Can Dual Mobility Cups Reduce Revision and Dislocation Risks? An Analysis of 107,528 Primary Total Hip Arthroplasties in the United States.

BACKGROUND: Dual mobility acetabular cups (DMC) were designed to increase the effective femoral head size and improve stability with the goal of reducing revision risk at the potential cost of polyethylene thickness. We sought to evaluate revision risk following primary elective total hip arthroplasty with DMC compared to highly cross-linked polyethylene (XLPE). METHODS: A cohort study was conducted using data from a Kaiser Permanente's total joint arthroplasty registry. Patients ≥18 years who underwent primary elective total hip arthroplasty using DMC, unipolar Metal-on-XLPE (MoXLPE), or unipolar Ceramic-on-XLPE (CoXLPE) were identified (2010 to 2021). The final sample comprised 2,219 DMC, 48,251 MoXLPE, and 57,058 CoXLPE. Multiple Cox proportional hazard regressions were used to evaluate aseptic revision and any dislocation regardless of revision within 6 years follow-up. RESULTS: In adjusted analyses, no differences in aseptic revision risk were observed for MoXLPE (hazard ratio [HR] = 1.04, 95% confidence interval [CI] = 0.72 to 1.51) or CoXLPE (HR = 0.98, 95% CI = 0.69 to 1.40) compared to DMC. No differences in dislocation risk were observed for MoXLPE (HR = 1.42, 95% CI = 0.93 to 2.15) or CoXLPE (HR = 1.25, 95% CI = 0.84 to 1.87) compared to DMC. CONCLUSIONS: In a US-based cohort, 6-year aseptic revision risk of DMC was similar to metal or ceramic femoral head unipolar constructs. Furthermore, no difference in dislocation risk was observed. Continued longer-term follow-up may reveal if there is a reduced risk of dislocation that comes at the cost of increased late revision. LEVEL OF EVIDENCE: Level III.

Risk for surgical interventions following endovascular aneurysm repair with Endologix AFX or AFX2 Endovascular AAA Systems compared with other devices.

OBJECTIVE: To evaluate the risk for 90-day returns to care and long-term subsequent surgical interventions after primary endovascular aneurysm repair (EVAR) with an Endologix AFX Endovascular AAA System compared with three other high-volume endograft devices. METHODS: We conducted a matched cohort study using data from Kaiser Permanente's Endovascular Stent Graft Registry. Patients aged ≥18 years who underwent primary EVAR for AAA in the health care system from January 1, 2011, to December 31, 2017, comprised the eligible study sample. The treatment group included patients who received an Endologix AFX or AFX2 device (n = 470). Patients who received one of three other high-volume endograft devices used within the health care system comprised the eligible comparison group (n = 2122). These patients were 2:1 propensity score matched without replacement to patients who received an Endologix device based on a number of patient and procedural characteristics. After the application of matching, conditional logistic regression was used to evaluate the likelihood for 90-day emergency department visit and readmission. Cause-specific Cox regression was used to evaluate the long-term risk of endoleak, graft revision, secondary reintervention (not including revision), conversion to open repair, and rupture during follow-up. Cox proportional hazards regression was used to evaluate the risk of mortality (overall and aneurysm related). RESULTS: The final matched study sample included 470 patients who received an Endologix AFX or AFX2 device and 940 patients who received a different high-volume device. compared with the other devices, AFX/AFX2 had a higher risk for type III endoleak (hazard ratio [HR], 38.79; 95% confidence interval [CI], 14.51-103.67), revision surgery >1 year after the primary EVAR (HR, 4.50; 95% CI, 3.10-6.54), rupture (HR, 6.52; 95% CI, 1.73-24.63), and aneurysm-related mortality (HR, 2.43; 95% CI, 1.32-4.47) was observed with the use of AFX/AFX2. CONCLUSIONS: In our matched cohort study, patients who received an Endologix AFX System during their primary EVAR had a higher risk for several adverse longitudinal outcomes, as well as aneurysm-related mortality, when compared with patients who received other high-volume devices. Patients who have received these devices should be monitored closely after EVAR.

Association between same-day discharge shoulder arthroplasty and risk of adverse events in patients with American Society of Anesthesiologists classification ≥3: a cohort study.

