National Joint Replacement Registry Research Articles

How Does the New Australian EQ-5D-5L Value Set Impact Utility Scores? Analysis of Data from the Australian Orthopaedic Association National Joint Replacement Registry.

With advances in health state valuation methods, new value sets may be developed for some countries. Quantifying the impact of moving between existing and new value sets is critical for guiding decisions around utility score interpretation, reporting and comparison with published scores. The aim of this study is to examine, using large-scale national registry data, how the new Australian EQ-5D-5L value set impacts utility scores for patients undergoing joint replacement. Data from the Australian Orthopaedic Association National Joint Replacement Registry were used for this analysis. All primary total hip (THR), knee (TKR), and shoulder replacement (TSR) procedures between 2018 and 2022 with pre-operative and 6-month post-operative EQ-5D-5L data were included. Utility scores were generated using the 2013 and 2023 Australian value sets ('previous' and 'new' value sets, respectively) and analysed descriptively for each joint replacement cohort. Agreement between the two utility score sets was evaluated using concordance correlation coefficients and Bland-Altman plots. EQ-5D-5L data were available for 17,576 THR, 23,010 TKR, and 1667 TSR procedures. The new value set produced a lowest possible EQ-5D-5L utility score of -0.30 (compared with -0.68 previously) and fewer patients had 'worse-than-dead' quality of life (score < 0.00) before surgery. Mean pre-operative scores were 0.21 (THR), 0.19 (TKR), and 0.17 (TSR) units higher with the new value set, and mean post-operative scores were 0.11-0.14 units higher. The new value set resulted in smaller effect sizes for the THR (1.08 versus 1.23) and TKR cohorts (0.86 versus 0.92). There was moderate-to-good overall agreement (coefficients: 0.70-0.80), but concordance varied by time point. Although acceptable agreement was evident, the new Australian value set produces less extreme negative utility scores and markedly higher group-level scores. Transition to reporting new EQ-5D-5L utility scores will require accompanying explanation to signal measurement modifications rather than better quality of life.

OBESITY AND TOTAL HIP ARTHROPLASTY SURGERY

Obesity is a known risk factor for developing osteoarthritis and is also associated with an increased risk of developing complications post total hip replacement (THR). This study investigated the association between obesity and the risk of undergoing THR in Australia.From July 2017 to June 2018 a National Health Survey was conducted by the Australian Bureau of Statistics to collect height and weight data on a representative sample of patients across urban and rural areas across the country. This study examined a cohort of patients undergoing primary THR utilising data from the Australian Orthopaedic Association National Joint Replacement Registry from the same time period. Obesity classes were determined according to WHO criteria.Body mass index (BMI) for patients undergoing THR were obtained and the distribution of THR patients by BMI category was compared to the general population, in age and sex sub-groups.Generalised linear models assuming a binomial distribution and a log link were used to generate relative risks. Data from underweight categories, and age categories 34 years and younger, were excluded from further analyses because of small numbers.Data from the health survey showed there were 35.6% of persons overweight and 31.3% obese. During the same period, 32,495 primary THR were performed for osteoarthritis in Australia on patients who had a BMI recorded. Of these patients 37.1% were overweight and 41.7% were obese. Compared to the general population, there was a higher incidence of Class I, II, and III obesity in patients undergoing THR in both sexes aged 35 to 74 years. Class III obese females and males aged 55–64 years were 2.9 and 1.7 times more likely to undergo HR, respectively (p&lt;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.Obese Australians are at increased risk of undergoing THR, and at a younger age. A national approach to address the prevalence of obesity, and possible prevention strategies, is needed.

What Are the Relative Associations of Surgeon Performance and Prosthesis Quality With THA Revision Rates?

