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Background Methods Results Conclusions Early revision for total hip arthroplasty is a serious adverse outcome. There are multiple contributing risk factors for early revision. Risk factors can exist at the level of the surgeon and the level of the institution. The primary research question of this study was to determine the relative contribution of surgeon‐level and hospital‐level variance to rates of early revision (overall and for infection) after primary total hip arthroplasty.This is a registry‐based study from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Data for the most commonly used stem (Exeter V40) were used to reduce prosthesis variation from the analysis. A mixed effects Cox Model (also known as a frailty model) with crossed random effects for surgeon and hospital was used. Outcomes were early revision (within 2 years) for all causes and for infection. This model allowed for the risk of early revision to be explained by the variability at the surgeon level or hospital level.There were 32 031 procedures performed by 735 surgeons across 250 hospitals between 1 January 2015 and 31 December 2019. Surgeon variability significantly contributed to overall variation in revision for any cause and revision for infection (P < 0.0001). There was no significant contribution of hospital‐level variation to overall revision or for infection.Surgeon‐level factors play a more important role than institution‐level factors in early revision after primary total hip arthroplasty. If surgeons are identified as having a higher risk of revision, there is potential for surgeon‐level practice change to reduce the risk of early revision. [ABSTRACT FROM AUTHOR]

Background: Despite wide adoption of hydroxyapatite (HA)-coated femoral stems in THA, no studies have found differences in the risk of revision surgery with its use or investigated the interaction of different prosthesis designs with stem coating.Questions/purposes: The purpose of this study was to evaluate the risk of revision in THAs with HA-coated stems compared with non-HA-coated. To achieve this purpose, we asked: (1) What is the difference in risk of revision of THAs with HA-coated femoral stems compared with non-HA-coated using an aggregate analysis? (2) What is the difference in risk of revision of THAs with HA-coated femoral stems compared with non-HA-coated for five prosthesis types that used the same femoral and acetabular component combination but where the femoral stem had both a HA and non-HA coating option?Methods: The Australian Orthopaedic Association National Joint Replacement Registry analyzed cementless primary THA registered between September 1, 1999, and December 31, 2014. Of the 147,645 cases that fit our selection criteria, 81.1% (N = 119,673) had HA-coated stems. Overall (that is, all procedures with any prostheses in the registry) and five prosthesis designs where both an HA-coated stem and non-HA-coated stem exist (Zimmer's VerSys®/Trilogy® [N = 3924], Biomet's Mallory-Head®/Mallory-Head [N = 2538], Smith & Nephew's SL-Plus/EP Fit-Plus [N = 2028], Biomet's Taperloc®/Exceed [N = 1668], and Biomet's Taperloc/Mallory-Head [N = 1240]) were evaluated. Revision surgery was the outcome of interest. Survival analyses were conducted and hazard ratios (HRs) were adjusted for age, sex, bearing surface, femoral head size, and acetabular component HA coating.Results: In the overall cohort, HA stems had a lower any-cause revision risk after 6 months (HR, 0.83; 95% confidence interval [CI], 0.72-0.95; p = 0.007). However, the risk of revision varied when we evaluated the effect of HA on revision for specific prothesis combinations that had both HA and non-HA options for the femoral stem. VerSys/Trilogy, Mallory-Head/Mallory-Head, Taperloc/Exceed, and Taperloc/Mallory-Head did not have a lower risk of any-cause revision with HA-coated stems compared with non-HA-coated. Only the SL-Plus/EP Fit-Plus subgroup showed a lower risk of revision for loosening (HR, 0.17; 95% CI, 0.06-0.44 between 0 and 7 years; p < 0.001) with HA- compared with non-HA-coated stems, but this was observed after an early (< 6 months) higher risk of revision for any reason (HR, 2.88; 95% CI, 1.15-7.21; p = 0.024).Conclusions: Overall, HA coating of femoral stems was found to be associated with a 17% lower risk of revision for any reason. However, the lower risk of revision associated with HA was not consistent for all prosthesis designs where both HA- and non-HA-coated femoral stem versions were available. Some HA-coated stems have higher revision rates compared with their non-HA-coated versions. Our findings suggest that the effect of HA coating on revision risk varies depending on prosthesis design.Level Of Evidence: Level II, therapeutic study. [ABSTRACT FROM AUTHOR]

Background and purpose — Trabecular metal (TM) cups have demonstrated favorable results in acetabular revision and their use in primary total hip arthroplasty (THA) is increasing. Some evidence show that TM cups might decrease periprosthetic infection (PPI) incidence. We compared the survivorship of TM cups with that of other uncemented cups in primary THA, and evaluated whether the use of TM cups is associated with a lower risk of PPI.Patients and methods — 10,113 primary THAs with TM cup and 85,596 THAs with other uncemented cups from 2 high-quality national arthroplasty registries were included. The mean follow-up times were 3.0 years for the TM cups and 3.8 years for the other uncemented cups.Results — The overall survivorship up to 8 years for TM cups and other uncemented cups was 94.4% and 96.2%, respectively (p = < 0.001). Adjusting for relevant covariates in a Cox regression model the TM cups had a persistently higher revision risk than other uncemented cups (HR =1.5, 95% CI 1.4-1.7, p = < 0.001). There was a slightly higher, though not statistically significant, revision rate for PPI in the TM group (1.2, 95% CI 1.0-1.6, p = 0.09).Interpretation — Risk of revision for any reason was higher for the TM cup than for other uncemented cups in primary THA. In contrast to our hypothesis, there was no evidence that the revision rate for PPI was lower in the TM cup patients. Regardless of the promising early and mid-term results for TM cups in hip revision arthroplasty, we would like to sound a note of caution on the increasing use of the TM design, especially in uncomplicated primary THAs, where uncemented titanium cups are considered to provide a reliable outcome. [ABSTRACT FROM AUTHOR]

Background: Earlier results with porous tantalum acetabular cups in revision THA generally have been favorable. Recently there has been some evidence presented that porous tantalum cups might decrease the risk of rerevision in the setting of revision hip surgery performed owing to prosthetic joint infection (PJI). As the data supporting this assertion come from a study with a limited study population, examining this issue with a large registry approach may be enlightening.Questions/purposes: By combining results from two large, national registries, we asked: (1) Do porous tantalum cups show improved survival after revision THA compared with other cementless designs? (2) Does the use of porous tantalum cups influence survivorship when rerevision for PJI is the endpoint?Methods: A total of 2442 first-time THA revisions with porous tantalum cups and 4401 first-time revisions with other uncemented cups were included in this collaborative study between the Australian and Swedish national joint registries. The mean age of the patients was 69 years (range, 19-97 years), 3754 (55%) of the patients were women, and the mean followup for the porous tantalum and uncemented control groups were 3.0 years (SD, ± 2.1 years) and 3.4 years (SD, ± 2.3 years), respectively. Concomitant stem revision was more common in the porous tantalum group (43% versus 36%). The use of porous tantalum augments also was analyzed as a proxy for more complex acetabular reconstructions. In an attempt to further reduce selection bias, we performed subgroup analysis for primary operations attributable to osteoarthritis and first revision attributable to aseptic loosening.Results: Kaplan-Meier survivorship with rerevisison for any reason up to 7 years was comparable between the porous tantalum cup group and the uncemented cup control group (86% [95% CI, 85%-89%] and 87% [95% CI, 85%-89%], respectively; p = 0.85) and the overall survivorship up to 7 years with a second revision for PJI as the endpoint (97% [95% CI, 95%-98%] and 97% [95% CI, 96%-98%], respectively; p = 0.64). Excluding procedures where augments had been used or studying primary osteoarthritis and first revision owing to aseptic loosening subgroups did not change this result.Conclusions: Implant survival for a porous tantalum cup in first-time THA revision was similar to the survival of the uncemented cup control group. With the numbers available, no benefit in survival with rerevision for infection as the endpoint could be ascribed to the porous tantalum cup group, as has been suggested by earlier work. Further studies with acetabular bone deficiency data, greater insight into host comorbidity factors, and a longer followup are needed to corroborate or refute these results.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: Australian healthcare relies on both private and public sectors to meet the demand for surgical care. Rapid growth of shoulder replacement surgery highlights a disparity in service provision, with two‐thirds occurring privately. This study aimed to assess the influence of hospital setting on shoulder replacement revision rate at a national level. Methods: All primary shoulder replacements recorded by the Australian Orthopaedic Association National Joint Replacement Registry from April 2004 to December 2020 were included. Private and public settings were compared for stemmed total shoulder replacement (sTSR) for osteoarthritis (OA), reverse total shoulder replacement (rTSR) for OA/cuff arthropathy (CA), and rTSR for fracture. The primary outcome was cumulative percent revision (CPR), with Kaplan–Meier estimates of survivorship to determine differences between private and public hospitals, recorded as hazard ratios (HR). Secondary analyses investigated differences between hospital settings, targeting hospital outliers for revision and prosthesis selection. Results: Primary sTSR (OA) demonstrated a higher revision rate in private hospitals compared to public hospitals (HR = 1.27; P = 0.001), as did rTSR (OA/CA) after 3 months (HR = 1.33; P = 0.003). However, no significant difference was observed for primary rTSR (fracture) (HR = 1.10; P = 0.484). Restricting rTSR (OA/CA) to the best performing prosthesis combinations eliminated the difference between private and public outcomes (HR 1.10; P = 0.415). No other secondary analysis altered the primary result. Conclusions: Differences exist between private and public hospitals for revision rate following primary shoulder replacement. Prosthesis selection accounts for some of the variation. Further analysis into patient specific characteristics is necessary to better understand these disparities. [ABSTRACT FROM AUTHOR]