BACKGROUND: Same-day discharge for shoulder arthroplasty (SA) is well-supported in the literature; however, most studies have focused on healthier patients. Indications for same-day discharge SA have expanded to include patients with more comorbidities, but safety of same-day discharge in this population remains unknown. We sought to compare outcomes following same-day discharge vs. inpatient SA in a cohort of patients considered higher risk for adverse events, defined as an American Society of Anesthesiologists (ASA) classification of ≥3. METHODS: Data from Kaiser Permanente's SA registry were utilized to conduct a retrospective cohort study. All patients with an ASA classification of ≥3 who underwent primary elective anatomic or reverse SA in a hospital from 2018 to 2020 were included. The exposure of interest was in-hospital length of stay: same-day discharge vs. ≥1-night hospital inpatient stay. The likelihood of 90-day post-discharge events, including emergency department (ED) visit, readmission, cardiac complication, venous thromboembolism, and mortality, was evaluated using propensity score-weighted logistic regression with noninferiority testing using a margin of 1.10. RESULTS: The cohort included a total of 1814 SA patients, of whom 1005 (55.4%) had same-day discharge. In propensity score-weighted models, same-day discharge was not inferior to an inpatient stay SA regarding 90-day readmission (odds ratio [OR] = 0.64, one-sided 95% upper bound [UB] = 0.89) and overall complications (OR = 0.67, 95% UB = 1.00). We lacked evidence in support of noninferiority for 90-day ED visit (OR = 0.96, 95% UB = 1.18), cardiac event (OR = 0.68, 95% UB = 1.11), or venous thromboembolism (OR = 0.91, 95% UB = 2.15). Infections, revisions for instability, and mortality were too rare to evaluate using regression analysis. CONCLUSIONS: In a cohort of over 1800 patients with an ASA of ≥3, we found same-day discharge SA did not increase the likelihood of ED visits, readmissions, or complications compared with an inpatient stay, and same-day discharge was not inferior to an inpatient stay with regard to readmissions and overall complications. These findings suggest that it is possible to expand indications for same-day discharge SA in the hospital setting.

Utilization of Total Joint Arthroplasty by Rural-Urban Designation in Patients With Osteoarthritis in a Universal Coverage System.

BACKGROUND: Utilization of total joint arthroplasty (TJA) is affected by differences linked to sex, race, and socioeconomic status; there is little information about how geographic variation contributes to these differences. We sought to determine whether discrepancies in TJA utilization exist in patients diagnosed with osteoarthritis (OA) based upon urban-rural designation in a universal coverage system. METHODS: We conducted a cohort study using data from a US-integrated healthcare system (2015 to 2019). Patients aged ≥50 years who had a diagnosis of hip or knee OA were included. Total hip arthroplasty and total knee arthroplasty utilization (in respective OA cohorts) was evaluated by urban-rural designation (urban, mid, and rural). Incidence rate ratios (IRRs) for urban-rural regions were modeled using multivariable Poisson regressions. RESULTS: The study cohort included 93,642 patients who have hip OA and 275,967 patients who had knee OA. In adjusted analysis, utilization of primary total hip arthroplasty was lower in patients living in urban areas (IRR = 0.87, 95% confidence interval = 0.81 to 0.94) compared to patients in rural regions. Similarly, total knee arthroplasty was used at a lower rate in urban areas (IRR = 0.88, 95% confidence interval = 0.82 to 0.95) compared with rural regions. We found no differences in the hip and knee groups within the mid-region. CONCLUSIONS: In hip and knee OA patients enrolled in a universal coverage system, we found patients living in urban areas had lower TJA utilization compared to patients living in rural areas. Further research is needed to determine how patient location contributes to differences in elective TJA utilization. LEVEL OF EVIDENCE: III.

Single Wedge Femoral Stem Designs are Associated With a Higher Risk for Revision After Cementless Primary Total Hip Arthroplasty.

BACKGROUND: Cementless total hip arthroplasty (THA) femoral stems are the most commonly selected prostheses in the United States. Optimal stem geometry remains controversial with excellent survivorship reported for many designs. We compared cause-specific stem revision of single-wedge versus double-wedge designs from a multicenter US cohort. METHODS: Data from an integrated healthcare network's total joint replacement registry were used to conduct a cohort study. Primary elective cementless THAs were identified (2001 to 2018). Implant exposure groups were classified by design geometry using the system proposed by Khanuja et al. Type 1 single-wedge (n = 11,082) and type 2 double-wedge (n = 32,380) designs were compared, and other design types were excluded; the final study cohort comprised 43,462 THAs. Cause-specific multivariable Cox regressions were used to evaluate risk for revision due to infection or aseptic reasons, including loosening, instability, periprosthetic fracture, or other reasons. RESULTS: After adjustment for covariates, a higher aseptic revision risk was observed for type 1 when compared to type 2 designs (hazard ratio = 1.91, 95% confidence interval = 1.33-2.75). When looking at specific revision reasons, revision for aseptic loosening (hazard ratio = 3.46, 95% confidence interval = 2.24-5.34) was higher for type 1 versus type 2 designs. No differences were found for septic revision, instability, periprosthetic fracture, or revisions for other reasons. CONCLUSIONS: Type 1 single-wedge designs were found to have a higher risk of revision due to aseptic loosening relative to type 2 double-wedge designs. Femoral stem geometry should be considered when selecting a cementless femoral implant. LEVEL OF EVIDENCE: Level III.