Many factors, including some related to the patient, implant selection, and the surgeon's skill and expertise, likely contribute to the risk of THA revision. However, surgeon factors have not been extensively analyzed in national joint replacement registries, and there is limited insight into their potential as a confounding variable for revision outcomes; for example, if surgeons with higher revision rates choose more successful prostheses, would this alone reduce their revision rate? This study used Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) data for patients receiving primary THA for a diagnosis of osteoarthritis to answer the following questions: (1) Will the difference in revision rates among surgeons change or disappear when only procedures performed with the best prostheses or prostheses that have been identified as having higher revision rates are considered? (2) Is the benefit associated with using the best-performing prostheses different among surgeons with different revision rates? (3) Do the reasons for revision differ between surgeons with higher rates of revision compared with surgeons with lower rates of revision? All primary THA procedures performed and recorded in the AOANJRR for osteoarthritis from September 1, 1999, to December 31, 2022, were considered for inclusion. Each THA prosthesis used was categorized per the AOANJRR as superior-performing, middle-performing, or identified as having a higher rate of revision by the AOANJRR benchmarking process. Surgeons who had performed at least 50 procedures and had a recorded 2-year cumulative percent revision (CPR) were included. After applying these restrictions, the study consisted of 302,066 procedures performed by 476 known surgeons. For the primary outcome measure of all-cause revision, we examined the variation in all-cause revision rates across individual surgeons when different classes of devices were used to assess whether differences between surgeons persisted when accounting for prosthesis selection. For the purposes of descriptively comparing reasons for revision between surgeons with higher-than-average or lower-than-average risk of revision, surgeons were classified into quartiles and outcomes compared when these surgeons used the same class of prosthesis. The difference in rates of revision among surgeons remained even after accounting for the effects of the prosthesis used. For any given surgeon, identified prostheses were associated with higher revision rates compared with both superior-performing prostheses (HR 1.73 [95% CI 1.57 to 1.92]; p < 0.01) and medium-performing prostheses (HR 1.31 [95% CI 1.20 to 1.43]; p < 0.01). All surgeons demonstrated a lower revision rate when using a superior-performing prosthesis, but the difference was greatest for surgeons with the highest rates of revision. Surgeons with the lowest rates of revision had a 19-year CPR of 3.9% (95% CI 3.0% to 5.0%) when using a superior-performing prosthesis compared with 5.4% (95% CI 4.0% to 7.3%) for procedures in which an identified prosthesis was used. Surgeons with the highest rates of revision had a 19-year CPR of 10.9% (95% CI 8.6% to 13.8%) when using a superior-performing prosthesis, and this increased to 20.4% (95% CI 18.0% to 23.1%) for procedures in which an identified prosthesis was used. The reasons for revision differ between surgeons, with causes of revision likely preventable and not related to the prosthesis choice being apparent for surgeons with high revision rates. The choice of implant and the surgeon performing the index procedure both affected the risk of revision as well as the reasons for revision. Surgeons could improve the survivorship of the arthroplasties they perform by choosing implants identified by registries as having lower revision rates. Acceptance of the fact that surgeons have different revision rates is needed, and detailed analysis is required to explain why surgeons with high revision rates have increased rates of likely preventable revisions, and outside of prosthesis choice, how revision rates can be lowered. The influence of training, fellowship completion, ongoing education, patient selection, indications for surgery, and factors underlying prosthesis decision-making should be assessed. The surgeon performing THA is an important confounder that should be considered in future registry analyses. Level III, therapeutic study.

The influence of implant factors on patient outcomes in primary total knee arthroplasty

BackgroundThe influence of implant factors on patient-reported outcome measures (PROMS) after total knee arthroplasty (TKA) has previously been studied but findings are often inconsistent, restricted in scope and biased by confounding factors. This study aims to determine the association between implant-related factors and early post-operative PROMs after TKA. MethodsUsing data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) PROMs program, the study included 9487 primary TKA procedures performed in 43 hospitals from July 31, 2018 to December 31, 2020. Data included baseline demographic data, surgical details and PROMs collected pre- and 6 months post-operatively. Seven prosthesis characteristics were incorporated in the multivariable model, with proportional odds ordinal regression analysis used to assess their effects on post-operative Oxford knee score (OKS) and joint pain. Adjustments were made for pre-operative OKS and joint pain, as well as potential patient confounders. ResultsAt six months, fixed bearing implants showed higher odds of better OKS compared to mobile bearing implants (odds ratio [OR] = 1.20, 95 % confidence interval [CI] 1.06–1.37. p < 0.004). Similar findings were found with the use of image derived instrumentation (IDI) (OR = 1.27, 95 % CI 1.11–1.46, p < 0.001), robotic assisted vs. non-navigated knees (OR = 1.21, 95 % CI 1.06–1.38, p < 0.005) and no patella resurfacing (OR = 1.10, 95 % CI 1.01–1.20, p < 0.032). For lower pain scores at six months, the use of highly crosslinked polyethylene (OR = 1.12, 95 % CI 1.02–1.22, p < 0.015), cemented femoral components (OR = 1.11, 95 % CI 1.01–1.22, p < 0.024), IDI (OR = 1.20, 95 % CI 1.05–1.37, p < 0.009) or no patella resurfacing (OR = 1.10, 95 % CI 1.01–1.20, p < 0.034) were associated. ConclusionUtilizing a fixed bearing or robotic assistance correlated with improved OKS scores, whereas highly crosslinked polyethylene or cemented femoral components were associated with improved pain scores. At six months, the use of IDI compared to non-navigated TKA, and patellar resurfacing showed both improved OKS and pain scores.