Background: There are many factors that may affect the learning curve for total hip arthroplasty (THA) and surgical approach is one of these. There has been renewed interest in the direct anterior approach for THA with variable outcomes reported, but few studies have documented a surgeon's individual learning curve when using this approach.Questions/purposes: (1) What was the revision rate for all surgeons adopting the anterior approach for placement of a particular implant? (2) What was the revision rate for surgeons who performed > 100 cases in this fashion? (3) Is there a minimum number of cases required to complete a learning curve for this procedure?Methods: The Australian Orthopaedic Association National Joint Replacement Registry prospectively collects data on all primary and revision joint arthroplasty surgery. We analyzed all conventional THAs performed up to December 31, 2013, with a primary diagnosis of osteoarthritis using a specific implant combination and secondarily those associated with surgeons performing more than 100 procedures. Ninety-five percent of these procedures were performed through the direct anterior approach. Procedures using this combination were ordered from earliest (first procedure date) to latest (last procedure date) for each individual surgeon. Using the order number for each surgeon, five operation groups were defined: one to 15 operations, 16 to 30 operations, 31 to 50 operations, 51 to 100 operations, and > 100 operations. The primary outcome measure was time to first revision using Kaplan-Meier estimates of survivorship.Results: Sixty-eight surgeons performed 5499 THAs using the specified implant combination. The cumulative percent revision at 4 years for all 68 surgeons was 3% (95% confidence interval [CI], 2.5-3.8). For surgeons who had performed over 100 operations, the cumulative revision rate was 3% (95% CI, 2.0-3.5). It was not until surgeons had performed over 50 operations that there was no difference in the cumulative percent revision compared with over 100 operations. The cumulative percent revision for surgeons performing 51 to 100 operations at 4 years was 3% (95% CI, 1.5-5.4) and over 100 operations 2% (95% CI, 1.2-2.7; hazard ratio, 1.40 [95% CI, 0.7-2.7]; p = 0.33).Conclusions: There is a learning curve for the anterior approach for THA even when using a prosthesis combination specifically marketed for that approach. We found that 50 or more procedures need to be performed by a surgeon before the rate of revision is no different from performing 100 or more procedures. Surgeons should be aware of this initial higher rate of revision when deciding which approach delivers the best outcome for their patients. [ABSTRACT FROM AUTHOR]

In recent years servicewomen with dependent children have for the first time in history been deployed into conflict zones in support of Australian Defence Force operations. This represents a significant social change, and the implications of deployment on the health of these service mothers are not fully understood. Data from women who participated in the Middle East Area of Operations Census study were analyzed to compare the psychological and physical symptoms reported by service mothers with service women who had no dependent children at the time of deploying to Afghanistan and/or Iraq. Of the 921 women who were included in this analysis, 235 had dependent children and 686 had no dependent children (comparison group). Service mothers were significantly older and were more likely to have served in the Air Force than women in the comparison group. Findings demonstrate that serving mothers were not at any significantly higher risk of psychological distress, post-traumatic stress symptoms, alcohol misuse, or reporting of somatic symptoms, than women who had no dependent children. A number of possible explanations for these findings are discussed, including the healthy soldier/mother effect, support from partners and extended family members, and collegial networks. [ABSTRACT FROM PUBLISHER]

During the 1850s and 1860s, white settlers perpetrated genocide against California Indians. Militia and regular troops supported by the state and federal governments committed acts of genocide as defined by the United Nations. Government officials, newspaper editors, and pioneers documented the genocide. History and social science textbooks ignore or barely mention murders, rapes, kidnappings, and enslavement of California Indians during the Gold Rush era. The California State Department of Education denies the genocide and textbook companies are silent of Indian genocide in spite of overwhelming evidence. [ABSTRACT FROM PUBLISHER]

A 5-year longitudinal study of the implementation of an affective curriculum in a school for gifted children, in the form of weekly development-oriented, teacher-led small-group discussions for all students in Grades 5 through 8, found that initial resistance changed to receptivity and gains over time. Analysis of Likert-type responses and brief comments from the students offered guidance for curriculum development and delivery. Differences in a positive direction reflected institutionalization of the group program and support for continuation. However, findings also underscored the need to clarify the purpose of the program to students, select discussion topics carefully, consider gender when forming groups, provide adequate time for group meetings, and provide adequate training for group facilitators. [ABSTRACT FROM AUTHOR]

Background: When arthroplasty is indicated for a femoral neck fracture (FNF), it is unclear whether total hip arthroplasty (THA) or hemiarthroplasty (HA) is best. This study compares data from the Australian Orthopaedic Association National Joint Replacement Registry using contemporary surgical options.Methods: Patients from 60 to 85 years old who were treated with arthroplasty for FNF, between September 1999 and December 2019, were included if the femoral stems were cemented. Only THAs with femoral heads of ≥36 mm or dual-mobility articulations were included. Patients who had monoblock HA were excluded. Rates of revision for all aseptic failures and dislocation were compared. Competing risks of revision and death were considered using the cumulative incidence function. Subdistribution hazard ratios (HRs) for revision or death from a Fine-Gray regression model were used to compare THA and HA. Interactions of procedure with age group and sex were considered. Secondary analysis adjusting for body mass index (BMI) and American Society of Anesthesiologists (ASA) classification was also considered.Results: There were 4,551 THA and 29,714 HA procedures included. The rate of revision for THA was lower for women from 60 to 69 years old (HR = 0.58 [95% confidence interval (CI), 0.39 to 0.85]) and from 70 to 74 years old (HR = 0.65 [95% CI, 0.43 to 0.98]) compared with HA. However, women from 80 to 85 years old (HR = 1.56 [95% CI, 1.03 to 2.35]) and men from 75 to 79 years old (HR = 1.61 [95% CI, 1.05 to 2.46]) and 80 to 85 years old (HR = 2.73 [95% CI, 1.89 to 3.95]) had an increased rate of revision when THA was undertaken compared with HA. There was no difference in the rate of revision for dislocation between THA and HA for either sex or age categories.Conclusions: When contemporary surgical options for FNF are used, there is a benefit with respect to revision outcomes for THA in women who are <75 years old and a benefit for HA in women who are ≥80 years old and men who are ≥75 years old. There is no difference in dislocation rates.Level Of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Delaying elective JR surgery prolongs pain and disability, and challenges the notion of what is considered "elective" surgery. Joint replacement (JR) is one of the most common and successful surgical procedures performed in Australia, with over 115 000 primary procedures undertaken in 2019.1 In 2020, most JR surgery was suspended in late March in response to Federal Government directives to allow only emergency and urgent surgery, which did not include elective JR.2,3 This suspension was gradually eased over subsequent months, which varied by jurisdiction. The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) is uniquely positioned to monitor the impact of COVID-19 related restrictions on JR surgery across the country. [Extracted from the article]

Background: Patient-reported outcome measures (PROMs) are commonly used to evaluate surgical outcome in patients undergoing joint replacement surgery, however routine collection from the target population is often incomplete. Representative samples are required to allow inference from the sample to the population. Although higher capture rates are desired, the extent to which this improves the representativeness of the sample is not known. We aimed to measure the representativeness of data collected using an electronic PROMs capture system with or without telephone call follow up, and any differences in PROMS reporting between electronic and telephone call follow up. Methods: Data from a pilot PROMs program within a large national joint replacement registry were examined. Telephone call follow up was used for people that failed to respond electronically. Data were collected pre-operatively and at 6 months post-operatively. Responding groups (either electronic only or electronic plus telephone call follow up) were compared to non-responders based on patient characteristics (joint replaced, bilaterality, age, sex, American Society of Anesthesiologist (ASA) score and Body Mass Index (BMI)) using chi squared test or ANOVA, and PROMs for the two responder groups were compared using generalised linear models adjusted for age and sex. The analysis was restricted to those undergoing primary elective hip, knee or shoulder replacement for osteoarthritis. Results: Pre-operatively, 73.2% of patients responded electronically and telephone follow-up of non-responders increased this to 91.4%. Pre-operatively, patients responding electronically, compared to all others, were on average younger, more likely to be female, and healthier (lower ASA score). Similar differences were found when telephone follow up was included in the responding group. There were little (if any) differences in the post-operative comparisons, where electronic responders were on average one year younger and were more likely to have a lower ASA score compared to those not responding electronically, but there was no significant difference in sex or BMI. PROMs were similar between those reporting electronically and those reporting by telephone. Conclusion: Patients undergoing total joint replacement who provide direct electronic PROMs data are younger, healthier and more likely to be female than non-responders, but these differences are small, particularly for post-operative data collection. The addition of telephone call follow up to electronic contact does not provide a more representative sample. Electronic-only follow up of patients undergoing joint replacement provides a satisfactory representation of the population invited to participate. [ABSTRACT FROM AUTHOR]

