Search

Background: Anterior approach total hip arthroplasty (THA) decreases the rate of dislocation but increases femoral-sided complications in the way of periprosthetic fractures and component loosening. A cemented prosthesis may reduce femoral-sided complications and improve the risk:benefit profile of anterior approach THA. Methods: Data from the Australian National Joint Replacement Registry were analysed for patients undergoing primary THA via the anterior or posterior approach using a cemented polished femoral stem from January 2015 to December 2021. The primary outcome measure was the cumulative percent revision (CPR) for all causes and CPR for femoral component loosening and fracture. The CPR for the primary outcome measures were compared between the anterior and posterior approach and adjusted for age, sex, ASA score, BMI and femoral head size. Results: The study included 60,739 THAs with cemented stems (10,742 anterior, 49,997 posterior). The rate of revision of the anterior versus the posterior approach did not significantly differ (HR 0.87 (95% CI, 0.74–1.03), p = 0.100). Anterior approach THA had a significantly higher rate of revision for femoral component loosening (HR 5.06 [95% CI, 3.08–8.30], p < 0.001); and a decreased rate of revision for infection (HR 0.59 [95% CI, 0.43–0.81], p = 0.001) and dislocation/instability (HR 0–3 months 0.48 [95% CI, 0.27–0.83], p = 0.008; HR >3 months 0.30 [95% CI, 0.15–0.61], p < 0.001). There was no difference in the rate of revision surgery for fracture between the 2 approaches (HR 1.01 [95% CI, 0.71–1.43]), p = 0.975). Conclusions: There is no significant difference in overall revision rates with cemented femoral fixation performed with an anterior or posterior approach. Cemented fixation performed with the anterior approach partly mitigates femoral complications with no difference in the revision rate for fracture but an increased rate of femoral component loosening. [ABSTRACT FROM AUTHOR]

Background: The collection of patient-reported outcome measures (PROMs) following arthroplasty is common. PROMs data collection programs seek to maximise completeness in order to minimise selection bias and optimise representativeness of the sample attained. We aimed to determine if patient factors influence variation in PROMs program completeness between-hospitals. Methods: Using data from a national arthroplasty registry PROMs program, we tested for associations between patient characteristics (age, sex, body mass index [BMI] and American Society of Anaesthesiologists [ASA] class) and both potential completeness (registration completeness: the proportion of arthroplasty patients that were registered in the PROMs electronic system) and actual completeness (response completeness: the proportion of arthroplasty patients who provided PROMs data) using linear regression. Results: When using all elective primary total hip, knee or shoulder arthroplasty procedures (N = 31,801) from 43 hospitals as the denominator, overall registration completeness was 52%, varying from 5 to 87% between hospitals. Overall pre-operative response completeness was 46%, varying from 5 to 82% between hospitals. There were no significant associations between hospital-level registration completeness or response completeness and age, sex, BMI or ASA score. Conclusion: Completeness rates of a PROMs program in arthroplasty varied widely between hospitals but in the absence of a relationship between measured patient factors and completeness rates, the observed variation likely relates to local site factors such as access to patients, local resources and clinician engagement with the program. Efforts to improve the rates of completeness of arthroplasty PROMs programs at individual hospitals may not improve the representativeness of the sample. Plain English summary: Hospitals vary in how completely they include and follow up patients when measuring patient-reported health. It is important to know if the completeness of inclusion and follow up by hospitals is affected by patient characteristics. This study addresses that problem by using data from a national patient outcome survey involving over 30,000 patients from 43 hospitals to look at the correlation between certain patient characteristics (like age, sex, obesity and general health) and the rates of inclusion and follow up for each hospital. Rates of inclusion (registering patients in the program) and follow up rates varied widely between hospitals (from 5 to 87%). The rates of inclusion and follow up were not correlated with patient age, sex, body mass index or their general health. These findings suggest that the variation between hospitals in the rates of inclusion of joint replacement patients in health surveys are not due to differences in patient characteristics. The differences may be due to local hospital factors, such as resources and clinician engagement. [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]

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]

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]

