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Various pedagogies have been proposed in the engineering education literature. However, simply applying pedagogical approaches might be ineffective in helping learners acquire and exhibit skills necessary for future industrial endeavours, if learning activities and learning objects are not structurally designed. In this paper, we present an integrative and interpretive review of studies to show how instructional design principles listed in the First Principles of Instruction (FPI) framework are in alignment with teaching and learning of and with cognitive and psychomotor skills, particularly in industrial training and engineering education. The applications of FPI and its impacts on learning were discussed, whereas congruence between the i) FPI and the Bloom’s Taxonomy, and ii) FPI and psychomotor instruction, were identified. This study aims to offer insights for redesigning teaching and training in engineering education with an effective instructional design, ultimately enhancing the pedagogical values of its learning objects and activities.

ObjectiveThere is debate about the effectiveness of intra-articular (IA) hyaluronic acid (HA) injections. We asked the following questions: (1) What is the epidemiology of IA HA use in knee arthroplasty (KA) patients? (2) Is Synvisc associated with a delay to KA? (3) Is there a difference in the delay to KA with the number of HA courses?DesignThe Optum Clinformatics data set (2006–June 2016) was used to identify patients with knee osteoarthritis (OA). Patients who did not receive IA HA were identified, along with those who received Synvisc or non-Synvisc HA. The median duration from knee OA to KA was compared using quantile regression modeling with propensity score weighting. The trend in time to KA with each HA course was evaluated.ResultsOf 4,027,848 knee OA patients, 141,305 patients underwent KA. Overall median time from knee OA diagnosis to KA was 1.2 years (average: 1.9 ± 1.9 years; interquartile range of 0.4-2.8 years). HA patients had significantly longer adjusted median time to KA by at least 7 months ( P < 0.001). After adjusting for the time to HA and number of injections, Synvisc patients had 1.7 months longer time to KA than non-Synvisc HA patients ( P < 0.001). There was a trend toward longer time to KA with more HA courses.ConclusionsMost KA patients did not use HA (73.7%) and when received, it was associated with a longer median time to KA by at least 7 months, though the cause and effect could not be examined. The delay to KA increased with more HA courses.

BACKGROUND The purpose of this study is to analyze whether the cost for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) bearings used in primary total hip arthroplasty (THA) was changing over time, and if the cost differential between ceramic bearings and metal-on-polyethylene (M-PE) bearings was approaching the previously published tipping point for cost-effectiveness of $325. METHODS A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The inpatient hospital cost, calculated using cost-to-charge ratios, and hospital payment were analyzed. The differential cost of C-PE and COC bearings, compared to M-PE, were evaluated using parametric and nonparametric models. RESULTS After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost and payments for primary THA with a C-PE or COC was within ±1% of the cost for primary THA with M-PE bearings (P < .001). From the nonparametric analysis, the median hospital cost was $318-$360 more for C-PE and COC than M-PE. The differential in median Medicare payment for THA with ceramic bearings compared to M-PE was

The authors hypothesized that unplanned readmissions, which are often caused by infections and dislocation, may be reduced with ceramic bearing usage. They also sought to confirm that the readmission rates for ceramic bearings were associated with the year of surgery. They identified 245,077 elderly patients (65+) who underwent primary total hip arthroplasty (THA) between 2010 and 2015 with known bearing types (ceramic-on-polyethylene [C-PE] ceramic-on-ceramic [COC], and metal-on-polyethylene [M-PE]) from the Medicare 100% inpatient database. Outcomes included relative risk of 30- and 90-day readmission. Propensity scores were developed to adjust for selection bias in the choice of bearing type at index surgery. Cox regression incorporating propensity score stratification (10 levels) was used to evaluate the impact of bearing selection on outcomes, after adjusting for patient-, hospital-, surgeon-related factors, as well as the year of surgery. With C-PE bearings, the unadjusted (crude) 90-day readmission rate decreased from 8.7% in 2010 to 8.3% in 2015. For COC bearings, the crude 90-day readmission rate decreased from 10.5 to 9.1% from 2010 to 2015. After adjustment, year of surgery was associated with reduced readmission risk for both types of ceramic bearings in 30-day readmissions (p

The Affordable Care Act of 2010 advanced the economic model of bundled payments for total joint arthroplasty (TJA), in which hospitals will be financially responsible for readmissions, typically at 90 days after surgery. However, little is known about the financial burden of readmissions and what patient, clinical, and hospital factors drive readmission costs. (1) What is the incidence, payer mix, and demographics of THA and TKA readmissions in the United States? (2) What patient, clinical, and hospital factors are associated with the cost of 30- and 90-day readmissions after primary THA and TKA? (3) Are there any differences in the economic burden of THA and TKA readmissions between payers? (4) What types of THA and TKA readmissions are most costly to the US hospital system? The recently developed Nationwide Readmissions Database from the Healthcare Cost and Utilization Project (2006 hospitals from 21 states) was used to identify 719,394 primary TJAs and 62,493 90-day readmissions in the first 9 months of 2013 based on International Classification of Diseases, 9th Revision, Clinical Modification codes. We classified the reasons for readmissions as either procedure- or medical-related. Cost-to-charge ratios supplied with the Nationwide Readmissions Database were used to compute the individual per-patient cost of 90-day readmissions as a continuous variable in separate general linear models for THA and TKA. Payer, patient, clinical, and hospital factors were treated as covariates. We estimated the national burden of readmissions by payer and by the reason for readmission. The national rates of 30- and 90-day readmissions after THA were 4% (95% confidence interval [CI], 4.2%–4.5%) and 8% (95% CI, 7.5%–8.1%), respectively. The national rates of 30- and 90-day readmissions after primary TKA were 4% (95% CI, 3.8%–4.0%) and 7% (95% CI, 6.8%–7.2%), respectively. The five most important variables responsible for the cost of 90-day THA readmissions (in rank order, based on the Type III F-statistic, p