Background: Well-validated data from arthroplasty registries provide an opportunity to understand contemporary use of revision hip replacement at a national level. Such information can underpin health-care resource allocation and surgical workforce planning. The purposes of the present study were to describe the demographic characteristics of patients managed with revision hip replacement surgery in Australia and to examine changes in the lifetime risk of revision hip replacement over a decade.Methods: Deidentified individual-level data on all revision hip replacement procedures performed in Australia from 2007 to 2017 were obtained from the Australian Orthopaedic Association National Joint Replacement Registry. Life tables and population data were sourced from the Australian Bureau of Statistics. The lifetime risk of revision surgery each year was estimated with use of a standardized approach, with separate calculations for males and females.Results: A total of 46,086 revision hip replacement procedures were performed from 2007 to 2017. The median age at the time of surgery was 72 years (interquartile range, 63 to 80 years). While loosening or lysis became less frequent reasons for revision over time (from 51% in 2007 to 28% in 2017), revision hip replacement for infection became increasingly common (from 14% in 2007 to 25% in 2017). Revisions for metal-related pathology peaked in 2011. Utilization rates were highest for males ≥80 years of age (127.9 procedures per 100,000 population in 2017). Although a small rise was evident in 2011 and 2012 (to 2.39% and 2.22%, respectively), the lifetime risk of revision hip replacement in females decreased from 1.90% (95% confidence interval [CI], 1.82% to 1.99%) in 2007 to 1.74% (95% CI, 1.66% to 1.82%) in 2017. A similar pattern was evident for males; the lifetime risk was 1.78% (95% CI, 1.69% to 1.86%) in 2007 and 1.57% (95% CI, 1.49% to 1.65%) in 2017.Conclusions: These data enable us to understand the epidemiology of revision hip replacement in Australia, including the shifting clinical indications for this procedure. At a population level, the lifetime risk of revision hip replacement remains low at <1 in 50 people in 2017. These methods can be utilized for population-level surveillance of revision burden and to enable between-country benchmarking.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: A number of surgical approaches are available for total hip arthroplasty (THA), but there are limited large-volume, multi-surgeon data comparing the rates of early revisions following these approaches. The aim of this study was to compare the rate of revision of primary conventional THA related to surgical approach.Methods: Data from the Australian Orthopaedic Association National Joint Replacement Registry were analyzed for all patients who had undergone a primary THA for osteoarthritis from January 2015 to December 2018. The primary outcome measure was the cumulative percent revision (CPR) for all causes. Secondary outcome measures were major revision (a revision procedure requiring change of the acetabular and/or femoral component) and revision for specific diagnoses: fracture, component loosening, infection, and dislocation. Age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) score, femoral head size, and femoral fixation were assessed as potential confounders.Results: There was a total of 122,345 primary conventional THAs for which the surgical approach was recorded in the registry; 65,791 were posterior, 24,468 were lateral, and 32,086 were anterior. There was no difference in the overall CPR among approaches, but the anterior approach was associated with a higher rate of major revisions. There were differences among the approaches with regard to the types of revision. When adjusted for age, sex, ASA score, BMI, femoral head size, and femoral fixation, the anterior approach was associated with a higher rate of femoral complications-i.e., revision for periprosthetic fracture and femoral loosening. There was a lower rate of revision for infection after the anterior approach compared with the posterior approach in the entire period, and compared with the lateral approach in the first 3 months. The posterior approach was associated with a higher rate of revision for dislocation compared with both the anterior and the lateral approach in all time periods. The anterior approach was associated with a lower rate of revision compared with the lateral approach in the first 6 months only.Conclusions: There was no difference in the overall early CPR among the surgical approaches, but the anterior approach was associated with a higher rate of early major revisions and femoral complications (revisions for periprosthetic fracture and femoral loosening) compared with the posterior and lateral approaches and with a lower rate of dislocation and infection.Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

This study aims to assess whether older adults with low muscle mass or strength, in the presence of obesity, have an increased risk of knee (TKR) and hip replacement (THR) over 13 years. 1082 community-dwelling older adults (51% women; mean age 62.9 ± 7.5 years) were studied at baseline and multiple time points over 13 years. The incidence of TKR and THR was determined by data linkage to National Joint Replacement Registry. Appendicular lean and fat mass were measured using DXA. Lower-limb muscle strength (LMS) was assessed by dynamometer. Low muscle mass and strength were defined as the lowest sex-specific tertiles for appendicular lean mass (adjusted for height and total body fat mass) and lower-limb strength, respectively. Obesity was defined as the highest sex-specific tertile for total body fat mass. Competing risk regression models were used to estimate the sub-distribution hazard ratio (SHR) for TKR and THR. Over 13 years of follow-up, 6.8% (n = 74/1082) of the participants had a TKR and 4.7% (n = 50/1066) had THR. Participants with the combination of obesity and low muscle strength (SHR   3.36, 95% CI 1.50, 7.53) but low muscle mass (SHR 1.11, 95% CI 0.52, 2.40) had a significantly increased risk of TKR, compared to individuals with neither obesity nor low muscle mass/strength. However, obesity with low muscle strength did not lead to a significantly greater risk of TKR compared to having low muscle strength or obesity alone. There was no evidence for an association between obesity with low muscle mass or strength and THR (all p > 0.05). This finding suggests that combining muscle and fat assessments to predict the future risk of TKR is no better than each condition on its own. [ABSTRACT FROM AUTHOR]

Background: Patellofemoral arthroplasty (PFA) is one option for the treatment of isolated patellofemoral osteoarthritis, but there are limited data regarding the procedure and results. Because isolated patellofemoral arthritis is relatively uncommon, available case series generally are small, and even within national registries, sample sizes are limited. Combining data from multiple registries may aid in assessing worldwide PFA usage and survivorship.Questions/purposes: We combined and compared data from multiple large arthroplasty registries worldwide to ask: (1) What proportion of patients undergoing primary knee arthroplasty have PFA? (2) What are the patient and prosthesis characteristics associated with PFA in common practice, as reflected in registries? (3) What is the survivorship free from revision of PFA and what are the reasons for and types of revisions?Methods: Data were provided by eight registries that are members of the International Society of Arthroplasty Registries (ISAR) who agreed to share aggregate data: Australia, New Zealand, Canada, Sweden, Finland, Norway, the Netherlands, and the United States. De-identified data were obtained for PFA performed from either the beginning of year 2000, or the earliest recorded implantation date after that in each individual registry when PFA data collection commenced, up to December 31, 2016. This included patient demographics, implant use, all-cause revision rate (determined by cumulative percent revision [CPR]), and reasons for and type of revision.Results: During the data collection period, 6784 PFAs were performed in the eight countries. PFAs comprised less than 1% of primary knee replacements in all registries. Patient demographics were comparable in all countries. Patients were generally more likely to be women than men, and the mean age ranged from 50 years to 60 years. All registries showed a high rate of revision for PFA. The 5-year CPR for any reason ranged from 8.0% (95% CI 4.5 to 11.5) in Norway to 18.1% (95% CI 15.5 to 20.7) in the Netherlands. The most common reason for revision across all countries was disease progression (42%, 434 of 1034). Most PFAs (83%, 810 of 980) were revised to a TKA.Conclusions: The revision risk of PFA in all registries surveyed was more than three times higher than the reported revision risk of TKA at the same times. The survivorship of PFA is similar to that of the no-longer-used procedure of metal-on-metal conventional hip replacement. Although there may be potential functional benefits from PFA, these findings of consistent and alarmingly high rates of revision should create concern, particularly as this procedure is often used in younger patients.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: This study determined the contributing factors of hospital sector (private versus public) variation in revision rates after elective total hip replacement (THR) for hip fracture, and elective total knee replacement (TKR). Methods: Using data from a large national arthroplasty registry, funnel plots for hospitals were generated, displaying the proportion of revised primary procedures. The proportion of outliers for each distribution was defined as the proportion outside the upper 99.7% confidence limit. Survival analyses determined differences between hospital sector revision rates separately for implants with the lowest revision rate, and for all other implants. Multivariate Cox regression determined the role of hospital sector in revision, adjusting for possible confounders. Results: For THR performed for osteoarthritis, 17.4% of private and 4.4% of public hospitals were outliers. For TKR performed for osteoarthritis, 19.6% of private and 10.0% of public hospitals were outliers. For THR for fractured neck of femur, 8.1% of private and 0.0% of public hospitals were outliers. Adjusted and unadjusted Kaplan–Meier analyses showed higher THR revision rates in private hospitals for osteoarthritis and fractured neck of femur, but no difference when restricted to the 10 prostheses with the lowest revision rate. The Kaplan–Meier analysis of TKR showed higher revision rates for private hospitals, with the association reversing when restricted to prostheses with the lowest revision rate. Conclusions: Considerable variation was seen in the revision rate after THR and TKR between hospital sectors in Australia. The variation was largely due to differences in prosthesis selection. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background and purpose -- Given similar functional outcomes with mobile and fixed bearings, a difference in survivorship may favor either. This study investigated the risk of aseptic loosening for the most used subtypes of mobile-bearing rotating-platform knees, in Norway and Australia. Patients and methods -- Primary TKRs reported to the Norwegian and Australian joint registries, between 2003 and 2014, were analyzed with aseptic loosening as primary end-point and all revisions as secondary end-point. We hypothesized that no difference would be found in the rate of revision between rotating-platform and the most used fixed-bearing TKRs, or between keeled and non-keeled tibia. Kaplan-Meier estimates and curves, and Cox regression relative risk estimates adjusted for age, sex, and diagnosis were used for comparison. Results -- The rotating-platform TKRs had an increased risk of revision for aseptic loosening compared with the most used fixed-bearing knees, in Norway (RR = 6, 95% CI 4-8) and Australia (RR = 2.1, 95% CI 1.8-2.5). The risk of aseptic loosening as a reason for revision was highest in Norway compared with Australia (RR = 1.7, 95% CI 1.4-2.0). The keeled tibial component had the same risk of aseptic loosening as the non-keeled tibia (Australia). Fixation method and subtypes of the tibial components had no impact on the risk of aseptic loosening in these mobile-bearing knees. Interpretation -- The rotating-platform TKRs in this study appeared to have a higher risk of revision for aseptic loosening than the most used fixed-bearing TKRs. [ABSTRACT FROM AUTHOR]

