Obesity is associated with an increased risk of undergoing hip replacement in Australia.

BACKGROUND: Obesity is a known risk factor for the development of hip osteoarthritis. The aim of this study was to investigate whether obesity is associated with the risk of undergoing total hip replacement (THR) in Australia. METHODS: A cohort study was conducted comparing data from the Australian Bureau of Statistics and the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2017 to 2018. Body mass index (BMI) data for patients undergoing primary total hip replacement and resurfacing for osteoarthritis were obtained from the AOANJRR. The distribution of THR patients by BMI category was compared to the general population, in age and sex sub-groups. RESULTS: During the study period, 32 495 primary THR were performed for osteoarthritis in Australia. Compared to the general population, there was a higher prevalence of Class I, II and III obesity in patients undergoing THR in both sexes aged 35-74 years. Class III obese females and males aged 55-64 years were 2.9 and 1.7 times more likely to undergo THR, respectively (P < 0.001). Class III obese females and males underwent THR on average 5.7 and 7.0 years younger than their normal weight counterparts, respectively. CONCLUSION: Obese Australians are at increased risk of undergoing THR, and at a younger age.

Obesity is associated with an increased risk of undergoing shoulder arthroplasty in Australia.

BACKGROUND: The aim of this study was to examine the incidence of overweight and obesity in patients undergoing primary total shoulder arthroplasty (TSA) for osteoarthritis (OA) in Australia compared to the incidence of obesity in the general population. MATERIALS AND METHODS: A 2017/18 cohort consisting of 2997 patients from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) who underwent TSA were compared with matched controls from the Australian Bureau of Statistics (ABS) National Health Survey from the same time period. The 2 groups were analyzed according to body mass index (BMI) category, sex, and age. RESULTS: According to the 2017/18 National Health Survey, 35.6% of Australian adults were overweight and 31.3% were obese. Of the primary TSA cases performed, 34.9% were overweight and 50.1% were obese. The relative risk of requiring TSA for OA increased with increasing BMI category. Class III obese females, aged 55-64, were 8.6 times more likely to receive a TSA compared to their normal weight counterparts. Males in the same age and BMI category were 2.5 times more likely. Class III obese patients underwent TSA 4 years (female) and 6 years (male) younger than their normal weight counterparts. CONCLUSION: Obesity significantly increases the risk of requiring TSA. The association appears to be particularly strong for younger females.

Hip Arthroplasty Outcomes in the Presence of Kidney Failure: A National Data Linkage Study.

BACKGROUND: Patients who have kidney failure are at higher risk of requiring total hip arthroplasty (THA) and are at higher risk of complications. This study compared the rate of revision surgery and mortality following THA between patients who have kidney failure receiving long term dialysis or who had a kidney transplant and those who did not have kidney failure. METHODS: A data linkage study was performed using data from 2 national registries: a registry of dialysis and kidney transplant patients and a registry of THA procedures. Both registries had coverage of almost all procedures or treatments in Australia. Data from September 1999 to December 2016 were used. Mortality and revision surgery were compared between patients receiving dialysis, those who had a functioning kidney transplant, and patients who did not have kidney failure using Cox and Fine-Gray (competing risk) regression models. A total of 383,478 primary THA procedures were identified as people receiving dialysis (n = 490), who had a functioning kidney transplant (n = 459), or who did not have kidney failure (n = 382,529). RESULTS: There was no significant difference in the overall rate of revision surgery between the groups (dialysis versus no kidney failure HR = 1.20; 95% CI 0.76, 1.88, transplant versus no kidney failure (hazard ratio) HR = 1.01; 95% (confidence interval) CI 0.66, 1.53). The risk for death after surgery was significantly higher in the dialysis group compared to both the functioning transplant group (HR = 3.44; 95%CI 1.58, 7.5), and in those without kidney failure (HR = 4.13; 95%CI 3.25, 5.25). CONCLUSION: The rate of mortality after THA in patients on dialysis is higher than in patients who have a functioning transplant or those who do not have kidney failure, but there is no early excess mortality to suggest a difference in this metric due to the surgery.