Prolonged Opioid Usage Following Hip Fracture Surgery in Opioid-Naïve Older Patients.

BACKGROUND: While the risk of long-term dependence following the opioid treatment of musculoskeletal injury is often studied in younger populations, studies in older patients have centered on short-term risks such as oversedation and delirium. This study investigated prolonged opioid usage after hip fracture in older individuals, focusing on prevalence, risk factors, and changes over time. METHODS: In this retrospective cohort study of 47,309 opioid-naïve patients aged ≥ 60 years who underwent hip fracture surgery (2009 to 2020), outpatient opioid use was evaluated in 3 postoperative time periods: P1 (day 0 to 30 postsurgery); P2 (day 31 to 90); and P3 (day 91 to 180). The primary outcome was prolonged outpatient opioid use, defined as having one or more opioid prescriptions dispensed in all 3 time periods. RESULTS: The incidence of prolonged opioid usage among patients surviving to P3 was 6.3% (2,834 of 44,850). Initial prescription quantities decreased over time, as did the risk of prolonged opioid usage (from 8.0% in 2009 to 3.9% in 2019). In the multivariable analyses, risk factors for prolonged opioid usage included younger age, women, current/former smoking, fracture fixation (as compared to hemiarthroplasty), and anxiety. Prolonged opioid usage was less common among patients who were Asian or had a history of dementia. CONCLUSIONS: While prior research on the hazards of opioids in the elderly has focused on short-term risks such as oversedation and delirium, these findings suggest that prolonged opioid usage may be a risk for this older population as well. As initial prescription amounts have decreased, declines in prolonged opioid medication usage have also been observed.

Association Between Race/Ethnicity and 90-Day Emergency Department Visits in Patients Undergoing Elective Total Knee Arthroplasty or Total Hip Arthroplasty in a Universally Insured Population.

BACKGROUND: Research has identified disparities in returns to care by race/ethnicity following primary total joint arthroplasty. We sought to identify risk factors for 90-day emergency department (ED) returns following primary total knee arthroplasty (TKA) or total hip arthroplasty (THA) for these populations. METHODS: Black, Hispanic, and non-Hispanic White patients who underwent elective primary unilateral TKA and THA in an integrated US healthcare system were identified. Risk factors for 90-day postoperative ED visits including patient demographics, household income and education, comorbidities, preoperative healthcare utilization, and copay data were identified with multivariable logistic regression. RESULTS: Postoperative 90-day ED visits occurred in 13.3% of 79,565 TKA patients (17.2% Black; 14.9% Hispanic; 12.5% White) and 11.0% of THA patients (13.4% Black; 12.1% Hispanic; 10.7% White). Across racial/ethnic categories, patients who had an ED visit within 1 year of their TKA or THA date were more likely to have a 90-day ED return. Shared risk factors for TKA patients were chronic lung disease and outpatient utilization (25th and 75th percentile), while peripheral vascular disease was a shared risk factor for THA patients. Risk factors for multiple races of TKA and THA patients included depression, drug abuse, and psychosis. Prior copay for White (TKA) and Hispanic (TKA and THA) patients was protective, while preoperative primary care was protective for Black THA patients. CONCLUSION: Future strategies to reduce postoperative ED returns should include directed patient outreach for patients who had ED visits and mental health in the year prior to TKA and THA. LEVEL OF EVIDENCE: III.

Does Aseptic Revision Risk Differ for Primary Total Knee Arthroplasty Patients Who Have and Do not Have a Prior Primary or Revision Arthroplasty?