Background: Controversy still exists as to the optimum management of the posterior cruciate ligament (PCL) in total knee arthroplasty. Surgeons can choose to kinematically substitute the PCL with a posterior-stabilized total knee replacement or alternatively to utilize a cruciate-retaining, also known as minimally stabilized, total knee replacement. Proponents of posterior-stabilized total knee replacement propose that the reported lower survivorship in registries when directly compared with minimally stabilized total knee replacement is due to confounders such as selection bias because of the preferential usage of posterior-stabilized total knee replacement in more complex or severe cases. In this study, we aimed to eliminate these possible confounders by performing an instrumental variable analysis based on surgeon preference to choose either posterior-stabilized or minimally stabilized total knee replacement, rather than the actual prosthesis received.Methods: Cumulative percent revision, hazard ratio (HR), and revision diagnosis data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1, 1999, to December 31, 2014, for 2 cohorts of patients, those treated by high-volume surgeons who preferred minimally stabilized replacements and those treated by high-volume surgeons who preferred posterior-stabilized replacements. All patients had a diagnosis of osteoarthritis and underwent fixed-bearing total knee replacement with patellar resurfacing.Results: At 13 years, the cumulative percent revision was 5.0% (95% confidence interval [CI], 4.0% to 6.2%) for the surgeons who preferred the minimally stabilized replacements compared with 6.0% (95% CI, 4.2% to 8.5%) for the surgeons who preferred the posterior-stabilized replacements. The revision risk for the surgeons who preferred posterior-stabilized replacements was significantly higher for all causes (HR = 1.45 [95% CI, 1.30 to 1.63]; p < 0.001), for loosening or lysis (HR = 1.93 [95% CI, 1.58 to 2.37]; p < 0.001), and for infection (HR = 1.51 [95% CI, 1.25 to 1.82]; p < 0.001). This finding was irrespective of patient age and was evident with cemented fixation and with both cross-linked polyethylene and non-cross-linked polyethylene. However, the higher revision risk was only evident in male patients.Conclusions: There was a 45% higher risk of revision for the patients of surgeons who preferred a posterior-stabilized total knee replacement compared with the patients of surgeons who preferred a minimally stabilized total knee replacement.Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background and purpose — There are concerns that mental health (MH) may influence outcomes of total knee arthroplasty (TKA) or total hip arthroplasty (THA). We examined effects of poor MH before surgery on long-term outcomes of osteoarthritis-related TKA or THA in women. Patients and methods — The data were from 9,737 middle-aged participants (47–52 years) and 9,292 older participants (73–78 years) in the Australian Longitudinal Study on Women’s Health who completed surveys between 1998 and 2013. Dates of arthroplasties were obtained from the Australian Orthopaedics Association National Joint Replacement Registry. Participants without procedures were matched with participants with procedures. Trajectories of the Short-Form 36 scores for physical functioning, bodily pain, social functioning, and mental health based on mixed modeling were plotted for participants with and without surgery (stratified according to mental health, separately for TKA and THA, and for middle-aged and older participants). Results — In middle-aged women with poor and good MH, TKA improved physical function and reduced bodily pain, with improvements sustained up to 10 years after surgery. TKA contributed to restoration of social function in women with good MH, but this was less clear in women with poor MH. In both MH groups, mental health appeared to be unaffected by TKA. Similar patterns were observed after THA, and in older women. Interpretation — Recovery of physical and social function and reductions in pain were sustained for up to 10 years after surgery. Improvements in physical function and pain were also observed in women with poor mental health. Thus, in our view poor mental health should not be a contraindication for arthroplasty. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: The ability to identify which patients are at a greater risk of early revision knee arthroplasty has important practical and resource implications. Many international arthroplasty registries administer patient-reported outcome measures (PROMs) to provide a holistic assessment of pain, function, and quality of life. However, few PROM scores have been evaluated as potential indicators of early revision knee arthroplasty, and earlier studies have largely focused on knee-specific measures.Questions/purposes: This national registry-based study asked: (1) Which 6-month postoperative knee-specific and generic PROM scores are associated with early revision knee arthroplasty (defined as revision surgery performed 6 to 24 months after the primary procedure)? (2) Is a clinically important improvement in PROM scores (based on thresholds for the minimal important change) after primary knee arthroplasty associated with a lower risk of early revision?Methods: Preoperative and 6-month postoperative PROM scores for patients undergoing primary knee arthroplasty were sourced from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and Arthroplasty Clinical Outcomes Registry National. Between January 2013 and December 2020, PROM data were available for 19,402 primary total knee arthroplasties; these data were linked to AOANJRR data on revision knee arthroplasty. Of these, 3448 procedures were excluded because they did not have 6-month PROM data, they had not reached the 6-month postoperative point, they had died before 24 months, or they had received revision knee arthroplasty before the 6-month PROMs assessment. After these exclusions, data were analyzed for 15,954 primary knee arthroplasties. Associations between knee-specific (knee pain, Oxford Knee Score, and 12-item Knee injury and Osteoarthritis Outcome Score [KOOS-12]) or generic PROM scores (5-level EuroQol quality of life instrument [EQ-5D], EQ VAS, perceived change, and satisfaction) and revision surgery were explored using t-tests, chi-square tests, and regression models. Ninety-four revision procedures were performed at 6 to 24 months, most commonly for infection (39% [37 procedures]). The early revision group was younger than the unrevised group (mean age 64 years versus 68 years) and a between-group difference in American Society of Anesthesiologists (ASA) grade was noted. Apart from a small difference in preoperative low back pain for the early revision group (mean low back pain VAS 4.2 points for the early revision group versus 3.3 points for the unrevised group), there were no between-group differences in preoperative knee-specific or generic PROM scores on univariate analysis. As the inclusion of ASA grade or low back pain score did not alter the model results, the final multivariable model included only the most clinically plausible confounders (age and gender) as covariates. Multivariable models (adjusting for age and gender) were also used to examine the association between a clinically important improvement in PROM scores (based on published thresholds for minimal important change) and the likelihood of early revision.Results: After adjusting for age and gender, poor postoperative knee pain, Oxford, KOOS-12, EQ-5D, and EQ VAS scores were all associated with early revision. A one-unit increase (worsening) in knee pain at 6 months was associated with a 31% increase in the likelihood of revision (RR 1.31 [95% confidence interval (CI) 1.19 to 1.43]; p < 0.001). Reflecting the reversed scoring direction, a one-unit increase (improvement) in Oxford or KOOS-12 score was associated with a 9% and 5% reduction in revision risk, respectively (RR for Oxford: 0.91 [95% CI 0.90 to 0.93]; p < 0.001; RR for KOOS-12 summary: 0.95 [95% CI 0.94 to 0.97]; p < 0.001). Patient dissatisfaction (RR 6.8 [95% CI 3.7 to 12.3]) and patient-perceived worsening (RR 11.7 [95% CI 7.4 to 18.5]) at 6 months were also associated with an increased likelihood of early revision. After adjusting for age and gender, patients who did not achieve a clinically important improvement in PROM scores had a higher risk of early revision (RR 2.9 for the knee pain VAS, RR 4.2 for the Oxford Knee Score, RR 6.3 to 8.6 for KOOS-12, and RR 2.3 for EQ-5D) compared with those who did (reference group).Conclusion: Knee-specific and generic PROM scores offer an efficient approach to identifying patients at greater risk of early revision surgery, using either the 6-month score or the magnitude of improvement. These data indicate that surgeons can use single- and multi-item measures to detect a patient-perceived unsuccessful surgical outcome at 6 months after primary knee arthroplasty. Surgeons should be alert to poor PROM scores at 6 months or small improvements in scores (for example, less than 2 points for knee pain VAS or less than 10.5 points for Oxford Knee Score), which signal a need for direct patient follow-up or expedited clinical review.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background and purpose —While highly crosslinked polyethylene has shown reduced in vivo wear and lower rates of revision for total hip arthroplasty, there have been few long-term studies on its use in total knee arthroplasty (TKA). We compared the rate of revision of non-crosslinked polyethylene to that of crosslinked polyethylene in patients who underwent TKA for osteoarthritis. Patients and methods —We examined data from the Australian Orthopaedic Association National Joint Replacement Registry on 302,214 primary TKA procedures with non-crosslinked polyethylene and 83,890 procedures with crosslinked polyethylene, all of which were performed for osteoarthritis. The survivorship of the different polyethylenes was estimated using the Kaplan-Meier method and was compared using proportional hazard models. Results —The 10-year cumulative revision rate for non-crosslinked polyethylene was 5.8% (95% CI: 5.7–6.0) and for crosslinked polyethylene it was 3.5% (95% CI: 3.2–3.8) (> 6.5-year HR = 2.2 (1.5–3.1); p < 0.001). There was no effect of surgical volume or method of prosthesis fixation on outcome. There were 4 different TKA designs that had a minimum of 2,500 procedures in at least 1 of the polyethylene groups and a follow-up of ≥ 5 years. 2 of these, the NexGen and the Natural Knee II, had a lower rate of revision for crosslinked polyethylene. The Scorpio NRG/Series 7000 and the Triathlon Knee did not show a lower rate of revision for crosslinked polyethylene. Interpretation —There is a lower rate of revision for crosslinked polyethylene in TKA, and this appears to be prosthesis-specific and when it occurs is most evident in patients < 65 years of age. The difference in revision rates was mainly due to revisions because of lysis and loosening. [ABSTRACT FROM PUBLISHER]