The Microbiology of Knee Prosthetic Joint Infection and its Influence on Persistent Infection.

Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a severe complication causing a significant burden. The study aims were to establish the epidemiology of microorganisms in TKA PJI, the rate of persistent infection requiring further surgery, and the risk factors for this. Microbiological specimens between June 2002 and March 2017 at five regional hospital sites were identified with revision TKA procedures in the National Joint Replacement Registry. The time between procedures, type of revision strategy, and any subsequent further revision operations were collected. At minimum 2-year follow-up, 174 revision TKA were identified, with a mean patient age of 69 ± 11 years. A broad range of pathogens were identified. Fifty cases (29%) had persistent infection requiring at least one further operative procedure, 13 cases required 3 or more. Coagulase-negative Staphylococcus species (CNS) was seen most with failed surgery, polymicrobial infections also posing a significant risk factor. The best chance of a successful PJI surgical strategy was < 12 months from primary TKA, with the greatest risk between 3 and 5 years (p < 0.05). Younger age significantly increased the risk of further surgery (p < 0.05). Management varied; 103 (59%) debridement, antibiotic therapy and implant retention, with further surgery in 29%; 45 (17%) single-stage revision, with further surgery in 13%; and 26 (15%) two-stage revision, with further surgery in 12%. This study presents the most common causative pathogens for PJI in TKA, and the high rate of persistent infection after initial revision surgery. Risk factors for persistent infection and further revision surgery were polymicrobial and CNS infections, patients who presented between 3 and 5 years following primary TKA, and younger age. This study therefore raises important risk factors and areas for future research to reduce the burden of multiple operations after PJI.

Collared Cementless Femoral Components Reduce the Revision Rates in Primary Total Hip Arthroplasty Using the Direct Anterior Approach: An Australian Orthopaedic Association National Joint Replacement Registry Study

BackgroundAn increased risk of periprosthetic fracture and aseptic loosening is reported when the direct anterior approach (DAA) is used for total hip arthroplasty (THA), especially with cementless implants. We assessed the rate of revision comparing collared and collarless femoral stems when using the DAA for THA. MethodsWe used data from the Australian Orthopaedic Association National Joint Replacement Registry for primary THA for osteoarthritis inserted with the DAA between January 2015 and December 2022. There were 48,567 THAs that used the DAA (26,690 collarless cementless, 10,161 collared cementless, and 11,716 cemented). Cumulative percent revision was calculated for all-cause revision, revision for periprosthetic femoral fractures, and aseptic femoral stem loosening. Cox proportional hazard ratios [HRs] were used to compare the revision of collared and collarless cementless stems. We also compared collared cementless stems and cemented stems. ResultsA higher rate of all-cause revision within 3 months of surgery was observed with collarless compared to collared cementless implants (HR: 1.99 [95% confidence interval (CI), 1.56 to 2.54]; P < .001). Similarly, collarless cementless implants were associated with a greater rate of revision for fracture in the first 6 months (HR: 2.90 [95% CI, 1.89 to 4.45]; P < .001) and after 6 months (HR 10.04 [95% CI 1.38 to 73.21]; P = .02), as well as an increased rate of revision for aseptic loosening after 2 years (HR: 5.76 [95% CI, 1.81 to 18.28], P = .003). Collared cementless and cemented stems performed similarly. ConclusionCollared stems were associated with a reduced rate of all-cause revision for cementless THA performed via the DAA. The reduction in risk may be due to protection from periprosthetic femoral fracture and aseptic loosening.

Risk of early revision in total hip arthroplasty: the relative contribution of the surgeon versus the hospital.

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.

