Preoperative Patient Optimization: Outcomes from Elective Total Joint Arthroplasty in a Large US Healthcare System.

INTRODUCTION: Patient factors are known to affect outcomes in arthroplasty surgery. A preoperative program to address modifiable factors may aid in more appropriate patient selection. We sought to assess patient selection and 90-day postoperative outcomes for total joint arthroplasty (TJA) candidates before and after implementation of a preoperative optimization protocol. METHODS: A retrospective time-trend study using data from an integrated healthcare system's total joint replacement registry was done. The study sample consisted of patients aged 18 years or older who underwent primary elective total hip arthroplasty (THA) and total knee arthroplasty (TKA) for osteoarthritis between 2009 and 2019. Patients were divided into two cohorts: procedures performed from 2009 to 2013 ("preoptimization protocol") and those from 2015 to 2019 ("postoptimization protocol"); 2014 was excluded because an evidence-based preoperative patient optimization protocol was progressively implemented throughout the year. Patient characteristics, optimization factors, and 90-day outcomes (including emergency department [ED] visits, readmission, all-cause revision, deep infection, venous thromboembolism, and mortality) were compared between the two cohorts using the Pearson chi-square test or Wilcoxon test. RESULTS: The study sample included 25,925 THA and 60,484 TKA. In the THA cohort, 10,364 (40.0%) and 15,561 (60.0%) were from the preoptimization and postoptimization cohorts, respectively. The postoptimization THA cohort saw lower rates of ED visits (12.1% vs. 9.4%, P < 0.001) and readmissions (5.6% vs. 3.8%, P < 0.001). In the TKA cohort, 24,054 (39.8%) and 36,430 (60.2%) were from the preoptimization and postoptimization cohorts, respectively. The postoptimization TKA cohort saw lower rates of ED visits (13.1% vs. 11.9%, P < 0.001), readmissions (5.6% vs. 3.0%, P < 0.001), all-cause revisions (0.5% vs. 0.3%, P = 0.003), venous thromboembolism (1.3% vs. 0.9%, P < 0.001), and mortality (0.3% vs. 0.2%, P = 0.011). DISCUSSION: An evidence-based protocol to improve patient selection based on modifiable patient factors was adopted by orthopaedic surgeons in the system and utilization of the protocol before TJA was associated with fewer postoperative complications over time. LEVEL OF EVIDENCE: Level IV.

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.

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.

The effect of a statewide COVID-19 shelter-in-place order on shoulder arthroplasty for proximal humerus fracture volume and length of stay.

BACKGROUND: Although the COVID-19 pandemic has disrupted elective shoulder arthroplasty throughput, traumatic shoulder arthroplasty procedures are less apt to be postponed. We sought to evaluate shoulder arthroplasty utilization for fracture during the COVID-19 pandemic and California's associated shelter-in-place order compared to historical controls. METHODS: We conducted a cohort study with historical controls, identifying patients who underwent shoulder arthroplasty for proximal humerus fracture in California using our integrated electronic health record. The time period of interest was following the implementation of the statewide shelter-in-place order: March 19, 2020-May 31, 2020. This was compared to three historical periods: January 1, 2020-March 18, 2020, March 18, 2019-May 31, 2019, and January 1, 2019-March 18, 2019. Procedure volume, patient characteristics, in-hospital length of stay, and 30-day events (emergency department visit, readmission, infection, pneumonia, and death) were reported. Changes over time were analyzed using linear regression adjusted for usual seasonal and yearly changes and age, sex, comorbidities, and postadmission factors. RESULTS: Surgical volume dropped from an average of 4.4, 5.2, and 2.6 surgeries per week in the historical time periods, respectively, to 2.4 surgeries per week after shelter-in-place. While no more than 30% of all shoulder arthroplasty procedures performed during any given week were for fracture during the historical time periods, arthroplasties performed for fracture was the overwhelming primary indication immediately after the shelter-in-place order. More patients were discharged the day of surgery (+33.2%, P = .019) after the shelter-in-place order, but we did not observe a change in any of the corresponding 30-day events. CONCLUSIONS: The volume of shoulder arthroplasty for fracture dropped during the time of COVID-19. The reduction in volume could be due to less shoulder trauma due to shelter-in-place or a change in the indications for arthroplasty given the perceived higher risks associated with intubation and surgical care. We noted more patients undergoing shoulder arthroplasty for fracture were safely discharged on the day of surgery, suggesting this may be a safe practice that can be adopted moving forward. LEVEL OF EVIDENCE: Level III; Retrospective Case-control Comparative Study.