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. Methods: 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: For patient-reported outcome measures (PROMs) to provide meaningful information to support clinical care, we need to understand the magnitude of change that matters to patients. The aim of this study was to estimate minimal clinically important changes (MCICs) for the 12-item Hip disability and Osteoarthritis Outcome Score (HOOS-12) and Knee injury and Osteoarthritis Outcome Score (KOOS-12) among people undergoing joint replacement for osteoarthritis.Methods: Individual-level data from the Australian Orthopaedic Association National Joint Replacement Registry's pilot PROMs program were used for this analysis. Preoperative and 6-month postoperative HOOS-12 and KOOS-12 domain and summary impact scores plus a rating of patient-perceived change after surgery (on a 5-point scale ranging from "much worse" to "much better") were available. Three anchor-based approaches-mean change, receiver operating characteristics (ROC) based on Youden's J statistic, and predictive modeling using a binary logistic regression model-were used to calculate MCICs based on patient-perceived change.Results: Data were available for 1,490 patients treated with total hip replacement (THR) (mean age, 66 years; 54% female) and 1,931 patients treated with total knee replacement (TKR) (mean age, 66 years; 55% female). Using the mean change method, the MCIC ranged from 24.0 to 27.5 points for the HOOS-12 and 17.5 to 21.8 points for the KOOS-12. The ROC analyses generated comparable MCIC values (28.1 for HOOS-12 and a range of 15.6 to 21.9 for KOOS-12) with high sensitivity and specificity. Lower estimates were derived from predictive modeling following adjustment for the proportion of improved patients (range, 15.7 to 19.2 for HOOS-12 and 14.2 to 16.5 for KOOS-12).Conclusions: We report MCIC values for the HOOS-12 and KOOS-12 instruments that we derived using 3 different methods. As estimates obtained using predictive modeling can be adjusted for the proportion of improved patients, these may be the most clinically applicable. These MCIC values can be used to interpret important changes in pain, function, and quality of life from the patient's perspective.Levels Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: Relatively little is known about the social distribution of total knee joint replacement (TKR) uptake in Australia. We examine associations between socioeconomic status (SES) and TKR performed for diagnosed osteoarthritis 2003–10 for all Australian males and females aged ≥30 yr. Methods: Data of primary TKR (n = 213,018, 57.4% female) were ascertained from a comprehensive national joint replacement registry. Residential addresses were matched to Australian Census data to identify area-level social disadvantage, and categorised into deciles. Estimated TKR rates were calculated. Poisson regression was used to model the relative risk (RR) of age-adjusted TKR per 1,000py, stratified by sex and SES. Results: A negative relationship was observed between TKR rates and SES deciles. Females had a greater rate of TKR than males. Surgery utilisation was greatest for all adults aged 70-79 yr. In that age group differences in estimated TKR per 1,000py between deciles were greater for 2010 than 2003 (females: 2010 RR 4.32 and 2003 RR 3.67; males: 2010 RR 2.04 and 2003 RR 1.78). Conclusions: Identifying factors associated with TKR utilisation and SES may enhance resource planning and promote surgery utilisation for end-stage osteoarthritis. [ABSTRACT FROM AUTHOR]

Background: Long-term implant survivorship in THA and TKA involves a combination of factors related to the patient, the implants used, and the decision-making and technical performance of the surgeon. It is unclear which of these factors is the most important in reducing the proportion of revision surgery.Questions/purposes: We used data from a large national registry to ask: In patients receiving primary THA and TKA for a diagnosis of osteoarthritis, do (1) the reasons for revision and (2) patient factors, the implants used, and the surgeon or surgical factors differ between surgeons performing THA and TKA who have a lower revision rate compared with all other surgeons?Methods: Data were analyzed for all THA and TKA procedures performed for a diagnosis of osteoarthritis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from September 1, 1999, when collection began, to December 31, 2018. The AOANJRR obtains data on more than 98% of joint arthroplasties performed in Australia. The 5-year cumulative percent revision (CPR) was identified for all THAs and TKAs performed for a diagnosis of osteoarthritis with 95% confidence intervals (overall CPR); the 5-year CPR with 95% CIs for each surgeon was calculated for THA and TKA separately. For surgeons to be included in the analysis, they had to have performed at least 50 procedures and have a 5-year CPR. The 5-year CPR with 95% CIs for each THA and TKA surgeon was compared with the overall CPR. Two groups were defined: low revision rate surgeons (the upper confidence level for a given surgeon at 5 years is less than 3.84% for THA and 4.32% for TKA), and all other surgeons (any surgeon whose CPR was higher than those thresholds). The thresholds were determined by setting a cutoff at 20% above the upper confidence level for that class. The approach we used to define a low revision rate surgeon was similar to that used by the AOANJRR for determining the better-performing prostheses and is recommended by the International Prosthesis Benchmarking Working Group. By defining the groups in this way, a significant difference between these two groups is created. Determining a reason for this difference is the purpose of presenting the proportions of different factors within each group. The study group for THA included 116 low revision rate surgeons, who performed 88,392 procedures (1619 revised, 10-year CPR 2.7% [95% CI 2.6% to 2.9%]) and 433 other surgeons, who performed 170,094 procedures (6911 revised, 10-year CPR 5.9% [95% CI 5.7% to 6.0%]). The study group for TKA consisted of 144 low revision rate surgeons, who performed 159,961 procedures (2722 revised, 10-year CPR 2.6% [95% CI 2.5% to 2.8%]) and 534 other surgeons, who performed 287,232 procedures (12,617 revised, 10-year CPR 6.4% [95% CI 6.3% to 6.6%]). These groups were defined a priori by their rate of revision, and the purpose of this study was to explore potential reasons for this observed difference.Results: For THA, the difference in overall revision rate between low revision rate surgeons and other surgeons was driven mainly by fewer revisions for dislocation, followed by component loosening and fracture in patients treated by low revision rate surgeons. For TKA, the difference in overall revision rate between low revision rate surgeons and other surgeons was driven mainly by fewer revisions for aseptic loosening, followed by instability and patellofemoral complications in patients treated by low revision rate surgeons. Patient-related factors were generally similar between low revision rate surgeons and other surgeons for both THA and TKA. Regarding THA, there were differences in implant factors, with low revision rate surgeons using fewer types of implants that have been identified as having a higher-than-anticipated rate of revision within the AOANJRR. Low revision rate surgeons used a higher proportion of hybrid fixation, although cementless fixation remained the most common choice. For surgeon factors, low revision rate surgeons were more likely to perform more than 100 THA procedures per year, while other surgeons were more likely to perform fewer than 50 THA procedures per year. In general, the groups of surgeons (low revision rate surgeons and other surgeons) differed less in terms of years of surgical experience than they did in terms of the number of cases they performed each year, although low revision rate surgeons, on average, had more years of experience and performed more cases per year. Regarding TKA, there were more differences in implant factors than with THA, with low revision rate surgeons more frequently performing patellar resurfacing, using an AOANJRR-identified best-performing prosthesis combination (with the lowest rates of revision), using fewer implants that have been identified as having a higher-than-anticipated rate of revision within the AOANJRR, using highly crosslinked polyethylene, and using a higher proportion of cemented fixation compared with other surgeons. For surgeon factors, low revision rate surgeons were more likely to perform more than 100 TKA procedures per year, whereas all other surgeons were more likely to perform fewer than 50 procedures per year. Again, generally, the groups of surgeons (low revision rate surgeons and other surgeons) differed less in terms of years of surgical experience than they did in terms of the number of cases they performed annually, although low revision rate surgeons, on average, had more years of experience and performed more cases per year.Conclusion: THAs and TKAs performed by surgeons with the lowest revision rates in Australia show reductions in all of the leading causes of revision for both THA and TKA, in particular, causes of revision related to the technical performance of these procedures. Patient factors were similar between low revision rate surgeons and all other surgeons for both THA and TKA. Low revision rate THA surgeons were more likely to use cement fixation selectively. Low revision rate TKA surgeons were more likely to use patella resurfacing, crosslinked polyethylene, and cemented fixation. Low revision rate THA and TKA surgeons were more likely to use an AOANJRR-identified best-performing prosthesis combination and to use fewer implants identified by the AOANJRR as having a higher-than-anticipated revision rate. To reduce the rate of revision THA and TKA, surgeons should consider addressing modifiable factors related to implant selection. Future research should identify surgeon factors beyond annual case volume that are important to improving implant survivorship.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background: A socioeconomic gradient exists in the utilisation of total hip replacements (THR) and total knee replacements (TKR) for osteoarthritis. However, the relations between socioeconomic status (SES) and time to THR or TKR is unknown. Aim: To describe the association between SES and time to THR and TKR. Methods: One thousand and seventy‐two older adults residing in Tasmania, Australia, were studied. Incident primary THR and TKR were determined by data linkage to the Australian Orthopaedic Association National Joint Replacement Registry. At baseline, each participant's area‐level SES was determined using the Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD) from the Australian Bureau of Statistics' 2001 census data. The IRSAD was analysed in two ways: (i) categorised into quartiles, whereby quartile 1 represented the most socioeconomically disadvantaged group; and (ii) the cohort dichotomised at the quartile 1 cut‐point. Results: The mean age was 63.0 (±7.5) years and 51% were women. Over the median follow up of 12.9 (interquartile range: 12.2–13.9) years, 56 (5%) participants had a THR and 79 (7%) had a TKR. Compared with the most disadvantaged quartile, less disadvantaged participants were less likely to have a THR (i.e. less disadvantaged participants had a longer time to THR; hazard ratio (HR): 0.56; 95% confidence interval (CI) 0.32, 1.00) but not TKR (HR: 0.90; 95% CI 0.53, 1.54). However, the former became non‐significant after adjustment for pain and radiographic osteoarthritis, suggesting that the associations may be mediated by these factors. Conclusions: The present study suggests that time to joint replacement was determined according to the symptoms/need of the participants rather than their SES. [ABSTRACT FROM AUTHOR]