THE INFLUENCE OF BEARING SURFACE ON PERIPROSTHETIC JOINT INFECTION IN TOTAL HIP ARTHROPLASTY

BackgroundIncreasing evidence suggests a link between the bearing surface used in total hip arthroplasty (THA) and the occurrence of infection. It is postulated that polyethylene has immunomodulatory effects and may influence bacterial function and survival, thereby impacting the development of periprosthetic joint infection (PJI). This study aimed to investigate the association between polyethylene type and revision surgery for PJI in THA using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). We hypothesized that the use of XLPE would demonstrate a statistically significant reduction in revision rates due to PJI compared to N-XLPE.MethodsData from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) spanning September 1, 1999, to December 31, 2021, were used to compare the infection revision rates between THA using N-XLPE and XLPE. We calculated the Cumulative Percentage Revision rate (CPR) and Hazard Ratio (HR) while controlling for factors like age, sex, body mass index (BMI), American Society of Anesthesiologists’ (ASA) grade, and head size.ResultsFrom the total 361,083 primary THAs, 26,827 used N-XLPE and 334,256 used XLPE. Excluding data from the first 6 months post-surgery, 220 revisions occurred in the N-XLPE group and 1,055 in the XLPE group for PJI. The HR for infection revision was significantly higher in N-XLPE compared to XLPE, at 1.64 (95% CI, 1.41–1.90, p&lt;0.001).ConclusionsThis analysis provides evidence of an association between N-XLPE and revision for infection in THA. We suspect that polyethylene wear particles contribute to the susceptibility of THA to PJI, resulting in a significantly higher risk of revision for infection in N-XLPE hips compared to those with XLPE.Level of EvidenceTherapeutic Level III.

Comparable low revision rates of stemmed and stemless total anatomic shoulder arthroplasties after exclusion of metal-backed glenoid components: a collaboration between the Australian and Danish national shoulder arthroplasty registries

BackgroundThe stemmed anatomical total shoulder arthroplasty is the gold standard in the treatment of glenohumeral osteoarthritis. However, the use of stemless total shoulder arthroplasties has increased in recent years. The number of revision procedures are relatively low and therefore it has been recommended that national joint replacement registries should collaborate when comparing revision rates. Therefore, we aimed to compare the revision rates of stemmed and stemless TSA used for the diagnosis of glenohumeral osteoarthritis using data from both the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Danish Shoulder Arthroplasty Registry (DSR). MethodsWe included all patients who were registered in the AOANJRR and the DSR from January 1 2012 to December 2021 with an anatomical total shoulder arthroplasty used for osteoarthritis. Revision for any reason was used as the primary outcome. We used the Kaplan-Meier method to illustrate the cumulative revision rates and a multivariate cox regression model to calculate the hazard ratios. All analyses were performed separately for data from AOANJRR and DSR, and the results were then reported using a qualitative approach. Results13066 arthroplasties from AOANJRR and 2882 arthroplasties from DSR were included. The hazard ratio for revision of stemmed TSA with stemless TSA as reference, adjusted for age and gender, was 1.67 (95% CI 1.34-2.09, p<0.001) in AOANJRR and 0.57 (95% CI 0.36-0.89, p=0.014) in DSR. When including glenoid type and fixation, surface bearing (only in AOANJRR) and hospital volume in the cox regression model the hazard ratio for revision of stemmed TSA compared to stemless TSA was 1.22 (95% CI 0.85-1.75, p=0.286) in AOANJRR and 1.50 (95% CI 0.91-2.45, p=0.109) in DSR. The adjusted hazard ratio for revision of total shoulder arthroplasties with metal backed glenoid components compared to all-polyethylene glenoid components was 2.54 (95% CI 1.70-3.79, p < 0.001) in AOANJRR and 4.1 (95% CI 1.92-8.58, p<0.001) in DSR. ConclusionBased on data from two national shoulder arthroplasty registries, we found no significant difference in risk of revision between stemmed and stemless total shoulder arthroplasties after adjusting for the type of glenoid component. We advocate that metal-backed glenoid components should be used with caution and not on a routine basis.

A comparison of cemented femoral fixation via anterior versus posterior approach total hip arthroplasty: an analysis of 60,739 total hip arthroplasties.

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. 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. 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). 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.

Hip-specific and generic patient-reported outcome measure scores after primary hip replacement are associated with early revision surgery: a national registry study