Lumbar Spine Fusion Patients See Similar Improvements in Physical Activity Level to Non-Spine Fusion Patients Following Total Hip Arthroplasty.

BACKGROUND: The impact of prior lumbar spinal fusion on the change in physical activity level following total hip arthroplasty (THA) has not been thoroughly examined. Therefore, we sought to compare the change in physical activity level following THA for patients with and without a history of lumbar spine fusion. METHODS: Patients who underwent primary elective THA were identified using an integrated healthcare system's Total Joint Replacement Registry (2010-2013). Prior lumbar spine fusion was identified using the healthcare system's Spine Registry. Physical activity was self-reported by patients and measured in min/wk. Generalized linear models were used to evaluate the association between prior spine fusion and the change in physical activity from 1 year pre-THA to 1-2 years post-THA. RESULTS: Of 11,416 THAs, 90 (0.8%) had a history of lumbar spinal fusion. Patients with a prior lumbar fusion had a median physical activity level of 28 min/wk prior to THA compared to 45 min/wk in the patients with no history of lumbar spinal fusion. One year after THA, patients with a history of lumbar spinal fusion reported a median of 120 min/wk of physical activity compared to 150 min/wk for patients without a history of lumbar spinal fusion. The difference in physical activity level change between groups was not statistically significant (estimate = -23.1, 95% confidence interval -62.1 to 15.9, P = .246). CONCLUSION: Patients with prior lumbar fusion were found to have lower self-reported physical activity levels than patients without spine fusion both before and after THA surgery. However, both groups saw the same degree of improvement in physical activity level following THA. These findings may help in counseling patients who have had a prior lumbar spine fusion and in setting appropriate expectations prior to THA.

Risk Factors for Reaching the Post-Operative Transfusion Trigger in a Community Primary Total Knee Arthroplasty Population.

BACKGROUND: Little data exist to evaluate an individual's pre-operative risk of blood transfusion following total knee arthroplasty (TKA). Our aim is to identify the risk factors associated with reaching the transfusion trigger of Hb <8 g/dL (TT8) following surgery and how perioperative tranexamic acid (TXA) affects that outcome. METHODS: Using a retrospective cohort study design, routine, unilateral TKAs performed between 2011 and 2013 in 19 hospitals were reviewed. Patients hospitalized ≤1 day or ≥4 days were excluded. Demographic data, clinical characteristics, and potential confounders were included in statistical models. Data were abstracted from electronic clinical and utilization databases. The main outcome was the risk of reaching the TT8. The primary exposure was use of single dose intravenous TXA. Logistic regression was used to model the adjusted association between TXA usage and post-operative risk of reaching TT8. RESULTS: A total of 10,518 TKAs met criteria; 2566 (24.3%) received TXA (+TXA). The proportion that reached the TT8 was 2.1% for + TXA and 5.3% for -TXA (P < .0001). Pre-operative Hb levels were associated with increasing odds of reaching the TT8. Increasing age was weakly associated with this outcome. The odds of reaching the TT8 were lower for patients who had received TXA, had increasing body mass index, and surgical duration in the third quartile. CONCLUSION: Not receiving TXA within 24 hours of TKA and pre-operative Hb levels <13 g/dL were independently associated with the odds of reaching the post-operative TT8 following a primary TKA.

Midterm-Adjusted Survival Comparing the Best Performing Unicompartmental and Total Knee Arthroplasties in a Registry.

BACKGROUND: Recent literature suggests that the difference in revision risk between unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) can be influenced by surgeon volume and other confounders. We hypothesized that implant selection might decrease the relative risk of revision in an adjusted model. METHODS: We selected the best performing (BP) primary UKAs and TKAs performed for osteoarthritis between January 2001 and December 2012 collected through a joint replacement registry. We compared aseptic and all-cause risk of revision using a surgeon-stratified Cox regression model with propensity score adjustment. RESULTS: One thousand fifty-four UKAs were compared with 74,185 TKAs. The rate for all-cause revision was lower for UKAs (2.1%) than for TKAs (2.4%), whereas the rate for aseptic revision was higher for UKAs (2.0%) than TKAs (1.4%). The adjusted risk of aseptic revision was not significantly higher for UKA than TKA (hazard ratio = 2.02 [0.68, 5.96], P = .203) or all-cause revision (hazard ratio = 1.24 [0.52, 2.98], P = .603). CONCLUSION: When comparing the survivorship of the BP UKAs to the BP TKAs in our registry, the adjusted risk of revision remained higher for UKAs than for TKAs, although the difference did not reach statistical significance.

