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

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.

A Systematic Review of Data Collection by National Joint Replacement Registries: What Opportunities Exist for Enhanced Data Collection and Analysis?

BACKGROUND: National joint replacement registries assist surgeons and hospitals with guiding decision making and quality of care. The data points collected are essential to interpret and analyze data and to understand confounding variables and other sources of bias, which can impair retrospective observational research. The aim of this study was to review all national joint replacement registries to assess what data points are recorded, and in what manner, for primary and revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) so that improvements can be made to enhance data collection, interpretation, and analysis. METHODS: All national registries were identified through Internet and publication search and contacted to invite participation. Data collection forms for both primary and revision THA and TKA were requested. Data collected were entered into an Excel spreadsheet. RESULTS: The study group for primary and revision THA consisted of 28 national registries, with 26 agreeing to participate. The study group for primary TKA consisted of 27 national registries, with 24 agreeing to participate. Patient identification details were recorded uniformly. Only a minority recorded patient details beyond American Society of Anesthesiologists and body mass index. Most registries did not record surgeon variables: who actually performed or assisted the procedure and their level of training. There was variation in the degree of detail recorded for diagnosis, mostly regarding secondary causes of osteoarthritis and fracture. The details regarding case complexity were limited. Half recorded previous operations, and fewer recorded bone defects. The location of knee arthritis, preoperative limb alignment, and deformities were rarely recorded. Surgical approach and technological adjuncts were routinely collected, but few other details on the surgical technique were recorded. Implant details and fixation were uniformly collected, although a minority recorded specific details, including cement antibiotic or cementing technique. It was uncommon to record whether additional or adjunctive procedures were concurrently performed. Approximately half the registries lacked a revision specific form. The majority recorded reoperations in addition to revision procedures. Patient, surgeon, case, and postoperative details were recorded similar to primary procedures. There was variation in the degree of details recorded for the reasons underlying the revision +/- reoperation, with most recording greater detail for infection and fracture. Many included details on case complexity and bone defects, including the severity, classification, and how the defect was managed. The majority recorded the specific revision procedure that was performed (total or partial), the fixation used, and the components removed or revised. Other specific aspects of fixation including acetabular screws, cone or sleeve use, stems, and augments were less commonly recorded. CONCLUSION: Substantial data are recorded by all registries, although each one is different. Data solicited lack many patient factors, surgeon variables, case complexity, and surgical techniques. Separate revision forms are not universal, and many registries do not record reoperation procedures, specific causes of revision, and the revision construct. LEVEL OF EVIDENCE: Level II, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Do the Revision Rates of Arthroplasty Surgeons Correlate With Postoperative Patient-reported Outcome Measure Scores? A Study From the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: Patient-reported outcome measures (PROMs) are a pragmatic and efficient means to evaluate the functional quality of arthroplasty beyond revision rates, which are used by most joint replacement registries to judge success. The relationship between these two measures of quality-revision rates and PROMs-is unknown, and not every procedure with a poor functional result is revised. It is logical-although still untested-that higher cumulative revision rates correlate inversely with PROMs for individual surgeons; more revisions are associated with lower PROM scores. QUESTIONS/PURPOSES: We used data from a large national joint replacement registry to ask: (1) Does a surgeon's early THA cumulative percent revision (CPR) rate and (2) early TKA CPR rate correlate with the postoperative PROMs of patients undergoing primary THA and TKA, respectively, who have not undergone revision? METHODS: Elective primary THA and TKA procedures in patients with a primary diagnosis of osteoarthritis that were performed between August 2018 and December 2020 and registered in the Australian Orthopaedic Association National Joint Replacement Registry PROMs program were eligible. THAs and TKAs were eligible for inclusion in the primary analysis if 6-month postoperative PROMs were available, the operating surgeon was clearly identified, and the surgeon had performed at least 50 primary THAs or TKAs. Based on the inclusion criteria, 17,668 THAs were performed at eligible sites. We excluded 8878 procedures that were not matched to the PROMs program, leaving 8790 procedures. A further 790 were excluded because they were performed by unknown or ineligible surgeons or were revised, leaving 8000 procedures performed by 235 eligible surgeons, including 4256 (53%; 3744 cases of missing data) patients who had postoperative Oxford Hip Scores and 4242 (53%; 3758 cases of missing data) patients who had a postoperative EQ-VAS score recorded. Complete covariate data were available for 3939 procedures for the Oxford Hip Score and for 3941 procedures for the EQ-VAS. A total of 26,624 TKAs were performed at eligible sites. We excluded 12,685 procedures that were not matched to the PROMs program, leaving 13,939 procedures. A further 920 were excluded because they were performed by unknown or ineligible surgeons, or because they were revisions, leaving 13,019 procedures performed by 276 eligible surgeons, including 6730 (52%; 6289 cases of missing data) patients who had had postoperative Oxford Knee Scores and 6728 (52%; 6291 cases of missing data) patients who had a postoperative EQ-VAS score recorded. Complete covariate data were available for 6228 procedures for the Oxford Knee Score and for 6241 procedures for the EQ-VAS. The Spearman correlation between the operating surgeon's 2-year CPR and 6-month postoperative EQ-VAS Health and Oxford Hip or Oxford Knee Score was evaluated for THA and TKA procedures where a revision had not been performed. Associations between postoperative Oxford and EQ-VAS scores and a surgeon's 2-year CPR were estimated based on multivariate Tobit regressions and a cumulative link model with a probit link, adjusting for patient age, gender, ASA score, BMI category, preoperative PROMs, as well as surgical approach for THA. Missing data were accounted for using multiple imputation, with models assuming they were missing at random and a worst-case scenario. RESULTS: Of the eligible THA procedures, postoperative Oxford Hip Score and surgeon 2-year CPR were correlated so weakly as to be clinically irrelevant (Spearman correlation ρ = -0.09; p < 0.001), and the correlation with postoperative EQ-VAS was close to zero (ρ = -0.02; p = 0.25). Of the eligible TKA procedures, postoperative Oxford Knee Score and EQ-VAS and surgeon 2-year CPR were correlated so weakly as to be clinically irrelevant (ρ = -0.04; p = 0.004 and ρ = 0.03; p = 0.006, respectively). All models accounting for missing data found the same result. CONCLUSION: A surgeon's 2-year CPR did not exhibit a clinically relevant correlation with PROMs after THA or TKA, and all surgeons had similar postoperative Oxford scores. PROMs, revision rates, or both may be inaccurate or imperfect indicators of successful arthroplasty. Missing data may limit the findings of this study, although the results were consistent under a variety of different missing data scenarios. Innumerable factors contribute to arthroplasty results, including patient-related variables, differences in implant design, and the technical quality of the procedure. PROMs and revision rates may be analyzing two different facets of function after arthroplasty. Although surgeon variables are associated with revision rates, patient factors may exert a stronger influence on functional outcomes. Future research should identify variables that correlate with functional outcome. Additionally, given the gross level of function that Oxford scores record, outcome measures that can identify clinically meaningful functional differences are required. The use of Oxford scores in national arthroplasty registries may rightfully be questioned. LEVEL OF EVIDENCE: Level III, therapeutic study.