BACKGROUND: We sought to evaluate the risk of aseptic revision in total knee arthroplasty (TKA) patients who have and do not have a history of primary or revision arthroplasty of a different major joint. METHODS: We conducted a matched cohort study using data from Kaiser Permanente's arthroplasty registries. Patients who underwent primary unilateral TKA (index knee) were identified (2009-2018). Two matches based on exposure history were performed: (1) 33,714 TKAs with a history of primary arthroplasty of a different joint (contralateral knee, either hip, and/or either shoulder) were matched to 67,121 TKAs without an arthroplasty history and (2) 597 TKAs with a history of aseptic revision in a different joint were matched to 1,190 TKAs with a history of a prior arthroplasty in a different joint, but without any revision. After the matches were performed, Cox regressions were used to evaluate aseptic revision risk of the index knee using the no history groups as the reference in regression models. RESULTS: No difference in aseptic revision risk for the index knee was observed when comparing patients who had a prior primary arthroplasty in a different joint to those who did not have an arthroplasty history (hazard ratio = 0.95, 95% CI = 0.86-1.06). Those patients who did not have any prior aseptic revision history in a different joint had higher risk of aseptic revision in the index knee (hazard ratio = 2.06, 95% CI = 1.17-3.63). CONCLUSION: Patients who had a prior revision history had over a 2-fold higher risk of aseptic revision in the index knee, warranting close surveillance of these patients. LEVEL OF EVIDENCE: Level III.

The use of antibiotic-loaded bone cement and systemic antibiotic prophylactic use in 2,971,357 primary total knee arthroplasties from 2010 to 2020: an international register-based observational study among countries in Africa, Europe, North America, and Oceania.

BACKGROUND AND PURPOSE: Antibiotic-loaded bone cement (ALBC) and systemic antibiotic prophylaxis (SAP) have been used to reduce periprosthetic joint infection (PJI) rates. We investigated the use of ALBC and SAP in primary total knee arthroplasty (TKA). PATIENTS AND METHODS: This observational study is based on 2,971,357 primary TKAs reported in 2010-2020 to national/regional joint arthroplasty registries in Australia, Denmark, Finland, Germany, Italy, the Netherlands, New Zealand, Norway, Romania, South Africa, Sweden, Switzerland, the UK, and the USA. Aggregate-level data on trends and types of bone cement, antibiotic agents, and doses and duration of SAP used was extracted from participating registries. RESULTS: ALBC was used in 77% of the TKAs with variation ranging from 100% in Norway to 31% in the USA. Palacos R+G was the most common (62%) ALBC type used. The primary antibiotic used in ALBC was gentamicin (94%). Use of ALBC in combination with SAP was common practice (77%). Cefazolin was the most common (32%) SAP agent. The doses and duration of SAP used varied from one single preoperative dosage as standard practice in Bolzano, Italy (98%) to 1-day 4 doses in Norway (83% of the 40,709 TKAs reported to the Norwegian arthroplasty register). CONCLUSION: The proportion of ALBC usage in primary TKA varies internationally, with gentamicin being the most common antibiotic. ALBC in combination with SAP was common practice, with cefazolin the most common SAP agent. The type of ALBC and type, dose, and duration of SAP varied among participating countries.

Do Dual-mobility Cups Reduce Revision Risk in Femoral Neck Fractures Compared With Conventional THA Designs? An International Meta-analysis of Arthroplasty Registries.

BACKGROUND: Dual-mobility cups in THA were designed to reduce prosthesis instability and the subsequent risk of revision surgery in high-risk patients, such as those with hip fractures. However, there are limited data from clinical studies reporting a revision benefit of dual-mobility over conventional THA. Collaboration between anthroplasty registries provides an opportunity to describe international practice variation and compare between-country, all-cause revision rates for dual-mobility and conventional THA. QUESTIONS/PURPOSES: We summarized observational data from multiple arthroplasty registries for patients receiving either a dual-mobility or conventional THA to ask: (1) Is dual-mobility use associated with a difference in risk of all-cause revision surgery compared with conventional THA? (2) Are there specific patient characteristics associated with dual-mobility use in the hip fracture population? (3) Has the use of dual-mobility constructs changed over time in patients receiving a THA for hip fracture? METHODS: Six member registries of the International Society of Arthroplasty Registries (from Australia, Denmark, Sweden, the Netherlands, the United Kingdom, and the United States) provided custom aggregate data reports stratified by acetabular cup type (dual-mobility or conventional THA) in primary THA for hip fracture between January 1, 2002, and December 31, 2019; surgical approach; and patient demographic data (sex, mean age, American Society of Anesthesiologists class, and BMI). The cumulative percent revision and mortality were calculated for each registry. To determine a global hazard ratio of all-cause revision for dual-mobility compared with conventional THA designs, we used a pseudoindividual patient data approach to pool Kaplan-Meier prosthesis revision data from each registry and perform a meta-analysis. The pseudoindividual patient data approach is a validated technique for meta-analysis of aggregate time-to-event survival data, such as revision surgery, from multiple sources. Data were available for 15,024 dual-mobility THAs and 97,200 conventional THAs performed for hip fractures during the study period. RESULTS: After pooling of complete Kaplan-Meier survival data from all six registries, the cumulative percent revision for conventional THA was 4.3% (95% confidence interval [CI] 4.2% to 4.5%) and 4.7% (95% CI 4.3% to 5.3%) for dual-mobility THA at 5 years. We did not demonstrate a lower risk of all-cause revision for patients receiving dual-mobility over conventional THA designs for hip fracture in the meta-analysis once between-registry differences were adjusted for (HR 0.96 [95% CI 0.86 to 1.06]). A lower proportion of dual-mobility procedures were revised for dislocation than conventional THAs (0.9% versus 1.4%) but a higher proportion were revised for infection (1.2% versus 0.8%). In most registries, a greater proportion of dual-mobility THA patients were older, had more comorbidities, and underwent a posterior approach compared with conventional THA (p < 0.001). The proportion of dual-mobility THA used to treat hip fractures increased in each registry over time and constituted 21% (2438 of 11,874) of all THA procedures in 2019. CONCLUSION: The proportion of dual-mobility THAs in patients with hip fractures increased over time, but there was large variation in use across countries represented here. Dual-mobility cups were not associated with a reduction in the overall risk of revision surgery in patients with hip fractures. A randomized controlled trial powered to detect the incidence of dislocation and subsequent revision surgery is required to clarify the efficacy of dual-mobility cups to treat hip fractures. LEVEL OF EVIDENCE: Level III, therapeutic study.