What Is the Outcome of the First Revision Procedure of Primary THA for Osteoarthritis? A Study From the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: Joint arthroplasty registries traditionally report survivorship outcomes mainly on primary joint arthroplasty. The outcome of first revision procedures is less commonly reported, because large numbers of primary procedures are required to analyze a sufficient number of first revision procedures. Additionally, adequate linkage of primary procedures to revisions and mortality is required. When undertaking revision hip surgery, it is important for surgeons to understand the outcomes of these procedures to better inform patients. QUESTIONS/PURPOSES: Using data from a large national joint registry, we asked: (1) What is the overall rate of revision of the first aseptic revision procedure for a primary THA? (2) Does the rate of revision of the first revision vary by the diagnosis for the first revision? (3) What is the mortality after the first revision, and does it vary by the reason for first revision? METHODS: The Australian Orthopaedic Association National Joint Replacement Registry longitudinally maintains data on all primary and revision joint arthroplasties, with nearly 100% capture. The analyses for this study were performed on primary THA procedures in patients with a diagnosis of osteoarthritis up to December 31, 2020, who had undergone subsequent revision. We excluded all primary THAs involving metal-on-metal and ceramic-on-metal bearing surfaces and prostheses with exchangeable necks because these designs may have particular issues associated with revisions, such as extensive soft tissue destruction, that are not seen with conventional bearings, making a comparative analysis of the first revision involving these bearing surfaces more complicated. Metal-on-metal bearing surfaces have not been used in Australia since 2017. We identified 17,046 first revision procedures from the above study population and after exclusions, included 13,713 first revision procedures in the analyses. The mean age at the first revision was 71 ± 11 years, and 55% (7496 of 13,713) of the patients were women. The median (IQR) time from the primary procedure to the first revision was 3 years (0.3 to 7.3), ranging from 0.8 years for the diagnosis of dislocation and instability to 10 years for osteolysis. There was some variation depending on the reason for the first revision. For example, patients undergoing revision for fracture were slightly older (mean age 76 ± 11 years) and patients undergoing revision for dislocation were more likely to be women (61% [2213 of 3620]). The registry has endeavored to standardize the sequence of revisions and uses a numerical approach to describe revision procedures. The first revision is the revision of a primary procedure, the second revision is the revision of the first revision, and so on. We therefore described the outcome of the first revision as the cumulative percent second revision. The outcome measure was the cumulative percent revision, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the second revision. Hazard ratios from Cox proportional hazards models, adjusting for age and gender, were performed to compare the revision rates among groups. When possible, the cumulative percent second revision at the longest follow-up timepoint was determined with the available data, and when there were insufficient numbers, we used appropriate earlier time periods. RESULTS: The cumulative percent second revision at 18 years was 26% (95% confidence interval [CI] 24% to 28%). When comparing the outcome of the first revision by reason, prosthesis dislocation or instability had the highest rate of second revision compared with the other reasons for first revision. Dual-mobility prostheses had a lower rate of second revision for dislocation or instability than head sizes 32 mm or smaller and when compared to constrained prostheses after 3 months. There was no difference between dual-mobility prostheses and head sizes larger than 32 mm. There were no differences in the rate of second revision when first revisions for loosening, periprosthetic fracture, and osteolysis were compared. If cemented femoral fixation was performed at the time of the first revision, there was a higher cumulative percent second revision for loosening than cementless fixation from 6 months to 6 years, and after this time, there was no difference. The overall mortality after a first revision of primary conventional THA was 1% at 30 days, 2% at 90 days, 5% at 1 year, and 40% at 10 years. A first revision for periprosthetic fracture had the highest mortality at all timepoints compared with other reasons for the first revision. CONCLUSION: Larger head sizes and dual-mobility cups may help reduce further revisions for dislocation, and the use of cementless stems for a first revision for loosening seems advantageous. Surgeons may counsel patients about the higher risk of death after first revision procedures, particularly if the first revision is performed for periprosthetic fracture.Level of Evidence Level III, therapeutic study.