Dual-mobility constructs versus large femoral head bearings in primary and revision total hip arthroplasty: a systematic review and meta-analysis of comparative studies.

BACKGROUND: Both dual-mobility (DM) constructs and large femoral head bearings (⩾36 mm) reduce dislocation following total hip arthroplasty (THA). There is limited research comparing DM with large bearings. METHODS: A systematic review of published literature was performed including studies that compared DM with large femoral head bearings in primary or revision THA according to PRISMA guidelines. The primary outcome was revision surgery for dislocation. The secondary outcome was all-cause revision surgery. Other complications were recorded. 2 authors independently selected studies, performed data extraction, and risk of bias assessment. Treatment effects were assessed using odds ratios and data were pooled using a fixed-effect model, where appropriate. RESULTS: 9 studies, all retrospective, met the final inclusion criteria. 2722 patients received DM and 9,789 large femoral head bearings. The difference in the odds of revision surgery for dislocation (OR 0.67; 95% CI, 0.45-1.01; p = 0.06) and aseptic loosening are unclear (OR 0.61; 95% CI, 0.36-1.05; p = 0.07); including important benefits and no difference. There was a benefit favouring DM for the risk of all-cause revision (OR 0.70; 95% CI, 0.56-0.86; p = 0.001), revision for fracture (OR 0.49; 95% CI, 0.29-0.81; p = 0.005) and dislocation not requiring revision (OR 0.29; 95% CI, 0.14-0.57; p < 0.001). The estimate in the difference in the odds of revision surgery for infection was imprecise (OR 0.78; 95% CI, 05.1-1.20; p = 0.26). CONCLUSIONS: This study provides evidence that there may be clinically relevant benefits of DM constructs over large femoral head bearings. Prospective randomised studies are warranted given these findings.

Is the Revision Rate for Femoral Neck Fracture Lower for Total Hip Arthroplasty Than for Hemiarthroplasty?: A Comparison of Registry Data for Contemporary Surgical Options.

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.

A Comparison of Revision Rates and Dislocation After Primary Total Hip Arthroplasty with 28, 32, and 36-mm Femoral Heads and Different Cup Sizes: An Analysis of 188,591 Primary Total Hip Arthroplasties.