Cause-Specific Stem Revision Risk in Primary Total Hip Arthroplasty Using Cemented vs Cementless Femoral Stem Fixation in a US Cohort.

BACKGROUND: We sought to evaluate the cause-specific revision risk following hybrid (cemented stem mated to a cementless acetabular implant) vs cementless total hip arthroplasty (THA) in a US cohort. METHODS: Primary elective THA for osteoarthritis was identified using Kaiser Permanente's Total Joint Replacement Registry (2001-2018). Multivariable Cox regression was used to evaluate cause-specific revision, including aseptic loosening, infection, instability, and periprosthetic fracture (PPF), for hybrid vs cementless THA. Analysis was stratified by age (<65, 65-74, and ≥75 years) and gender. RESULTS: The study cohort comprised 88,830 THAs, including 4539 (5.1%) hybrid THAs. In stratified analysis, hybrid THA had a higher revision risk for loosening in females in all 3 age subgroups. A lower risk of revision for PPF was observed following hybrid THA in females aged ≥75 years. For females ≥75 years, cementless THA had an excess PPF risk of 0.9% while hybrid THA had an excess loosening risk of 0.2%, translating to a theoretical prevention of 10 PPF revisions but a price of 3 loosening revisions per 1000 hybrid THAs. No difference in revision risk was observed in males. CONCLUSION: We observed differences in cause-specific revision risks by method of stem fixation which depended upon patient age and gender. Although the trend toward all cementless fixation continue, there may be a role for hybrid fixation in females ≥75 years to mitigate risk for revision due to PPF at the potential cost of a slight increase in longer term aseptic loosening. LEVEL OF EVIDENCE: Level III.

Revision Risk in a Cohort of US Patients Younger Than 55 Undergoing Primary Elective Total Hip Arthroplasty.

BACKGROUND: As indications for elective total hip arthroplasty (THA) expand to younger patients, we sought to (1) compare revision risk following primary elective THA in patients <55 years at the time of their THA to patients aged ≥65 years and (2) identify specific risk factors for revision in patients <55 years. METHODS: A Kaiser Permanente's total joint replacement registry was used to conduct a cohort study including primary elective THA patients aged ≥18 (2001-2018). In total, 11,671 patients <55 years and 53,106 patients ≥65 years were included. Multiple Cox regression was used to evaluate cause-specific revision risk, including septic revision, aseptic loosening, instability, and periprosthetic fracture. Stepwise Cox regression was used to identify patient and surgical factors associated with cause-specific revision in patients <55 years. RESULTS: Patients <55 years had a higher risk of septic revision (hazard ratio [HR] = 1.30, 95% confidence interval [CI] = 1.02-1.66), aseptic loosening (HR = 2.60, 95% CI = 1.99-3.40), and instability (HR = 1.35, 95% CI = 1.09-1.68), but a lower risk of revision for periprosthetic fracture (HR = 0.36, 95% CI = 0.22-0.59) compared to patients aged ≥65 years. In the <55 age group, risk factors for septic revision included higher body mass index, drug abuse, and liver disease. Hypertension, anterior approach, and ceramic-on-ceramic were associated with aseptic loosening. White race, American Society of Anesthesiologists classification ≥3, smoker, paralysis, posterior approach, ceramic-on-ceramic, and smaller head diameter were associated with instability. CONCLUSION: Identified risk factors varied depending on the cause for revision. Although septic revisions were related to patient characteristics, more modifiable factors, such as implant or surgical approach, were associated with revision due to aseptic loosening and instability. LEVEL OF EVIDENCE: III.