As life expectancy increases, more elderly patients with end-stage hip arthritis are electing to undergo primary THA. Octogenarians undergoing THA have more comorbidities than younger patients, but this is not reflected in risk adjustment models for bundled care programs. The burden of care associated with THA in octogenarians has not been well characterized, and doing so may help these value-based programs make adjustments so that this vulnerable patient population does not risk losing access under accountable care models.The purpose of this study was to describe care use, comorbidities, and complications among octogenarians undergoing primary THA.Five percent of the Medicare national administrative claims data was queried to identify patients diagnosed with hip osteoarthritis between January 1, 1998, and December 31, 2013. Patients who underwent primary THA were identified and followed longitudinally during the study period using their unique, encrypted Medicare beneficiary identifiers. We compared risk factors and complications between the octogenarian group versus those aged 65 to 69 years. Multivariate Cox regression was used to evaluate the effect of patient/hospital factors on risk of revision, periprosthetic joint infection, dislocation, venous thromboembolism (VTE), and mortality. Patient factors in the model included age, sex, race, region, socioeconomic status, and health status based on Charlson comorbidity score 12 months before replacement surgery.There were 11,960 THAs in the octogenarians in 1998, which increased to 21,620 in 2013, an 81% increase during this study period. Octogenarians were more likely to have a Charlson score of 3 or higher than those patients aged 65 to 69 years (30% versus 17%, odds ratio [OR] 2.07 [1.98-2.20]; p0.001), and they were more likely to have coronary artery disease or congestive heart failure (47% versus 29%, OR 2.16 [2.06-2.26]; p0.001). The octogenarian group had a greater risk of dislocation (+12%, p = 0.01), VTE (+14%, p0.001), and mortality (+150%, p0.001) compared with the younger age cohort. A total of 21% of the octogenarians were readmitted after surgery compared with 12% for patients in the younger group (OR=1.64, 95% confidence interval 1.54-1.75; p0.001).Because octogenarians are at increased risk of dislocation, VTE, medical complications, and mortality after THA, value-based care models that penalize hospitals for readmissions and complications may inadvertently result in loss of access to care for this group of patients as a result of the financial makeup of these bundled care models. Value-based care models were developed to improve care and decrease healthcare costs but may have unintended consequences in the octogenarian with higher complication and readmission risks. Financial losses may lead to institutions from withdrawing from the Bundled Payments for Care Improvement program. To try to prevent this from happening to this vulnerable patient population, bundled care programs should evolve and be modified to allow for risk stratification in the overall payment formula to account for increased age and comorbid conditions to ensure continued successful participation in the program among all the stakeholders.Level III, therapeutic study.

The purpose of this study was to determine whether the cost of readmissions after primary total hip and knee arthroplasty (THA and TKA) has decreased since the introduction of health care reform legislation and what patient, clinical, and hospital factors drive such costs.The 100% Medicare inpatient dataset was used to identify 1,654,602 primary THA and TKA procedures between 2010 and 2014. The per-patient cost of readmissions was evaluated in general linear models in which the year of surgery and patient, clinical, and hospital factors were treated as covariates in separate models for THA and TKA.The year-to-year risk of 90-day readmission was reduced by 2% and 4% (P.001) for THA and TKA, respectively. By contrast, the cost of readmissions did not change significantly over time. The 5 most important variables associated with the cost of 90-day THA readmissions (in rank order) were the nature of the readmission (ie, due to medical or procedure-related reasons), the length of stay, hospital's teaching status, discharge disposition, and hospital's overall total joint arthroplasty volume. The top 5 factors associated with the cost of 90-day TKA readmissions were (in rank order) the length of stay, hospital's teaching status, discharge disposition, patient's gender, and age.Although readmission rates declined slightly, the results of this study do not support the hypothesis that readmission costs have decreased since the introduction of health care reform legislation. Instead, we found that clinical and hospital factors were among the most important cost drivers.

The potential for developmental neurotoxicity (DNT) of environmental chemicals may be evaluated using specific test guidelines from the US Environmental Protection Agency or the Organisation for Economic Cooperation and Development (OECD). These guidelines generate neurobehavioral, neuropathological, and morphometric data that are evaluated by regulatory agencies globally. Data from these DNT guideline studies, or the more recent OECD extended one-generation reproductive toxicity guideline, play a pivotal role in children's health risk assessment in different world areas. Data from the same study may be interpreted differently by regulatory authorities in different countries resulting in inconsistent evaluations that may lead to inconsistencies in risk assessment decisions internationally, resulting in regional differences in public health protection or in commercial trade barriers. These issues of data interpretation and reporting are also relevant to juvenile and pre-postnatal studies conducted more routinely for pharmaceuticals and veterinary medicines. There is a need for development of recommendations geared toward the operational needs of the regulatory scientific reviewers who apply these studies in risk assessments, as well as the scientists who generate DNT data sets. The workshops summarized here draw upon the experience of the authors representing government, industry, contract research organizations, and academia to discuss the scientific issues that have emerged from diverse regulatory evaluations. Although various regulatory bodies have different risk management decisions and labeling requirements that are difficult to harmonize, the workshops provided an opportunity to work toward more harmonized scientific approaches for evaluating DNT data within the context of different regulatory frameworks. Five speakers and their coauthors with neurotoxicology, neuropathology, and regulatory toxicology expertise discussed issues of variability, data reporting and analysis, and expectations in DNT data that are encountered by regulatory authorities. In addition, principles for harmonized evaluation of data were suggested using guideline DNT data as case studies.

BackgroundThe purpose of this study was to analyze the outcomes of ceramic bearings used in primary total hip arthroplasty (THA) in the Medicare population.MethodsA total of 315,784 elderly Medicare patients (65+) who underwent primary THA between 2005 and 2014 were identified from the United States Medicare 100% national administrative hospital claims database. Outcomes of interest included infection, dislocation, revision, or mortality at any time point after primary surgery. Propensity scores were developed to adjust for selection bias in the choice of bearing type at index primary surgery.ResultsFor primary THA patients treated with ceramic-on-polyethylene (C-PE) bearings and ceramic-on-ceramic (COC) bearings, there was significantly reduced risk of infection relative to metal-on-polyethylene (M-PE) bearings (C-PE hazard ratio [HR]: 0.86, P = .001; COC HR: 0.74, P = .01). For the C-PE cohort, we also observed reduced risk of dislocation (HR: 0.81, P < .001) and mortality (HR: 0.92, P < .001). There was no significant difference in risk of revision for either the C-PE or COC bearing cohorts when compared with M-PE. For the COC cohort, there was no significant difference in dislocation or mortality risk.ConclusionAs in previous studies, we found that ceramic bearings have similar overall revision risk as M-PE bearings in primary THA at 8-9 years of follow-up. The results indicate that, after adjusting for selection bias and various confounding patient-, surgeon-, and hospital-related factors, Medicare primary THA patients treated with ceramic bearings exhibit lower risk of infection than those treated with M-PE bearings. In addition, C-PE bearings were associated with lower risk of dislocation and mortality.