UPDATE: This article was updated on August 17, 2022, because of previous errors, which were discovered after the preliminary version of the article was posted online. On page 1462, in the first sentence of the Abstract section entitled "Results," the phrase that had read "and 36-mm heads had fewer dislocations than 28-mm (HR = 0.33 [95% CI, 0.16 to 0.68]; p = 0.003), but more dislocations than 32-mm heads (HR for >2 weeks = 2.25 [95% CI, 1.13 to 4.49]; p = 0.021)" now reads "and 36-mm heads had fewer dislocations than 28-mm (HR = 0.33 [95% CI, 0.16 to 0.68]; p = 0.003) and 32-mm heads (HR for ≥2 weeks = 0.44 [95% CI, 0.22 to 0.88]; p = 0.021)." On page 1468, in the last sentence of the section entitled "Acetabular Components with a Diameter of <51 mm," the phrase that had read "and HR for ≥2 weeks = 2.25 [95% CI, 1.13 to 4.49; p = 0.021]) ( Fig. 3 )" now reads "and HR for ≥2 weeks = 0.44 [95% CI, 0.22 to 0.88; p = 0.021]) ( Fig. 3 )." Finally, on page 1466, in the upper right corner of Figure 3 , under "32mm vs 36mm," the second line that had read "2Wks+: HR=2.25 (1.13, 4.49), p=0.021" now reads "2Wks+: HR=0.44 (0.22, 0.88), p= 0.021."

The acetabular component diameter can influence the choice of femoral head size in total hip arthroplasty (THA). We compared the rates of revision by femoral head size for different acetabular component sizes. Data from the Australian Orthopaedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for a diagnosis of osteoarthritis from September 1999 to December 2019. Acetabular components were stratified into quartiles by size: <51 mm, 51 to 53 mm, 54 to 55 mm, and 56 to 66 mm. Femoral head sizes of 28 mm, 32 mm, and 36 mm were compared for each cup size. The primary outcome was the cumulative percent revision (CPR) for all aseptic causes and for dislocation. The results were adjusted for age, sex, femoral fixation, femoral head material, year of surgery, and surgical approach and were stratified by femoral head material. For acetabular components of <51 mm, 32-mm (hazard ratio [HR] = 0.75 [95% confidence interval (CI), 0.57 to 0.97]; p = 0.031) and 36-mm femoral heads (HR = 0.58 [95% CI, 0.38 to 0.87]; p = 0.008) had a lower CPR for aseptic causes than 28-mm heads; and 36-mm heads had fewer dislocations than 28-mm (HR = 0.33 [95% CI, 0.16 to 0.68]; p = 0.003), and 32-mm heads (HR for ≥2 weeks = 0.44 [95% CI, 0.22 to 0.88]; p = 0.021). For 51 to 53-mm, 54 to 55-mm, and 56 to 66-mm-diameter acetabular components, there was no difference in the CPR for aseptic causes among head sizes. A femoral head size of 36 mm had fewer dislocations in the first 2 weeks than a 32-mm head for the 51 to 53-mm acetabular components (HR for <2 weeks = 3.79 [95% CI, 1.23 to 11.67]; p = 0.020) and for the entire period for 56 to 66-mm acetabular components (HR = 1.53 [95% CI, 1.05 to 2.23]; p = 0.028). The reasons for revision differed for each femoral head size. There was no difference in the CPR between metal and ceramic heads. There is no clear advantage to any single head size except with acetabular components of <51 mm, in which 32-mm and 36-mm femoral heads had lower rates of aseptic revision. If stability is prioritized, 36-mm femoral heads may be indicated. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

