Is American Joint Replacement Registry Data Consistent With International Survivorship in Hip and Knee Arthroplasty? A Comparative Analysis.

BACKGROUND: In collaboration with the Orthopedic Data Evaluation Panel (ODEP), the American Joint Replacement Registry (AJRR) investigated the consistency of hip and knee arthroplasty survivorship results compared to the UK National Joint Registry (NJR). METHODS: A total of three primary knee devices and three primary hip devices were selected by AJRR and ODEP with known variation in performance. Implant manufacturers independently produced Kaplan Meier survivorship based on NJR data and submitted to ODEP for comparison. The AJRR mirrored the methodology, and results from both sources were stratified into three cohorts (all-age, < 65, and ≥ 65 years). RESULTS: There were 42,671 AJRR and 60,439 NJR primary knee cases and 70,169 AJRR and 422,657 NJR primary total hip arthroplasty cases. For TKA, performance between the AJRR and NJR were consistent, showing similar trends for comparatively high and low performing devices. Both PS and CR devices showed statistical agreement in survivorship for all 3 cohorts. Unicompartmental comparison also showed statistical agreement for the Medicare cohort. The all-age and < 65-year-old cohorts showed similar trends and reached statistical agreement through 7 and 6 years. For total hip arthroplasty, performance between the AJRR and NJR were consistent, showing similar trends for comparatively high and low performing devices; 0.18% average difference in survivorship at final follow-up (8 years). One femoral device did not reach statistical agreement but showed only 0.61% difference in survivorship. The remaining acetabular and femoral devices reached statistical agreement in all-ages and through 7 and 8 years in the ≥ 65-year-old cohort. CONCLUSIONS: AJRR and NJR performance trends and survivorship were similar across hip and knee arthroplasty with greatest consistency in the all-age and ≥ 65 cohorts. This focused comparison of survivorship showed encouraging results for reliability of patient outcomes in AJRR compared to the world's largest joint arthroplasty registry which has strong implications for global improvement in patient safety.

Antibiotic Laden Bone Cement Does Not Reduce Acute Periprosthetic Joint Infection Risk in Primary Total Knee Arthroplasty.

BACKGROUND: Periprosthetic joint infection (PJI) can be a serious complication of total knee arthroplasty (TKA). A method believed to decrease the incidence of PJI is antibiotic-laden bone cement (ALBC). Current clinical practice guidelines do not recommend ALBC in primary TKA. The purpose of this study was to compare ALBC to plain cement (PC) in preventing PJI in primary TKA. METHODS: This retrospective analysis included 109,242 Medicare patients in the American Joint Replacement Registry who underwent a cemented primary TKA from January 2017 to March 2021, and had at least 1 year of follow-up. Patients who received ALBC were compared to patients who received PC. Demographic and case-specific variables such as age, sex, race, body mass index, Charlson Comorbidity Index, anesthesia type, and operative time were used to create propensity scores. A logistic regression was run to predict the probability of receiving ALBC. Also, a multivariate model was run on the full unstratified population, using the same covariates as were used to create the propensity model. The primary outcome was differences in PJI rates. RESULTS: Logistic regression analysis showed that a higher preoperative diagnosis of osteoarthritis, higher Charlson Comorbidity Index, higher body mass index, women, race, and anesthesia requirements increased a patient's probability of receiving ALBC. In the full unstratified multivariate model, ALBC did not show a statistically significant difference in risk of revision for infection compared to PC. CONCLUSIONS: The use of ALBC in primary TKA has not been shown to be more efficacious in preventing PJI within the population of Medicare patients in the United States. However, this study is limited given it is a retrospective database study that may inherently have biases and the large dataset has a potential for overpowering the findings.

Is the American Joint Replacement Registry Able to Correctly Classify Revision Total Knee Arthroplasty Procedural Diagnoses?

