periprosthetic infection still remains a difficult diagnosis. A prospective study over 6 months of 59 patients undergoing either primary total hip or knee arthroplasty was performed, which included 32 hips. The mean age was 70 years. There were no exclusion criteria. Serum blood samples for PCT, CRP, ESR and WCC were taken pre- operatively and on days 1, 3 and 5 post- operatively. Patient records were reviewed after their routine 6 week follow- up. There was no clinical suspicion of infection at this stage, or during their hospital stay. Fifty patients (85%) had PCT concentrations within the normal range (< 0.5ng/ml) on all 4 days, and only 5 recorded a value > 1.0ng/ml. Only 1 patient had an elevated level on day 5. The other markers all showed sporadic elevation over the 3 post- operative days. The usefulness of PCT in diagnosing surgical infection has been frequently researched in cardio- thoracic and abdominal surgery. However, there is debate as to what cut- off value should represent infection, ranging from 1– 10ng/ml. This is largely because the natural acute phase response caused by these operations elevates PCT levels. This study convincingly shows that PCT, unlike the routine inflammatory markers, is not significantly stimulated by primary hip and knee arthroplasty. This would imply that PCT may be useful in diagnosing periprosthetic infection. A large multicentre study involving patients undergoing revision surgery would help validate this assumption

Abstract

Background

There is growing clinical and policy emphasis on minimizing transfusion use in elective joint arthroplasty, but little is known about the degree to which transfusion rates vary across US hospitals. This study aimed to assess hospital-level variation in use of allogeneic blood transfusion in patients undergoing elective joint arthroplasty, and to characterize the extent to which variability is attributable to differences in patient and hospital characteristics.

Given the high prevalence of psychiatric illness in the total joint arthroplasty (TJA) population, relatively little is known about how these two conditions affect each other. Therefore, the purpose of this study is to evaluate the role of major psychiatric illness on patient specific outcomes after TJA. We hypothesize that patients with major psychiatric illnesses will report inferior outcomes and have more complications after TJA compared to those without any psychiatric illness.

We matched and compared two cohorts of patients undergoing TJA from a prospectively collected database registry, which included those with and without a major psychiatric disorder. Major psychiatric disorder was identified in the registry database by determining if patients had been formally diagnosed with any of the following conditions: bipolar disorder, major personality disorder, chronic mental health diagnoses, depression, or schizophrenia. Primary outcomes of interest included patient specific outcomes measured using the WOMAC or EQ5D. Secondary outcomes included complications, infections, hospital length of stay, 30-day readmission rates and final discharge destination.

In total we included 1828 TJAs (1000 THAs, 828 TKAs). In terms of the primary outcome, both the THA experimental group (37.80 ± 17.91 vs. 40.74 ± 19.3, p=0.023) and TKA experimental group (43.38 ± 18.41 vs 45.45 ± 20.07, p=0.050) had significantly lower preoperative WOMAC scores compared to their respective control groups. At the 3-month period both the THA experimental group (76.74 ± 16.94 vs. 79.16 ± 16.19, p=0.036) and TKA experimental group (71.09 ± 18.64 vs. 75.92 ± 16.22, p=0) again had significantly lower 3-month postoperative WOMAC score. Clinical outcomes at the 1-year mark were similar for both groups in terms of WOMAC and EQ5D. Patients with psychiatric illness were more likely to have increased LOS and non-routine discharge from hospital. In the THA subset, the experimental group had an increased LOS by 1.43 days (p=0.0028), in the TKA subset, the experimental group had an increased LOS by 0.77 days (p= 0.050). In terms of non-routine discharge, the THA experimental group was discharged home 86.9% of the time compared to the control group at 91.8% (p=0.024). In the TKA subset, the experimental group was discharged home 87.6% of the time compared to the control group at 92% (p=0.022). There were no other differences between the two subsets in regards to transfusions, 30-day readmissions, infections, mechanical adverse events, and medical complications.