In Revision THA, Is the Re-revision Risk for Dislocation and Aseptic Causes Greater in Dual-mobility Constructs or Large Femoral Head Bearings? A Study from the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: Dislocation is one of the most common causes of a re-revision after a revision THA. Dual-mobility constructs and large femoral head bearings (≥ 36 mm) are known options for mitigating this risk. However, it is unknown which of these choices is better for reducing the risk of dislocation and all-cause re-revision surgery. It is also unknown whether there is a difference between dual-mobility constructs and large femoral head bearings according to the size of the acetabular component. QUESTIONS/PURPOSES: We used data from a large national registry to ask: In patients undergoing revision THA for aseptic causes after a primary THA performed for osteoarthritis, (1) Does the proportion of re-revision surgery for prosthesis dislocation differ between revision THAs performed with dual-mobility constructs and those performed with large femoral head bearings? (2) Does the proportion of re-revision surgery for all aseptic causes differ between revision THAs performed with dual-mobility constructs and those performed with large femoral head bearings? (3) Is there a difference when the results are stratified by acetabular component size? METHODS: Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) were analyzed for 1295 first-revision THAs for aseptic causes after a primary THA performed for osteoarthritis. The study period was from January 2008-when the first dual-mobility prosthesis was recorded-to December 2019. There were 502 dual-mobility constructs and 793 large femoral head bearings. There was a larger percentage of women in the dual-mobility construct group (67% [334 of 502]) compared with the large femoral head bearing group (51% [402 of 793]), but this was adjusted for in the statistical analysis. Patient ages were similar for the dual-mobility construct group (67 ± 11 years) and the large femoral head group (65 ± 12 years). American Society of Anesthesiologists (ASA) class and BMI distributions were similar. The mean follow-up was shorter for dual-mobility constructs at 2 ± 1.8 years compared with 4 ± 2.9 years for large femoral head bearings. The cumulative percent revision (CPR) was determined for a diagnosis of prosthesis dislocation as well as for all aseptic causes (excluding infection). Procedures using metal-on-metal bearings were excluded. The time to the re-revision was described using Kaplan-Meier estimates of survivorship, with right censoring for death or database closure at the time of analysis. The unadjusted CPR was estimated each year of the first 5 years for dual-mobility constructs and for each of the first 9 years for large femoral head bearings, with 95% confidence intervals using unadjusted pointwise Greenwood estimates. The apparent shorter follow-up of the dual-mobility construct group relates to the more recent increase in dual-mobility numbers recorded in the registry. The results were adjusted for age, gender, and femoral fixation. Results were subanalyzed for acetabular component sizes < 58 mm and ≥ 58 mm, set a priori on the basis of biomechanical and other registry data. RESULTS: There was no difference in the proportion of re-revision for prosthesis dislocation between dual-mobility constructs and large femoral head bearings (hazard ratio 1.22 [95% CI 0.70 to 2.12]; p = 0.49). At 5 years, the CPR of the re-revision for prosthesis dislocation was 4.0% for dual mobility constructs (95% CI 2.3% to 6.8%) and 4.1% for large femoral head bearings (95% CI 2.7% to 6.1%). There was no difference in the proportion of all aseptic-cause second revisions between dual-mobility constructs and large femoral head bearings (HR 1.02 [95% CI 0.76 to 1.37]; p = 0.89). At 5 years, the CPR of dual-mobility constructs was 17.6% for all aseptic-cause second revision (95% CI 12.6% to 24.3%) and 17.8% for large femoral head bearings (95% CI 14.9% to 21.2%). When stratified by acetabular component sizes less than 58 mm and at least 58 mm, there was no difference in the re-revision CPR for dislocation or for all aseptic causes between dual-mobility constructs and large femoral head bearings. CONCLUSION: Either dual-mobility constructs or large femoral head bearings can be used in revision THA, regardless of acetabular component size, as they did not differ in terms of re-revision rates for dislocation and all aseptic causes in this registry study. Longer term follow-up is required to assess whether complications develop with either implant or whether a difference in revision rates becomes apparent. Ongoing follow-up and comparison in a registry format would seem the best way to compare long-term complications and revision rates. Future studies should also compare surgeon factors and whether they influence decision-making between prosthesis options and second revision rates. Nested randomized controlled trials in national registries would seem a viable option for future research. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Can We Learn From Surgeons Who Perform THA and TKA and Have the Lowest Revision Rates? A Study from the Australian Orthopaedic Association National Joint Replacement Registry.

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.

The Effect of Surgical Approach and Femoral Prosthesis Type on Revision Rates Following Total Hip Arthroplasty: An Analysis of the Most Commonly Utilized Cementless Stems.

BACKGROUND: Compared with other total hip arthroplasty (THA) approaches, the anterior approach has an increased rate of revision for femoral-sided complications, and certain stems may increase this risk. The present study aimed to assess the outcome of THA by surgical approach, according to the femoral stem utilized in the procedure. METHODS: Data from the Australian Orthopaedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis via the anterior or posterior approach with use of 1 of 5 of the most common cementless femoral stems from January 2015 to December 2019. The primary outcome measures were the cumulative percent revision (CPR) for all causes and for femoral stem loosening and fracture. The CPR was compared between THAs performed via the anterior and posterior approaches for all stems and for each individual femoral stem, as well as between individual femoral stems for each approach. RESULTS: The study included 48,716 THAs performed with use of cementless stems, of which 22,840 utilized an anterior approach and 25,876 utilized a posterior approach. There was no difference in the all-cause CPR between the anterior and the posterior approach, but the anterior approach had a higher CPR for loosening (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.48 to 2.69; p < 0.001) and fracture (HR, 1.78; 95% CI, 1.34 to 2.35; p < 0.001). There was apparent variation in the CPR across the different cementless stems when an anterior approach was utilized. The Quadra-H (Medacta) had a higher all-cause CPR when compared with the Polarstem (Smith & Nephew; HR, 1.49; 95% CI, 1.16 to 1.91; p = 0.002) and Corail (DePuy Synthes; HR, 1.31; 95% CI, 1.00 to 1.70; p = 0.0478). Variation was less apparent with the posterior approach. CONCLUSIONS: THAs performed via the anterior approach had higher rates of revision for femoral stem loosening and fracture, with greater variation in outcomes between individual stems. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Subtrochanteric Femur Fractures Treated With Femoral Nail: The Effect of Cerclage Wire Augmentation on Complications, Fracture Union, and Reduction: A Systematic Review and Meta-Analysis of Comparative Studies.