• Micronutrient malnutrition, often called ‘hidden hunger’, affects over two billion people globally. This is particularly problematic in developing countries where widespread zinc (Zn) deficiency exists as a result of a predominantly plant-based diet. Furthermore, supplemental fertilizers are often unavailable or unaffordable in impoverished regions where soil infertility is common. Delivery of more Zn via food grains is theoretically possible through selective breeding strategies, but severe technical difficulties associated with trace element research have limited research on the underlying genetic components of Zn nutrition. • Genetic dissection of Zn nutrition involved a pre-existing doubled haploid mapping population of barley ( Hordeum vulgare). Association of mineral nutrient accumulation traits with regions of the barley genome was determined in two seasons of growth to maturity, usingmapmanager qtx and QGene 4.0. • Nine genetic loci segregating in the population associated clearly with measured traits, including five that contributed to grain Zn status. Pooling two-row doubled haploids by selecting the three most favourable alleles increased grain Zn content and concentration by an average of 53 and 75%, respectively. • These results will inform breeding efforts for increased Zn density in the major food grain, wheat ( Triticum aestivum), by enabling syntenic marker-assisted selection in conventional breeding programmes. [ABSTRACT FROM AUTHOR]

Abstract: The microbiological profiles of kangaroo carcasses and minced meat at game meat processing plants in South Australia were determined in surveys undertaken in 2002 and 2004. In 2002 mean values for log10 total viable counts (TVC) on carcasses at individual plants ranged from 0.9 to 3.9 log10 cfu/cm2, with the mean for all plants being 2.3 log10 cfu/cm2. In 2004 the between plant range was narrower, by about 1 log unit, and the mean value for carcasses at all plants was 1.2 log10 cfu/cm2. Minced kangaroo meat, was sampled in 2002 only. The overall mean log10 TVC was 3.9 log10 cfu/g, with mean counts at individual plants ranging from 3.1 to 4.6 log10 cfu/g. The overall prevalence of E. coli was 70%, with mean numbers of 2.1 log10 cfu/g on positive samples. Salmonella was not detected in any of 60 samples from carcasses in 2002. However, in 2004 Salmonella was detected in 4/385 samples (1.04%, 95% CI: 0.28%–2.64%). In minced kangaroo meat, Salmonella was detected in 9/50 (18%, 95% CI: 9%–31%) samples. The abdominal cavity, sampled in 2004, was found to be highly contaminated, with E. coli isolated from 46% of samples and the mean number for positive samples being 2.7 log10 cfu/cm2; Salmonella was isolated from 14/120 (12%; 95% CI: 6.52%–18.80%) of abdominal cavities. The practice of collecting carcasses together and pushing grouped carcasses into the chiller likely leads to cross contamination of carcasses from the abdominal cavities of others. To align results of sampling by swabbing for domestic purposes with excision sampling, required for export purposes, both methods were used to sample opposite sides of each of the 50 carcasses sampled in 2004. The results obtained with the two methods of sampling were similar. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

Background: This a priori statistical analysis plan describes the analysis for CRISTAL.Methods: CRISTAL (cluster-randomised, crossover, non-inferiority trial of aspirin compared to low molecular weight heparin for venous thromboembolism prophylaxis in hip or knee arthroplasty, a registry nested study) aims to determine whether aspirin is non-inferior to low molecular weight heparin (LMWH) in preventing symptomatic venous thromboembolism (VTE) following hip arthroplasty (HA) or knee arthroplasty (KA). The study is nested within the Australian Orthopaedic Association National Joint Replacement Registry. The trial was commenced in April 2019 and after an unplanned interim analysis, recruitment was stopped (December 2020), as the stopping rule was met for the primary outcome. The clusters comprised hospitals performing > 250 HA and/or KA procedures per annum, whereby all adults (> 18 years) undergoing HA or KA were recruited. Each hospital was randomised to commence with aspirin, orally, 85-150 mg daily or LMWH (enoxaparin), 40 mg, subcutaneously, daily within 24 h postoperatively, for 35 days after HA and 14 days after KA. Crossover was planned once the registration target was met for the first arm. The primary end point is symptomatic VTE within 90 days. Secondary outcomes include readmission, reoperation, major bleeding and death within 90 days, and reoperation and patient-reported pain, function and health status at 6 months. The main analyses will focus on the primary and secondary outcomes for patients undergoing elective primary total HA and KA for osteoarthritis. The analysis will use an intention-to-treat approach with cluster summary methods to compare treatment arms. As the trial stopped early, analyses will account for incomplete cluster crossover and unequal cluster sizes.Conclusions: This paper provides a detailed statistical analysis plan for CRISTAL.Trial Registration: Australian and New Zealand Clinical Trials Registry ACTRN12618001879257 . Registered on 19/11/2018. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: TKA generally has excellent long-term survivorship. When a new knee system supersedes a previous model, increased survivorship, improved functional performance, or both may be expected, because key areas of design modification are often targeted to address wear, stability, and the patellofemoral articulation. However, not all design changes are beneficial, and to our knowledge, knee arthroplasty has not been systematically evaluated in the context of design changes that occur during the development of new knee arthroplasty systems.Questions/purposes: Using the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) we performed multiple old-to-new comparisons of frequently used contemporary knee implants to ask: (1) does overall prosthesis survivorship free from revision increase when a new knee prosthesis system is introduced to replace a prior prosthesis system? (2) Has survivorship free from revision improved for the revision indications of wear, instability, and patellofemoral articulation issues, where development efforts have been concentrated?Methods: Data from the AOANJRR from September 1999 to December 2017 were used to compare the survivorship of prostheses free from revision at a maximum of 17 years in procedures where a new design model was introduced to replace a prior knee system from the same manufacturer. Only prosthesis systems used in a minimum of 2000 primary TKA procedures for osteoarthritis that had a minimum of 5 years of follow-up were included. Varus-valgus constrained and hinge TKA designs were excluded. Cruciate-retaining, posterior-stabilized, and medial pivot-design knees were considered separately. The new and old prosthesis systems were paired for analysis. Survivorship was calculated with Kaplan Meier estimates and comparisons were performed using the Cox proportional hazards method. Subanalyses according to the three main revision indications were performed, and where possible, analyses were performed based on polyethylene types (highly cross-linked polyethylene and ultra-high-molecular-weight polyethylene), combined and separated. Revision was defined as a reoperation of a previous knee arthroplasty in which one or more of the components was removed, replaced, or added. There were 323,955 TKA procedures and 11 new prosthesis system designs that were introduced to replace an earlier knee system from the same manufacturer. Of these prosthesis system pairs, six were cruciate-retaining prostheses, four were posterior-stabilized designs, and one was a medial pivot design.Results: Six of the 11 knee system pairs showed improved survivorship with the new design, three were no different, and in two, the newer prosthesis systems had a higher rate of revision than the old one did. When revision for wear was analyzed, five prosthesis systems showed improvement, five were no different, and one had a higher rate of revision than the previous system did. There was no improvement in the rate of revision for instability; seven new prosthesis systems showed no difference from the previous system and four new prosthesis systems had a higher rate of revision than the previous system did. A subanalysis of revision for patellofemoral complications showed improvement in two comparisons, no difference in six, and a higher revision rate in two; one could not be calculated because of an insufficient number of revisions for this reason.Conclusions: It is difficult to predict whether a new system will demonstrate better survival than a previous one, and widespread uptake of a new design before a benefit is shown in robust clinical studies is unwise. Similarly, adoption of a new system for which there is no difference in survivorship from a previous model may be premature because a new device may have associated unknown and unintended consequences. Healthcare policy makers and therapeutic device regulators should similarly be guided by results and seek out peer-reviewed evidence before accepting change to established practice. Surgeons must be aware that implant changes may not translate into better survivorship and must seek compelling evidence of improvement in survival and/or function before changing systems.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Introduction: Breakage of the femoral stem component of a total hip replacement is now uncommon but continues to be seen with certain stem designs and in certain patient groups. Data previously published on this topic has been limited, either gathered from a single surgeon or centre, or included only a single stem design. Methods: We reviewed the data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), identified and analysed 143 stem breakages over a period of 16 years, covering 44 different stem designs. Results: Our data confirms previously published findings that risk factors for stem breakage include patient age at implantation of under 70, male gender, as well as the use of exchangeable necks. We found no association with initial diagnosis, or type of acetabular component implanted. We did however also find, excluding exchangeable neck designs, that after 4.5 years a cemented stem had a significantly higher risk of breakage then a cementless stem. Discussion: To our knowledge this is the 1st paper to suggest cemented fixation as a specific risk factor for stem breakage. The analysis of rare complications such as stem breakage is only possible through large data collection systems such as the AOANJRR. Whilst there have been recent advances in materials and manufacturing techniques, we recommend that surgeons are aware of all the specific risks when considering implant choices for individual patients. [ABSTRACT FROM AUTHOR]