BACKGROUND: The American Joint Replacement Registry (AJRR) is a powerful tool for the study of revision total knee arthroplasty (rTKA). The AJRR uses International Classification of Diseases-10 (ICD-10-CM) codes for recording surgical diagnoses. However, the validity of this methodology is unknown. The purpose of this study was to determine the accuracy of ICD-10-CM codes, as used by AJRR, in classifying rTKA diagnoses. METHODS: There were 988 rTKAs performed from 2015 to 2021 identified in our institutional total joint registry (TJR). Revision diagnoses were obtained from TJR, in which trained abstractors prospectively record diagnoses independent of ICD-10-CM data. The ICD-10-CM diagnosis codes submitted to AJRR were retrieved for the same procedures. The accuracy of ICD-10-CM codes for classifying rTKA diagnoses as septic versus aseptic, aseptic loosening, instability, and periprosthetic fracture was assessed using Cohen's Kappa statistics, sensitivities, and specificities. RESULTS: Concordance between AJRR-submitted codes and TJR was excellent (97.3%, k = 0.9) for identifying septic versus aseptic revisions. Agreement for aseptic diagnoses varied from very good for loosening (k = 0.65) and instability (k = 0.64) to fair for periprosthetic fracture (k = 0.36). Specificity was high (> 94%) for all three diagnoses, but sensitivity was lower at 71%, 63%, and 28% for loosening, instability, and periprosthetic fracture, respectively. CONCLUSION: The AJRR submitted ICD-10-CM diagnosis codes correctly classified rTKA cases as septic or aseptic with remarkable accuracy, but accuracy for more granular diagnoses varied. These data demonstrate the potential for diagnosis-specific limitations when using administrative claims data for registry reporting and have important implications for researchers using ICD-10-CM data.

Spinal Versus General Anesthesia in Total Knee Arthroplasty: Are There Differences in Complication and Readmission Rates?

BACKGROUND: Spinal anesthesia (SP) utilization continues to expand in total knee arthroplasty (TKA). However, little is known regarding differences in complication rates between spinal and general anesthesia used for primary TKA. Therefore, the purpose of this study is to compare the length of stay (LOS), operative time, and readmission and revision rates between patients who received spinal and general anesthesia during TKA. METHODS: The American Joint Replacement Registry (AJRR) was used to identify primary elective TKA patients from 2017 to 2020. Patients were divided into 2 cohorts, general (GN) and SP, based on the mode of anesthesia administered during the index surgery. In total, 270,251 TKAs were identified, of which 126,970 (47.0%) received general anesthesia and 143,281 (53.0%) received spinal anesthesia. Length of stay, operative time, 90-day readmission, and 90-day revisions were compared between the 2 groups. Multivariable logistic regression analyses were used to adjust for potential confounders. RESULTS: After accounting for confounding factors, SP was associated with a lower risk of having a LOS greater than 3 days (odds ratio [OR] 0.470, 95% confidence interval [CI] 0.454-0.487, P < .0001), but a slightly higher likelihood of having a longer operative time (OR 1.075, 95% CI 1.056-1.094, P < .0001). SP was also linked to lower rates of 90-day readmission (OR 0.845, 95% CI 0.790-0.904, P < .0001) and lower risk of 90-day all-cause revision (OR 0.506, 95% CI 0.462-0.555, P < .0001). CONCLUSION: SP was associated with a lower 90-day readmission rate and a lower risk of 90-day revision. These findings support the best practice guidelines of The Joint Commission to use spinal anesthesia when possible as part of an enhanced recovery after surgery (ERAS) pathway.

Can the American Joint Replacement Registry Utilize Administrative Claims Data to Accurately Classify Revision Total Hip Arthroplasty (THA) Surgical Diagnoses?

BACKGROUND: The American Joint Replacement Registry (AJRR) is a valuable tool for studying revision total hip arthroplasty (rTHA). Currently, International Classification of Diseases-10 (ICD-10) codes are utilized by the AJRR for classifying surgical diagnoses. However, the validity of this methodology is unknown. The purpose of this study was to determine the accuracy of these codes, as used by AJRR, in classifying rTHA diagnoses. METHODS: We identified 908 rTHAs performed at our institution from 2015 to 2021 using our total joint registry (TJR). Revision diagnoses were obtained from the TJR, which contains prospectively recorded surgical diagnoses collected by trained abstractors, independent from ICD-10 data. The ICD-10 diagnosis codes, as submitted to AJRR, were retrieved for the same procedures. The accuracy of ICD-10 codes for classifying rTHA diagnoses as septic versus aseptic, instability, aseptic loosening, and periprosthetic fracture was assessed using Cohen's Kappa statistic, sensitivity, and specificity. RESULTS: Concordance between AJRR-submitted data and TJR for classifying rTHA as septic or aseptic was excellent (96.9%; k = 0.87). Agreement for aseptic diagnoses varied from very good for instability (k = 0.76) and loosening (k = 0.67) to moderate for periprosthetic fracture (k = 0.54). Specificity was high (>96%) for all 3 aseptic diagnoses, but sensitivity was lower at 74%, 68%, and 44% for instability, loosening, and periprosthetic fracture, respectively. CONCLUSION: The AJRR submitted ICD-10 data correctly classifies the infection status of rTHA procedures with outstanding accuracy, but the accuracy for more granular diagnoses was variable. These data demonstrate the potential for diagnosis specific limitations when utilizing ICD-10 administrative claims for registry reporting.