OBJECTIVE: To perform a systematic review and meta-analysis of subtrochanteric femur fractures treated with an intramedullary nail, augmented with or without cerclage wiring, comparing the risk of reoperation, nonunion, loss of fixation, and implant failure; fracture reduction and time to union. DATA SOURCE: A systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed through MEDLINE, EMBASE, PubMed, Web of Science, and Scopus databases using a combination of controlled vocabulary and keywords on September 30, 2020. STUDY SELECTION: All comparative (prospective and retrospective) studies of subtrochanteric fractures managed with intramedullary nail, that compared the addition of cerclage wire to without in patients 16 years of age or older were included. Pathological, atypical bisphosphonate, and segmental fractures were excluded, as were non-English literature. DATA EXTRACTION: Data from each study were independently recorded by 2 investigators. DATA SYNTHESIS: Agreement was obtained on 18 studies (all retrospective) for final inclusion, with 378 patients receiving cerclage wire and 911 without. A random-effects meta-analysis was used to analyze the pooled aggregate data. CONCLUSIONS: There is no statistically significant advantage in using cerclage wire with femoral intramedullary nail when treating subtrochanteric femur fractures regarding risk of reoperation, nonunion, loss of fixation, and implant failure or time to union. An advantage favoring cerclage wire was seen for accuracy of fracture reduction. Cerclage wiring was used more often in cases associated with high-energy trauma. Given the relatively small number of events available to be modelled, a clinical benefit for cerclage wiring may still exist for certain fracture types. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Revision for Aseptic Loosening of Highly Porous Acetabular Components in Primary Total Hip Arthroplasty: An Analysis of 20,993 Total Hip Replacements.

BACKGROUND: Highly porous-coated titanium acetabular components have a high coefficient of friction and ultraporous surfaces to enhance bone ingrowth and osseointegration in total hip arthroplasty (THA). There have been concerns with the development of early radiolucent lines and aseptic loosening of highly porous acetabular components. It is unclear whether these concerns relate to a specific implant or the entire class. The aim of this study is to compare the revision rates for aseptic loosening of highly porous acetabular combinations in primary THA using data from a large joint replacement registry. METHODS: Data were retrieved from the Australian Orthopedic Association National Joint Replacement Registry for the study period September 1999 to December 2019. All primary THA procedures recorded and performed for osteoarthritis using the most common combinations for each highly porous acetabular component with highly cross-linked polyethylene and a 32-mm or 36-mm femoral head were included. The primary outcome measure was revision for aseptic loosening of the acetabular component. Results were adjusted for patient age and gender. RESULTS: There were 20,993 primary THA procedures performed for osteoarthritis using a highly porous acetabular component across 6 combinations. Relative to the POLARSTEM/R3 (StikTite), the Exeter V40/Tritanium had a significantly higher risk of revision for aseptic loosening of the acetabular component (hazard ratio 0.21, 95% confidence interval 0.06-0.74, P = .014). There was no difference between any other highly porous acetabular component combination and no late revisions for aseptic loosening. CONCLUSION: Highly porous-coated titanium acetabular components have low rates of aseptic loosening with long-term follow-up. A difference between components may exist. LEVEL OF EVIDENCE: Level III.

Fracture reduction has a dominant effect over cerclage wiring in increasing stiffness of intertrochanteric OTA/AO 31-A3.1 (reverse oblique) fractures managed with cephalomedullary osteosynthesis.

OBJECTIVES: To investigate the mechanical properties of cephalomedullary nailing of intertrochanteric OTA/AO 31-A3.1 (reverse oblique) fractures and to test the hypothesis that anatomical reduction and augmentation with cerclage wire produces a more stable construct. METHODS: A standardized fracture model in composite saw bone was created to stimulate an intertrochaneric 31-A3.1 fracture, using a 3D printed cutting guide. Simulated osteosynthesis was performed with 12 femurs divided into anatomically reduced and varus malreduced groups. Each femur was tested with and without cerclage wire augmentation. All femurs were fixed with a 215 mm, 130 degree, 11.5 mm nail. An Instron 8874 biaxial materials testing machine was used to assess the axial stiffness. Cyclic loading consisted of 5000 cycles of sinusoidal combined axial-torsion loading at 3 Hz. Axial load was 100 N to 2000 N and torsion -4.5 Nm to +4.5 Nm. Stiffness was measured before and after cyclic loading. RESULTS: Reduced constructs were stiffer than residual varus constructs. The mean overall fracture stiffness was 508.7 N/mm for reduced constructs and 379.2 N/mm for varus constructs. Removing the cables significantly decreased the fracture stiffness for both constructs (mean difference 60.0 N/mm, 95% CI 7.7-112.3, P = .032). CONCLUSIONS: Anatomical reduction has a dominant effect on facture stiffness. Anatomically reduced fractures are stiffer than varus malreduced fractures. A cerclage wire further improves construct stiffness if anatomical reduction is achieved. Cerclage wiring is less effective if anatomical reduction is not achieved.