Reduced Revision Rates in Total Shoulder Arthroplasty With Crosslinked Polyethylene: Results From the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: Loss of glenoid fixation is a key factor affecting the survivorship of primary total shoulder arthroplasty (TSA). It is not known whether the lower revision rates associated with crosslinked polyethylene (XLPE) compared with those of non-XLPE identified in hip and knee arthroplasty apply to shoulder arthroplasty. QUESTIONS/PURPOSES: We used data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) to compare the revision rates of primary stemmed anatomic TSA using XLPE to procedures using non-XLPE. In patients receiving a primary stemmed anatomic TSA for osteoarthritis, we asked: (1) Does the rate of revision or reason for revision vary between XLPE and non-XLPE all-polyethylene glenoid components? (2) Is there any difference in the revision rate when XLPE is compared with non-XLPE across varying head sizes? (3) Is there any difference in survival among prosthesis combinations with all-polyethylene glenoid components when they are used with XLPE compared with non-XLPE? METHODS: Data were extracted from the AOANJRR from April 16, 2004, to December 31, 2020. The AOANJRR collects data on more than 97% of joint replacements performed in Australia. The study population included all primary, stemmed, anatomic TSA procedures performed for osteoarthritis using all-polyethylene glenoid components. Procedures were grouped into XLPE and non-XLPE bearing surfaces for comparison. Of the 10,102 primary stemmed anatomic TSAs in the analysis, 39% (3942 of 10,102) used XLPE and 61% (6160 of 10,102) used non-XLPE. There were no differences in age, gender, or follow-up between groups. Revision rates were determined using Kaplan-Meier estimates of survivorship to describe the time to the first revision, with censoring at the time of death or closure of the database at the time of analysis. Revision was defined as removal, replacement, or addition of any component of a joint replacement. The unadjusted cumulative percent revision after the primary arthroplasty (with 95% confidence intervals [CIs]) was calculated and compared using Cox proportional hazard models adjusted for age, gender, fixation, and surgeon volume. Further analyses were performed stratifying according to humeral head size, and a prosthesis-specific analysis adjusted for age and gender was also performed. This analysis was restricted to prosthesis combinations that were used at least 150 times, accounted for at least four revisions, had XLPE and non-XLPE options available, and had a minimum of 3 years of follow-up. RESULTS: Non - XLPE had a higher risk of revision than XLPE after 1.5 years (HR 2.3 [95% CI 1.6 to 3.1]; p < 0.001). The cumulative percent revision at 12 years was 5% (95% CI 4% to 6%) for XLPE and 9% (95% CI 8% to 10%) for non-XLPE. There was no difference in the rate of revision for head sizes smaller than 44 mm. Non-XLPE had a higher rate of revision than XLPE for head sizes 44 to 50 mm after 2 years (HR 2.3 [95% CI 1.5 to 3.6]; p < 0.001) and for heads larger than 50 mm for the entire period (HR 2.2 [95% CI 1.4 to 3.6]; p < 0.001). Two prosthesis combinations fulfilled the inclusion criteria for the prosthesis-specific analysis. One had a higher risk of revision when used with non-XLPE compared with XLPE after 1.5 years (HR 3.7 [95% CI 2.2 to 6.3]; p < 0.001). For the second prosthesis combination, no difference was found in the rate of revision between the two groups. CONCLUSION: These AOANJRR data demonstrate that noncrosslinked, all-polyethylene glenoid components have a higher revision rate compared with crosslinked, all-polyethylene glenoid components when used in stemmed anatomic TSA for osteoarthritis. As polyethylene type is likely an important determinant of revision risk, crosslinked polyethylene should be used when available, particularly for head sizes larger than 44 mm. Further studies will need to be undertaken after larger numbers of shoulder arthroplasties have been performed to determine whether this reduction in revision risk associated with XLPE bears true for all TSA designs. LEVEL OF EVIDENCE: Level III, therapeutic study.

Between-hospital and between-surgeon variation in thresholds for hip and knee replacement.

