Costs of Joint Replacement in Osteoarthritis: A Study Using the National Joint Registry and Clinical Practice Research Datalink Data Sets.

OBJECTIVE: To estimate the costs of primary hip and knee replacement in individuals with osteoarthritis up to 2 years postsurgery, compare costs before and after the surgery, and identify predictors of hospital costs. METHODS: Patients age ≥18 years with primary planned hip or knee replacements and osteoarthritis in England between 2008 and 2016 were identified from the National Joint Registry and linked with Hospital Episode Statistics data containing inpatient episodes. Primary care data linked with hospital outpatient records were also used to identify patients age ≥18 years with primary hip or knee replacements between 2008 and 2016. All health care resource use was valued using 2016/2017 costs, and nonparametric censoring methods were used to estimate total 1-year and 2-year costs. RESULTS: We identified 854,866 individuals undergoing hip or knee replacement. The mean censor-adjusted 1-year hospitalization costs for hip and knee replacement were £7,827 (95% confidence interval [95% CI] 7,813, 7,842) and £7,805 (95% CI 7,790, 7,818), respectively. Complications and revisions were associated with up to a 3-fold increase in 1-year hospitalization costs. The censor-adjusted 2-year costs were £9,258 (95% CI 9,233, 9,280) and £9,452 (95% CI 9,430, 9,475) for hip and knee replacement, respectively. Adding primary and outpatient care, the mean total hip and knee replacement 2-year costs were £11,987 and £12,578, respectively. CONCLUSION: There are significant costs following joint replacement. Revisions and complications accounted for considerable costs and there is a significant incentive to identify best approaches to reduce these.

How Accurate Are the Surgical Risk Preoperative Assessment System (SURPAS) Universal Calculators in Total Joint Arthroplasty?

BACKGROUND: Surgical outcome prediction models are useful for many purposes, including informed consent, shared decision making, preoperative mitigation of modifiable risk, and risk-adjusted quality measures. The recently reported Surgical Risk Preoperative Assessment System (SURPAS) universal risk calculators were developed using 2005-2012 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), and they demonstrated excellent overall and specialty-specific performance. However, surgeons must assess whether universal calculators are accurate for the small subset of procedures they perform. To our knowledge, SURPAS has not been tested in a subset of patients undergoing lower-extremity total joint arthroplasty (TJA). QUESTIONS/PURPOSES: How accurate are SURPAS models' predictions for patients undergoing TJA? METHODS: We identified an internal subset of patients undergoing non-emergency THA or TKA from the 2012 ACS-NSQIP, the most recent year of the SURPAS development dataset. To assess the accuracy of SURPAS prediction models, 30-day postoperative outcomes were defined as in the original SURPAS study: mortality, overall morbidity, and six complication clusters-pulmonary, infectious, cardiac or transfusion, renal, venous thromboembolic, and neurologic. We calculated predicted outcome probabilities by applying coefficients from the published SURPAS logistic regression models to the TJA cohort. Discrimination was assessed with C-indexes, and calibration was assessed with Hosmer-Lemeshow 10-group chi-square tests and decile plots. RESULTS: The 30-day postoperative mortality rate for TJA was 0.1%, substantially lower than the 1% mortality rate in the SURPAS development dataset. The most common postoperative complications for TJA were intraoperative or postoperative transfusion (16%), urinary tract infection (5%), and vein thrombosis (3%). The C-indexes for joint arthroplasty ranged from 0.56 for venous thromboembolism (95% CI 0.53 to 0.59 versus SURPAS C-index 0.78) to 0.82 for mortality (95% CI 0.76 to 0.88 versus SURPAS C-index 0.94). All joint arthroplasty C-index estimates, including CIs, were lower than those reported in the original SURPAS development study. Decile plots and Hosmer-Lemeshow tests indicated poor calibration. Observed mortality rates were lower than expected for patients in all risk deciles (lowest decile: no observed deaths, 0.0% versus expected 0.1%; highest decile: observed mortality 0.7% versus expected 2%; p < 0.001). Conversely, observed morbidity rates were higher than expected across all risk deciles (lowest decile: observed 12% versus expected 8%; highest decile: observed morbidity 32% versus expected 25%; p < 0.001) CONCLUSIONS: The universal SURPAS risk models have lower accuracy for TJA procedures than they do for the wider range of procedures in which the SURPAS models were originally developed. CLINICAL RELEVANCE: These results suggest that SURPAS model estimates must be evaluated for individual surgical procedures or within restricted groups of related procedures such as joint arthroplasty. Given substantial variation in patient populations and outcomes across numerous surgical procedures, universal perioperative risk calculators may not produce accurate and reliable results for specific procedures. Surgeons and healthcare administrators should use risk calculators developed and validated for specific procedures most relevant to each decision. Continued work is needed to assess the accuracy of universal risk calculators in more narrow procedural categories based on similarity of outcome event rates and prevalence of predictive variables across procedures.

Pulmonary Complications After Hip and Knee Arthroplasty in the United States, 2004-2014.