Poorer Arthroscopic Outcomes of Mild Dysplasia With Cam Femoroacetabular Impingement Versus Mixed Femoroacetabular Impingement in Absence of Capsular Repair.

PURPOSE: To compare outcomes of mild dysplasia with cam femoroacetabular impingement (FAI) vs mixed FAI with hip arthroscopy without capsular repair. METHODS: A retrospective review of a 2009 to 2010 multicenter prospective outcome study was performed comparing a cohort with mild dysplasia and cam femoroacetabular impingement (cohort D) to a cohort with mixed FAI (cohort M). Outcome measures included Nonarthritic Hip Score (NAHS) and satisfaction with minimum 2-year follow-up. RESULTS: Of 150 patients/159 hips enrolled in the initial prospective outcome study, 10 patients/10 hips had acetabular dysplasia and 8 patients met the inclusion criteria. Cohort D had 8 patients (5 female) of mean age 49.6 years with mean lateral center-edge angle (LCEA) of 19° (range, 16°-24°) demonstrating a mean change in NAHS of +20.00 at 3 months (P = .25), +14.33 at 12 months (P = .03), and -0.75 at 24 months (P = .74). Mean satisfaction was 2.88 out of 5. Cohort M had 69 patients (32 female) of mean age 38.6 years with a mean LCEA of 33° (range, 25°-38°) demonstrating a mean change in NAHS of +12.09 at 3 months (P < .0001), +20.39 at 12 months (P < .0001), and +21.99 at 24 months (P < .0001). Mean satisfaction was 3.58 out of 5. Cohort D demonstrated significantly less improvement in NAHS (P = .002) and a difference of -31.06 points compared to cohort M at minimum 2-year follow-up. Dysplasia was the only statistically significant predictor of poorer outcomes. CONCLUSION: The common combination of mild dysplasia and cam FAI has poorer outcomes than mixed FAI following arthroscopic surgery without capsular repair.

Antibiotic cement was associated with half the risk of re-revision in 1,154 aseptic revision total knee arthroplasties.

BACKGROUND AND PURPOSE: Aseptic revisions comprise 80% of revision total knee arthroplasties (TKAs). We determined the incidence of re-revision TKA, the reasons for re-revision, and risk factors associated with these procedures. PATIENTS AND METHODS: We conducted a retrospective cohort study of 1,154 patients who underwent aseptic revision TKA between 2002 and 2013 and were followed prospectively by a total joint replacement registry in the USA. Revision was defined as any operation in which an implanted component was replaced. Patient-, surgeon-, and procedure-related risk factors were evaluated. Survival analyses were conducted. RESULTS: There were 114 re-revisions (10%) with a median time to reoperation of 3.6 years (interquartile range (IQR): 2.6-5.2). The infection rate was 2.9% (34/1,154) and accounted for 30% of re-revisions (34 of 114). In adjusted models, use of antibiotic-loaded cement was associated with a 50% lower risk of all-cause re-revision surgery (hazard ratio (HR) = 0.5, 95% CI: 0.3-0.9), age with a 20% lower risk for every 10-year increase (HR = 0.8, CI: 0.7-1.0), body mass index (BMI) with a 20% lower risk for every 5-unit increase (HR = 0.8, CI: 0.7-1.0), and a surgeon's greater cumulative experience (≥ 20 cases vs. < 20 cases) with a 3 times higher risk of re-revision (HR = 2.8, CI: 1.5-5). INTERPRETATION: Revised TKAs were at high risk of subsequent failure. The use of antibiotic-loaded cement, higher age, and higher BMI were associated with lower risk of further revision whereas a higher degree of surgeon experience was associated with higher risk.