BACKGROUND: Total hip replacement (THR) and total knee replacement (TKR) are cost-effective interventions to reduce pain and disability associated with osteoarthritis, however there is no clear guidelines available to determine appropriate patient selection and the timing of surgery. This prospective cohort study aimed to evaluate the hospital- and surgeon-level variation in the severity of patient-reported symptoms prior to THR and TKR. METHODS: Patients undergoing primary THR (n = 4330) or TKR (n = 7054) for osteoarthritis who participated in a national registry-led Patient Reported Outcome Measures (PROMs) pilot program were included in the analysis. Pre-operative Oxford Hip Score (OHS) and Oxford Knee Score (OKS) (range 0-48; representing worst to best hip/knee pain and function) data were examined for variation between private and public hospitals and between surgeons using linear mixed models. RESULTS: Pre-operative mean OHS was significantly higher (better) in patients whose surgery was performed in a private hospital compared to public hospitals; 21.39 versus 18.11 (mean difference 3.27, 95% CI 1.75, 4.79). For OKS, the difference between private hospital and public hospital scores was dependent on BMI and gender. Most of the variation in pre-operative OHS and OKS was not at the individual hospital- or surgeon-level, which explained only a negligible proportion of the model variance (⟨5%) for THR and TKR. CONCLUSION: Apart from a difference between private and public hospitals, there was little between-hospital or between-surgeon symptom variation in joint-specific pain and function prior to THR or TKR. The findings suggest consistency in the surgical thresholds for patients being offered hip and knee joint replacement procedures.

A Prospective, Longitudinal Study of the Influence of Obesity on Total Knee Arthroplasty Revision Rate: Results from the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: The aim of this study was to investigate the relationship of obesity with all-cause revision and revision for infection, loosening, instability, and pain after total knee arthroplasty (TKA) performed in Australia. METHODS: Data for patients undergoing primary TKA for osteoarthritis from January 1, 2015, to December 31, 2020, were obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). The rates of all-cause revision and revision for infection, loosening, instability, and pain were compared for non-obese patients (body mass index [BMI], 18.50 to 29.99 kg/m 2 ), class-I and II obese patients (BMI, 30.00 to 39.99 kg/m 2 ), and class-III obese patients (BMI, ≥40.00 kg/m 2 ). The results were adjusted for age, sex, tibial fixation, prosthesis stability, patellar component usage, and computer navigation usage. RESULTS: During the study period, 141,673 patients underwent primary TKA for osteoarthritis in Australia; of these patients, 48.0% were class-I or II obese, and 10.6% were class-III obese. The mean age was 68.2 years, and 54.7% of patients were female. The mean follow-up period was 2.8 years. Of the 2,655 revision procedures identified, the reasons for the procedures included infection in 39.7%, loosening in 14.8%, instability in 12.0%, and pain in 6.1%. Class-I and II obese patients had a higher risk of all-cause revision (hazard ratio [HR], 1.12 [95% confidence interval (CI), 1.03 to 1.22]; p = 0.007) and revision for infection (HR, 1.25 [95% CI, 1.10 to 1.43]; p = 0.001) than non-obese patients. Class-III obese patients had a higher risk of all-cause revision after 1 year (HR, 1.30 [95% CI, 1.14 to 1.52]; p < 0.001), revision for infection after 3 months (HR, 1.72 [95% CI, 1.33 to 2.17]; p < 0.001), and revision for loosening (HR, 1.39 [95% CI, 1.00 to 1.89]; p = 0.047) than non-obese patients. The risks of revision for instability and pain were similar among groups. CONCLUSIONS: Obese patients with knee osteoarthritis should be counseled with regard to the increased risks associated with TKA, so they can make informed decisions about their health care. Health services and policymakers need to address the issue of obesity at a population level. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Obesity is associated with an increased risk of undergoing knee replacement in Australia.

BACKGROUND: Obesity is associated with the development of knee osteoarthritis (OA). The aim of this study was to examine the incidence of obesity in patients undergoing knee replacement (KR) for OA in Australia compared to the incidence of obesity in the general population. METHODS: A cohort study was conducted, comparing data from the Australian Bureau of Statistics (ABS) 2017-2018 National Health Survey with data from the National Joint Replacement Registry. The distribution of patients who underwent KR from July 2017 to June 2018 by BMI category was compared to the distribution of the general population, in age and gender sub-groups. RESULTS: During the study period, 35.6% of Australian adults were overweight and 31.3% were obese. Of the 56 217 patients who underwent primary KR for OA, 31.9% were overweight and 57.7% were obese. The relative risk of undergoing KR for OA increased with increasing BMI category. Class 1, 2 and 3 obese females aged 55-64 years were 4.7, 8.4 and 17.3 times more likely to undergo KR than their normal weight counterparts, respectively. Males in the same age and BMI categories were 3.4, 4.5 and 5.8 times more likely to undergo KR, respectively. Class 3 obese patients underwent KR 7 years younger, on average, than normal weight individuals. CONCLUSION: Obesity is associated with an increased risk of undergoing KR, and at a younger age, particularly for females. There is an urgent need for a societal level approach to address the prevalence of obesity, to reduce the burden of obesity related KR.