AimsCephalomedullary nails (CMNs) are commonly used for the treatment of intertrochanteric hip fractures. Total hip arthroplasty (THA) may be used as a salvage procedure when fixation fails in these patients. The aim of this study was to analyze the complications of THA following failed intertrochanteric hip fracture fixation using a CMN.Patients and MethodsPatients who underwent THA were identified from the 5% subset of Medicare Parts A/B between 2002 and 2015. A subgroup involving those with an intertrochanteric fracture that was treated using a CMN during the previous five years was identified and compared with the remaining patients who underwent THA. The length of stay (LOS) was compared using both univariate and multivariate analysis. The incidence of infection, dislocation, revision, and re-admission was compared between the two groups, using multivariate analysis adjusted for demographic, hospital, and clinical factors.ResultsThe Medicare data yielded 56 522 patients who underwent primary THA, of whom 369 had previously been treated with a CMN. The percentage of THAs that were undertaken between 2002 and 2005 in patients who had previously been treated with a CMN (0.346%) more than doubled between 2012 and 2015 (0.781%). The CMN group tended to be older and female, and to have a higher Charlson Comorbidity Index and lower socioeconomic status. The mean LOS was 1.5 days longer (5.3 vs 3.8) in the CMN group (p < 0.0001). The incidence of complications was significantly higher in the CMN group compared with the non-CMN group: infection (6.2% vs 2.6%), dislocation (8.1% vs 4.5%), revision (8.4% vs 4.3%), revision for infection (1.1% vs 0.37%), and revision for dislocation (2.2% vs 0.6%).ConclusionThe incidence of conversion to THA following failed intertrochanteric hip fracture fixation using a CMN continues to increase. This occurs in elderly patients with increased comorbidities. There is a significantly increased risk of infection, dislocation, and LOS in these patients. Patients with failed intertrochanteric hip fracture fixation using a CMN who require THA should be made aware of the increased risk of complications, and steps need to be taken to reduce this risk. Cite this article: Bone Joint J 2019;101-B(6 Supple B):91–96.

BACKGROUND Evaluation of total joint arthroplasty (TJA) patient-reported outcomes and survivorship requires that records of the index and potential revision arthroplasty procedure are reliably captured. Until the goal of the American Joint Replacement Registry (AJRR) of more-complete nationwide capture is reached, one must assume that patient migration from hospitals enrolled in the AJRR to nonAJRR hospitals occurs. Since such migration might result in loss to followup and erroneous conclusions on survivorship and other outcomes of interest, we sought to quantify the level of migration and identify factors that might be associated with migration in a specific AJRR population. QUESTIONS/PURPOSES (1) What are the out-of-state and within-state migration patterns of U.S. Medicare TJA patients over time? (2) What patient demographic and institutional factors are associated with these patterns? METHODS Hospital records of Medicare fee-for-service beneficiaries enrolled from January 1, 2004 to December 31, 2015, were queried to identify primary TJA procedures. Because of the nationwide nature of the Medicare program, low rates of loss to followup among Medicare beneficiaries, as well as long-established enrollment and claims processing procedures, this database is ideal for examining patient migration after TJA. We identified an initial cohort of 5.33 million TJA records from 2004 to 2016; after excluding patients younger than 65 years of age, those enrolled solely due to disability, those enrolled in a Medicare HMO, or residing outside the United States, the final analytical dataset consisted of 1.38 million THAs and 3.03 million TKAs. The rate of change in state or county of residence, based on Medicare annual enrollment data, was calculated as a function of patient demographic and institutional factors. A multivariate Cox model with competing risk adjustment was used to evaluate the association of patient demographic and institutional factors with risk of out-of-state or out-of-county (within-state) migration. RESULTS One year after the primary arthroplasty, 0.61% (95% confidence interval [CI], 0.60-0.61; p < 0.001 for this and all comparisons in this Results section) of Medicare patients moved out of state and another 0.62% (95% CI, 0.60-0.63) moved to a different county within the same state. Five years after the primary arthroplasty, approximately 5.41% (95% CI, 5.39-5.44) of patients moved out of state and another 5.50% (95% CI, 5.46-5.54) Medicare patients moved to a different county within the same state. Among numerous factors of interest, women were more likely to migrate out of state compared with men (hazard ratios [HR], 1.06), whereas black patients were less likely (HR, 0.82). Patients in the Midwest were less likely to migrate compared with patients in the South (HR, 0.74). Patients aged 80 and older were more likely to migrate compared with 65- to 69-year-old patients (HR, 1.19). Patients with higher Charlson Comorbidity Index scores compared with 0 were more likely to migrate (index of 5+; HR, 1.19). CONCLUSIONS Capturing detailed information on patients who migrate out of county or state, with associated changes in medical facility, requires a nationwide network of participating registry hospitals. At 5 years from primary arthroplasty, more than 10% of Medicare patients were found to migrate out of county or out of state, and the rate increases to 18% after 10 years. Since it must be assumed that younger patients might exhibit even higher migration levels, these findings may help inform public policy as a "best-case" estimate of loss to followup under the current AJRR capture area. Our study reinforces the need to continue aggressive hospital recruitment to the AJRR, while future research using an increasingly robust AJRR database may help establish the migration patterns of nonMedicare patients. LEVEL OF EVIDENCE Level III, therapeutic study.

The purpose of this study was to determine the risk factors associated with reinfection in patients treated with irrigation and debridement (I&D) with liner exchange for an acute (less than 3 months) prosthetic joint infection following the index primary total knee arthroplasty (TKA). Medicare claims database was queried to identify patients with periprosthetic joint infection within 3 months of their index TKA who underwent I&D with tibial polyethylene liner exchange. Exclusion criteria included age 85 years old (p 6 weeks after index procedure compared with those performed within 2 weeks. Patients older than 85 years, diabetics, or treated with I&D with liner exchange > 14 days following the primary TKA had a significantly higher risk of reinfection within 1 year. Patients should be cautioned on the risk of reinfection prior to proceeding with I&D with liner exchange > 2 weeks following the index procedure.