BackgroundThe ability to efficiently identify patients at higher risk of poor outcomes after joint replacement would enable limited resources for post-operative follow-up to be directed to those with the greatest clinical need. This is particularly important as joint replacement rates continue to grow internationally, stretching health system capabilities. Patient-reported outcome measures (PROMs) are routinely administered in many settings and offer an opportunity to detect suboptimal patient outcomes early. This study aimed to determine whether hip-specific and generic PROM scores are associated with early revision hip replacement within six to 24 months after the primary procedure.MethodsPre-operative and six-month post-operative PROM scores for patients undergoing primary total hip replacement (THR) were obtained from the Australian Orthopaedic Association National Joint Replacement Registry and Arthroplasty Clinical Outcomes Registry National and linked to revision surgery data. Clinically important improvement was defined using anchor-based thresholds. Associations between PROM scores (hip pain, Oxford Hip Score, HOOS-12, EQ-5D-5L, EQ VAS, patient-perceived change, satisfaction) and revision surgery were evaluated using t-tests, chi-square tests and regression models.ResultsData were analysed for 21,236 primary THR procedures between 2013 and 2022. Eighty-eight revision procedures were performed at six to 24 months. Patients who were revised had more back pain and worse HOOS-12 scores pre-operatively but between-group differences were small. Worse post-operative PROM scores (hip pain, Oxford, HOOS-12, EQ-5D-5L, EQ VAS) were associated with early revision, after adjusting for age and sex (p < 0.001 for all analyses). Patient dissatisfaction (relative risk (RR) 10.18, 95%CI 6.01–17.25) and patient-perceived worsening (RR 19.62, 95%CI 11.33–33.98) were also associated with a higher likelihood of revision. Patients who did not achieve clinically important improvement in hip pain, function, or quality of life had a higher revision risk (RRs 2.54–5.64), compared with those who did (reference).ConclusionSix-month hip-specific and generic PROM scores can identify patients at higher risk of early revision surgery. Our data highlight the utility of routine post-operative PROM assessment for signaling suboptimal surgical outcomes.

Characteristics associated with rerevision of primary inlay and onlay reverse shoulder arthroplasty. Analysis from the Australian Orthopaedic Association National Joint Replacement Registry

BackgroundTwo designs of primary reverse total shoulder arthroplasty (rTSA), inlay reverse total shoulder arthroplasty (in-rTSA) and onlay reverse total shoulder arthroplasty (on-rTSA) that had undergone an aseptic revision were compared to determine differences in the rate of rerevision. MethodsIn this comparative observational national registry study between January 1, 2012, and December 31, 2021, all rTSA utilizing either a modular inlay or onlay metaphyseal humeral component that had been revised for aseptic reasons formed 2 cohort groups. The cumulative percentage rerevision (2nd CPR) was determined using Kaplan-Meier estimates of survivorship and hazard ratios (HRs) from Cox proportional hazard models adjusted for age and sex. A minor category revision involved exchange of parts not fixed to bone whilst major revisions did. The primary and revision diagnoses, surgeon primary volume experience, and revision category were compared. Shoulder Modular Replacement (SMR)/SMR L1 or L2 combination (Lima Corporate, San Daniele del Friuli, Italy) was excluded at subanalysis. ResultsThe 2nd CPR at 3 years was 20.4% (95% confidence interval 17.1, 24.1) for in-rTSA (n = 571) and 16.1%(11.6, 22.2) for on-rTSA (n = 249). The risk of rerevision was not different between the 2 cohort groups. Primary diagnosis fracture was associated with an increased risk of rerevision for on-rTSA (entire period on-rTSA HR = 3.16(1.50, 6.68), P = .002), and in-rTSA at subanalysis (entire period on-rTSA HR = 2.91(1.33, 6.33), P = .007). 59.9% of in-rTSA and 24.1% of on-rTSA aseptic revisions were minor. The revision diagnosis, the surgical experience of rTSA and if the revision was major or minor did not change the rate of rerevision. The most common reason for both in-rTSA (50%) and (43.2%) on-rTSA rerevision was instability/dislocation. DiscussionRerevision rates of in-rTSA and on-rTSA after aseptic revision are high. The primary rather the revision diagnosis changed rerevision rates in contemporary rTSA surgery. Minor revisions did not reduce rerevision rates for in-rTSA or on-rTSA compared to humeral/glenoid revision. Increased surgical experience of primary rTSA did not change the rate of rerevision of in-rTSA or on-rTSA.

Registry-based study of survivorship of cemented femoral components versus collared cementless femoral components in total hip arthroplasty in older patients with osteoarthritis.