Primary Total Knee Arthroplasty Revised for Instability: A Detailed Registry Analysis.

BACKGROUND: Instability after total knee arthroplasty is a common but poorly understood complication. METHODS: Data from a large national registry was used to study patient and prosthesis characteristics of 2605 total knee arthroplasty revisions for instability. The cumulative percent revision was calculated using Kaplan-Meier estimates, and Cox proportional models used to compare revision rates. The rate of further revision was analyzed with regard to prostheses used in the first revision. RESULTS: Instability increased from 6% of all first revision procedures in 2003 to 13% in 2019. The revision risk was lower for minimally stabilized prostheses, males, and patients aged ≥65 years. Polyethylene insert exchange was used for 55% of revision procedures, using a thicker insert in 93% and a change in insert conformity in 24% of cruciate-retaining knees. The increase in either thickness or conformity had no effect on the rate of further revision. After a revision for instability, 24% had a second revision by 14 years. Recurrent instability accounted for 32% of further revisions. A lower second revision rate was seen after revision of both femoral and tibial components, and where constrained components were used. CONCLUSION: Revision for instability is increasing. Revising both femoral and tibial components led to a lower rate of second revision compared to a change in insert alone. Recurrent instability was common.

Does a Prescription-based Comorbidity Index Correlate with the American Society of Anesthesiologists Physical Status Score and Mortality After Joint Arthroplasty? A Registry Study.

BACKGROUND: When analyzing the outcomes of joint arthroplasty, an important factor to consider is patient comorbidities. The presence of multiple comorbidities has been associated with longer hospital stays, more postoperative complications, and increased mortality. The American Society of Anesthesiologists (ASA) physical status classification system score is a measure of a patient's overall health and has been shown to be associated with complications and mortality after joint arthroplasty. The Rx-Risk score is another measure for determining the number of different health conditions for which an individual is treated, with a possible score ranging from 0 to 47. QUESTIONS/PURPOSES: For patients undergoing THA or TKA, we asked: (1) Which metric, the Rx-Risk score or the ASA score, correlates more closely with 30- and 90-day mortality after TKA or THA? (2) Is the Rx-Risk score correlated with the ASA score? METHODS: This was a retrospective analysis of the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) database linked to two other national databases, the National Death Index (NDI) database and the Pharmaceutical Benefits Scheme (PBS), a dispensing database. Linkage to the NDI provided outcome information on patient death, including the fact of and date of death. Linkage to the PBS was performed to obtain records of all medicines dispensed to patients undergoing a joint replacement procedure. Patients were included if they had undergone either a THA (119,076 patients, 131,336 procedures) or TKA (182,445 patients, 215,712 procedures) with a primary diagnosis of osteoarthritis, performed between 2013 and 2017. We excluded patients with missing ASA information (THA: 3% [3055 of 119,076]; TKA: 2% [4095 of 182,445]). This left 127,761 primary THA procedures performed in 116,021 patients (53% [68,037 of 127,761] were women, mean age 68 ± 11 years) and 210,501 TKA procedures performed in 178,350 patients (56% [117,337 of 210,501] were women, mean age 68 ± 9 years) included in this study. Logistic regression models were used to determine the concordance of the ASA and Rx-Risk scores and 30-day and 90-day postoperative mortality. The Spearman correlation coefficient (r) was used to estimate the correlation between the ASA score and Rx-Risk score. All analyses were performed separately for THAs and TKAs. RESULTS: We found both the ASA and Rx-Risk scores had high concordance with 30-day mortality after THA (ASA: c-statistic 0.83 [95% CI 0.79 to 0.86]; Rx-Risk: c-statistic 0.82 [95% CI 0.79 to 0.86]) and TKA (ASA: c-statistic 0.73 [95% CI 0.69 to 0.78]; Rx-Risk: c-statistic 0.74 [95% CI 0.70 to 0.79]). Although both scores were strongly associated with death, their correlation was moderate for patients undergoing THA (r = 0.45) and weak for TKA (r = 0.38). However, the median Rx-Risk score did increase with increasing ASA score. For example, for THAs, the median Rx-Risk score was 1, 3, 5, and 7 for ASA scores 1, 2, 3, and 4, respectively. For TKAs, the median Rx-Risk score was 2, 4, 5, and 7 for ASA scores 1, 2, 3, and 4, respectively. CONCLUSION: The ASA physical status and RxRisk were associated with 30-day and 90-day mortality; however, the scores were only weakly to moderately correlated with each other. This suggests that although both scores capture a similar level of patient illness, each score may be capturing different aspects of health. The Rx-Risk may be used as a complementary measure to the ASA score. LEVEL OF EVIDENCE: Level III, therapeutic study.