BACKGROUND: Pulmonary complications after total joint arthroplasty (TJA) are uncommon but have significant cost impact. Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are 2 of the 5 top procedures requiring inpatient stay within the United States. Subsequent pulmonary complications therefore may impose substantial cost burden for US health care. The purpose of this study was to describe the incidence, risk factors, and clinical implications of pulmonary complications (ie, pneumonia, respiratory failure, pulmonary embolism [PE], and aspiration) after TJA in the United States. METHODS: The National Inpatient Sample (NIS) was queried for all patients undergoing primary, elective THA and TKA between years 2004 and 2014. Pulmonary complications were defined as the occurrence of pneumonia, respiratory failure, PE, or aspiration after TJA. Demographic and clinical characteristics, inpatient cost, length of stay (LOS), and mortality were compared between patients with and without documented perioperative pulmonary complications. Given the stratified nature of the NIS database, estimates of incidence throughout the United States were made with application of trend weights to observed database frequencies. Analyses of estimated annual complication rates were made using χ tests. RESULTS: Between 2004 and 2014, an estimated 2,679,351 patients underwent elective primary THA. A total of 5,527,205 patients were estimated to have undergone elective primary TKA. THA 1.42% (95% CI, 1.37%-1.47%) and 1.71% (95% CI, 1.66%-1.76%) of TKA procedures were complicated by pneumonia, respiratory failure, PE, or aspiration. During this time, the incidence of perioperative pulmonary complications decreased from 1.57% (95% CI, 1.41%-1.73%) to 1.01% (95% CI, 0.92%-1.10%) after THA (P < .0001) and from 2.03% (95% CI, 1.88%-2.18%) to 1.33% (95% CI, 1.25%-1.42%) after TKA (P < .0001). The adjusted odds ratio (aOR) of experiencing a pulmonary complication was highest among patients with history of significant weight loss (aOR = 4.77; 99.9% CI, 3.97-5.73), fluid/electrolyte disorders (aOR = 3.33; 99.9% CI, 3.11-3.56), congestive heart failure (CHF; aOR = 3.32; 99.9% CI, 3.07-3.58), preexisting paralytic condition (aOR = 2.03; 99.9% CI, 1.57-2.61), and human immunodeficiency virus infection (aOR = 2.00; 99.9% CI, 1.06-3.78). Perioperative pulmonary complications were associated with increased LOS (THA = 3.03 days; 99.9% CI, 2.76-3.31; TKA = +2.72 days; 99.9% CI, 2.58-2.86), increased hospital costs (THA = +9163 US dollars; 99.9% CI, 8054-10,272; TKA = +7257 US dollars; 99.9% CI, 6650-7865), and increased mortality (THA: aOR = 121; 99.9% CI, 78-187; TKA: aOR = 150; 95% CI, 97-233). CONCLUSIONS: Despite a decline in overall incidence, perioperative pulmonary complications represent a significant potential source of perioperative morbidity and mortality. The current study highlights potential risk factors for pulmonary complications. Recognition of these factors may help to better stratify patients and mitigate risk of potential complications. This is particularly true of respiratory failure as it is associated with the high increases in resource utilization and mortality in this group.

Enhanced recovery after surgery (ERAS) pathway for primary hip and knee arthroplasty: study protocol for a randomized controlled trial.

BACKGROUND: With the substantially growing trend of the aging populations in China and the rest of the world, the number of total hip and total knee arthroplasty (THA and TKA) cases are increasing dramatically. It is important to develop practical strategies to improve the quality of healthcare and better outcome for patients undergoing THA and TKA. Enhanced recovery after surgery (ERAS) pathways have been reported to promote earlier recovery and be beneficial for patients. We propose the hypothesis that the ERAS pathway could reduce the length of stay (LOS) in hospital for patients undergoing primary THA or TKA. METHODS/DESIGN: This trial is a prospective, open-labelled, multi-centered, randomized controlled trial that will test the superiority of the ERAS pathway in term of LOS in hospital for the patients undergoing primary THA or TKA compared to current non-ERAS clinical practice. A total of 640 patients undergoing primary THA or TKA will be randomly allocated to either ERAS pathway (ERAS group) or conventional care according to individual participating center (non-ERAS group). The primary outcome is the total LOS in hospital; the secondary outcomes include postoperative LOS, all-cause mortality by 30 days after operation, in-hospital complications, early mobilization, postoperative pain control, total in-hospital cost, and readmission rate by 30 days after discharge from the hospital. DISCUSSION: This trial is designed to evaluate the superiority of the ERAS pathway to conventional non-ERAS clinical practice in reducing the LOS. The results may provide new insight into the clinical applications of the ERAS pathway for THA and TKA. TRIAL REGISTRATION: National Institutes of Health Clinical Trials Registry, NCT03517098 . Registered on 4 May 2018.

Medicaid insurance status predicts postoperative mortality after total knee arthroplasty in state inpatient databases.

Aim: Medicaid versus private primary insurance status may predict in-hospital mortality and morbidity after total knee arthroplasty (TKA). Materials & methods: Regression models were used to test our hypothesis in patients in the State Inpatient Database (SID) from five states who underwent primary TKA from January 2007 to December 2014. Results: Medicaid patients had greater odds of in-hospital mortality (odds ratio [OR]: 1.73; 95% CI: 1.01-2.95), greater odds of any postoperative complications (OR: 1.25; 95% CI: 1.18-1.33), experience longer lengths of stay (OR: 1.09; 95% CI: 1.08-1.10) and higher total charges (OR: 1.03; 95% CI: 1.02-1.04). Conclusion: Medicaid insurance status is associated with higher in-hospital mortality and morbidity in patients after TKA compared with private insurance.