A Comparison of Revision Rates for Dislocation and Aseptic Causes Between Dual Mobility and Large Femoral Head Bearings in Primary Total Hip Arthroplasty With Subanalysis by Acetabular Component Size: An Analysis of 106,163 Primary Total Hip Arthroplasties.

BACKGROUND: Dual mobility (DM) and large femoral head bearings (≥36 mm) both decrease the risk of dislocation in total hip arthroplasty (THA). There is limited comparable data in primary THA. This study compared the revision rates for dislocation and aseptic causes between DM and large femoral heads and subanalyzed by acetabular component size. METHODS: Data from the Australian Orthopedic Association National Joint Replacement Registry were analyzed for patients undergoing primary THA for osteoarthritis from January 2008 (the year of first recorded DM use) to December 2019. All DM and large femoral head bearings were identified. The primary outcome measure was the cumulative percent revision (CPR) for dislocation and for all aseptic causes. The results were adjusted by age, sex, and femoral fixation. A subanalysis was performed stratifying acetabular component diameter <58 m and ≥58 mm. RESULTS: There were 4942 DM and 101,221 large femoral head bearings recorded. There was no difference in the CPR for dislocation (HR = 0.69 (95% CI 0.42, 1.13), P = .138) or aseptic causes (HR = 0.91 (95% CI 0.70, 1.18), P = .457). When stratified by acetabular component size, DM reduced the CPR for dislocation in acetabular component diameter <58 mm (HR = 0.55 (95% CI 0.30, 1.00), P = .049). There was no difference for diameter ≥58 mm. There was no difference in aseptic revision when stratified by acetabular component diameter. CONCLUSION: There is no difference in revision rates for dislocation or aseptic causes between DM and large femoral heads in primary THA. When stratified by acetabular component size, DM reduces dislocation for acetabular component diameter <58 mm. LEVEL OF EVIDENCE: Level III.

Hip Hemiarthroplasty for Fractured Neck of Femur Revised to Total Hip Arthroplasty: Outcomes Are Influenced by Patient Age Not Articulation Options.

BACKGROUND: Hip hemiarthroplasty is the most common arthroplasty option for fractured neck of femur (FNOF). Revision to total hip arthroplasty (THA) is occasionally required. This study aimed to assess the outcome of hemiarthroplasty revised to THA and to assess the impact of femoral head size, dual mobility (DM), and constrained liners. METHODS: All aseptic 1st revisions reported to the Australian Joint Replacement Registry after hemiarthroplasty performed for FNOF when a THA was used as the revision procedure were included from September 1999 to December 2019. The primary outcome measure was the cumulative percent revision for all-causes and dislocation. The impact of prosthesis factors on revision THA was assessed: standard head THA (≤32 mm), large head THA (≥36 mm), DM, and constrained liners. Outcomes were compared using Kaplan Meyer and competing risk. RESULTS: There were 96,861 hemiarthroplasties performed, with 985 revised to THA. The most common reasons for 1st revision were loosening (49.3%), fracture (17.7%), and dislocation (11.0%). Of the hemiarthroplasty procedures revised to THA, 76 had a 2nd revision. The most common reasons for 2nd revision were fracture (27.6%), dislocation (26.3%), loosening (23.7%), and infection (18.4%). Femoral head size, DM, or constrained liner use did not alter the incidence of all-cause 2nd revision. This did not change when solely looking at patients still alive. A 2nd revision was more likely in patients aged <75 years. CONCLUSION: The outcome of hemiarthroplasty performed for FNOF revised to THA is influenced by patient age, not by the articulation used.

Incidence, Risk Factors, and Outcome of Ceramic-On-Ceramic Bearing Breakage in Total Hip Arthroplasty.

BACKGROUND: Ceramic-on-ceramic bearing breakage is a rare but significant complication of total hip arthroplasty. This study aimed to identify risk factors for breakage and to determine the outcome of different revision options. METHODS: All ceramic-on-ceramic primary total hip arthroplasty procedures reported to the Australian Joint Replacement Registry from September 1999 to December 2019 were included. Procedures were subdivided into alumina or mixed ceramic (alumina/zirconia). All breakages were identified. The association between ceramic type and head size was assessed. Subsequent revision rates were compared and cause of revision assessed. RESULTS: There were 23,534 alumina and 71,144 mixed ceramic procedures. Breakage was the reason for 1st revision in 84 alumina (5.27% of all revisions and 0.36% of procedures) and 56 mixed ceramic procedures (2.46% of all revisions; 0.08% of procedures). Alumina had a higher breakage rate than mixed ceramic (HR 2.50 (95% CI 1.75, 3.59), P < .001), and breakage was higher for 36-38mm head sizes using alumina (HR 2.84 (1.52, 5.31), P = .001). 17.8% of 2nd revisions occur by 3 years, due to dislocation, infection, metal-related pathology, and loosening. A neck adapter sleeve did not reduce 2nd revisions. Numbers were too low to compare revision bearing surface options. CONCLUSION: Ceramic breakage has reduced with mixed ceramics but has a 0.79/1000 incidence at 15-year follow-up. It is unclear what the risk factors are for modern ceramics with increasing head size a risk for alumina only. Risk of 2nd revision is high and occurs early. The optimal revision option is unknown.