Early revision in anatomic total shoulder arthroplasty in osteoarthritis: a cross-registry comparison.

BACKGROUND: We evaluated anatomic total shoulders undergoing early revision (less than two years) in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Kaiser Permanente Shoulder Arthroplasty Registry (KPSAR). METHODS: A cross-sectional comparison of both registries was performed between the years of 2009 and 2012. Only patients who underwent anatomic total shoulder arthroplasty for a primary diagnosis of osteoarthritis were included. Aggregate-level data of patients undergoing early revisions done within two years of index arthroplasty were evaluated, and descriptive analysis was conducted. RESULTS: During the study period, 4614 patients were identified in the AOANJRR compared to 2036 in the KPSAR. Rotator cuff pathology, component loosening, and prosthetic instability were among the most common reasons for revision in both registries. A higher rate of revision in the AOANJRR was found to be secondary to the failure of one specific prosthesis, which has since been discontinued. DISCUSSION: Comparing reasons for early revision in total shoulder arthroplasty revealed several similarities between the AOANJRR and KPSAR. Differences were also noted, and this study served to highlight the importance prosthesis selection can play in determining outcomes. Cooperation among registries may allow for earlier identification of risk factors for failure in shoulder arthroplasty.

The Outcome of Cemented Acetabular Components in Total Hip Arthroplasty for Osteoarthritis Defines a Proficiency Threshold: Results of 22,956 Cases From the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: The declining popularity of cemented acetabular components is incongruous, given the published results of prostheses implanted using contemporary techniques. The outcome of arthroplasty has previously been demonstrated to correlate with surgeon experience and volume of practice. We aim to explore if surgeon volume alters outcomes of cemented acetabular components based on survivorship data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). METHODS: An observational study was undertaken using a cohort of 22,956 patients with a primary diagnosis of osteoarthritis in the period 2003-2016 in whom cemented acetabular components were implanted. The cohort was stratified by age (greater than or less than 65 years) and annualized surgical volume of ≤10, >10-≤25, and >25 cases. RESULTS: Stratified by age and volume, there was a protective benefit against revision conveyed at volume thresholds of 10 cases per annum and 25 cases per annum for patients ≥65 years of age and <65 years of age, respectively. CONCLUSION: Cemented total hip arthroplasty has excellent survivorship out to 15 years based on AOANJRR data. This survivorship is further improved if surgeons perform a higher volume of cases, with >25 cases conferring the greatest benefit. The AOANJRR data set is used to define best practice; surgeons who choose to utilize cemented acetabular fixation should be encouraged to perform this technique in adequate volumes to minimize revision risk and ensure the preservation of this important surgical skill set.