In conclusion, our results demonstrate that psychiatric illness can result in worse outcomes in the early perioperative period after TJA, although outcomes are equivalent 1 year postoperatively. Patients with psychiatric illness can be expected to gain significant improvements in outcome after surgery that are comparable to a baseline population without psychiatric illness. Nonetheless, patients with psychiatric illness are at increased risk of delayed discharge and non-routine discharge. As such, they may require personalized care post-operatively, and should be counseled accordingly. Based on our results, psychiatric illness should not be an impediment to proceeding with TJA.

Introduction:

The prevalence of total hip (THA) and knee arthroplasty (TKA) is growing dramatically, with more than 1 million procedures performed annually in the United States. As the cost of and demand for the newest orthopaedic implants continue to rise, the price paid to medical device companies for implants is a growing concern. Some high-volume healthcare institutions have adopted price capitation strategies to control costs, in which a flat purchase price is negotiated for all implant line items regardless of technology and material. The purpose of this study was to evaluate whether the implementation of price capitation in a large health system affected trends in THA and TKA premium implant selection by surgeons. A secondary objective was to compare selection trends between surgeons with an academic center affiliation and community practice surgeons, within a single health system.

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.

Background

The evaluation and management of outcomes risk has become an essential element of a modern total joint replacement program. Our multidisciplinary team designed an evidence-based tool to address modifiable risk factors for adverse outcomes after primary hip and knee arthroplasty surgery.

Orthopaedic surgery accounts for about 10% of red cell transfusions used in hospital. In view of the recognized risks and decreasing availability of donor blood, every effort should be made to minimize inappropriate transfusions. Methods: Data was collected on the number of patients prescribed blood transfusion after primary total hip and knee replacement at the North Devon District Hospital. It involved 211 patients in 2004, 599 patients in 2005 and 812 patients in ‘06/’07. The effect of withdrawing the use of drains and instigating local infiltration of the wound with diluted adrenaline on transfusion rates was monitored and the results compared against the national average. Results: The transfusion rates for hip arthroplasty came down from 15.2% in 2004 to 8.8% in 2007 and for knee arthroplasty from 12.2% in 1004 to 5.3% in 2007. Conclusion: Our current transfusion rates are well below the national average, without the use of cell savers. We wish to discuss the factors which might affect transfusion rates and share our experience after introducing a simple, inexpensive, safe and effective post-operative blood transfusion policy. The respective contributions of drains and infiltration will be emphasized

Introduction: The recent UK national comparative audit of the use of blood in primary, elective, unilateral THR found that 25% of patients required a peri-operative transfusion. We felt this figure was higher than should be expected, especially of surgeons with a dedicated arthroplasty subspecialty. We therefore audited our own practice with particular emphasis on the relationship between surgeon volume, implant and the need for transfusion.

Methods: A retrospective review of 508 consecutive primary, elective, unilateral hip and knee arthroplasties performed over a 12 month period. Pre- and post- operative haemoglobin levels, need for transfusion, and the timing and volume of any transfusion were recorded for each patient. Analysis determined the overall rate of transfusion, the details of any such transfusion, and the effects of surgeon volume upon the transfusion rate.

Results: The transfusion rate following THR (10%) was significantly lower than those found in the national audit. The transfusion rate following TKR was 7%. Multivariate analysis demonstrated that surgeon volume (< 50 THRs/yr Vs > 50 THRs/yr) and a preop-erative Hb < 12g/dl were the only significant determinants of a need for post operative transfusion (Both p< 0.05) following both THR and TKR. Other variables (age, gender, anaesthetic type, ASA, indication, surgeon grade and experience, implant, approach) were not significant. A preoperative haemoglobin of < 12g/dl was associated with a 6 fold and 3 fold increased risk of needing a transfusion following hip and knee replacement respectively.

Discussion: The need for allogenic blood transfusion following primary arthroplasty is influenced by both patient and surgeon related factors. Surgeons who have a dedicated arthroplasty practice and perform a high volume of procedures have significantly lower transfusion rates when compared to nationally accepted figures. This has implications for both patient care and resource management.