THA for a Fractured Femoral Neck: Comparing the Revision and Dislocation Rates of Standard-head, Large-head, Dual-mobility, and Constrained Liners.

BACKGROUND: THA is a reasonable surgical option for some patients with fragility fractures of the femoral neck, but it has the risk of prosthesis dislocation. The prosthesis combination that reduces the risk of dislocation and the rate of revision surgery is not known. QUESTIONS/PURPOSES: In patients receiving primary THA for a femoral neck fracture, does (1) the rate of all-cause revision or (2) the reason for revision and rate of revision for dislocation differ among THA with a standard head size, large head size, dual mobility (DM), or constrained liner? (3) Is there a difference in the revision risk when patients are stratified by age at the time of surgery? METHODS: Data were analyzed for 16,692 THAs performed to treat fractures of the femoral neck reported in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from January 2008 to December 2018, as this included the first use of DM prostheses. The AOANJRR includes information on more than 98% of arthroplasty procedures performed in Australia. Most patients were female (72%) and the mean age was 74 years ± 11. There were 8582 standard-head prostheses, 5820 large-head prostheses, 1778 DM prostheses, and 512 constrained prostheses identified. The cumulative percent revision (CPR) was determined for all causes as well as CPR for dislocation. The time to the first revision was described using Kaplan-Meier estimates of survivorship, with right censoring for death or closure of the database at the time of analysis. The unadjusted CPR was estimated each year of the first 10 years for standard heads, 10 years for large heads, 8 years for constrained liners, and 7 years for DM prostheses, with 95% confidence intervals using unadjusted pointwise Greenwood estimates. The results were adjusted for age, sex, femoral fixation, and head size where appropriate and were considered by age groups < 70 and ≥ 70 years. RESULTS: When adjusted for age, sex, femoral fixation and head size, there was no difference in the rate of all-cause revision at 7 years for any of the four groups. There was no difference in the rate of all-cause revision when patients were stratified by < 70 or ≥ 70 years of age. Dislocation was the most common reason for revision (32%). When analyzing revision for dislocation alone, large-head THA had a lower rate of revision for dislocation compared with standard head (HR 0.6 [95% CI 0.4 to 0.8]; p < 0.001) and DM prostheses had a lower rate of revision for dislocation than standard head for the first 3 months (HR 0.3 [95% CI 0.1 to 0.7]; p < 0.004) but not after this time point. CONCLUSION: The Australian registry shows that there is no difference in the rate of all-cause revision for standard-head, large-head, DM prostheses or constrained liner THA after femoral neck fractures for all patients or for patients stratified into younger than 70 years and at least 70 years of age groups. Dislocation is the most common cause of revision. Large-head prostheses are associated with a lower revision risk for dislocation and DM prostheses have a lower rate of revision for dislocation than standard heads for the first 3 months only. Surgeons treating a femoral neck fracture with THA might consider a large head size if the diameter of the acetabulum will allow it and a DM prosthesis if a large head size is not possible. The age, life expectancy and level of function of patients with femoral neck fractures minimizes the potential long-term consequences of these prostheses. The lack of significant differences in survival between most prosthesis combinations means surgeons should continue to look for factors beyond head size and prosthesis to minimize dislocation and revision surgery. LEVEL OF EVIDENCE: Level III, therapeutic study.

Standard, Large-Head, Dual-Mobility, or Constrained-Liner Revision Total Hip Arthroplasty for a Diagnosis of Dislocation: An Analysis of 1,275 Revision Total Hip Replacements.