Lower Total Knee Arthroplasty Revision Risk Associated With Bisphosphonate Use, Even in Patients With Normal Bone Density.

BACKGROUND: Bisphosphonates (BPs) are associated with lower total knee arthroplasty (TKA) revision risk, but the effect of bone mineral density has not been evaluated. METHODS: A cohort of 34,116 primary TKA patients was evaluated with revision surgery and periprosthetic fractures as end points. BP usage was the exposure of interest. Bone quality (normal, osteopenia, and osteoporosis) and patient age (<65 vs ≥65 years) were evaluated as effect modifiers of risk estimates. RESULTS: Of the patients, 19.6% were BP users. In BP users, 0.5% underwent an aseptic revision; and 0.6%, a periprosthetic fracture. In non-BP users, 1.6% underwent aseptic revision; and 0.1%, a periprosthetic fracture. CONCLUSION: Bisphosphonate use was associated with lower risk of revision in all bone quality categories in those older than 65 years. The risk of periprosthetic fractures was higher for patients on BP.

Multicenter outcomes of arthroscopic surgery for femoroacetabular impingement in the community hospital setting.

The purpose of this study is to determine multi-center outcomes from arthroscopic surgery for femoroacetabular impingement in the community hospital setting. A prospective design with 2-year minimum follow-up using the nonarthritic hip score (NAHS), a 100-point scale of perceived post-operative change for pain, activities of daily living, sports activities, and patient satisfaction was implemented at three community hospitals. Of 150 enrolled patients (159 hips) with mean age of 40 years (range, 12-73), there was 81% participation. Mean NAHS at preoperative was 54.9, 3 months: 66.6, 12 months: 74.9 and 24 months: 75.4. This represents a 20.5-point improvement in NAHS (P < 0.001). On the 100-point scale, pain was rated +73.5, ADL's: +76.2 and sports: +68.6. 64% of patients were satisfied with their surgical outcome. Conversion arthroplasty rate was 8.8% and complication rate was 2.5%. In conclusion, arthroscopic surgery for symptomatic femoroacetabular impingement in the community setting provides safe and successful outcomes.

Risk calculators predict failures of knee and hip arthroplasties: findings from a large health maintenance organization.

BACKGROUND: Considering the cost and risk associated with revision Total knee arthroplasty (TKAs) and Total hip arthroplasty (THAs), steps to prevent these operations will help patients and reduce healthcare costs. Revision risk calculators for patients may reduce revision surgery by supporting clinical decision-making at the point of care. QUESTIONS/PURPOSES: We sought to develop a TKA and THA revision risk calculator using data from a large health-maintenance organization's arthroplasty registry and determine the best set of predictors for the revision risk calculator. METHODS: Revision risk calculators for THAs and TKAs were developed using a patient cohort from a total joint replacement registry and data from a large US integrated healthcare system. The cohort included all patients who had primary procedures performed in our healthcare system between April 2001 and July 2008 and were followed until January 2014 (TKAs, n = 41,750; THAs, n = 22,721), During the study period, 9% of patients (TKA = 3066/34,686; THA=1898/20,285) were lost to followup and 7% died (TKA= 2350/41,750; THA=1419/20,285). The outcome of interest was revision surgery and was defined as replacement of any component for any reason within 5 years postoperatively. Candidate predictors for the revision risk calculator were limited to preoperative patient demographics, comorbidities, and procedure diagnoses. Logistic regression models were used to identify predictors and the Hosmer-Lemeshow goodness-of-fit test and c-statistic were used to choose final models for the revision risk calculator. RESULTS: The best predictors for the TKA revision risk calculator were age (odds ratio [OR], 0.96; 95% CI, 0.95-0.97; p < 0.001), sex (OR, 0.84; 95% CI, 0.75-0.95; p = 0.004), square-root BMI (OR, 1.05; 95% CI, 0.99-1.11; p = 0.140), diabetes (OR, 1.32; 95% CI, 1.17-1.48; p < 0.001), osteoarthritis (OR, 1.16; 95% CI, 0.84-1.62; p = 0.368), posttraumatic arthritis (OR, 1.66; 95% CI, 1.07-2.56; p = 0.022), and osteonecrosis (OR, 2.54; 95% CI, 1.31-4.92; p = 0.006). The best predictors for the THA revision risk calculator were sex (OR, 1.24; 95% CI, 1.05-1.46; p = 0.010), age (OR, 0.98; 95% CI, 0.98-0.99; p < 0.001), square-root BMI (OR, 1.07; 95% CI, 1.00-1.15; p = 0.066), and osteoarthritis (OR, 0.85; 95% CI, 0.66-1.09; p = 0.190). CONCLUSIONS: Study model parameters can be used to create web-based calculators. Surgeons can enter personalized patient data in the risk calculators for identification of risk of revision which can be used for clinical decision making at the point of care. Future prospective studies will be needed to validate these calculators and to refine them with time. LEVEL OF EVIDENCE: Level III, prognostic study.