Prior work suggests that computer-assisted navigation improves acetabular component position during primary total hip arthroplasty (THA). However, it is not known whether this translates to improvements in clinical outcomes. The purpose of this study was to test for associations between navigation use and the risk of dislocation, aseptic revision of the acetabular component, aseptic revision of the femoral component, aseptic revision of either component, and acute periprosthetic joint infection (PJI).This was a retrospective cohort study, conducted using the 100% Medicare Part A claims data set. Inclusion criteria were an age of ≥65 years and primary THA for osteoarthritis. First, the association between navigation use and patient and hospital characteristics was assessed. Second, while controlling for these characteristics, multivariate regression was used to test for the association of navigation use and the outcomes listed above.A total of 803,732 primary THA procedures were identified; 14,540 (1.81%) involved the use of navigation. Navigation use was associated with younger age, other/unknown race, the Western census region, higher socioeconomic status, lower Charlson Comorbidity Index, shorter length of stay, private hospitals, teaching hospitals, and larger hospitals (p0.05 for each). Navigation use was associated with a lower rate of dislocation (1.00% versus 1.70% for no navigation; adjusted hazard ratio [HR] = 0.69; 95% confidence interval [CI] = 0.58 to 0.82; p0.001) and aseptic revision of the acetabular component (1.03% versus 1.55%; adjusted HR = 0.75; 95% CI = 0.64 to 0.88; p0.001). Navigation was not associated with aseptic revision of the femoral component (1.54% versus 1.87%; p = 0.064), aseptic revision of either component (1.91% versus 2.31%; p = 0.077), acute PJI at 6 weeks (0.34% versus 0.45%; p = 0.121), or acute PJI at 90 days (0.50% versus 0.66%; p = 0.458).The findings of this study suggest that navigation is associated with reductions in the rates of dislocation and aseptic acetabular revision following primary THA. However, these results should be interpreted carefully in the setting of potential confounding by unmeasured variables, such as surgeon volume, family support, and patient compliance. Causality cannot be inferred until further prospective trials can vet this technology.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Publications on the prevalence of unicompartmental knee arthroplasty in the United States using a single database may have underestimated the "true" number of cases performed, given that several unicondylar knee arthroplasty (UKA) patients are65 years and have private insurance. The prevalence of UKA in elderly (≥65 years) and younger (65 years) populations was evaluated using the 2002 to 2011 5% sample of the Medicare data (Part B) and the 2004 to June 2012 MarketScan Commercial and Medicare Supplemental databases, respectively. The prevalence of UKA was stratified by age, gender, census region, Charlson comorbidity index, Medicare buy-in status, and diagnosis. The annual rate of change in the UKA rate was examined using Poisson regression to evaluate temporal changes considering year as a covariate. A total of 5235 and 23,310 UKA procedures were identified from the 5% Medicare and MarketScan databases, respectively. The rates of UKA generally increased until 2008, after which there was a decline. In both cohorts, gender and year of operation were found to be significantly associated with UKA rate. Analysis of data obtained over the past few years revealed that males 55 to 64 years, 65 to 69 years, and 70 to 74 years were the only age-gender groups whose UKA rates appeared to be trending upward. From 2002 to 2011, the rate of UKAs performed in the United States has increased, and a significant proportion of the surgeries were performed in younger (65 years) patients.

Pulmonary veno-occlusive disease (PVOD) and pulmonary capillary haemangiomatosis (PCH) are rare causes of pulmonary hypertension, and they are now known to represent manifestations of a common disease characterized by fibrous remodelling of the small pulmonary veins and endothelial cell proliferation within the pulmonary capillaries. Heritable PVOD and PCH are caused by the same genetic defect of biallelic mutations of the EIF2AK4 gene. Other risk factors associated with the development of PVOD/PCH include chemotherapy treatment, organic solvent exposure, and systemic sclerosis.

Industrial/Engineering training act as a supportive role in developing students' working skills. However, traditional training only involves face-to-face learning environments. Therefore, enforcing learning among students with different learning speed would be difficult. In this work-in-progress paper, we proposed adopting the Flipped Classroom approach to an engineering training course (Internet of Things module). Students can have a flexible laboratory schedule in exploring on acquired technical skills. For streamlining the learning process, the “First Principles of Instruction” framework had been used for guiding the design of learning activities. Ways of adopting the framework for learning activity design had been described in details.

Instability is a common reason for revision surgery after total hip arthroplasty (THA). Recent studies suggest that revisions performed in the early postoperative period are associated with higher complication rates. The purpose of this study is to assess the effect of timing of revision for instability on subsequent complication rates.The Medicare Part A claims database was queried from 2010 to 2017 to identify revision THAs for instability. Patients were divided based on time between index and revision surgeries:1, 1-2, 2-3, 3-6, 6-9, 9-12, and12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics and comorbidities.Of 445,499 THAs identified, 9298 (2.1%) underwent revision for instability. Revision THA within 3 months had the highest rate of periprosthetic joint infection (PJI): 14.7% at1 month, 12.7% at 1-2 months, and 10.6% at 2-3 months vs 6.9% at12 months (P.001). Adjusting for confounding factors, PJI risk remained elevated at earlier periods:1 month (adjusted odds ratio [aOR]: 1.84, 95% confidence interval [CI]: 1.51-2.23, P.001), 1-2 months (aOR: 1.45, 95% CI: 1.16-1.82, P = .001), 2-3 months (aOR: 1.35, 95% CI: 1.02-1.78, P = .036). However, revisions performed within 9 months of index surgery had lower rates of subsequent instability than revisions performed12 months (aOR: 0.67-0.85, P.050), which may be due to lower rates of acetabular revision and higher rates of head-liner exchange in this later group.When dislocation occurs in the early postoperative period, delaying revision surgery beyond 3 months from the index procedure may be warranted to reduce risk of PJI.