Objectives: To identify subgroups of community-dwelling older adults and to assess their longitudinal associations with long-term osteoarthritis (OA) outcomes. Methods: 1046 older adults aged 50–80 years were studied. At baseline, body mass index (BMI), pedometer-measured ambulatory activity (AA), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) determined knee pain and information on comorbidities were obtained. Tibial cartilage volume and bone-marrow lesions (BMLs) were assessed using MRI at baseline and 10 years and total knee replacements (TKR) by data linkage to the Australian Orthopaedic Association National Joint Replacement Registry. Latent class analysis was used to determine participant subgroups, considering baseline BMI, AA, pain and comorbidities, and linear mixed-effects or log-binomial models were used to assess the associations. Results: Three subgroups/classes were identified: subgroup 1 (43%): Normal/overweight participants with higher AA, lower pain and lower comorbidities; subgroup 2 (32%): Overweight participants with lower AA, mild pain and higher comorbidities; subgroup 3 (25%): Obese participants with lower AA, mild pain and higher comorbidities. Subgroup 3 had greater cartilage volume loss (β − 60.56 mm3, 95% CI − 105.91, − 15.21) and a higher risk of TKR (RR 3.19, 95% CI 1.75, 5.81), compared to subgroup 1. Subgroup 2 was not associated with cartilage volume change (β 13.06 mm3, 95% CI − 30.87, 57.00) or risk of TKR (RR 1.16, 95% CI 0.56, 2.36), compared to subgroup 1. Subgroup membership was not associated with worsening BMLs. Conclusions: Our findings suggest the existence of homogeneous subgroups of participants and support the utility of identifying patterns of characteristics/risk factors that may cluster together and using them to identify subgroups of people who may be at a higher risk of developing and/or progressing OA. Key Points • Complex interplay among characteristics/factors leads to conflicting evidence between ambulatory activity and knee osteoarthritis. • Distinct subgroups are identifiable based on ambulatory activity, body mass index, knee pain, and comorbidities. • Identifying subgroups can be used to determine those who are at risk of developing/progressing osteoarthritis. [ABSTRACT FROM AUTHOR]

Background: To provide an estimate of the population at risk for late complications of arthroplasty, we aimed to determine the prevalence of Australians living with one or more joint replacements. Methods: Data included all arthroplasty procedures performed in Australia from 2003 to 2016 recorded by the Australian Orthopaedic Association National Joint Replacement Registry. The age‐ and gender‐specific Australian population was obtained from the Australian Bureau of Statistics and used as denominator data. Survival data for each joint replacement, and of individuals, were used to estimate the arthroplasty prevalence. Analyses by age, gender and joint replacement site were undertaken. Prevalence estimates were augmented with procedural data captured before 2003 modelled with assumptions accounting for age and gender distributions, overall survival and arthroplasty revision rates. Results: By the end of 2016, there were 824 769 Australians living with at least one joint replacement, representing 3.4% of the total population. The prevalence of joint replacement is increasing in all age groups, but was highest amongst older Australians, with an overall prevalence of 22.5%, and 13.3% in those aged >85 years and 65–84 years, respectively. The prevalence of people living with multiple joint replacements is increasing more rapidly than patients who have undergone only one joint replacement procedure. Conclusion: The prevalence of older Australians living with joint replacements is rapidly increasing, providing an estimate of the population‐at‐risk for late complications of arthroplasty including peri‐prosthetic infection and fracture. [ABSTRACT FROM AUTHOR]

Background: Mortality after THA and TKA is lower than expected for several years after surgery when compared with age- and sex-adjusted population data. With long-term followup (beyond approximately 10 years), some evidence has suggested that this trend reverses, such that postsurgical mortality is higher than expected as more time passes. However, the degree to which this may be the case has not been clearly established.Questions/purposes: In this large-registry study, we asked: What is the long-term mortality after THA and TKA compared with the expected mortality, adjusted for age, sex, and calendar year.Methods: Using data on 243,057 THAs and 363,355 TKAs performed for osteoarthritis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2003 to 2016, and life tables from the Australian Bureau of Statistics the Standardised Mortality Ratio (SMR), relative mortality and excess mortality (relative to the expected mortality for people of the same sex and age in the same country) was calculated separately for hips and knees. The AOANJRR contains near-complete (98%-100%) data from all hospitals in Australia performing arthroplasty but does not include followup data on people who have left the country. Followup was from the date of surgery to 13 years, mean 5.8 years.Results: We found a lower-than-expected mortality for THA and TKA in the early years after surgery. This association diminished over time and the mortality became higher than expected after 12 years for both THA and TKA. For THA, the excess mortality (per thousand people) increased from 11 fewer deaths (95% CI, 10-11 fewer) after 1 year to four more deaths (95% CI, 0-9 more) in the 13th year, and the SMR increased from 0.50 (95% CI, 0.48-0.52) after 1 year to 1.07 (95% CI, 0.99-1.14) in the 13th year. For TKA, the excess mortality (per thousand people) increased from 12 fewer deaths (95% CI, 12-13 fewer) after 1 year to five more deaths (95% CI 2-9 more) in the 13th year, and the SMR increased from 0.39 (95% CI, 0.37-0.40) after 1 year to 1.09 (95% CI, 1.03-1.15) in the 13th year.Conclusions: Mortality after hip and knee arthroplasty is lower than expected (based on population norms) in the first 8 years to 9 years but gradually increases over time, becoming higher than expected after 12 years. The lower-than-expected mortality in the early years after surgery is likely the result of patient selection with patients undergoing primary arthroplasty having better health at the time of surgery than that of the age- and sex-matched population. The increasing mortality over time cannot be regression to the mean, as late mortality is higher than expected, moving beyond the mean. It is important to understand if there are modifiable factors associated with this increased mortality. The reasons for the change are uncertain. Factors to consider in future research include determining the effect of different patient factors on late mortality. Some of these included higher obesity rates for joint replacement patients and the association or causal impact of osteoarthritis and/or its treatment to increase late mortality in a similar manner to other forms of arthritis. There is also a possibility that the arthroplasty device itself may affect late mortality.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]