Association of Bisphosphonate Use and Risk of Revision After THA: Outcomes From a US Total Joint Replacement Registry.

BACKGROUND: Total hip arthroplasty (THA) is often performed in patients who are older and may take bisphosphonates to treat a variety of conditions, most commonly osteoporosis. However, the clinical effects of bisphosphonate use on patients who have undergone THA are not well described. QUESTIONS/PURPOSES: (1) Is bisphosphonate use in patients with osteoarthritis undergoing primary THA associated with a change in the risk of all-cause revision, aseptic revision, or periprosthetic fracture compared with patients not treated with bisphosphonates? (2) Does the risk of bisphosphonate use and revision and periprosthetic fracture vary by patient bone mineral density and age? METHODS: A retrospective cohort study of 12,878 THA recipients for the diagnosis of osteoarthritis was conducted; 17.8% of patients were bisphosphonate users. Data sources for this study included a joint replacement registry (93% voluntary participation) and electronic health records and an osteoporosis screening database with complete capture of cases as part of the Kaiser Permanente integrated healthcare system. The endpoints for this study were revision surgery for any cause, aseptic revision, and periprosthetic fracture. The exposure of interest was bisphosphonate use; patients were considered users if prescriptions were continuously refilled for a period equal to or longer than 6 months. Bone quality (based on dual-energy x-ray absorptiometery ordered based on the National Osteoporosis Foundation's clinical guidelines taken within 5 years of the THA) and patient age (< 65 versus ≥ 65 years) were evaluated as effect modifiers. Patient, surgeon, and hospital factors were evaluated as confounders. Cox proportional hazards models were used. Hazard ratios (HRs) and 95% confidence intervals (CIs) were determined. RESULTS: Age- and sex-adjusted risks of all-cause (HR, 0.50; 95% CI, 0.33-0.74; p < 0.001) and aseptic revision (HR, 0.53; 95% CI, 0.34-0.81; p = 0.004) was lower in bisphosphonate users than in nonusers. The adjusted risk of periprosthetic fractures in patients on bisphosphonates was higher than in patients not on bisphosphonates (HR, 1.92; 95% CI, 1.13-3.27; p = 0.016). Lower risks of all-cause revision and aseptic revision were observed in patients with osteopenia (HR, 0.49; 95% CI, 0.29-0.84; and HR, 0.53; 95% CI, 0.29-0.99, respectively) and osteoporosis (HR, 0.22; 95% CI, 0.08-0.62; and HR, 0.33; 95% CI, 0.11-0.99, respectively). CONCLUSIONS: Patients considered bisphosphonate users who underwent THA had a lower risk for revision surgery. Bisphosphonate use was associated with a higher risk of periprosthetic fractures in younger patients with normal bone quantity. Evaluation of bone quality and bisphosphonate use for the diagnosis of osteoporosis is encouraged in patients with osteoarthritis who are candidates for primary THA. Further research is required to determine the optimal duration of therapy because long-term bisphosphonate use has been associated with atypical femur fractures. LEVEL OF EVIDENCE: Level III, therapeutic study.

Revision total hip arthoplasty: factors associated with re-revision surgery.