Aim. A large body of evidence is emerging to implicate that dysregulation of the gut microbiome (dysbiosis) increases the risk of surgical site infections. Gut dysbiosis is known to occur in patients with inflammatory bowel disease (IBD), allowing for translocation of bacteria across the inflamed and highly permeable intestinal mucosal wall. The null hypothesis was that IBD was not associated with increased risk of periprosthetic joint infection (PJI) after primary total hip and knee arthroplasty. Our aim was to investigate whether a prior diagnosis of IBD was associated with a higher risk of PJI following primary total hip and knee arthroplasty. Method. A matched cohort study was designed. Primary endpoint was the occurrence of PJI at 2-year. Secondary endpoints were aseptic revisions, as well as discharge to rehab facility, complications up to 30 days, and readmission up to 90 days after TJA. ICD-9 and −10 codes were used to identify patients with IBD and the control cohort. A chart review was performed to confirm diagnosis of IBD. Using our institutional database, 154 patients with IBD were identified and matched (3 to 1) for age, sex, body mass index (BMI), year of surgery, and joint affected with 462 individuals without IBD undergoing TJA. Results. The cumulative incidence of PJI was 4.55% among patients with IBD versus 1.32% among the control cohort (p=0.024). When bivariate logistic regression was performed, a diagnosis of IBD was found to be an independent risk factor for PJI (OR 3.56 95% C.I. 1.17 – 11.23; p=0.024) and aseptic revisions (OR 3.47, 95% C.I. 1.30 – 3.47; p=0.012). The rate of postoperative complications was also higher in patients with IBD. Conclusions. Based on the findings of this study, it appears that patients with IBD are at higher risk for failure due to PJI or aseptic loosening after TJA. The exact reason for this finding is not known but could be related to the bacterial translocation from the inflamed intestinal mucosa, the dysregulated inflammatory status of these patients, malnutrition, and potentially other factors. Some of the so-called aseptic failures maybe also as a result of infection that may have escaped detection and/or recognition

Aims. Prophylactic antibiotic regimens for elective primary total hip and knee arthroplasty vary widely across hospitals and trusts in the UK. This study aimed to identify antibiotic prophylaxis regimens currently in use for elective primary arthroplasty across the UK, establish variations in antibiotic prophylaxis regimens and their impact on the risk of periprosthetic joint infection (PJI) in the first-year post-index procedure, and evaluate adherence to current international consensus guidance. Methods. The guidelines for the primary and alternative recommended prophylactic antibiotic regimens in clean orthopaedic surgery (primary arthroplasty) for 109 hospitals and trusts across the UK were sought by searching each trust and hospital’s website (intranet webpages), and by using the MicroGuide app. The mean cost of each antibiotic regimen was calculated using price data from the British National Formulary (BNF). Regimens were then compared to the 2018 Philadelphia Consensus Guidance, to evaluate adherence to international guidance. Results. The primary choice and dosing of the prophylactic antimicrobial regimens varied widely. The two most used regimens were combined teicoplanin and gentamicin, and cefuroxime followed by two or three doses of cefuroxime eight-hourly, recommended by 24 centres (22.02%) each. The alternative choice and dosing of the prophylactic antimicrobial regimen also varied widely across the 83 centres with data available. Prophylaxis regimens across some centres fail to cover the likeliest causes of surgical site infection (SSI). Five centres (4.59%) recommend co-amoxiclav, which confers no Staphylococcus coverage, while 33 centres (30.28%) recommend cefuroxime, which confers no Enterococcus coverage. Limited adherence to 2018 Philadelphia Consensus Guidance was observed, with 67 centres (61.50%) not including a cephalosporin in their guidance. Conclusion. This analysis of guidance on antimicrobial prophylaxis in primary arthroplasty across 109 hospitals and trusts in the UK has identified widespread variation in primary and alternative antimicrobial regimens currently recommended. Cite this article: Bone Jt Open 2023;4(10):742–749