Association of Preoperative Opioid Use With Mortality and Short-term Safety Outcomes After Total Knee Replacement.

Importance: Prescription opioid use is common among patients with moderate to severe knee osteoarthritis before undergoing total knee replacement (TKR). Preoperative opioid use may be associated with worse clinical and safety outcomes after TKR. Objective: To determine the association of preoperative opioid use among patients 65 years and older with mortality and other complications at 30 days post-TKR. Design, Setting, And Participants: This cohort study used claims data from January 1, 2010, to December 31, 2014, from a random sample of US Medicare enrollees 65 years and older who underwent TKR. Based on opioid dispensing in 360 days prior to TKR, patients were classified as continuous (≥1 opioid dispensing in each of the past 12 months) or intermittent (any dispensing of opioids in the past 12 months but not continuous use) opioid users or as opioid-naive patients (no opioids dispensed in the past 12 months). Data analyses were conducted from October 3, 2017, to November 8, 2018. Main Outcomes and Measures: Primary outcomes included in-hospital mortality and 30-day post-TKR mortality, hospital readmission, and revision operation. Secondary safety outcomes at 30 days post-TKR included opioid overdose and vertebral and nonvertebral fracture. Multivariable Cox proportional hazards models estimated hazard ratios (HRs) and 95% CIs. Results: Of 316 593 patients (mean [SD] age, 73.9 [5.8] years; 214 677 [67.8%] women) who underwent TKR, 22 895 (7.2%) were continuous opioid users, 161 511 (51.0%) were intermittent opioid users, and 132 187 (41.7%) were opioid naive. In-hospital mortality occurred in 276 patients (0.09%). At 30 days post-TKR, 828 patients (0.26%) died, 16 786 patients (5.30%) had hospital readmission, and 921 patients (0.29%) had a revision operation. All primary and secondary outcomes occurred more frequently among continuous opioid users compared with opioid-naive patients. Compared with opioid-naive patients and after adjusting for demographic characteristics, combined comorbidity score, number of different prescription medications, and frailty, continuous opioid users had greater risk of revision operations (HR, 1.63; 95% CI, 1.15-2.32), vertebral fractures (HR, 2.37; 95% CI, 1.37-4.09), and opioid overdose (HR, 4.82; 95% CI, 1.36-17.07) at 30 days post-TKR. However, after adjusting covariates, there were no statistically significant differences in in-hospital (HR, 1.18; 95% CI, 0.73-1.90) or 30-day (HR, 1.05; 95% CI, 0.73-1.51) mortality between continuous opioid users and opioid-naive patients. Conclusions and Relevance: After adjusting for baseline risk profiles, including comorbidities and frailty, continuous opioid users had a higher risk of revision operations, vertebral fractures, and opioid overdose at 30 days post-TKR but not of in-hospital or 30-day mortality, compared with opioid-naive patients. These results highlight the need for better understanding of patient characteristics associated with chronic opioid use to optimize preoperative assessment of overall risk after TKR.

Anaesthetic care of patients undergoing primary hip and knee arthroplasty: consensus recommendations from the International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) based on a systematic review and meta-analysis.

BACKGROUND: Evidence-based international expert consensus regarding anaesthetic practice in hip/knee arthroplasty surgery is needed for improved healthcare outcomes. METHODS: The International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) systematic review, including randomised controlled and observational studies comparing neuraxial to general anaesthesia regarding major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, genitourinary, thromboembolic, neurological, infectious, and bleeding complications. Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, from 1946 to May 17, 2018 were queried. Meta-analysis and Grading of Recommendations Assessment, Development and Evaluation approach was utilised to assess evidence quality and to develop recommendations. RESULTS: The analysis of 94 studies revealed that neuraxial anaesthesia was associated with lower odds or no difference in virtually all reported complications, except for urinary retention. Excerpt of complications for neuraxial vs general anaesthesia in hip/knee arthroplasty, respectively: mortality odds ratio (OR): 0.67, 95% confidence interval (CI): 0.57-0.80/OR: 0.83, 95% CI: 0.60-1.15; pulmonary OR: 0.65, 95% CI: 0.52-0.80/OR: 0.69, 95% CI: 0.58-0.81; acute renal failure OR: 0.69, 95% CI: 0.59-0.81/OR: 0.73, 95% CI: 0.65-0.82; deep venous thrombosis OR: 0.52, 95% CI: 0.42-0.65/OR: 0.77, 95% CI: 0.64-0.93; infections OR: 0.73, 95% CI: 0.67-0.79/OR: 0.80, 95% CI: 0.76-0.85; and blood transfusion OR: 0.85, 95% CI: 0.82-0.89/OR: 0.84, 95% CI: 0.82-0.87. CONCLUSIONS: Recommendation: primary neuraxial anaesthesia is preferred for knee arthroplasty, given several positive postoperative outcome benefits; evidence level: low, weak recommendation. RECOMMENDATION: neuraxial anaesthesia is recommended for hip arthroplasty given associated outcome benefits; evidence level: moderate-low, strong recommendation. Based on current evidence, the consensus group recommends neuraxial over general anaesthesia for hip/knee arthroplasty. TRIAL REGISTRY NUMBER: PROSPERO CRD42018099935.