Patients with morbid obesity, defined as a BMI greater than 40 kg/mWe sought to quantify (1) the surgical risk, and (2) the costs associated with complications after THA in patients who were morbidly obesity (BMI ≥ 40 kg/mThis is a retrospective study of patients, using Medicare hospital claims data, who underwent THA. The ICD-9 Clinical Modification (CM) diagnosis code V85.4x was used to identify patients with morbid obesity and with super obesity from October 1, 2010 through December 31, 2014. Patients without any BMI-related diagnosis codes were used as the control group. Twelve complications occurring during the 90 days after THA were analyzed using multivariate Cox models adjusting for patient demographic, comorbidities, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through the subsequent 90 days.Patients with morbid obesity had increased postoperative complications including prosthetic joint infection (hazard ratio [HR], 3.71; 95% CI, 3.2-4.31; p0.001), revision (HR, 1.91; 95% CI, 1.69-2.16; p0.001), and wound dehiscence (HR, 3.91; 95% CI, 3.14-4.86; p0.001). In addition, patients with morbid obesity had increased risk of deep vein thrombosis (HR, 1.43; 95% CI, 1.14-1.79; p0.002), pulmonary embolism (HR, 1.57; 95% CI, 1.25-1.99; p0.001), implant failure (HR, 1.48; 95% CI, 1.3-1.68; p0.001), acute renal failure (HR, 1.68; 95% CI, 1.56-1.80; p0.001), and all-cause readmission (HR, 1.48; 95% CI, 1.40-1.56; p0.001). However, death (HR, 0.94 95% CI, 0.73-1.19 p0.592), acute myocardial infarction (HR, 0.94; 95% CI, 0.74-1.2 p0.631), and dislocation (HR 1.07; 95% CI, 0.85-1.34; p0.585) were not different between patients in the control and morbidly obese groups. Super obese patients had an increased risk of infection (HR, 6.48; 95% CI, 4.54-9.25; p0.001), wound dehiscence (HR, 9.81; 95% CI, 6.31-15.24; p0.001), and readmission (HR, 2.16; 95% CI, 1.84-2.54; p0.001) compared with patients with normal BMI. Controlling for patient and institutional factors, each THA had mean total hospital charges of USD 88,419 among patients who were super obese compared with USD 73,827 for the control group, a difference of USD 14,591. Medicare payment for the patients who were super obese also was higher, but only by USD 3631.Patients who are super obese are at increased risk for serious complications compared with patients with morbid obesity, whose risks are elevated relative to patients whose BMI is less than 40 kg/mLevel III, therapeutic study.

Background This study investigated the risk and cost of postoperative complications associated with morbid and super obesity after total knee arthroplasty (TKA). Methods A retrospective cohort study was conducted of patients who underwent TKA using Medicare hospital claims data. The International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code V85.4x was used to identify morbidly obese patients (body mass index [BMI] ≥40 kg/m 2 ) and superobese patients (BMI ≥50 kg/m 2 ) in 2011-2013. Patients without any BMI-related diagnosis codes were used as controls. Twelve complications occurred in the 90-day period after TKA were analyzed using multivariate Cox models, adjusting for patient demographic, morbidity, and institutional factors. In addition, hospital charges and payments were compared from primary surgery through subsequent 90 days. Results Morbidly obese patients showed a significantly elevated risk in most complications examined, with a 2-fold or higher risk in dislocation and wound dehiscence. In addition, death, periprosthetic joint infection, acute renal failure, and knee revision had significant hazard ratios between 1.5 and 2.0. However, risk of deep vein thrombosis and acute myocardial infarction did not increase for the morbidly obese patients. Superobese patients had significant increase in risk of infection, wound dehiscence, acute renal failures, revisions, death, and readmission compared with patients with BMI 40-49 kg/m 2 . Significant dose–response trend was found between the level of BMI and risk for death, dislocation, implant failure, infection, readmission, revision, wound dehiscence, and acute renal failure. Controlling for patient and institutional factors, each TKA had an average total hospital charges of $75,884 among superobese patients, compared to $65,118 for the control group, a difference of $10,767. Medicare payment for the superobese patients was also higher, but only by $2703. Conclusion Morbidly obese patients pose a significantly higher risk profile than normal-weight patients in a broad range of complications after TKA. Superobese patients add another layer of risk compared with less obese patients and are considerably more expensive to treat by health care systems. Technical difficulties and the high demand on resources present a severe challenge for providing treatment for such patients.

The purpose of this study was to determine the incidence of subsequent reinfections after initial treatment of an infected total knee arthroplasty, identify risk factors leading to reinfection, and compare results among the varying treatment modalities.A total of 1,493,924 primary TKA patients were identified from the Medicare data between October 1, 2005, and December 31, 2011. Patients who encountered periprosthetic joint infection (PJI) after TKA were identified using International Classification of Diseases, Ninth Revision, Clinical Modification code 996.66. The risk of subsequent PJI was stratified based on the first-line treatment and compared between the various first-line treatment groups.A total of 16,622 patients (1.1%) were diagnosed with PJI. The Kaplan-Meier risk of PJI was 0.77% at 1 year and 1.58% at 6 years. Age (P.001), Charlson score (P.001), hospital control (P.001), race (P = .036), census region (P = .031), gender (P.001) were identified as risk factors for PJI. Of the PJI patients, 20.8% (n = 2806) were treated with incision and drainage (ID), 15.9% (n = 2150) treated with ID and liner exchange, 22.7% (n = 3069) treated with 1-stage revision, 39.7% (n = 5364) treated with 2-stage revision, and 0.98% (n = 132) treated with amputation. After first-line treatment, 26% of patients with PJI had a subsequent PJI. Patients undergoing ID as a first-line treatment had the highest risk of reinfection, with risks of 28.2% at 1 year and 43.2% at 6 years. One-stage revision patients had 33.9% greater adjusted risk of reinfection than 2-stage revision patients (P.001).Two-stage reimplantation, despite 19% recurrence, had the highest success rate. Given the higher failure rates of ID and single-stage revisions, guidelines need to be established for their specific indications.