Trends in Polyethylene Design and Manufacturing Characteristics for Total Knee Arthroplasty: An Analysis From the American Joint Replacement Registry.

BACKGROUND: Advances in polyethylene bearing characteristics have led to various options for total knee arthroplasty. We examine trends in use of polyethylene in the United States. METHODS: An analysis of American Joint Replacement Registry data from 2012 to 2019 for primary total knee arthroplasty procedures was conducted. Design and manufacturing characteristics were obtained and validated in the American Joint Replacement Registry dataset. Polyethylene bearing design and manufacturing use characteristics were compared by year, gender, age group, and geographic region of the procedure. Descriptive analysis was performed. RESULTS: We identified 993,292 cases over the study period. In total, 791,233 (80%) cases had complete device data available and were included in analysis. In addition, 366,280 (49.4%) cases utilized minimally stabilized bearings compared to 374,809 (50.6%) for posterior-stabilized bearings. Posterior-stabilized use was stable over the study period and highest in the Northeast (64.5%; P < .0001). Cruciate-retaining use decreased from 29.7% to 20.2% and anterior-stabilized use increased from 17.4% to 25.2%. Conventional polyethylene use decreased from 42.8% to 21.9%, and was highest in the 81+ age group (37.8%; P < .0001) and Northeast (43.0%; P < .0001). Highly cross-linked polyethylene (HXLPE) with antioxidant use increased from 9.08% to 31.8%, while HXLPE without antioxidant use remained constant. CONCLUSION: There was an increase in use of anterior-stabilized and pivot bearings and an increase in use of HXLPE with antioxidant. Additionally, there were noted age group and regional differences in the use of various bearings. Further study should evaluate if these changing utilization trends are related to clinical outcomes, or due to regional training, preferences, or manufacturer pressures. LEVEL OF EVIDENCE: Level III, retrospective.

Early Results From the American Joint Replacement Registry: A Comparison With Other National Registries.

BACKGROUND: The American Joint Replacement Registry (AJRR) was created to capture knee and hip arthroplasty data in the United States. The purpose of this study was to compare early reports from the AJRR to other national registries to identify topics for future analysis. METHODS: Hip and knee arthroplasty data were extracted from the AJRR, Australia, New Zealand, United Kingdom, Norway, and Sweden from 2014 to 2016. Hip arthroplasty data including femoral and acetabular fixation, bearing surface, head size, dual-mobility bearings, resurfacing, and revision burden were compared. Knee arthroplasty data including polyethylene type, unicondylar arthroplasty, mobile bearings, cruciate-retaining implants, patella resurfacing, and revision burden were compared. Registry characteristics and patient demographics were reported using descriptive statistics. RESULTS: In 2016, the AJRR captured 28% of arthroplasty procedures performed in the United States compared with 95%-98.3% among other registries. Cementless femoral fixation was 96.7% in the AJRR compared with 21.8%-63.4%. Ceramic and 36-mm heads were most common in AJRR; all other registries reported that metal and 32-mm heads were most popular. Dual-mobility articulations were used in 8% of primary and 28% of revision total hip arthroplasty procedures in the AJRR. The AJRR reported a unicondylar knee arthroplasty rate of 3.2% compared with 5.1%-13.3% in other registries, but the highest rates of posterior-stabilized total knee arthroplasties (48.5% compared to 8.2%-28.7%) and patella resurfacing (93.9% compared to 2.4%-51.6%). CONCLUSION: Several differences in hip and knee arthroplasty practices exist between the United States and other countries. Future studies should focus on understanding why differences in practice trends exist and assess outcomes associated with these practices. LEVEL OF EVIDENCE: Level III, retrospective.