Sickle cell disease and readmissions rates after lower extremity arthroplasty: a multistate analysis 2007-2014.

AIM: To compare readmission rates between patients with sickle cell disease (SCD) and non-sickle cell disease undergoing total hip and knee arthroplasty (THA and TKA). METHODS: Identified adult patients who underwent THA or TKA from 2007 to 2014 in California, Florida, New York, Maryland and Kentucky using a multistate database. Outcomes were 30- and 90-day readmission rates, mortality, complications, length of stay and hospital charges. Logistic regression models were used for analysis. RESULTS: Compared with non-sickle cell disease patients following TKA and THA, SCD patients had higher odds of 30- (odds ratio [OR]: 3.79) and 90-day readmissions (OR: 4.15), mortality (OR: 6.54), more complications, longer length of stay, and higher total charges. CONCLUSION: Following TKA and THA, SCD is associated with higher readmissions and worse outcomes.

Reconsidering Strategies for Managing Chronic Periprosthetic Joint Infection in Total Knee Arthroplasty: Using Decision Analytics to Find the Optimal Strategy Between One-Stage and Two-Stage Total Knee Revision.

BACKGROUND: Periprosthetic joint infection (PJI) following total knee arthroplasty is a growing concern, as the demand for total knee arthroplasty (TKA) expands annually. Although 2-stage revision is considered the gold standard in management, there is substantial morbidity and mortality associated with this strategy. One-stage revision is associated with lower mortality rates and better quality of life, and there has been increased interest in utilizing the 1-stage strategy. However, surgeons are faced with a difficult decision regarding which strategy to use to treat these infections, considering uncertainty with respect to eradication of infection, quality of life, and societal costs with each strategy. The purpose of the current study was to use decision analysis to determine the optimal decision for the management of PJI following TKA. METHODS: An expected-value decision tree was constructed to estimate the quality-adjusted life-years (QALYs) and costs associated with 1-stage and 2-stage revision. Two decision trees were created: Decision Tree 1 was constructed for all pathogens, and Decision Tree 2 was constructed solely for difficult-to-treat infections, including methicillin-resistant infections. Values for parameters in the decision model, such as mortality rate, reinfection rate, and need for additional surgeries, were derived from the literature. Medical costs were derived from Medicare data. Sensitivity analysis determined which parameters in the decision model had the most influence on the optimal strategy. RESULTS: In both decision trees, the 1-stage strategy produced greater health utility while also being more cost-effective. In the Monte Carlo simulation for Decision Trees 1 and 2, 1-stage was the dominant strategy in about 85% and 69% of the trials, respectively. Sensitivity analysis showed that the reinfection and 1-year mortality rates were the most sensitive parameters influencing the optimal decision. CONCLUSIONS: Despite 2-stage revision being considered the current gold standard for infection eradication in patients with PJI following TKA, the optimal decision that produced the highest quality of life was 1-stage revision. These results should be considered in shared decision-making with patients who experience PJI following TKA. LEVEL OF EVIDENCE: Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

New 5-Factor Modified Frailty Index Predicts Morbidity and Mortality in Primary Hip and Knee Arthroplasty.

BACKGROUND: While the 11-factor modified frailty index (mFI) has been shown to predict adverse outcomes in patients undergoing total joint arthroplasty, the 5-factor index has not been evaluated in this patient population. The goal of this study was to evaluate the utility of the mFI-5 as a predictor of morbidity and mortality in patients undergoing primary total hip and knee arthroplasty. METHODS: A retrospective analysis of the American College of Surgeons National Surgical Quality Improvement Program's database for patients undergoing total hip arthroplasty and total knee arthroplasty between the years 2005 and 2016 was conducted. The 5-factor score, which includes the presence of comorbid diabetes, hypertension, congestive heart failure, chronic obstructive pulmonary disease, and functional status, was calculated for each patient. Multivariate logistic regression models were used to assess the relationship between the mFI-5 and postoperative complications while controlling for demographic variables. RESULTS: One hundred forty thousand one hundred fifty-eight patients undergoing total hip arthroplasty and 226,398 patients undergoing total knee arthroplasty were identified. After adjusting for demographic variables and comorbid conditions, logistic regression analyses revealed that the mFI-5 was a strong predictor for total complications, Clavien-Dindo grade IV complications (cardiac arrest, myocardial infarction, septic shock, pulmonary embolism, postoperative dialysis, reintubation, and prolonged ventilator requirement), surgical site infections, readmission, and 30-day mortality (P < .001). CONCLUSIONS: The mFI-5 is an independent predictor of postoperative complications including life-threatening medical complications, surgical site infections, hospital readmission, and 30-day mortality after primary hip and knee arthroplasty. This clinical tool can be used to identify high-risk surgical patients and guide preoperative counseling to optimize outcomes. LEVEL OF EVIDENCE: III.