Introduction Hyaluronic acid (HA) and corticosteroid (CS) injections are frequently used in the management of osteoarthritis (OA) of the knee, despite a lack of strong evidence supporting their efficacy in the literature. The purpose of this study is to evaluate trends in HA and CS usage in Medicare patients over the past 15 years. Methods The Medicare 5% national sample database was used to identify 581,022 patients (representing an estimated 11.6 million) with a diagnosis of knee OA between 1999 and 2013. Results The percentage of newly diagnosed knee OA patients who received any injection trended from 39% in 1999 to 47% in 2006 and then declined to 37.5% in 2013. However, the mean number of injections per newly diagnosed OA patient nearly doubled from 0.27 to 0.45 for CS and from 0.18 to 0.36 for HA. Among those having both HA and CS injections, 69% had CS as first-line treatment, whereas 31% had HA first. Conclusion The percentage of newly diagnosed knee OA patients receiving injections peaked in 2007 and then decreased steadily through 2013, as did the proportion of patients receiving HA injections as first-line therapy. However, the number of injections per patient has increased significantly over the past 15 years in both groups.

Advances in surgical technique, implant design, and clinical care pathways have resulted in higher expectations for improved clinical outcomes after primary THA; however, despite these advances, it is unclear whether the risk of revision THA actually has decreased with time. Understanding trends in short- and mid-term risks of revision will be helpful in directing clinical, research, and policy efforts to improve THA outcomes. We therefore asked (1) whether there have been changes in overall short- and mid-term risks of revision THA among patients in the Medicare population who underwent primary THA between 1998 and 2010; and (2) whether there are different demographic factors associated with short- and mid- term risks of revision THA. Using the Medicare 5% national sample database, patients who underwent primary THA between 1998 and 2010 followed by subsequent revision through 2011 were identified by ICD-9-CM procedure codes 81.51 and 81.53/80.05/00.70–00.73, respectively. This dataset included a random sample of Medicare beneficiaries based on their social security number. Only patients with minimum 1-year followup after primary THA were included in our analysis. A total of 64,260 patients who underwent primary THA were identified from the 1998 to 2010 Medicare 5% dataset. Eighty-eight percent of the patients had 1-year followup providing a final study cohort of 56,700 patients. The risk of revision was evaluated at 1, 3, 5, and 7 years. Multivariate Cox regression was used to evaluate temporal trends in revision risk using two methods to account for time effects with periods 1998 to 2002, 2003 to 2007, and 2008 to 2010 for the index year of primary THA, and individual year of index of primary THA as independent variables. The analysis adjusted for patient age, sex, race, census region, Charlson score, and socioeconomic status. The 7-year crude risk of revision THA declined from 7.10% in 1998 to 2002 to 6.09% in 2008 to 2010, representing a 14.4% overall reduction in adjusted risk of revision (p = 0.0058; 95% CI, 4.4%–23%). Similarly, the 5-year crude risk of revision THA declined from 5.96% in 1998 to 2002 to 5.11% in 2008 to 2010, representing a 14.2% overall reduction in adjusted risk of revision (p = 0.0069; 95% CI, 4.1%–23%). However, the adjusted risk of revision THA at 3 years was not different from 1998 to 2002 (4.70%) and 2008 to 2010 (4.03%; p = 0.1176). Similarly, the adjusted risk of revision at 1 year did not differ from 1998 to 2002 (2.83%) and 2008 to 2010 (2.42%; p = 0.3386). Patients with more comorbidities had a greater adjusted risk of revision (p < 0.001) at all times: 94% (95% CI, 58%–138%) and 56% (95% CI, 33%–84%) at 1 year and 7 years, respectively, for Charlson score of 5+ vs 0). Although the mid-term (5 and 7 years) risk of revision THA has decreased during the past 14 years among Medicare beneficiaries who underwent primary THA, the short-term risk has not. These findings suggest that greater clinical, research, and policy emphasis is needed to identify potentially avoidable causes of early failure after primary THA in patients in the Medicare population, and multistakeholder solutions are needed to optimize short-term outcomes. Level III, therapeutic study.

There is general agreement that femoral nerve blocks (FNB) provide adequate immediate postoperative analgesia after total knee arthroplasty (TKA), although the effect of this technique on hospital readmission and other complications has not been quantified in a large sample. The Medicare 5% sample was used to identify TKA patients who were grouped according to postoperative FNB administration: FNB via injection; FNB via pain pump; and no FNB. Multivariate Cox regressions were used to evaluate risk factors for the postoperative outcomes. Both FNB groups were associated with a lower risk of readmission (30, 90 and 365 days, P

There is a trend towards shortening inpatient hospital stays following total hip arthroplasty (THA) in an effort to reduce healthcare costs and potentially decrease complications. The purpose of this study was to identify patients who are at risk for readmission, complications, and mortality after short stay THA. The Medicare sample (1997–2011) was used to identify THA patients with 1–2-day (Group A, n=2949) or 3–day (Group B, n=8707) stays. Complication risks were similar between groups, though there was a reduced risk for hospitalization for Group A (adjusted hazard ratio=0.90, P =0.029). These findings suggest that age and comorbidities, particularly diabetes and cardiovascular conditions, have the greatest effect on readmission and event risk after short stay THA.

Patients undergoing primary total hip arthroplasty (THA) following lumbar spine fusion have an increased incidence of dislocation compared to those without prior lumbar fusion. The purpose of this study is to determine if timing of THA prior to or after lumbar fusion would have an effect on dislocation and revision incidence in patients with both hip and lumbar spine pathology.One hundred percent Medicare inpatient claims data from 2005 to 2015 were used to compare dislocation and revision risks in patients with primary THA with pre-existing lumbar spine fusion vs THA with subsequent lumbar spine fusion within 1, 2, and 5 years after the index THA. A total of 42,300 patients met inclusion criteria, 28,668 patients of which underwent THA with pre-existing lumbar spinal fusion (LSF) and 13,632 patients who had prior THA and subsequent LSF. Patients who had THA first followed by LSF were further stratified based on the interval between index THA and subsequent LSF (1, 2, and 5 years), making 4 total groups for comparison. Multivariate cox regression analysis was performed adjusting for age, socioeconomic status, race, census region, gender, Charlson score, pre-existing conditions, discharge status, length of stay, and hospital characteristics.Patients with prior LSF undergoing THA had a 106% increased risk of dislocation compared to those with LSF done 5 years after THA (P.001). Risk of revision THA was greater in the pre-existing LSF group by 43%, 41%, and 49% at 1, 2, and 5 years post THA compared to the groups with THA done first with subsequent LSF. Dislocation was the most common etiology for revision THA in all groups, but significantly higher in the prior LSF group (26.6%).Results of this study demonstrate that sequence of surgical intervention for concomitant lumbar and hip pathology requiring LSF and THA respectively significantly impacts the fate of the THA performed. Patients with prior LSF undergoing THA are at significantly higher risk of dislocation and subsequent revision compared to those with THA first followed by delayed LSF.3.