BACKGROUND: Dislocation remains a leading cause of revision following primary and revision total hip arthroplasty (THA). The aim of the present study was to compare the rate of second revision THA following a major first revision for the treatment of dislocation using an implant with a standard, large head, dual-mobility, or constrained acetabular liner. METHODS: Data were obtained from the Australian Orthopaedic Association National Joint Replacement Registry from September 1999 through December 2018. All primary THAs that had been performed for the treatment of osteoarthritis and subsequently revised for dislocation were included. All revision THA prostheses with a standard head (≤32 mm), large head (≥36 mm), dual-mobility, or constrained acetabular liner that were used for the first revision procedure were identified. The primary outcome measures were the cumulative rates of second revisions for all causes and for a subsequent diagnosis of dislocation for the 4 different constructs used in the first revision. RESULTS: A total of 1,275 hips underwent a major first revision because of prosthesis dislocation, with 203 of these hips going on to have a second revision. The rate of all-cause second revision was significantly higher in the standard-head group compared with the constrained-acetabular-liner group (hazard ratio [HR], 1.53 [95% confidence interval (CI), 1.01 to 2.30]; p = 0.044). There was no difference in the rates of revision between other articulations. The most common cause of second revision for all implants was dislocation. There were a total of 91 second revisions for a diagnosis of dislocation. Standard heads had a higher rate of second revision compared with constrained acetabular liners (HR, 2.44 [95% CI, 1.30 to 4.60]; p = 0.005), dual-mobility implants (HR, 2.04 [95% CI, 1.03 to 4.01]; p = 0.039), and large heads (HR, 1.80 [95% CI, 1.09, 2.99]; p = 0.022). There was no difference in the rates of second revision between other articulations. CONCLUSIONS: Surgeons have a number of options for prostheses when performing a first revision for the treatment of dislocation following a primary THA. The most common cause of a second revision is recurrent dislocation. The use of constrained acetabular liners, dual-mobility liners, and large heads (≥36 mm) are options for reducing subsequent dislocation. Standard head sizes have a higher rate of second revision for further dislocation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Early Rate of Revision of Total Hip Arthroplasty Related to Surgical Approach: An Analysis of 122,345 Primary Total Hip Arthroplasties.

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.

High incidence of radiolucent lines at the implant-cement interface of a new total knee replacement.

BACKGROUND: Recently introduced total knee arthroplasty (TKA) implants have been linked with the early development of periprosthetic radiolucency (PPRL). The aim of this study was to carry out a retrospective clinical and radiographical analysis of a consecutive series of a new TKA, and to assess the incidence and distribution of PPRL. METHODS: A retrospective review of all new TKA implants performed by a single surgeon at a single hospital between March 2013 and October 2017 was performed. The minimum follow-up period was 3 months, with ongoing patient review at 6, 12 and 36 months. Sequential post-operative radiographs were performed to determine the presence of PPRL. RESULTS: A total of 122 TKAs were identified in 112 patients over the 4.5-year study period. The average follow-up time was 21 months (range 3-51 months). PPRL was noted in 29 TKAs (23.8%). When comparing the PPRL group to those without PPRL, there was a difference in body mass index, with body mass index associated with an increased likelihood of PPRL (P = 0.003). There was no difference in constraint of implant (P = 0.818), cement type (P = 0.340), patella resurfacing (P = 0.286), age (P = 0.984) gender (P = 0.376) or initial mechanical axis deviation (P = 0.054) between groups. PPRL were most commonly seen in tibial anterior-posterior (AP) zone 1 and zone 2 (96.6%), followed by femoral lateral zone 5 (58.6%), tibia lateral zone 1 (55.2%) and tibial lateral zone 2 (53.2%). No patients have required revision surgery. CONCLUSION: A high incidence of early PPRL is seen in patients undergoing primary TKA using a new implant system, mainly involving the tibial component. Ongoing clinical and radiological assessment for patients seems warranted based on these findings.

The Effect of Size for a Hydroxyapatite-Coated Cementless Implant on Component Revision in Total Hip Arthroplasty: An Analysis of 41,265 Stems.

BACKGROUND: The cementless Corail is one of the most commonly used stems in total hip arthroplasty (THA). The aim of this study was to investigate whether there was a difference in revision rate for smaller stems. METHODS: All primary THA procedures recorded by the Australian Joint Replacement Registry from September 1999 to December 2017 performed for osteoarthritis using the Corail stem, a cementless acetabular cup, modern bearing surfaces (ceramic/ceramic, ceramic/cross-linked polyethylene, and metal/cross-linked polyethylene), and 28 mm, 32 mm, and 36 mm head sizes were included. The primary outcome measure was femoral component revision. Data were analyzed and adjusted for age, gender, and head size. Further analysis investigated the effects of surgical approach. RESULTS: There was 41,265 primary THAs recorded. The cumulative percent revision (CPR) at 13 years was 7.7% (5.5, 10.7) for stem sizes 8 and 9 and 3.0% (2.4, 3.8) for sizes 10-20 (P < .001). When adjusted for age and gender, the sizes 8 and 9 collared (hazard ratio [HR]: 6.22 [3.84-10.06], P < .001) and collarless (HR: 3.28 [2.41-4.45], P < .001) had a higher CPR than the collared and collarless size 10-20. The size 8 and 9 stems performed with an anterior approach had the highest CPR (HR: 14.44 [6.21-33.56], P < .001). The main reason for revision of size 8 and 9 femoral stems was loosening (65.2%, compared to 31.5% for 10-20 femoral stems). CONCLUSIONS: Smaller Corail stems have 4 times the rate of revision compared with the larger femoral sizes with loosening being the most common diagnosis. This is most evident when using an anterior approach.