BACKGROUND: The survivorship of implants after revision total hip arthroplasty and risk factors associated with re-revision are not well defined. We evaluated the re-revision rate with use of the institutional total joint replacement registry. The purpose of this study was to determine patient, implant, and surgeon factors associated with re-revision total hip arthroplasty. METHODS: A retrospective cohort study was conducted. The total joint replacement registry was used to identify patients who had undergone revision total hip arthroplasty for aseptic reasons from April 1, 2001, to December 31, 2010. The end point of interest was re-revision total hip arthroplasty. Risk factors evaluated for re-revision total hip arthroplasty included: patient risk factors (age, sex, body mass index, race, and general health status), implant risk factors (fixation type, bearing surface, femoral head size, and component replacement), and surgeon risk factors (volume and experience). A multivariable Cox proportional hazards model was used. RESULTS: Six hundred and twenty-nine revision total hip arthroplasties with sixty-three (10%) re-revisions were evaluated. The mean cohort age (and standard deviation) was 57.0 ± 12.4 years, the mean body mass index (and standard deviation) was 29.5 ± 6.1 kg/m(2), and most of the patients were women (64.5%) and white (81.9%) and had an American Society of Anesthesiologists score of <3 (52.9%). The five-year implant survival after revision total hip arthroplasty was 86.8% (95% confidence interval, 83.57% to 90.25%). In adjusted models, age, total number of revision surgical procedures performed by the surgeon, fixation, and bearing surface were associated with the risk of re-revision. For every ten-year increase in patient age, the hazard ratio for re-revision decreases by a factor of 0.72 (95% confidence interval, 0.58 to 0.90). For every five revision surgical procedures performed by a surgeon, the risk of revision decreases by a factor of 0.93 (95% confidence interval, 0.86 to 0.99). At the time of revision, a new or retained cemented femoral implant or all-cemented hip implant increases the risk of revision by a factor of 3.19 (95% confidence interval, 1.22 to 8.38) relative to a retained or new uncemented hip implant. A ceramic on a highly cross-linked polyethylene bearing articulation decreases the hazard relative to metal on highly cross-linked polyethylene by a factor of 0.32 (95% confidence interval, 0.11 to 0.95). Metal on constrained bearing increases the hazard relative to metal on highly cross-linked polyethylene by a factor of 3.32 (95% confidence interval, 1.16 to 9.48). CONCLUSIONS: When evaluating patient, implant, and surgical factors at the time of revision total hip arthroplasty, age, surgeon experience, implant fixation, and bearing surfaces had significant impacts on the risk of re-revision.

Risk factors for total hip arthroplasty aseptic revision.

The purpose of this study was to evaluate patient, operative, implant, surgeon, and hospital factors associated with aseptic revision after primary THA in patients registered in a large US Total Joint Replacement Registry. A total of 35,960 THAs registered from 4/2001-12/2010 were evaluated. The 8-year survival rate was 96.7% (95% CI 96.4%-97.0%). Females had a higher risk of aseptic revision than males. Hispanic and Asian patients had a lower risk of revision than white patients. Ceramic-on-ceramic, ceramic-on-conventional polyethylene, and metal-on-conventional polyethylene bearing surfaces had a higher risk of revision than metal-on-highly cross-linked polyethylene. Body mass index, health status, diabetes, diagnosis, fixation, approach, bilateral procedures, head size, surgeon fellowship training, surgeon and hospital volume were not revision risk factors.

Surgeon, implant, and patient variables may explain variability in early revision rates reported for unicompartmental arthroplasty.