Background and purpose — Recent direct comparative reports suggest that hybrid fixation may have a similar or superior outcome to cemented fixation in total knee replacement (TKR); however, a paucity of long-term data exists. To minimize the confounders of a direct comparison, we performed an instrumental variable analysis examining the revision rate of 2 cohorts of patients based on their surgeon’s preference for cemented or hybrid fixation.Methods — Registry data were obtained from 1999 until 2015 for 2 cohorts of patients who received minimally stabilized TKR, defined as those treated by high-volume hybrid fixation preferring surgeons, designated routinely hybrid (RH), and those treated by high-volume cemented fixation preferring surgeons, designated routinely cemented (RC).Results — At 13 years, the cumulative percentage revision of the RC cohort was 4.8% (CI 4.1-5.7) compared with 5.5% (CI 3.5-8.7) for the RH cohort. The revision risk for each cohort was the same for all causes (HR =1.0 (CI (0.84-1.20)), non-infective causes, and for infection. This finding was irrespective of patient age or sex, patella resurfacing, and with non-cross-linked polyethylene (NXLPE). The RH cohort who received cross-linked polyethylene (XLPE) had a lower revision risk than the RC cohort with XLPE (HR =0.57 (0.37-0.88), p = 0.01).Interpretation — The risk of revision for the patients of surgeons who prefer cemented fixation in minimally stabilized TKR is the same as for the patients of surgeons who prefer hybrid fixation, except when used with XLPE, where hybrid fixation has a lower revision risk. [ABSTRACT FROM AUTHOR]

Introduction: Periprosthetic joint infection (PJI) is a serious complication after total hip arthroplasty (THA) and bearing material's associations to PJI prevalence is largely unknown. The main purposes of this study were to determine if revision for infection varied depending on the type of bearing surface used in primary THA and to study whether patient or implant related factors had an effect on this variation. Methods: A total of 177,237 primary THA procedures from the Australian Registry (AOANJRR) were analysed. 3 bearing surfaces were compared. Metal-on-highly cross-linked polyethylene (MoXP) bearing had been used in 95,129 hips, ceramic-on-highly cross-linked polyethylene (CoXP) in 24,269 hips, and ceramic-on-ceramic (CoC) in 57,839 hips. Revision rates for infection were compared between the 3 groups. Results: Both MoXP and CoXP had a higher revision rate for infection compared to CoC hips (hazard ratio [HR] 1.46 (1.25, 1.72), p < 0.001) and HR 1.42 (1.15, 1.75), p = 0.001 respectively). Patients aged 70 years or less had a lower revision rate for infection when a CoC bearing was used. This difference was independent of sex, and prostheses selection. No difference was evident if the femoral component was cemented or a head size of 28 mm was used. Discussion: In this registry-based material, use of a CoC bearing was associated with a lower risk of revision for infection in patients younger than 70 years when cementless femoral components were used. Further studies are needed to verify this finding. [ABSTRACT FROM AUTHOR]

Background: Associations between socioeconomic position (SEP) and the uptake of primary total shoulder arthroplasty (TSA) is not well understood in the Australian population, thus potentially limiting equitable allocation of healthcare resources. We used the Australian Orthopaedic Association National Joint Replacement Registry (AOA NJRR) to examine whether geographic or socioeconomic variations exist in TSA performed for a diagnosis of osteoarthritis 2007-11 for all Australians aged ≥40 years.Methods: Primary anatomical and reverse TSA data were extracted from the AOA NJRR which captures >99 % of all TSA nationally. Residential addresses were cross-referenced to Australian Bureau of Statistics 2011 Census data to identify SEP measured at the area-level (categorised into deciles), and geographic location defined as Australian State/Territory of residence. We used a Poisson distribution for the number of TSA over the study period, and modelled the effects of age, SEP and geographic location using multilevel modelling.Results: During 2007-11, we observed 6,123 TSA (62.2 % female). For both sexes, TSA showed a proportional increase with advancing age. TSA did not vary by SEP or geographic location, with the exception of greater TSA among men in New South Wales.Conclusions: Using a national registry approach we provide the first reliable picture of TSA at a national level. The uptake of TSA was equitable across SEP; however, there was some variation between the States/Territories. With an aging population, it is imperative that monitoring of major surgical procedures continues, and be focused toward determining whether TSA uptake correlates with need across different social and area-based groups. [ABSTRACT FROM AUTHOR]