Rates of Registry Research Have Increased in Podium and Poster Presentations at the American Association of Hip and Knee Surgeons.

Background: As state, regional, and national registries have rapidly expanded, the goal of this study is to assess the frequency of registry abstracts accepted for both podium and poster presentations at the American Association of Hip and Knee Surgeons between 2012 and 2022. Methods: Final programs and poster e-collections were examined over the past 11 years. Two reviewers evaluated each abstract to determine if they utilized large datasets and the location of each registry. Studies were excluded if they used institutional registries. Reviewers also identified the most frequently utilized registries to determine how their use has fluctuated over this time frame. Results: A total of 3354 abstracts were reviewed and included. Of those, 577 abstracts utilized data obtained from orthopaedic registries (17.2%): 450 of which were poster presentations (16.5% of total poster acceptances), and 127 were podium presentations (20.5% of accepted podiums). The National Surgical Quality Improvement Program (NSQIP) was the most frequent dataset utilized, with 118 (20.5%) abstracts. Of note, NSQIP's use peaked between 2018 and 2020 and has since slowly trended downward. On the other hand, use of both American Joint Replacement Registry (AJRR) and PearlDiver registry have drastically increased since 2019, with only 6 abstracts chosen in 2019 and 28 abstracts in 2022 (10 AJRR [3 podiums] and 18 PearlDiver [6 podiums]). The proportion of registry data has increased, with the registry abstracts peaking in 2022 as 24% of posters and 37% of podium utilized data from large registry data sets (P < .001). Conclusions: There has been a significant increase in the number of studies utilizing registry data for both podium and poster presentations at the American Association of Hip and Knee Surgeons annual meeting. While NSQIP was the most utilized, its use has steadily declined while AJRR and PearlDiver use have increased over the past 3 years. Individuals should understand the strengths and weaknesses of each registry before making conclusions on study results. Level of Evidence: Level IV.

Trends in the use of dual mobility bearings in hip arthroplasty.

AIMS: Dual mobility (DM) bearings are an attractive treatment option to obtain hip stability during challenging primary and revision total hip arthroplasty (THA) cases. The purpose of this study was to analyze data submitted to the American Joint Replacement Registry (AJRR) to characterize utilization trends of DM bearings in the USA. METHODS: All primary and revision THA procedures reported to AJRR from 2012 to 2018 were analyzed. Patients of all ages were included and subdivided into DM and traditional bearing surface cohorts. Patient demographics, geographical region, hospital size, and teaching affiliation were assessed. Associations were determined by chi-squared analysis and logistic regression was performed to assess outcome variables. RESULTS: A total of 406,900 primary and 34,745 revision THAs were identified, of which 35,455 (8.7%) and 8,031 (23.1%) received DM implants respectively. For primary THA, DM usage increased from 6.7% in 2012 to 12.0% in 2018. Among revision THA, DM use increased from 19.5% in 2012 to 30.6% in 2018. Patients < 50 years of age had the highest rates of DM implantation in every year examined. For each year of increase in age, there was a 0.4% decrease in the rate of DM utilization (odds ratio (OR) 0.996 (95% confidence interval (CI) 0.995 to 0.997); p < 0.001). Females were more likely to receive a DM implant compared to males (OR 1.077 (95% CI 1.054 to 1.100); p < 0.001). Major teaching institutions and smaller hospitals were associated with higher rates of utilization. DM articulations were used more commonly for dysplasia compared with osteoarthritis (OR 2.448 (95% CI 2.032 to 2.949); p < 0.001) during primary THA and for instability (OR 3.130 (95% CI 2.751 to 3.562) vs poly-wear; p < 0.001) in the revision setting. CONCLUSION: DM articulations showed a marked increase in utilization during the period examined. Younger patient age, female sex, and hospital characteristics such as teaching status, smaller size, and geographical location were associated with increased utilization. DM articulations were used more frequently for primary THA in patients with dysplasia and for revision THA in patients being treated for instability. Cite this article: Bone Joint J 2020;102-B(7 Supple B):27-32.