Insurance Status Affects In-Hospital Complication Rates After Total Knee Arthroplasty.

Insurance status has been shown to be a predictor of patient morbidity and mortality. The purpose of this study was to evaluate the effect of patient insurance status on the in-hospital complication rates following total knee arthroplasty. Data were obtained from the Nationwide Inpatient Sample (2004 through 2011). Patient demographics and comorbidities were analyzed and stratified by insurance type. Analysis was performed with a matched cohort comparing complication rates between patients with Medicare vs private insurance using the coarsened exact matching algorithm and multivariable logistic regression. A total of 1,352,505 patients (Medicare, 57.8%; private insurance, 35.6%; Medicaid/uninsured, 3.1%; other, 3.3%; unknown, 0.2%) fulfilled the inclusion criteria. The matched cohort analysis comparing Medicare with privately insured patients showed significantly higher risk of mortality (relative risk [RR], 1.34; P<.001), wound dehiscence (RR, 1.32; P<.001), central nervous system complications (RR, 1.16; P=.030), and gastrointestinal complications (RR, 1.13; P<.001) in Medicare patients, whereas privately insured patients had a higher risk of cardiac complications (RR, 0.93; P=.003). Independent of insurance status, older patients and patients with an increased comorbidity index were also associated with a higher complication rate and mortality following total knee arthroplasty. These data suggest that insurance status may be considered as an independent risk factor for increased complications when stratifying patients preoperatively for total knee replacement. Further research is needed to investigate the disparities in these findings to optimize patient outcomes following total knee arthroplasty. [Orthopedics. 2018; 41(3):e340-e347.].

Risk Adjustment Is Necessary in Value-based Outcomes Models for Infected TKA.

BACKGROUND: The Medicare Access and CHIP Reauthorization Act of 2015 provides the framework to link reimbursement for providers based on outcome metrics. Concerns exist that the lack of risk adjustment for patients undergoing revision TKA for an infection may cause problems with access to care. QUESTIONS/PURPOSES: (1) After controlling for confounding variables, do patients undergoing revision TKA for infection have higher 30-day readmission, reoperation, and mortality rates than those undergoing revision TKA for aseptic causes? (2) Compared with patients undergoing revision TKA who are believed not to have infections, are patients undergoing revision for infected TKAs at increased risk for complications? METHODS: We queried the American College of Surgeons National Surgical Quality Improvement Program database for patients undergoing revision TKA from 2012 to 2015 identified by Current Procedural Terminology (CPT) codes 27486, 27487, and 27488. Of the 10,848 patients identified, four were excluded with a diagnosis of malignancy (International Classification of Diseases, 9th Revision code 170.7, 170.9, 171.8, or 198.5). This validated, national database records short-term outcome data for inpatient procedures and does not rely on administrative coding data. Demographic variables, comorbidities, and outcomes were compared between patients believed to have infected TKAs and those undergoing revision for aseptic causes. A multivariate logistic regression analysis was performed to identify independent factors associated with complications, readmissions, reoperations, and mortality. RESULTS: After controlling for demographic factors and medical comorbidities, TKA revision for infection was independently associated with complications (odds ratio [OR], 3.736; 95% confidence interval [CI], 3.198-4.365; p < 0.001), 30-day readmission (OR, 1.455; 95% CI, 1.207-1.755; p < 0.001), 30-day reoperation (OR, 1.614; 95% CI, 1.278-2.037; p < 0.001), and 30-day mortality (OR, 3.337; 95% CI, 1.213-9.180; p = 0.020). Patients with infected TKA had higher rates of postoperative infection (OR, 3.818; 95% CI, 3.082-4.728; p < 0.001), renal failure (OR, 36.709; 95% CI, 8.255-163.231; p < 0.001), sepsis (OR, 7.582; 95% CI, 5.529-10.397; p < 0.001), and septic shock (OR, 3.031; 95% CI, 1.376-6.675; p = 0.006). CONCLUSIONS: Policymakers should be aware of the higher rate of mortality, readmissions, reoperations, and complications in patients with infected TKA. Without appropriate risk adjustment or excluding these patients all together from alternative payment and quality reporting models, fewer providers will be incentivized to care for patients with infected TKA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Hospital costs, length of stay and prevalence of hip and knee arthroplasty in patients with inflammatory bowel disease.