In recent years, the use of a collared cementless femoral prosthesis has risen in popularity. The design intention of collared components is to transfer some load to the resected femoral calcar and prevent implant subsidence within the cancellous bone of the metaphysis. Conversely, the load transfer for a cemented femoral prosthesis depends on the cement-component and cement-bone interface interaction. The aim of our study was to compare the three most commonly used collared cementless components and the three most commonly used tapered polished cemented components in patients aged ≥ 75 years who have undergone a primary total hip arthroplasty (THA) for osteoarthritis (OA). Data from the Australian Orthopaedic Association National Joint Replacement Registry from 1 September 1999 to 31 December 2022 were analyzed. Collared cementless femoral components and cemented components were identified, and the three most commonly used components in each group were analyzed. We identified a total of 11,278 collared cementless components and 47,835 cemented components. Hazard ratios (HRs) from Cox proportional hazards models, adjusting for age and sex, were obtained to compare the revision rates between the groups. From six months postoperatively onwards, patients aged ≥ 75 years undergoing primary THA with primary diagnosis of OA have a lower risk of all-cause revision with collared cementless components than with a polished tapered cemented component (HR 0.78 (95% confidence interval 0.64 to 0.96); p = 0.018). There is no difference in revision rate prior to six months. Patients aged ≥ 75 years with a primary diagnosis of OA have a significantly lower rate of revision with the most common collared cementless femoral component, compared with the most common polished tapered cemented components from six months postoperatively onwards. The lower revision rate is largely due to a reduction in revisions for fracture and infection.

Measurement Properties of the Oxford Shoulder Score and Minimal Clinically Important Changes After Primary Total Shoulder Replacement Surgery.

We evaluated the measurement properties of the Oxford Shoulder Score (OSS) and estimated the minimal clinically important change (MCIC) in patients undergoing primary total shoulder replacement in Australia. Deidentified data from the Australian Orthopaedic Association National Joint Replacement Registry were used for this analysis. Pre- and 6-month postoperative OSS scores were used, with the 5-level EuroQoL quality of life instrument and shoulder pain scores used as comparators. Floor and ceiling effects, internal consistency reliability, construct validity, and responsiveness to change were evaluated using standard psychometric methods. Mean change and predictive modeling approaches (with and without adjustment for the proportion of improved patients) were used to calculate MCIC thresholds, with patient-perceived improvement after surgery as the anchor. Preoperative OSS data were available for 1,117 patients (59% female; 90% aged ≥60 years) undergoing primary total shoulder replacement. No floor or ceiling effects were observed pre- or postoperatively. The OSS showed high internal consistency reliability (Cronbach alpha >0.89), good construct validity, and high responsiveness to change (effect size 1.88). The MCIC derived from the mean change method was 6.50 points (95% confidence interval [95% CI] 4.41-8.61). The predictive modeling approach produced an MCIC estimate of 8.42 points (95% CI 5.68-12.23) after adjustment. The OSS has good measurement properties to capture pain and function outcomes after shoulder replacement procedures and is highly responsive to change. Based on robust methods, an increase in OSS scores of at least eight points can be considered as meaningful improvement after surgery from the patient's perspective.

Increasing Use of Total Wrist Arthroplasty-An Australian National Joint Registry Report.

Background and Purpose There is limited literature reporting the long-term results and outcomes of total wrist arthroplasty (TWA). The aim of this study was to describe the incidence, usage, and survival of wrist arthroplasty using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Methods Data included all primary TWA procedures from 2006 to 2021. The primary outcome assessed was revision surgery. Utilization of TWA, etiology leading to TWA, patient demographics, and surgical factors were also assessed. Results There were 439 primary TWA procedures performed across the 16-year reporting period. Four prostheses (Motec, Universal 2, Freedom, and ReMotion) have been used, with a recent increased usage toward the Motec, which accounted for 97.4% of prostheses implanted in 2021. There has also been an increase in the number of surgeons performing TWA over time. The most common underlying etiology was osteoarthritis (72.7%), followed by rheumatoid arthritis (15.9%). Implantation for inflammatory arthropathy remained relatively constant across time; however, TWA has been utilized with increasing frequency for the treatment of osteoarthritis and other indications more recently. The cumulative percent revision at 10 years was 18.3%. Loosening accounted for 25.6% of all revisions, followed by osteolysis (12.8%), pain (12.8%), and instability (7.7%). Attempted conversion to an arthrodesis occurred in 10.3% of all revisions. Conclusion There has been an increase in both the volume of TWA performed and the number of surgeons undertaking this procedure in Australia over the past 16 years. The Motec system has become the prosthesis of choice. Medium-term revision rates are inferior when compared with Australian data for hip, knee, and shoulder arthroplasty.