Background: Pain is an indication for total hip arthroplasty (THA) and it should be resolved post-surgery. Because patients' pain is typically treated pharmacologically we tested whether opioid use can be used as a surrogate for patient-reported pain and as an indicator for early surgical failure. Specifically, we evaluated whether the amount of opioids taken within the year after THA was associated with one and five years risk of revision surgery.Methods: A cohort of 9943 THAs (01/2001-12/2012) was evaluated. Post-operative opioid use was the exposure of interest and cumulative daily oral morphine equivalent (OME) amounts were calculated. Total OMEs/90-day periods were categorised into quartiles. Revisions within one and five years were the outcomes of interest.Results: Of the THAs, 2.0 % (N = 200) were revised within one year and 4.2 % (N = 413) within five years. After adjustments for gender, age, surgical indication, co-morbidities, and other analgesics, revision was associated with amount of OMEs in the second quarter after THA (days 91-180 after discharge). Patients on medium-high amounts of OME (400-1119 mg) had higher risk of one (hazard ratio (HR) = 2.22, 95 % CI 1.08-4.56) and five year (HR = 1.66, 95 % CI 1.08-2.56) revision than a patient not taking opioids. During the same period, patients taking the highest amounts of OMEs (≥1120 mg) had a 2.64 (95 % CI 1.03-6.74) times higher risk of one year and a 2.11 (95 % CI 1.13-3.96) times higher risk of five year revision.Conclusions: Opioid use 91-180 days post-surgery is associated with higher risk of revision surgery and therefore is an early and useful indicator for surgical failure. [ABSTRACT FROM AUTHOR]

Objectives. To examine the relationships between weight at early and middle adulthood and adult weight gain and the risk of total knee and hip replacement for OA.Methods. At baseline interview during 1990–94, 38 149 participants [mean age 54.9 (s.d. 8.6) years] of the Melbourne Collaborative Cohort Study were asked to recall their weight at age 18–21 years and had their middle age height and weight measured. Total knee and hip replacement for OA between 2001 and 2009 was determined by linking the cohort records to the Australian Orthopaedic Association National Joint Replacement Registry.Results. Greater weight and BMI at age 18–21 years and middle age, weight gain and persistent overweight during this time were associated with an increased risk of total knee and hip replacement. Middle age weight [hazard ratio (HR) per 5 kg 1.25 (95% CI 1.23, 1.27) for knee vs 1.11 (1.09, 1.14) for hip] and BMI [HR per 5 kg/m2 1.80 (1.72, 1.89) vs 1.29 (1.21, 1.37)] and adult weight gain [HR per 5 kg 1.25 (1.23, 1.28) vs 1.10 (1.07, 1.13)] were more strongly associated with the risk of total knee replacement than total hip replacement (P for heterogeneity of HRs <0.0001).Conclusion. Greater body weight and BMI at early and middle adulthood, weight gain and persistent overweight from early to middle adulthood are risk factors for knee and hip OA. Adult weight gain confers stronger risk on knee OA than hip OA. Weight control from early adulthood and avoiding weight gain are important for the prevention of OA. [ABSTRACT FROM PUBLISHER]

Purpose Here we describe some available statistical models and illustrate their use for analysis of arthroplasty registry data in the presence of the competing risk of death, when the influence of covariates on the revision rate may be different to the influence on the probability (that is, risk) of the occurrence of revision. Patients and methods Records of 12,525 patients aged 75-84 years who had received hemiarthroplasty for fractured neck of femur were obtained from the Australian Orthopaedic Association National Joint Replacement Registry. The covariates whose effects we investigated were: age, sex, type of prosthesis, and type of fixation (cementless or cemented). Extensions of competing risk regression models were implemented, allowing the effects of some covariates to vary with time. Results The revision rate was significantly higher for patients with unipolar than bipolar prostheses (HR == 1.38, 95% CI: 1.01-1.89) or with monoblock than bipolar prostheses (HR == 1.45, 95% CI: 1.08-1.94). It was significantly higher for the younger age group (75-79 years) than for the older one (80-84 years) (HR == 1.28, 95% CI: 1.05-1.56) and higher for males than for females (HR == 1.37, 95% CI: 1.09-1.71). The probability of revision, after correction for the competing risk of death, was only significantly higher for unipolar prostheses than for bipolar prostheses, and higher for the younger age group. The effect of fixation type varied with time; initially, there was a higher probability of revision for cementless prostheses than for cemented prostheses, which disappeared after approximately 1.5 years. Interpretation When accounting for the competing risk of death, the covariates type of prosthesis and sex influenced the rate of revision differently to the probability of revision. We advocate the use of appropriate analysis tools in the presence of competing risks and when covariates have time-dependent effects. [ABSTRACT FROM AUTHOR]