AIM: To examined the prevalence of hip and knee arthroplasty in patients with inflammatory bowel disease (IBD) by comparing the diagnostic codes for these procedures in patients with IBD and a control group of patients. METHODS: The National Inpatient Sample database (NIS) is part of the Healthcare Cost and Utilization Project (HCUP), the largest publicly available inpatient healthcare database in the United States. The NIS samples about 20% of discharges from all community hospitals participating in HCUP, representative of more than 95% of the United States population, with approximately 7000000 hospitalizations reported annually. NIS contains data on diagnoses, procedures, demographics, length of stay (LOS), co-morbidities and outcomes. ICD-9-CM diagnostic codes for primary hospitalizations for arthroplasty of the hip or knee with a co-diagnosis of IBD [combining both Crohn's disease (CD) and ulcerative colitis (UC)] were used to identify study subjects for cost and LOS analysis for NIS from 1999-2012. Statistical analysis: 1: 2 propensity score matching between IBD vs a control group based on following factors: Patient age, gender, race, total co-morbidities, # of procedures, admission type, insurance, income quartiles, and hospital bed size, location and hospital teaching status. Categorical variables were reported as frequency and compared by χ2 tests or Fisher's exact tests. Individual 1:3 matching was also performed for patients carrying diagnostic codes for CD and for patients with the diagnostic code for UC. After matching, continuous variables were rcompared with Wilcoxon signed rank or Paired T-tests. Binary outcomes were compared with the McNemar's test. This process was performed for the diagnosis of hip or knee arthroplasty and IBD (CD and UC combined). Prevalence of the primary or secondary diagnostic codes for these procedures in patients with IBD was determined from NIS 2007. RESULTS: Costs and mortality were similar for patients with IBD and controls, but LOS was significantly longer for hip arthroplasties patients with IBD, (3.85 +/-2.59 d vs 3.68 +/-2.54 d, respectively, P = 0.009). Costs, LOS and survival from the procedures was similar in patients with CD and UC compared to matched controls. These results are shown in Tables 1-10. The prevalence of hip arthroplasty in patients with IBD was 0.5% in 2007, (170/33783 total patients with diagnostic codes for IBD) and was 0.66% in matched controls (P = 0.0012). The prevalence of knee arthroplasty in patients with IBD was 1.36, (292/21202 IBD patients) and was 2.22% in matched controls (P < 0.0001). CONCLUSION: Costs and mortality rates for hip and knee arthroplasties are the same in patients with IBD and the general population, while a statistical but non-relevant increase in LOS is seen for hip arthroplasties in patients with IBD. Compared to the general population, arthroplasties of the hip and knee are less prevalent in hospitalized patients with IBD.

Post-Discharge Care Duration, Charges, and Outcomes Among Medicare Patients After Primary Total Hip and Knee Arthroplasty.

BACKGROUND: In April 2016, the U.S. Centers for Medicare & Medicaid Services initiated mandatory 90-day bundled payments for total hip and knee arthroplasty for much of the country. Our goal was to determine duration of care, 90-day charges, and readmission rates by discharge disposition and U.S. region after hip or knee arthroplasty. METHODS: Using the 2008 Medicare Provider Analysis and Review database 100% sample, we identified patients who had undergone elective primary total hip or knee arthroplasty. We collected data on patient age, sex, comorbidities, U.S. Census region, discharge disposition, duration of care, 90-day charges, and readmission. Multivariate regression was used to assess factors associated with readmission (logistic) and charges (linear). Significance was set at p < 0.01. RESULTS: Patients undergoing 138,842 total hip arthroplasties were discharged to home (18%), home health care (34%), extended-care facilities (35%), and inpatient rehabilitation (13%); patients undergoing 329,233 total knee arthroplasties were discharged to home (21%), home health care (38%), extended-care facilities (31%), and inpatient rehabilitation (10%). Patients in the Northeast were more likely to be discharged to extended-care facilities or inpatient rehabilitation than patients in other regions. Patients in the West had the highest 90-day charges. Approximately 70% of patients were discharged home from extended-care facilities, whereas after inpatient rehabilitation, >50% of patients received home health care. Among those discharged to home, 90-day readmission rates were highest in the South (9.6%) for patients undergoing total hip arthroplasty and in the Midwest (8.7%) and the South (8.5%) for patients undergoing total knee arthroplasty. Having ≥4 comorbidities, followed by discharge to inpatient rehabilitation or an extended-care facility, had the strongest associations with readmission, whereas the region of the West and the discharge disposition to inpatient rehabilitation had the strongest association with higher charges. CONCLUSIONS: Among Medicare patients, discharge disposition and number of comorbidities were most strongly associated with readmission. Inpatient rehabilitation and the West region had the strongest associations with higher charges. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Outcomes Over 90-Day Episodes of Care in Medicare Fee-for-Service Beneficiaries Receiving Joint Arthroplasty.

BACKGROUND: In an effort to improve quality and reduce costs, payments are being increasingly tied to value through alternative payment models, such as episode-based payments. The objective of this study was to better understand the pattern and variation in outcomes among Medicare beneficiaries receiving lower extremity joint arthroplasty over 90-day episodes of care. METHODS: Observed rates of mortality, complications, and readmissions were calculated over 90-day episodes of care among Medicare fee-for-service beneficiaries who received elective knee arthroplasty and elective or nonelective hip arthroplasty procedures in 2013-2014 (N = 640,021). Post-acute care utilization of skilled nursing and inpatient rehabilitation facilities was collected from Medicare files. RESULTS: Mortality rates over 90 days were 0.4% (knee arthroplasty), 0.5% (elective hip arthroplasty), and 13.4% (nonelective hip arthroplasty). Complication rates were 2.1% (knee arthroplasty), 3.0% (elective hip arthroplasty), and 8.5% (nonelective hip arthroplasty). Inpatient rehabilitation facility utilization rates were 6.0% (knee arthroplasty), 6.7% (elective hip arthroplasty), and 23.5% (nonelective hip arthroplasty). Skilled nursing facility utilization rates were 33.9% (knee arthroplasty), 33.4% (elective hip arthroplasty), and 72.1% (nonelective hip arthroplasty). Readmission rates were 6.3% (knee arthroplasty), 7.0% (elective hip arthroplasty), and 19.2% (nonelective hip arthroplasty). Patients' age and clinical characteristics yielded consistent patterns across all outcomes. CONCLUSION: Outcomes in our national cohort of Medicare beneficiaries receiving lower extremity joint arthroplasties varied across procedure types and patient characteristics. Future research examining trends in access to care, resource use, and care quality over bundled episodes will be important for addressing the challenges of value-based payment reform.