Utilizing Stems in Primary Total Knee Arthroplasty: Analysis of the Australian Orthopaedic Association National Joint Replacement Registry Data

BackgroundWe compared revision rates and reasons for revision for primary total knee arthroplasty (TKA) performed for osteoarthritis with and without tibial stem extensions. MethodsData from the Australian Orthopaedic Association National Joint Replacement Registry were used to compare all-cause revision, reason, and type of revision between primary TKA using stemmed tibial prostheses and non-stemmed prostheses. ResultsAll-cause revision for TKA with stem extension was higher for the first 6 months (hazard ratio [HR] 1.47; 95% confidence interval [CI]1.19 to 1.82; P < .001); while after 1.5 years TKA with stem extension had a lower rate of revision (HR 0.84; 95% CI 0.73 to 0.97; P = .01). Stemmed components were more likely to be revised for infection between 3 months and 1.5 years after surgery (HR 1.39; 95% CI 1.05 to 1.83; P = .02). The revision rate for aseptic loosening was lower in the stemmed group beyond 2 years (HR = 0.45; 95% CI 0.31 to 0.63; P < .001). Insert-only revision was higher in the stemmed group at all times (HR = 1.42; 95% CI 1.21 to 1.66, P < .001). Isolated tibial component revision was lower in the stemmed group at all times (HR 0.47; 95% CI 0.29 to 0.74; P = .001). Aseptic loosening for tibial component-only revision was significantly lower in the stemmed group at all times (HR 0.23; 95% CI 0.11 to 0.50; P < .001). ConclusionsPatients undergoing primary stemmed TKA have lower rates of all-cause revision beyond 1.5 years and tibial component-only revision at all times. Further investigation is required to preoperatively select patients that benefit from augmentation with stems.

What is the most appropriate comparator group to use in assessing the performance of primary total hip prostheses within the community?

There are variations in the performance of individual prostheses used in hip replacements. Some of which have unexpectedly higher revision rates - outliers. The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) has established a standardised multi-stage approach for identifying these devices. This is done by comparing the revision rates of individual prostheses to all other prostheses in class, with the exception of large head metal-on-metal (LHMoM) prostheses. However, improvements in device design and performance over time have required a need to reconsider the comparator group. This study aimed to identify a more specific comparator to better reflect contemporary surgical practice. The time to first revision was estimated on the data of 413,417 primary total conventional hip replacements undertaken for osteoarthritis (OA) from 01 January 2003 to 31 December 2019. Survivorship analyses with stepwise exclusions were undertaken. The first exclusion was LHMoM, followed by other non-modern bearing surfaces (defined as all the bearing couples except metal or ceramic heads on cross-linked polyethylene and mixed ceramic-on-ceramic), and then devices with modular neck-stem design or used for specific purposes (incl. constrained, dual-mobility, and head size <28 mm). Lastly, all remaining prostheses previously identified as having a higher than anticipated rate of revision (HTARR) were also excluded. These exclusions progressively reduced the cumulative percent revision (CPR) rate. The final comparator, which only includes satisfactory-performed prostheses of contemporary design and use, has a 10-year CPR of 4.30% (95% CI, 4.2-4.41) which is lower than 4.93% (95% CI, 4.84-5.02) for the current comparator used by the AOANJRR (all prostheses excluding LHMOM). Over the study period, 13 additional components were identified utilising the modified comparator. The calculation of the comparator revision rate should be re-evaluated to include only modern prosthesis constructs to ensure that poorly performing prostheses are identified early.

National Registry Data Analysis on a Unique Highly-Crosslinked Polyethylene for Total Hip Arthroplasty

BackgroundSeveral types of highly-crosslinked polyethylene with different manufacturing processes and mechanical properties are commercially available, including HIGHCROSS (Medacta). The aim of this registry study is to ascertain the long-term safety of the HIGHCROSS liners in total hip arthroplasty and compare the revision rates with its contemporaries using real-world data to establish their safety and generalizability when used by multiple surgeons. MethodsThe Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) and the Swiss National Joint Registry (SIRIS) were selected for the large number of users of Medacta implants and the availability of long-term results. Three reports from SIRIS and 4 reports from AOANJRR were examined to establish the overall and Kaplan-Meier (KM) cumulative revision rate. ResultsAccording to SIRIS, the HIGHCROSS liner was the most commonly used bearing surface with Medacta stems with overall revision rates for wear/osteolysis at 9.7 years of 0.04% and 0.03%, respectively, for AMIStem and Quadra. Based on AOANJRR, the KM cumulative revision rate for any reason of Medacta stems with HIGHCROSS liners was lower than that with ceramic liners at 3 years for MasterLoc and at 10 years for Quadra. The KM cumulative revision rate for any reasons of Medacta cementless cups with HIGHCROSS liners at 12 years was lower than the comparator made of all other implants and tribological couplings (1.6% vs 2.1%). ConclusionsThis real-world data proves that long-term HIGHCROSS survival rates are comparable to other modern bearing surfaces.