Background: Patients with morbid obesity, defined as body mass index of greater than 40 kg/m2, are being referred for weight loss and bariatric surgery before being accepted for a total knee arthroplasty (TKA). Previous studies have identified the risks associated with doing a TKA in an individual with an increased body mass index. We now present data identifying the same risks in individuals who have undergone bariatric surgery before submitting to TKA. Questions/Purposes: (1) Has the bariatric surgery improved the risk profile for the subsequent TKA? (2) Does the type of bariatric procedure matter? Method: A retrospective cohort study was conducted of patients who underwent bariatric surgery followed by TKA using Medicare hospital claims data. A study was undertaken using the Current Procedure Terminology codes and International Classification of Diseases-9 and International Classification of Diseases-10 for bariatric surgery. These identified entries were then cross-referenced to individuals who later underwent TKA, identified by CPT 27447, between 2004 and 2016. Twelve different types of complications which occurred in the 90-day period after the TKA were analyzed. Results: Postbariatric bypass surgery patients showed a markedly elevated risk in most complications examined. In each category, the type of previous gastric surgery had notable differences in the post-TKA complication profile. In the implant failure category, the data demonstrated an even greater risk after a gastric bypass. When postbariatric patients were compared with morbidly obese individuals who had not undergone bariatric surgery, the hazard ratios (HRs) were markedly elevated for death (HR 1.47/bypass), implant failure (HR 1.58/sleeve), and pneumonia (HR 1.68/bypass). Conclusion: (1) Submitting to bariatric surgery is not sufficient to normalize risks. (2) The type of previous bariatric procedure is associated with the type of complications encountered. (3) We were unable to attribute TKA to bariatric failures. (4) Health systems and health care providers should be cautious in withholding care for patients with morbid obesity.

To evaluate opioid usage patterns for patients with low back pain (LBP) with and without spinal fusion surgery (fusion patients and nonfusion patients, respectively), including long-term prescriptions post fusion.Claims data of outpatient pharmaceutical prescriptions from privately insured patients.The 3-year utilization, cost, and morphine milligram equivalents (MME) of opioid prescriptions were evaluated for patients with LBP with and without lumbar fusion. For fusion patients, opioid prescriptions before and after fusion, as well as prescription use 3, 6, and 12 months following fusion surgery, were analyzed.Thirty-one percent of patients with LBP had opioid prescriptions within the first 6 months of initial diagnosis, which increased to 42.1% within 3 years. More than twice as many fusion patients as nonfusion patients filled opioid prescriptions (87.2% vs 41.5%; P.001). Fusion patients had 62% and 48% more days with opioid dosages of at least 50 and at least 90 MME/day, respectively, than nonfusion patients (≥50 MME/day, 84 days vs 52 days; ≥90 MME/day, 50 days vs 34 days; both P.001). Opioid burden was greater for fusion patients following surgery. Fusion patients continued to have 2 months' supply with at least 50 MME/day and 1 month's supply with at least 90 MME/day at least 12 months following surgery.The opioid burden in the LBP population is high and is further elevated in those who subsequently undergo fusion surgery. Long-term opioid prescriptions persisted in 27% of fusion patients 12 months post surgery. Efforts to identify efficacious alternative therapies to treat LBP may reduce the societal burden of chronic opioid use.

Background The American Joint Replacement Registry (AJRR) Total Joint Risk Calculator uses demographic and clinical parameters to provide risk estimates for 90-day mortality and 2-year periprosthetic joint infection (PJI). The tool is intended to help surgeons counsel their Medicare-eligible patients about their risk of death and PJI after total joint arthroplasty (TJA). However, for a predictive risk model to be useful, it must be accurate when applied to new patients; this has yet to be established for this calculator. Questions/purposes To produce accuracy metrics (ie, discrimination, calibration) for the AJRR mortality calculator using data from Medicare-eligible patients undergoing TJA in the Veterans Health Administration (VHA), the largest integrated healthcare system in the United States, where more than 10,000 TJAs are performed annually. Methods We used the AJRR calculator to predict risk of death within 90 days of surgery among 31,214 VHA patients older than 64 years of age who underwent primary TJA; data was drawn from the Veterans Affairs Surgical Quality Improvement Project (VASQIP) and VA Corporate Data Warehouse (CDW). We then used VHA mortality data to evaluate the extent to which the AJRR calculator estimates distinguished individuals who died compared with those who did not (C-statistic), and graphically depicted the relationship between estimated risk and observed mortality (calibration). As a secondary evaluation of the calculator, a sample of 39,300 patients younger than 65 years old was assigned to the youngest age group available to the user (65-69 years) as might be done in real-world practice. Results C-statistics for 90-day mortality for the older samples were 0.62 (95% CI, 0.60-0.64) and for the younger samples they were 0.46 (95% CI, 0.43-0.49), suggesting poor discrimination. Calibration analysis revealed poor correspondence between deciles of predicted risk and observed mortality rates. Poor discrimination and calibration mean that patients who died will frequently have a lower estimated risk of death than surviving patients. Conclusions For Medicare-eligible patients receiving TJA in the VA, the AJRR risk calculator had a poor performance in the prediction of 90-day mortality. There are several possible reasons for the model's poor performance. Veterans Health Administration patients, 97% of whom were men, represent only a subset of the broader Medicare population. However, applying the calculator to a subset of the target population should not affect its accuracy. Other reasons for poor performance include a lack of an underlying statistical model in the calculator's implementation and simply the challenge of predicting rare events. External validation in a more representative sample of Medicare patients should be conducted to before assuming this tool is accurate for its intended use. Level of evidence Level I, diagnostic study.