What Are the Frequency, Associated Factors, and Mortality of Amputation and Arthrodesis After a Failed Infected TKA?

BACKGROUND: For patients with failed surgical treatment of an infected TKA, salvage operations such as arthrodesis or above-knee amputation (AKA) may be considered. Clinical and institutional factors associated with AKA and arthrodesis after a failed TKA have not been investigated in a large-scale population, and the utilization rate and trend of these measures are not well known. QUESTIONS/PURPOSES: (1) How has the frequency of arthrodesis and AKA after infected TKA changed over the last 10 years? (2) What clinical or institutional factors are associated with patients undergoing arthrodesis or AKA? (3) What is the risk of mortality after arthrodesis or AKA? METHODS: The Medicare 100% National Inpatient Claims Database was used to identify 44,466 patients 65 years of age or older who were diagnosed with an infected TKA and who underwent revision between 2005 and 2014 based on International Classification of Diseases, 9th Revision, Clinical Modification codes. Overall, 1182 knee arthrodeses and 1864 AKAs were identified among the study population. One year of data before the index infection-related knee revision were used to examine patient demographic, institutional, and clinical factors, including comorbidities, hospital volumes, and surgeon volumes. We developed Cox regression models to investigate the risk of arthrodesis, AKA, and death as outcomes. In addition, the year of the index revision was included as a covariate to determine if the risk of subsequent surgical interventions was changing over time. The risk of mortality was also assessed as the event of interest using a similar multivariate Cox model for each patient group (arthrodesis, AKA) in addition to those who underwent additional revisions but who did not undergo either of the salvage procedures. RESULTS: The number of arthrodesis (hazard ratio [HR], 0.90, p < 0.001) and amputation (HR, 0.95, p < 0.001) procedures showed a declining trend. Clinical factors associated with arthrodesis included acute renal failure (HR, 1.22 [1.06-1.41], p = 0.006), obesity (HR, 1.58 [1.35-1.84], p < 0.001), and having additional infection-related revisions (HR for 2+ additional revisions, 1.36 [1.13-1.64], p = 0.001). Higher Charlson comorbidity score (HR for a score of 5+ versus 0, 2.56 [2.12-3.14], p < 0.001), obesity (HR, 1.14 [1.00-1.30], p = 0.044), deep vein thrombosis (HR, 1.34 [1.12-1.60], p = 0.001), and additional revisions (HR for 2+ additional revisions, 2.19 [1.91-2.49], p < 0.001) were factors associated with AKA, which in turn was an independent risk factor for mortality. The risk of death increased with amputation after adjusting for age, comorbidities, and other factors (HR, 1.28 [1.20-1.37], p < 0.001), but patients who received arthrodesis did not show a change in mortality compared with the patients who did not receive arthrodesis or amputation (HR, 1.00 [0.91-1.10], p = 0.971). CONCLUSIONS: The findings of this study suggest that clinicians may be more aggressively attempting to preserve the knee even in the face of chronic prosthetic joint infection but also show that a greater number of revisions is associated with a greater risk of subsequent AKA or arthrodesis. The results also suggest that recommending centers with a high volume of joint arthroplasties may be a way to reduce the risk of the salvage procedures. LEVEL OF EVIDENCE: Level III, therapeutic study.

Risk-Adjusted Hospital Outcomes in Medicare Total Joint Replacement Surgical Procedures.

BACKGROUND: Comparative measurement of hospital outcomes can define opportunities for care improvement and will assume great importance as alternative payment models for inpatient total joint replacement surgical procedures are introduced. The purpose of this study was to develop risk-adjusted models for Medicare inpatient and post-discharge adverse outcomes in elective lower-extremity total joint replacement and to apply these models for hospital comparison. METHODS: Hospitals with ≥50 qualifying cases of elective total hip replacement and total knee replacement from the Medicare Limited Data Set database of 2010 to 2012 were studied. Logistic risk models were designed for adverse outcomes of inpatient mortality, prolonged length-of-stay outliers in the index hospitalization, 90-day post-discharge deaths without readmission, and 90-day readmissions after excluding non-related readmissions. For each hospital, models were used to predict total adverse outcomes, the number of standard deviations from the mean (z-scores) for hospital performance, and risk-adjusted adverse outcomes for each hospital. RESULTS: A total of 253,978 patients who underwent total hip replacement and 672,515 patients who underwent total knee replacement were studied. The observed overall adverse outcome rates were 12.0% for total hip replacement and 11.6% for total knee replacement. The z-scores for 1,483 hospitals performing total hip replacements varied from -5.09 better than predicted to +5.62 poorer than predicted; 98 hospitals were ≥2 standard deviations better than predicted and 142 hospitals were ≥2 standard deviations poorer than predicted. The risk-adjusted adverse outcome rate for these hospitals was 6.6% for the best-decile hospitals and 19.8% for the poorest-decile hospitals. The z-scores for the 2,349 hospitals performing total knee replacements varied from -5.85 better than predicted to +11.75 poorer than predicted; 223 hospitals were ≥2 standard deviations better than predicted and 319 hospitals were ≥2 standard deviations poorer than predicted. The risk-adjusted adverse outcome rate for these hospitals was 6.4% for the best-decile hospitals and 19.3% for the poorest-decile hospitals. CONCLUSIONS: Risk-adjusted outcomes demonstrate wide variability and illustrate the need for improvement among poorer-performing hospitals for bundled payments of joint replacement surgical procedures. CLINICAL RELEVANCE: Adverse outcomes are known to occur in the experience of all clinicians and hospitals. The risk-adjusted benchmarking of hospital performance permits the identification of adverse events that are potentially preventable.