BACKGROUND: The reported revision rates for cemented unicompartmental knee arthroplasties have varied widely. The effect of implant selection, patient characteristics, and surgeon characteristics on revision risk has not been evaluated fully. The purpose of the present study was to determine the impact of these variables on the risk for aseptic revision arthroplasty. METHODS: We identified all cemented primary unicompartmental knee arthroplasties performed in our health-care system from 2002 to 2009 (median follow-up time = 2.6 years) to assess the risk for aseptic revision. A multivariate marginal Cox proportional-hazards model with robust standard errors (to adjust for the nesting of surgical cases within surgeons) was used to calculate the differential risk for revision of implants after adjusting for surgeon and hospital volume of unicompartmental knee arthroplasties performed; surgeon experience with unicompartmental knee arthroplasties at the time of surgery; surgeon fellowship training; and patient age, sex, weight, body mass index, and American Society of Anesthesiologists (ASA) score. RESULTS: A total of 1746 unicompartmental knee arthroplasties were identified. The overall revision rate during the study period was 4.98% (95% confidence interval [CI], 4.0% to 6.1%). In a multivariate Cox model, the hazard ratio (HR) for aseptic revision relative to a modern, fixed, metal-backed tibial bearing was significantly higher for an all-polyethylene tibial tray (HR = 3.85, 95% CI = 1.54 to 9.63, p = 0.004) but not significantly higher for a mobile-bearing implant (HR = 2.42, 95% CI = 0.55 to 10.65, p = 0.242) or an older-design, fixed, metal-backed bearing (HR = 1.89, 95% CI = 0.67 to 5.33, p = 0.23). Younger age was associated with increased risk (age less than fifty-five years compared with more than sixty-five years: HR = 4.83, 95% CI = 2.60 to 8.96, p < 0.001), and a higher ASA score (≥3 compared with <3 points: HR = 0.54, 95% CI = 0.32 to 0.93, p = 0.027) and a greater mean yearly surgeon volume of unicompartmental knee arthroplasties (twelve or fewer compared with more than twelve: HR = 2.18, 95% CI = 1.28 to 3.74, p = 0.004) were associated with reduced risk. CONCLUSIONS: Implant selection can have a considerable effect on the risk for aseptic revision following a cemented unicompartmental knee arthroplasty, as can patient and surgeon factors. Therefore, the variation among risk estimates reported in the literature for unicompartmental knee arthroplasty revision may be explained by differences in patient characteristics and implant selection as well as the surgeons' yearly volume of unicompartmental knee arthroplasties.

Risk factors for total knee arthroplasty aseptic revision.

Using a Total Joint Replacement Registry, patient, operative, implant, surgeon, and hospital risk factors associated with aseptic revision after primary total knee arthroplasty (TKA) were evaluated. From 04/2001 to 12/31/2010 64,017 primary TKA cases, followed for a median time of 2.9 years, were registered and included in the analysis. Patients were predominantly female, white, with osteoarthritis, and obese. The crude aseptic revision rate is 1.3% (N=826). The cumulative survival for aseptic revision at 8 years is 97.6% (95% CI 97.3%-97.8%). Adjusted models revealed that age, race, body mass index, diabetic status, bilateral procedures, high-flex implants, and the LCS mobile bearing knee are associated with risk of revision. Gender, general health status, diagnosis, surgeon fellowship training, surgeon volume, hospital volume, fixation, and bearing surface material were not associated with risk of aseptic revision. Recognition of surgical factors associated with TKA failures can help the surgeons with their choices of surgical techniques and implants.

Sex and risk of hip implant failure: assessing total hip arthroplasty outcomes in the United States.

IMPORTANCE: The role of sex in relationship to implant failure after total hip arthroplasty (THA) is important for patient management and device innovation. OBJECTIVE: To evaluate the association of sex with short-term risk of THA revision after adjusting for patient, implant, surgery, surgeon, and hospital confounders. DESIGN AND SETTING: A prospective cohort of patients enrolled in a total joint replacement registry from April 1, 2001, through December 31, 2010. PARTICIPANTS: Patients undergoing primary, elective, unilateral THA. MAIN OUTCOME MEASURES: Failure of THA, defined as revision procedure for (1) any reason, (2) septic reason, or (3) aseptic reason after the index procedure. RESULTS: A total of 35,140 THAs with 3.0 years of median follow-up were identified. Women constituted 57.5% of the study sample, and the mean (SD) patient age was 65.7 (11.6) years. A higher proportion of women received 28-mm femoral heads (28.2% vs 13.1%) and had metal on highly cross-linked polyethylene-bearing surfaces (60.6% vs 53.7%) than men. Men had a higher proportion of 36-mm or larger heads (55.4% vs 32.8%) and metal on metal-bearing surfaces (19.4% vs 9.6%). At 5-year follow-up, implant survival was 97.4% (95% CI, 97.2%-97.6%). Device survival for men (97.7%; 95% CI, 97.4%-98.0%) vs women (97.1%; 95% CI, 96.8%-97.4%) was significantly different (P = .01). After adjustments, the hazards ratios for women were 1.29 (95% CI, 1.11-1.51) for all-cause revision, 1.32 (95% CI, 1.10-1.58) for aseptic revision, and 1.17 (95% CI, 0.81-1.68) for septic revision. CONCLUSIONS: After considering patient-, surgery-, surgeon-, volume-, and implant-specific risk factors, women had a 29% higher risk of implant failure than men after THA in this community-based sample.