Aim. To date, the value of culture results after a debridement, antibiotics and implant retention (DAIR) for early (suspected) prosthetic joint infection (PJI) as risk indicators in terms of prosthesis retention is not clear. At one year follow-up, the relative risk of prosthesis removal was determined for culture-positive and culture-negative DAIRs after primary total hip or knee arthroplasty. The secondary aim was to explore differences in patient characteristics, infection characteristics and outcomes between these two groups. Methods. A retrospective regional registry study was performed in a group of 359 patients (positive cultures: n = 299, negative cultures n = 60) undergoing DAIR for high suspicion of early PJI in the period from 2014 to 2019. Differences in patient characteristics, deceased patients and number of subsequent DAIRs between the positive and negative DAIR groups were analyzed using independent t-tests, Mann-Whitney, Pearson's Chi-square tests and Fisher's Exact tests. Results. Overall implant survival rate following DAIR was 89%. The relative risk for prosthesis removal was 7.4 times higher (95% confidence interval (CI) 1.0–53.1) in the positive DAIR group (37/299, 12.4%) compared to the negative DAIR group (1/60, 1.7%). The positive group had a higher body mass index (p = 0.034), rate of wound leakage of >10 days (p = 0.016) and more subsequent DAIRs (p = 0.006). Conclusion. Since implant survival results after DAIR are favorable, the threshold to perform a DAIR procedure in early PJI should be low in order to retain the prosthesis. A DAIR procedure in case of negative cultures does not seem to have unfavorable results in terms of prosthesis retention

Background. We identified several opportunities to significantly reduce cost for hip and knee arthroplasty procedures:. Customized instruments: by identifying the essential instruments for arthroplasty cases, we managed to have one universal tray for each case, and 3 specific trays from the implant manufacturing company. Customized wrap-free, color-coded, stackable trays: by using a wrap-free trays, preparation time in central sterile, opening tray time in OR and turn-over time were reduced. Also, stackable trays were organized based on side and size, therefore only 2 trays needed to be used in each case. Discounted implants: negotiated through optional case coverage with revision system and reps available as backup. Optional rep coverage protocols: designed through process management of the operating room surgical staff and central sterile. Aim of the study was to measure the cost savings, efficacy, and outcomes associated with primary total hip and knee arthroplasty by implementing these protocol. Methods. This is a prospective study from January to October 2016 for selected primary total hip and knee arthroplasties were performed with the above protocols by 2 experienced arthroplasty trained surgeons, were followed for minimum 3 months. Initiating the cost saving protocols were achieved by re-engineering customized trays, discounted implants through optional case coverage (Sourced Based Selection of a Cooperating Manufacturer, MTD), and focused on process management of the staff training. Staff responsibilities were divided into 2 categories:. 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 achieved by a trained OR nurse and the surgeon. Results. We did not have any intra-operative complications. We also did not encounter 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

Aim. National Joint Replacement Registries, which are important sources for periprosthetic joint infection (PJI) data, report an average PJI incidence ranging from 0.5 to 2.0%. Unfortunately, national registries including the Dutch Arthroplasty Register (LROI), are not specifically designed to register PJI. In the Netherlands, the LROI is a nationwide population-based registry with an overall completeness of more than 95%. 3. To ensure usability and reliability of PJI data from the LROI, it is important to evaluate the quality and completeness of these data. From 2013 onwards, eight hospitals in the South-East of the Netherlands, collected their PJI data in a detailed regional infection cohort (RIC), specifically designed for this purpose. This study aimed to determine the accuracy and completeness of PJI registration (hip and knee arthroplasty) in the LROI, by comparing the LROI with the RIC. Method. All patients registered with an acute PJI in the RIC between 2014–2018 were selected for the study and were matched with the LROI. According to the Workgroup of American Musculoskeletal Infections Society (MSIS), an acute PJI was defined as at least two phenotypically identical pathogens, isolated in cultures from at least two separate tissues, obtained from the affected peri-prosthetic tissue during the DAIR treatment (debridement, antibiotics, irrigation, and retention). Only PJI occurring within 90 days after primary hip or knee arthroplasty were included. The LROI data and completeness was based on the entered procedures and documented reason for revision infection, which was not specially based on the MSIS criteria. After checks on missing and incorrectly data, the completeness of registration in the LROI was calculated by comparing the number of registrations in the LROI with data from the RIC (gold standard). Results. Of the 639 primary total hip and knee arthroplasty with a suspected PJI registered in the RIC between 2014–2018, 352 cases met the definition of acute PJI. The overall incidence was 1%. When compared with the LROI, 164 of these cases were also registered in the LROI as PJI revision, resulting in a 53% underestimation of PJI for the LROI. Conclusions. LROI data on acute PJI shows a significant underestimation, which is comparable to scarce other literature sources. To ensure reliability and usability of national PJI data, a specifically part of the LROI has to be designed for registering PJI similar to the regional cohort