Major Aseptic Revision Following Total Knee Replacement: A Study of 478,081 Total Knee Replacements from the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: Major revision is associated with less satisfactory outcomes, substantial complications, and added cost. Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) were analyzed to identify factors associated with major aseptic revision (MAR) of primary total knee replacement (TKR). METHODS: The cumulative percent major aseptic revision rate following all primary TKRs performed in Australia from September 1, 1999, to December 31, 2015, was assessed. Kaplan-Meier estimates of survivorship were utilized to describe the time to first revision. Hazard ratios (HRs) from Cox proportional hazard models, adjusted for age and sex, were utilized to compare revision rates. RESULTS: There were 5,973 MARs recorded from the total cohort of 478,081 primary TKRs. The cumulative percent MAR at 15 years was 3.0% (95% confidence interval [CI], 2.8% to 3.2%). Fixed bearings had a significantly lower rate of MAR at 15 years: 2.7% (95% CI, 2.4% to 2.9%) compared with 4.1% (95% CI, 3.8% to 4.5%) for mobile bearings (HR, 1.77 [95% CI, 1.68 to 1.86]; p < 0.001). Age had a significant effect on MAR rates, with a cumulative percent revision at 15 years for patients <55 years old of 7.8% (95% CI, 6.5% to 9.2%) compared with 1.0% for those ≥75 years old (95% CI, 0.8% to 1.1%; p < 0.001). Minimally stabilized TKR had a lower rate of MAR compared with posterior-stabilized TKR after 2 years (HR, 0.83 [95% CI, 0.77 to 0.90]; p < 0.001). Cementless fixation had a higher rate of revision than cemented or hybrid fixation. There was a higher rate of MAR with non-navigated compared with computer navigated TKR (HR, 1.32 [95% CI, 1.21 to 1.44], p < 0.001). The tibial component was revised more commonly than the femoral component. CONCLUSIONS: Younger age, posterior stabilization, cementless fixation, a mobile bearing, and non-navigation were risk factors for higher rates of MAR following TKR. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Late Dislocations After Total Hip Arthroplasty: Is the Bearing a Factor?

BACKGROUND: Dislocation is a leading cause of revision after primary total hip arthroplasty (THA). Although more common in the first few years after the procedure, dislocation can occur at any time. This study investigated the difference in late dislocation in ceramic-on-ceramic (CoC) bearings compared with metal-on-polyethylene and ceramic-on-polyethylene bearings in THA. METHODS: Data were used from the Australian Orthopaedic Association National Joint Replacement Registry, and the cumulative percent revision for dislocation was estimated using the Kaplan-Meier method for the different bearing surfaces. There were 192,275 THAs included in the study with 101,915 metal-on-cross-linked polyethylene (MoXLPE), 30,256 ceramic-on-cross-linked polyethylene (CoXLPE), and 60,104 CoC. RESULTS: The cumulative percent revision for dislocation at 13 years for MoXLPE, CoXLPE, and CoC groups was 1.2 (95% confidence interval [CI], 1.1-1.3), 1.0 (95% CI, 0.7-1.4), and 0.9 (95% CI, 0.8-1.1), respectively. There was an increased risk of revision for dislocation for MoXLPE compared with CoXLPE and CoC. When stratified for head size, there was no difference in the risk of revision for dislocation between MoXLPE, CoXLPE, and CoC in the 28- and 32-mm head sizes. With a head size of 36 mm, MoXLPE had a higher rate of dislocation compared with other materials. CONCLUSION: Bearing surface has little impact on revision for dislocation.

The Heart Health Study - increasing cardiovascular risk assessment in family practice for first degree relatives of patients with premature ischaemic heart disease: a randomised controlled trial.

BACKGROUND: This study aimed to increase cardiovascular disease (CVD) risk assessment in adult first degree relatives of patients with premature ischaemic heart disease (PIHD) using written and verbal advice. DESIGN: A prospective, randomised controlled trial. SETTING: Cardiovascular wards at three South Australian hospitals. Cardiovascular risk assessments were performed in general practice. PARTICIPANTS: Patients experiencing PIHD (heart disease in men aged <55 years or women aged < 65 years) and their first degree relatives. INTERVENTION: Patients distributed either general information about heart disease and written advice to attend their general practitioner (GP) for CVD risk assessment or general information about heart disease only, to their first degrees relatives. MAIN OUTCOME MEASURE: The primary outcome was the proportion of relatives who attended their GP for CVD risk assessment within 6 months of the patients' PIHD event. RESULTS: One hundred forty four patients were recruited who had 541 eligible relatives; 97/541 (18 %) of relatives agreed to participate. A larger number of intervention 41/55 (75 %) than control group 9/42 (21 %) [difference 53 %, 95 % CI 36 % - 71 %] relatives attended their GP for a CVD assessment, and 34 % of these had moderate to very high 5-year absolute risk for CVD. CONCLUSION: This low cost intervention demonstrates that individuals who have a family history of PIHD and are at moderate or high risk of CVD can be targeted for early intervention of modifiable risk factors. Further research is required to improve the uptake of the intervention in relatives. TRIAL REGISTRATION: The trial was registered with the Australian Clinical Trials Registry (ACTRN), Registration ID 12613000557730 .