The effect of patient and prosthesis factors on revision rates after total knee replacement using a multi-registry meta-analytic approach.

BACKGROUND AND PURPOSE: Characteristics of patients receiving total knee arthroplasty (TKA) and prostheses used vary between regions and change with time. How these practice variations influence revision remains unclear. We combined registry data for better understanding of the impact of variation, which could potentially improve revision rates. PATIENTS AND METHODS: We used data from 2003 to 2019 for primary TKA from arthroplasty registries of Sweden (SKAR), Australia (AOANJRR), and Kaiser Permanente (KPJRR). We included 1,072,924 TKA procedures for osteoarthritis. Factors studied included age, sex, ASA class, BMI category, prosthesis constraint, fixation, bearing mobility, patellar resurfacing, and polyethylene type. Cumulative percentage revision (CPR) was calculated using Kaplan-Meier estimates, and unadjusted Cox hazard ratios were used for comparisons. Random-effects generic inverse-variance meta-analytic methods were used to determine summary effects. RESULTS: We found similarities in age and sex, but between-registry differences occurred in the other 7 factors studied. Patients from Sweden had lower BMI and ASA scores compared with other registries. Use of cement fixation was similar in the SKAR and KPJRR, but there were marked differences in patellar resurfacing and posterior stabilized component use. Meta-analysis results regarding survivorship favored patients aged ≥ 65 years and minimally stabilized components. There were inconsistent results with time for sex, fixation, and bearing mobility, and no differences for the patellar resurfacing or polyethylene type comparisons. INTERPRETATION: Marked practice variation was found. Use of minimally stabilized and possibly also cemented and fixed bearing prostheses is supported.

Midterm outcomes for 605 patients receiving Endologix AFX or AFX2 Endovascular AAA Systems in an integrated healthcare system.

BACKGROUND: Endologix issued important safety updates for the AFX Endovascular AAA System in 2016 and 2018 owing to the risk of type III endoleaks. Outcomes with these devices are limited to small case series with short-term follow-up. We describe the midterm outcomes for a large cohort of patients who received an Endologix AFX or AFX2 device. STUDY DESIGN: Data from an integrated healthcare system's implant registry, which prospectively monitors all patients after endovascular aortic repair, was used for this descriptive study. Patients undergoing endovascular aortic repair with three AFX System variations (Strata [AFX-S], Duraply [AFX-D], and AFX2 with Duraply [AFX2]) were identified (2011-2017). Crude cumulative event probabilities for endoleak (types I and III), major reintervention, conversion to open, rupture, and mortality (aneurysm related and all cause) were estimated. RESULTS: Among 605 patients, 375 received AFX-S, 197 received AFX-D, and 33 received AFX2. Median follow-up for the cohort was 3.9 (interquartile range, 2.5-5.1) years. The crude 2-year incidence of overall endoleak, any subsequent reintervention or conversion, and mortality was 8.8% (95% confidence interval [CI], 6.3-12.3), 12.0% (95% CI, 9.1-15.9), and 8.8% (95% CI, 6.3-12.2) for AFX-S. Respective estimates for AFX-D were 7.9% (95% CI, 4.8-13.0), 10.6% (95% CI, 6.9-16.1), and 9.7% (95% CI, 6.3-14.7); for AFX2, they were 14.1% (95% CI, 4.7-38.2), 16.2% (95% CI, 6.4-37.7), and 21.2% (95% CI, 10.7-39.4). CONCLUSIONS: The midterm outcomes of a large U.S. patient cohort with an Endologix AFX or AFX2 System demonstrate a concerning rate of adverse postoperative events. Patients with these devices should receive close clinical surveillance to prevent device-related adverse events.

The association of multimorbidity to mortality in older adults after permanent pacemaker placement.