Background and purpose — International comparisons of total hip arthroplasty (THA) practices and outcomes provide an opportunity to enhance the quality of care worldwide. We compared THA patients, implants, techniques, and survivorship in Sweden, Australia, and the United States. Patients and methods — Primary THAs due to osteoarthritis were identified using Swedish (n = 159,695), Australian (n = 279,693), and US registries (n = 69,641) (2003–2015). We compared patients, practices, and implant usage across the countries using descriptive statistics. We evaluated time to all-cause revision using Kaplan–Meier survival curves. We assessed differences in countries' THA survival using chi-square tests of survival probabilities. Results — Sweden had fewer comorbidities than the United States and Australia. Cement fixation was used predominantly in Sweden and cementless in the United States and Australia. The direct anterior approach was used more frequently in the United States and Australia. Smaller head sizes (≤ 32 mm vs. ≥ 36 mm) were used more often in Sweden than the United States and Australia. Metal-on-highly cross-linked polyethylene was used more frequently in the United States and Australia than in Sweden. Sweden's 5- (97.8%) and 10-year THA survival (95.8%) was higher than the United States' (5-year: 97.0%; 10-year: 95.2%) and Australia (5-year: 96.3%; 10-year: 93.5%). Interpretation — Patient characteristics, surgical techniques, and implants differed across the 3 countries, emphasizing the need to adjust for demographics, surgical techniques, and implants and the need for global standardized definitions to compare THA survivorship internationally. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Periprosthetic infection following total knee replacement remains alarmingly frequent, is devastating for patients, and is an increasingly substantial public health burden. While both the prosthetic design elements and type of polyethylene used in total knee replacement can independently affect survivorship of the prosthesis, their influence on the risk of revision for infection is unknown. Therefore, we examined the effects of total knee prosthetic design and type of polyethylene bearing on the long-term revision risk for nonacute infection following total knee replacement by comparing 4 different cohorts: patients who had minimally stabilized total knee prostheses with crosslinked polyethylene (XLPE) bearing surfaces, minimally stabilized total knee prostheses with noncrosslinked polyethylene (NXLPE), posterior stabilized total knee prostheses with XLPE, and posterior stabilized total knee prostheses with NXLPE.Methods: National registry data on revision procedures for surgeon-reported infection following primary total knee replacement for osteoarthritis from September 1999 through December 2015 were obtained for 4 patient cohorts. The cohorts were defined by the total knee prosthetic design and polyethylene type used. Revisions at ≤6 months were censored to reduce confounding bias. Hazard ratios (HRs) were adjusted for age, sex, and antibiotic cement usage.Results: A total of 336,997 primary total knee prostheses were included, 1,651 (0.49%) of which underwent revision for periprosthetic infection. Compared with minimally stabilized total knee prostheses that had XLPE bearing surfaces, the revision risk for infection, adjusted for age, sex, and antibiotic cement usage, was 25% higher for minimally stabilized total knee prostheses with NXLPE bearing surfaces (HR = 1.25 [95% confidence interval (CI), 1.07 to 1.45]; p = 0.003), 89% higher for posterior stabilized total knee prostheses with XLPE (HR = 1.89 [95% CI, 1.52 to 2.35]; p < 0.001), and 102% higher for posterior stabilized total knee prostheses with NXLPE (HR = 2.02 [95% CI, 1.72 to 2.37]; p < 0.001). Posterior stabilized total knee prostheses with NXLPE had a 61% higher risk of infection compared with minimally stabilized total knee prostheses with NXLPE (HR = 1.61 [95% CI, 1.43 to 1.83]; p < 0.001). The revision risk for infection for posterior stabilized total knee prostheses with NXLPE was the same as that for posterior stabilized total knee prostheses with XLPE (HR = 1.08 [95% CI, 0.88 to 1.32]; p = 0.481).Conclusions: Minimally stabilized total knee prostheses with NXLPE bearing surfaces and posterior stabilized total knee prostheses, irrespective of bearing type, had a greater long-term revision risk for periprosthetic infection when compared with the revision risk for minimally stabilized total knee prostheses with XLPE bearing surfaces.Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of Levels of Evidence. [ABSTRACT FROM AUTHOR]

Background and purpose — Although common in medical research, meta-analysis has not been widely adopted in registry collaborations. A meta-analytic approach in which each registry conducts a standardized analysis on its own data followed by a meta-analysis to calculate a weighted average of the estimates allows collaboration without sharing patient-level data. The value of meta-analysis as an alternative to individual patient data analysis is illustrated in this study by comparing the risk of revision of porous tantalum cups versus other uncemented cups in primary total hip arthroplasties from Sweden, Australia, and a US registry (2003-2015). Patients and methods — For both individual patient data analysis and meta-analysis approaches a Cox proportional hazard model was fit for time to revision, comparing porous tantalum (n = 23,201) with other uncemented cups (n = 128,321). Covariates included age, sex, diagnosis, head size, and stem fixation. In the meta-analysis approach, treatment effect size (i.e., Cox model hazard ratio) was calculated within each registry and a weighted average for the individual registries’ estimates was calculated. Results — Patient-level data analysis and meta-analytic approaches yielded the same results with the porous tantalum cups having a higher risk of revision than other uncemented cups (HR (95% CI) 1.6 (1.4-1.7) and HR (95% CI) 1.5 (1.4-1.7), respectively). Adding the US cohort to the meta-analysis led to greater generalizability, increased precision of the treatment effect, and similar findings (HR (95% CI) 1.6 (1.4-1.7)) with increased risk of porous tantalum cups. Interpretation — The meta-analytic technique is a viable option to address privacy, security, and data ownership concerns allowing more expansive registry collaboration, greater generalizability, and increased precision of treatment effects. [ABSTRACT FROM AUTHOR]

The aim of this study is to describe the association of bone marrow lesions (BMLs) present on two different MRI sequences with clinical outcomes, cartilage defect progression, cartilage volume loss over 2.7 years, and total knee replacement (TKR) over 13.3 years. 394 participants (50-80 years) were assessed at baseline and 2.7 years. BML presence at baseline was scored on T1-weighted fat-suppressed 3D gradient-recalled acquisition (T1) and T2-weighted fat-suppressed 2D fast spin-echo (T2) sequences. Knee pain, function, and stiffness were assessed using WOMAC. Cartilage volume and defects were assessed using validated methods. Incident TKR was determined by data linkage. BMLs were mostly present on both MRI sequences (86%). BMLs present on T2, T1, and both sequences were associated with greater knee pain and functional limitation (odds ratio = 1.49 to 1.70; all p < 0.05). Longitudinally, BMLs present on T2, T1, and both sequences were associated with worsening knee pain (β = 1.12 to 1.37, respectively; p < 0.05) and worsening stiffness (β = 0.45 to 0.52, respectively; all p < 0.05) but not worsening functional limitation or total WOMAC. BMLs present on T2, T1, and both sequences predicted site-specific cartilage defect progression (relative risk = 1.22 to 4.63; all p < 0.05) except at the medial tibial and inferior patellar sites. Lateral tibial and superior patellar BMLs present on T2, T1, and both sequences predicted site-specific cartilage volume loss (β = - 174.77 to - 140.67; p < 0.05). BMLs present on T2, T1, and both sequences were strongly associated with incident TKR. BMLs can be assessed on either T2- or T1-weighted sequences with no clinical predictive advantage of either sequence. [ABSTRACT FROM AUTHOR]

Background: Climate factors have been shown to be associated with spontaneous musculoskeletal and some surgical site infections with increased rates of infection during warmer periods. To date, little research has been performed to determine if this phenomenon is associated with differences in the risk of revision for prosthetic joint infection (PJI) in primary TKA.Questions/purposes: (1) Does the rate of revision for early PJI within the first year after primary TKA differ between tropical and nontropical regions? (2) Is there a seasonal variation in the rate of revision for PJI? (3) Is the geographic and seasonal variation (if present) associated with the sex, age, and/or American Society of Anesthesiologists (ASA) grade of the patient?Methods: All 219,983 primary TKAs performed for osteoarthritis over a 5-year period (2011-2015) in the Australian Orthopaedic Association National Joint Replacement Registry were examined based on the month of the primary procedure to determine the rate of revision for PJI within 12 months. The data were analyzed to determine the differences in the risk of revision for PJI based on geographic region and season of the primary procedure adjusting for sex, age, and ASA grade of the patient.Results: The early revision rate for PJI was higher in the tropical compared with the nontropical region of Australia (0.73% versus 0.37%; odds ratio [OR], 1.87; 95% confidence interval [CI], 1.44-2.42; p < 0.001). The tropical region of Australia demonstrated a seasonal variation in the rate of revision for PJI with a higher rate during the warmer monsoon wet season of summer and fall (summer/fall 0.98% versus winter/spring 0.51%; OR, 1.88; 95% CI, 1.12-3.16; p = 0.02). A seasonal variation was not seen in the nontropical region (OR, 1.03; 95% CI, 0.90-1.19; p = 0.64). The regional and seasonal changes were independent of sex, age, and ASA grade.Conclusions: Climate factors are associated with the risk of early revision for PJI in patients undergoing primary TKA with rates of such revisions approximately double in tropical regions compared with nontropical regions. Additionally, tropical regions demonstrate a seasonal variation with the risk of PJI doubling during the warmer, monsoonal wet season of summer and fall. These findings should be confirmed in further studies that can better control for possible confounding variables. The mechanism for this phenomenon is not clear, and further research into this subject is also indicated.Level Of Evidence: Level III, therapeutic study. [ABSTRACT FROM AUTHOR]