A Polished Cobalt-Chrome Baseplate is not Associated With a Lower Revision Rate Than Matt Titanium in a Single Total Knee Arthroplasty Implant System With Identical Baseplate Design

BackgroundPolished baseplates were introduced into total knee arthroplasty (TKA) systems to reduce the incidence of backside wear. In 2004, a fixed-bearing knee arthroplasty system underwent a change in baseplate material from matt titanium to polished cobalt-chrome (CoCr) with the intention to reduce backside wear. Other design aspects were left unchanged. The aim of this study was to compare these implants with each baseplate using data from the Australian Orthopaedic Association National Joint Replacement Registry. MethodsPrimary TKA procedures performed between January 2010 and December 2021 for osteoarthritis, using a single design with cross-linked polyethylene inserts and matt titanium or polished CoCr baseplates, were analyzed. The primary outcome was all-cause revision, summarized using Kaplan-Meier estimates, with age- and sex-adjusted hazard ratios estimated from Cox proportional hazards models. In total, there were 2,091 procedures with matt titanium and 2,519 procedures with polished CoCr baseplates. ResultsThe 9-year cumulative percent revision was 2.5% (95% confidence interval [CI] 1.8 to 3.5%) and 4.2% (95% CI 3.1 to 5.6%) for the matt titanium and CoCr groups, respectively. Compared to matt titanium, the revision rate of CoCr baseplates was not significantly higher (hazard ratio 1.44; 95% CI 0.96 to 2.15; P = .076). ConclusionsPolished CoCr baseplates in a single TKA system were not associated with reduced all-cause revision rates compared to matt titanium up to 11 years post-TKA. Our results suggest that the predicted reduction in wear particle debris production from polished CoCr baseplates may not correlate with reduced revision rates in vivo, but further evaluation is required.

Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry.

The treatment of shoulder osteoarthritis in the young patient remains challenging. The higher functional demands and higher expectations of the young patient cohort are often coupled with increased failure and revision rates. Consequently, shoulder surgeons are faced with a unique challenge with implant selection. The aim of this study was to compare the survivorship and reasons for revision of 5 classes of shoulder arthroplasty in patients aged <55 years with a primary diagnosis of osteoarthritis by use of data from a large national arthroplasty registry. The study population included all primary shoulder arthroplasty procedures undertaken for osteoarthritis in patients aged <55 years and reported to the registry between September 1999 and December 2021. Procedures were grouped into the following classes: total shoulder arthroplasty (TSA), hemiarthroplasty resurfacing (HRA), hemiarthroplasty stemmed metallic head (HSMH), hemiarthroplasty stemmed pyrocarbon head (HSPH), and reverse total shoulder arthroplasty (RTSA). The outcome measure was the cumulative percent revision, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the first revision. Hazard ratios (HRs) were calculated from Cox proportional hazards models, adjusting for age and sex, to compare revision rates among groups. There were 1564 shoulder arthroplasty procedures in patients aged <55 years, of which 361 (23.1%) were HRA, 70 (4.5%) were HSMH, 159 (10.2%) were HSPH, 714 (45.7%) were TSA, and 260 (16.6%) were RTSA. HRA had a higher rate of revision than RTSA after 1 year (HRA = 2.51 (95% CI 1.30, 4.83), P=.005), with no difference prior to that time. In addition, HSMH had a higher rate of revision than RTSA for the entire period (HR,2.69 [95% confidence interval, 1.28-5.63], P=.008). There was no significant difference in the rate of revision for HSPH and TSA when they were compared with RTSA. Glenoid erosion was the most common cause of revision for HRA (28.6% of revisions) and HSMH (50%). Instability/dislocation was the leading cause of revision for RTSA (41.7%) and HSPH (28.6%), and for TSA, the majority of revisions were for either instability/dislocation (20.6%) or loosening (18.6%). These results should be interpreted within the context of the lack of availability of long-term data on RTSA and HSPH stems. RTSA outperforms all implants regarding revision rates at mid-term follow-up. The high early dislocation rate associated with RTSA, as well as the lack of revision options available to address this, indicates that careful selection of patients and a greater appreciation of anatomic risk factors are needed in the future.