Patients undergoing Joint Arthroplasty received a significant proportion of blood transfusions. In this study, we compared the risk of Deep Infection, and Superficial Infection post operation following Primary Total Hip or Knee replacement in blood-transfused and non-blood-transfused patients. Cohort of patients who underwent primary total Hip or Knee Arthroplasty from April 2012 to March 2015 in Alberta. Patient characteristics, comorbidity, received blood transfusion were collected from electronic medical records, operating room information systems, discharge abstract database, provincial clinical risk grouper data. Deep Infection and Superficial Infection were captured from Provincial Surgical Site Infection Surveillance data. Deep Infection include deep incisional and organ/space infections. Logistic regression analysis were used to compare Deep Infection and Superficial Infection in blood-transfused and non-blood-transfused cohorts, and risk-adjusted for age, gender, procedure type, and co-morbidities. Our study cohort contains 27891 patients, with mean of age at admission was 66.3±10.4, 57.5% female, 49.3% had 1 or more comorbidities. 58.8% underwent Knee Replacement. 11.1% received blood transfusion during hospital stay (Total Hip Replacement (THR) =13.1% and Total Knee Replacement (TKR) =9.7%,). 1.1% had Deep Infection (THR=1.4% and TKR=0.9%) and 0.5% had Superficial Infection (THR=0.5% and TKR=0.5%). Blood-transfused patients got 1.7% Deep Infection and 1.0% Superficial infection. Non-blood-transfused patients got 1.0% Deep Infection and 0.5% Superficial infection. Controlling for age, gender, procedure type, and co-morbidities, the odds of Deep Infection were 1.6 times higher for blood-transfused patients than for non-blood-transfused patients (adjusted odds ratio [OR]=1.6, 95% confidence interval [CI] [1.2–2.2], p=0.004). The odds of Superficial Infection were 2.0 times higher for transfused patients (adjusted OR=2.0, 95% CI [1.3–3.0], p=0.002). Blood transfusion increases Deep Infection and Superficial Infection post-surgery following Primary Total Knee or Hip Replacement. This finding suggests to reduce the unnecessary blood transfusion for patients considering Joint Arthroplasty. Reducing the blood transfusion will save the inpatient cost and decrease the infective complications post-surgery in Hip or Knee Arthroplasty patients

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

Following the outcomes of the RECORD trials the protocol of extended thromboprophylaxis in patients undergoing elective primary total hip or knee arthroplasty has been changed in our institution. Between June 2008 and May 2009 patients were offered extended thromboprophylaxis with 150mg of aspirin daily, commencing preoperatively on admission and continuing for a total of six weeks. From June 2009 onwards patients were treated with 10mg of rivaroxaban once daily for two weeks following total knee and five weeks following total hip arthroplasty commencing 4 to 6 hours postoperatively. Our cohorts were 700 patients before and after the introduction of the new regimen. The two groups were matched for age, sex and type of operation. All patients with no contraindication to treatment with aspirin or rivaroxaban respectively undergoing elective primary total hip or knee arthroplasty were included in the study. Patients receiving warfarin on admission were treated with warfarin postoperatively and were excluded. We have compared the two treatment protocols in terms of safety and efficacy. Results focus on 4 safety outcome measures including mortality, haemorrhagic complications, transfusion requirements and infection rates and 2 efficacy outcome measures including thromboembolic complications and length of inpatient stay. Rates of DVT were equal in the two cohorts (P< 0.005) as were the mortality rates. Transfusion requirements post-operatively were not affected by the introduction of the new regimen however there was a significant increase in both return to theatre rates and prolonged wound ooze (P< 0.005). Infection rates were slightly higher in the cohort treated with rivaroxaban but this was not statistically significant. We conclude that further trials need to be done to confirm the suitability of routine use of rivaroxiban

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