BACKGROUND: In the United States 2018 bradycardia guideline, the current class III recommendation that patients with permanent pacemaker (PPM) indications and high multimorbidity burden may not have meaningful clinical benefit from PPM therapy is based on limited data. METHODS: Observational study (January 1, 2008-December 31, 2015) of adults ≥65 years (N = 16,678) who underwent PPM implantation. Exposure variable: Elixhauser comorbidity number (ECN, 29 well-validated conditions). PRIMARY OUTCOME: ≤1-year mortality; secondary outcome: > 1-year mortality. RESULTS: Those who died ≤1-year were older, had a lower body mass index (BMI), and higher ECN (p < .001). Cumulative survival at 1-year was 92.3% (95% confidence interval [CI]: 91.9-92.7). One-year survival decreased by increasing ECN-with a difference at 1-year between lowest and highest ECN category of 17.3% (ECN 0-1: 97.1% [95% CI: 96.3-97.7]; ECN ≥8: 79.8% [95% CI: 77.9-81.5]). For those who survived the first year, cumulative survival at 8-years was 51.2% (95% CI = 49.8-52.6) with a difference between ECN 0-1 and ≥8 of 43.4%. Increasing ECN was associated equally with ≤1-year (HR 1.28 [95% CI: 1.25-1.30]) and >1-year (HR 1.19 [95% CI: 1.17-1.20]) mortality. A predictive model including age, sex, BMI, PPM type, race, and ECN had greater discriminative ability (p < .0001) than a bedside model (age, sex) for the primary outcome. CONCLUSION: Across the heterogeneity of indications for PPM placement, multimorbidity is increasingly common. The association of multimorbidity to mortality (≤1-year, >1-year) should be routinely discussed during the shared decision-making process as an important prognostic geriatric domain variable.

Modular Tibial Stem Use and Risk of Revision for Aseptic Loosening in Cemented Primary Total Knee Arthroplasty.

BACKGROUND: Modular tibial stem extensions in total knee arthroplasty (TKA) are designed to reduce the risk of aseptic loosening of the tibial base plate. However, these implants add significant cost and an evaluation of their effectiveness in reducing this risk of loosening has not been studied in a large cohort. We sought to evaluate modular tibial stem utilization in primary TKA. METHODS: We conducted a cohort study using our integrated healthcare system's Total Joint Replacement Registry. Patients who underwent cemented primary TKA were identified (2009-2019). Propensity scores were used to 1:1 match patients without to those with a stem extension. Cox proportional-hazards regression was used to evaluate the risk for revision due to aseptic loosening. RESULTS: Ten thousand four hundred seventy six TKA with a modular tibial stem were matched to 10,476 TKA without a tibial stem. Stem utilization associated with a lower risk of revision for loosening across all postoperative follow-up (hazard ratio = 0.38, 95% confidence interval = 0.17-0.85). CONCLUSION: In a matched cohort study, we observed presence of a stem extension was associated with a lower risk of revision for aseptic loosening. Further study to identify specific risk factors for aseptic loosening and confirm the findings presented here are warranted. LEVEL OF EVIDENCE: Level III.

Frequency and Timing of Complications and Catastrophic Events After Same-Day Discharge Compared With Inpatient Total Hip Arthroplasty.

BACKGROUND: Same-day discharge total hip arthroplasty (THA) has grown in utilization although concerns exist regarding early complications and catastrophic events. We sought to compare the risk of complications and catastrophic events for same-day and inpatient stay THA. METHODS: A cohort study was conducted using Kaiser Permanente's total joint replacement registry. Primary elective THA were identified (2017-2018). Propensity score-weighted Cox proportional hazards regression was used to evaluate risk for 90-day incident events, including emergency department (ED) visit, unplanned readmission, cardiac complication, deep infection, venous thromboembolism (VTE), and mortality, by in-hospital length of stay: same-day vs 1-2-night inpatient stay. RESULTS: The study sample comprised 13,646 THA, 6033 (44.1%) with a same-day discharge. Median days-to-events for same-day vs inpatient was 11 vs 12 for ED visit, 23 vs 20 for readmission, 38 vs 12 for cardiac complication, 28 vs 24 for deep infection, 14.5 vs 23.5 for VTE, and 7 vs 35.5 for mortality. In propensity score-weighted models, same-day discharge THA had a lower risk for 90-day ED visit (HR = 0.82, 95% CI = 0.72-0.94), readmission (HR = 0.75, 95% CI = 0.61-0.92), and cardiac complication (HR = 0.60, 95% CI = 0.47-0.76), compared with inpatient stay THA; no difference was observed for deep infection (HR = 1.59, 95% CI = 0.81-3.12), VTE (HR = 0.90, 95% CI = 0.52-1.58), or mortality (HR = 0.81, 95% CI = 0.27-2.40). CONCLUSION: We observed a lower or no difference in risk for complications and catastrophic events after same-day THA than an inpatient stay. Catastrophic events were more likely to occur early in the 90-day period, but an inpatient stay did not preclude events.

The Association Between Cement Viscosity and Revision Risk After Primary Total Knee Arthroplasty.