Effect of weight reduction and cardiometabolic risk factor management on symptom burden and severity in patients with atrial fibrillation: a randomized clinical trial.

IMPORTANCE: Obesity is a risk factor for atrial fibrillation. Whether weight reduction and cardiometabolic risk factor management can reduce the burden of atrial fibrillation is not known. OBJECTIVE: To determine the effect of weight reduction and management of cardiometabolic risk factors on atrial fibrillation burden and cardiac structure. DESIGN, SETTING, AND PATIENTS: Single-center, partially blinded, randomized controlled study conducted between June 2010 and December 2011 in Adelaide, Australia, among overweight and obese ambulatory patients (N = 150) with symptomatic atrial fibrillation. Patients underwent a median of 15 months of follow-up. INTERVENTIONS: Patients were randomized to weight management (intervention) or general lifestyle advice (control). Both groups underwent intensive management of cardiometabolic risk factors. MAIN OUTCOMES AND MEASURES: The primary outcomes were Atrial Fibrillation Severity Scale scores: symptom burden and symptom severity. Scores were measured every 3 months from baseline to 15 months. Secondary outcomes performed at baseline and 12 months were total atrial fibrillation episodes and cumulative duration measured by 7-day Holter, echocardiographic left atrial area, and interventricular septal thickness. RESULTS: Of 248 patients screened, 150 were randomized (75 per group) and underwent follow-up. The intervention group showed a significantly greater reduction, compared with the control group, in weight (14.3 and 3.6 kg, respectively; P < .001) and in atrial fibrillation symptom burden scores (11.8 and 2.6 points, P < .001), symptom severity scores (8.4 and 1.7 points, P < .001), number of episodes (2.5 and no change, P = .01), and cumulative duration (692-minute decline and 419-minute increase, P = .002). Additionally, there was a reduction in interventricular septal thickness in the intervention and control groups (1.1 and 0.6 mm, P = .02) and left atrial area (3.5 and 1.9 cm2, P = .02). CONCLUSIONS AND RELEVANCE: In this study, weight reduction with intensive risk factor management resulted in a reduction in atrial fibrillation symptom burden and severity and in beneficial cardiac remodeling. These findings support therapy directed at weight and risk factors in the management of atrial fibrillation. TRIAL REGISTRATION: anzctr.org.au Identifier: ACTRN12610000497000.

Low vitamin B12 levels among newly-arrived refugees from Bhutan, Iran and Afghanistan: a multicentre Australian study.

BACKGROUND: Vitamin B12 deficiency is prevalent in many countries of origin of refugees. Using a threshold of 5% above which a prevalence of low Vitamin B12 is indicative of a population health problem, we hypothesised that Vitamin B12 deficiency exceeds this threshold among newly-arrived refugees resettling in Australia, and is higher among women due to their increased risk of food insecurity. This paper reports Vitamin B12 levels in a large cohort of newly arrived refugees in five Australian states and territories. METHODS: In a cross-sectional descriptive study, we collected Vitamin B12, folate and haematological indices on all refugees (n = 916; response rate 94% of eligible population) who had been in Australia for less than one year, and attended one of the collaborating health services between July 2010 and July 2011. RESULTS: 16.5% of participants had Vitamin B12 deficiency (<150 pmol/L). One-third of participants from Iran and Bhutan, and one-quarter of participants from Afghanistan had Vitamin B12 deficiency. Contrary to our hypothesis, low Vitamin B12 levels were more prevalent in males than females. A higher prevalence of low Vitamin B12 was also reported in older age groups in some countries. The sensitivity of macrocytosis in detecting Vitamin B12 deficiency was only 4.6%. CONCLUSION: Vitamin B12 deficiency is an important population health issue in newly-arrived refugees from many countries. All newly-arrived refugees should be tested for Vitamin B12 deficiency. Ongoing research should investigate causes, treatment, and ways to mitigate food insecurity, and the contribution of such measures to enhancing the health of the refugee communities.