The impact of frailty on outcomes and healthcare resource usage after total joint arthroplasty: a population-based cohort study.

AIMS: Total joint arthroplasty (TJA) is commonly performed in elderly patients. Frailty, an aggregate expression of vulnerability, becomes increasingly common with advanced age, and independently predicts adverse outcomes and the use of resources after a variety of non-cardiac surgical procedures. Our aim was to assess the impact of frailty on outcomes after TJA. PATIENTS AND METHODS: We analysed the impact of pre-operative frailty on death and the use of resources after elective TJA in a population-based cohort study using linked administrative data from Ontario, Canada. RESULTS: Of 125 163 patients aged > 65 years having elective TJA, 3023 (2.4%) were frail according to the Johns Hopkins ACG frailty-defining diagnoses indicator. One year follow-up was complete for all patients. Frail patients had a higher adjusted one year risk of mortality (hazard ratio 3.03, 95% confidence interval (CI) 2.62 to 3.51), a higher rate of admission to intensive care (odds ratio (OR) 2.52, 95% CI 2.21 to 2.89), increased length of stay (incidence rate ratio 1.62, 95% CI 1.59 to 1.65), a higher rate of discharge to institutional care (OR 2.09, 95% CI 1.93 to 2.25), a higher rate of re-admission (OR 1.33, 95% CI 1.07 to 1.66) and increased costs at 30, 90 and 365 days post-operatively. Frailty affected outcomes after total hip arthroplasty more than after total knee arthroplasty. TAKE HOME MESSAGE: Frailty is an important risk factor for death after elective TJA, and increases post-operative resource utilisation across many metrics. Processes to optimise the outcomes and efficiency of TJA in frail patients are needed. Cite this article: Bone Joint J 2016;98-B:799-805.

Inpatient Mortality and Morbidity for Dialysis-Dependent Patients Undergoing Primary Total Hip or Knee Arthroplasty.

BACKGROUND: Dialysis-dependent patients can develop osteoarthritis or osteonecrosis, warranting hip or knee arthroplasty. Their comorbidities predispose them to complications. Our goal was to determine inpatient outcomes of dialysis-dependent patients after primary elective total hip or knee arthroplasty. METHODS: In the National Inpatient Sample, we identified 2934 dialysis-dependent patients who had undergone total hip or knee arthroplasty from 2000 through 2009 and compared them with 6,186,475 patients who had undergone the same procedures and were not dialysis-dependent. We described demographic characteristics, comorbidities, and outcomes and assessed associations of dialysis status with inpatient mortality and complications. RESULTS: In the hip arthroplasty group, dialysis-dependent patients were younger (63.2 compared with 65.2 years; p = 0.0476) and more commonly diagnosed with osteonecrosis (34.29% compared with 10.94%; p < 0.0001) than non-dialysis-dependent patients. Dialysis-dependent patients had higher inpatient mortality rates (1.88% compared with 0.13%; p < 0.0001) and greater overall complication rates (9.98% compared with 4.97%; p = 0.0001). Dialysis was an independent risk factor for mortality (odds ratio, 6.66; 95% confidence interval [95% CI], 2.66 to 16.66) and complications (odds ratio, 1.53; 95% CI, 1.01 to 2.33). In the knee arthroplasty group, dialysis-dependent patients were similar in age (66.7 compared with 66.8 years; p = 0.8085) and were more commonly diagnosed with osteonecrosis (3.32% compared with 0.74%; p < 0.0001) than non-dialysis-dependent patients. Dialysis-dependent patients had higher inpatient mortality rates (0.92% compared with 0.10%; p < 0.0001) and greater overall complication rates (12.48% compared with 5.00%; p < 0.0001). Dialysis status was an independent risk factor for mortality (odds ratio, 3.31; 95% CI, 1.04 to 10.54) and complications (odds ratio, 1.86; 95% CI, 1.34 to 2.60). CONCLUSIONS: Total hip and knee arthroplasty in dialysis-dependent patients presents high risk, with inpatient mortality rates ten to twenty times greater and overall complication rates two times greater than in non-dialysis-dependent patients. Arthroplasty should be approached with caution and preferably should be delayed until after renal transplantation.