BACKGROUND: Recent case series have reported early failure with the use of high-viscosity cement (HVC) in total knee arthroplasty (TKA). We evaluated revision risk after TKA with HVC compared with medium-viscosity cement (MVC) in a large cohort. METHODS: We conducted a cohort study using data from Kaiser Permanente's Total Joint Replacement Registry. Patients who underwent fully cemented primary TKA for osteoarthritis were identified (2001-2018). Only posterior-stabilized, fixed-mobility designs of the 3 highest-volume implant systems (DePuy PFC, Zimmer NexGen, and Zimmer Persona) were included to mitigate confounding from implant characteristics. Palacos (Zimmer/Heraeus) and Simplex (Stryker) cements comprised the HVC and MVC exposure groups, respectively. Propensity score-weighted Cox proportional hazards regression was used to evaluate risk for any revision during follow-up and risk for revision from aseptic loosening specifically. RESULTS: The final cohort comprised 76,052 TKAs, 41.1% using MVC. The crude 14-year cumulative revision probability was 4.55% and 5.12% for TKA with MVC and HVC, respectively. In propensity score-weighted Cox models, MVC compared with HVC had a lower risk of any revision (hazard ratio = 0.82, 95% confidence interval = 0.70-0.95) while no difference was observed for revision from aseptic loosening (hazard ratio = 0.80, 95% confidence interval = 0.56-1.13). CONCLUSION: While we observed a lower risk for any revision with the use of Simplex MVC compared with Palacos HVC, we did not observe a difference in revision for aseptic loosening specifically. Given the widespread use of HVC, additional research to investigate other HVC and potential mechanisms for failure outside of loosening is warranted. LEVEL OF EVIDENCE: Level III.

Variation and trends in reasons for knee replacement revision: a multi-registry study of revision burden.

Background and purpose - Studies describing time-related change in reasons for knee replacement revision have been limited to single regions or institutions, commonly analyze only 1st revisions, and may not reflect true caseloads or findings from other areas. We used revision procedure data from 3 arthroplasty registries to determine trends and differences in knee replacement revision diagnoses.Patients and methods - We obtained aggregated data for 78,151 revision knee replacement procedures recorded by the Swedish Knee Arthroplasty Register (SKAR), the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), and the Kaiser Permanente Joint Replacement Registry (KPJRR) for the period 2003-2017. Equivalent diagnosis groups were created. We calculated the annual proportions of the most common reasons for revision.Results - Infection, loosening, and instability were among the 5 most common reasons for revision but magnitude and ranking varied between registries. Over time there were increases in proportions of revisions for infection and decreases in revisions for wear. There were inconsistent proportions and trends for the other reasons for revision. The incidence of revision for infection showed a uniform increase.Interpretation - Despite some differences in terminology, comparison of registry-recorded revision diagnoses is possible, but defining a single reason for revision is not always clear-cut. There were common increases in revision for infection and decreases in revision for wear, but variable changes in other categories. This may reflect regional practice differences and therefore generalizability of studies regarding reasons for revision is unwise.

International variation in distribution of ASA class in patients undergoing total hip arthroplasty and its influence on mortality: data from an international consortium of arthroplasty registries.

Background and purpose - A challenge comparing outcomes from total hip arthroplasty between countries is variation in preoperative characteristics, particularly comorbidity. Therefore, we investigated between-country variation in comorbidity in patients based on ASA class distribution, and determined any variation of ASA class to mortality risk between countries.Patients and methods - All arthroplasty registries collecting ASA class and mortality data in patients with elective primary THAs performed 2012-2016 were identified. Survival analyses of the influence of ASA class on 1-year mortality were performed by individual registries, followed by meta-analysis of aggregated data.Results - 6 national registries and 1 US healthcare organization registry with 418,916 THAs were included. There was substantial variation in the proportion of ASA class III/IV, ranging from 14% in the Netherlands to 39% in Finland. Overall, 1-year mortality was 0.93% (95% CI 0.87-1.01) and increased from 0.2% in ASA class I to 8.9% in class IV. The association between ASA class and mortality measured by hazard ratios (HR) was strong in all registries even after adjustment for age and sex, which reduced them by half in all registries. Combined adjusted HRs were 2.0, 6.1, and 22 for ASA class II-IV vs. I, respectively. Associations were moderately heterogeneous across registries.Interpretation - We observed large variation in ASA class distribution between registries, possibly explained by differences in background morbidity and/or international variation in access to surgery. The similar, strong mortality trends by ASA class between countries enhance the relevance of its use as an indicator of comorbidity in international registry studies.