Background Periprosthetic joint infection (PJI) is a potentially deadly complication of total joint arthroplasty. This study was designed to address how the incidence of PJI and outcome of treatment, including mortality, are changing in the population over time. Methods Primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients with PJI from the 100% Medicare inpatient data set (2005-2015) were identified. Cox proportional hazards regression models for risk of PJI after THA/TKA (accounting for competing risks) or risk of all-cause mortality after PJI were adjusted for patient and clinical factors, with year included as a covariate to test for time trends. Results The unadjusted 1-year and 5-year risk of PJI was 0.69% and 1.09% for THA and 0.74% and 1.38% for TKA, respectively. After adjustment, PJI risk did not change significantly by year for THA (P = .63) or TKA (P = .96). The unadjusted 1-year and 5-year overall survival after PJI diagnosis was 88.7% and 67.2% for THA and 91.7% and 71.7% for TKA, respectively. After adjustment, the risk of mortality after PJI decreased significantly by year for THA (hazard ratio = 0.97; P Conclusion Despite recent clinical focus on preventing PJI, we are unable to detect substantial decline in the risk of PJI over time, although mortality after PJI has declined. Because PJI risk appears not to be changing over time, the incidence of PJI is anticipated to scale up proportionately with the demand for THA and TKA, which is projected to increase substantially in the coming decade.

Concerns exist that high-risk patients in alternative payment models may face difficulties with access to care without proper risk adjustment. The purpose of this study is to identify the effect of medical and orthopedic specific risk factors on the cost of a 90-day episode of care following total hip (THA) and knee arthroplasty (TKA).We queried the Medicare 5% Limited Data Set for all patients undergoing primary THA and TKA from 2010 to 2014. To evaluate the cost of an episode of care, we calculated all claims for 90 days following surgery. Multivariate analysis was performed to quantify the added episode-of-care costs for demographic variables, geography, medical comorbidities, and orthopedic specific risk factors.Of the 58,809 TKA patients, the median 90-day Medicare costs was $23,800 (interquartile range, $18,900-$32,300), while the median of the 27,293 THA patients was $24,000 (interquartile range, $18,500-$33,900). Independent risk factors (all P.05) resulting in at least a 10% increase in episode-of-care costs following TKA included malnutrition, age over 85, male gender, pulmonary disorder, failed internal fixation, Northeast region, lower socioeconomic status, neurologic disorder, and rheumatoid arthritis. Independent risk factors (all P.05) resulting in at least a 10% increase in episode-of-care costs following THA included malnutrition, male gender, age over 85, failed internal fixation, hip dysplasia, Northeast region, neurologic disorder, lower socioeconomic status, conversion THA, avascular necrosis, and depression.Certain comorbidities and orthopedic risk factors increase 90-day episode-of-care costs in the Medicare population. The current lack of proper risk stratification could be a powerful driver of decreased access to care for our most medically challenged members of society.

Periprosthetic joint infection (PJI) represents substantial clinical and economic burdens. This study evaluated patient and procedure characteristics and resource utilization associated with revision arthroplasty for PJI. The Nationwide Inpatient Sample (Q4 2005-2010) was analyzed for 235,857 revision THA (RTHA) and 301,718 revision TKA (RTKA) procedures. PJI was the most common indication for RTKA, and the third most common reason for RTHA. PJI was most commonly associated with major severity of illness (SOI) in RTHA, and with moderate SOI in RTKA. RTHA and RTKA for PJI had the longest length of stay. Costs were higher for RTHA/RTKA for PJI than for any other diagnosis except periprosthetic fracture. Epidemiologic differences exist in the rank, severity and populations for RTHA and RTKA for PJI.

STUDY DESIGN Vertebral compression fracture (VCF) patients in the 100% US Medicare data set (2005-2009). OBJECTIVE To compare the mortality and morbidity risks for VCF patients undergoing conservative treatment (nonoperated), balloon kyphoplasty (BKP), and vertebroplasty (VP). SUMMARY OF BACKGROUND DATA Studies have reported lower mortality risk for BKP or VP cohorts than nonoperated cohorts, but it is uncertain whether there are any differences in morbidity risks. METHODS Survival and morbidity was estimated by the Kaplan-Meier method, and the differences in outcomes were assessed by Cox regression between BKP, VP, and nonoperated cohorts. A propensity matching analysis was used to account for potential bias. RESULTS A total of 1,038,956 VCF patients were identified, including 141,343 BKP patients and 75,364 VP patients. The nonoperated cohort was found to have a 55% higher adjusted risk of mortality (P < 0.001) than the BKP cohort and 25% higher adjusted risk of mortality (P < 0.001) than the VP cohort. The BKP cohort was also found to have a 19% lower adjusted risk of mortality (P < 0.001) than the VP cohort. The findings were similar for mortality with pneumonia diagnosed in the 90 days before death and also after propensity matching, as well as for subgroups of osteoporotic VCF patients, including those who survived at least 1 year and those with no cancer diagnosis. With propensity matching, the nonoperated cohort had significantly higher adjusted risks of pneumonia, myocardial infarction/cardiac complications, DVT, and urinary tract infection than the BKP cohort but lower adjusted risks of subsequent augmentation/fusion, subsequent augmentation, and pulmonary/respiratory complications. The BKP cohort also had significantly lower risks of morbidity than the VP cohort, except for deep venous thrombosis (DVT), infection, and myocardial infarction/cardiac complications, which were similar between both cohorts. CONCLUSION VCF patients in the Medicare population who received vertebral augmentation therapies, specifically BKP and VP, experienced lower mortality and overall morbidity than VCF patients who received conservative management. LEVEL OF EVIDENCE 3.

Reverse shoulder arthroplasty (RSA) has been Food and Drug Administration approved in the United States since 2004 but did not obtain a unique code until 2010. Therefore, the use of this popular procedure has yet to be reported. The purpose of this study was to examine the use and reimbursement of RSA compared with total shoulder arthroplasty (TSA) and shoulder hemiarthroplasty (SHA).We analyzed the 100% sample of the 2011 Medicare Part A claims data for patients aged 65 years or older. Patient demographic characteristics, diagnoses, provider information, reimbursements, and lengths of stay were extracted from the claims data.In 2011, a total of 31,002 shoulder arthroplasty procedures were performed; 37% were RSAs, 42% were TSAs, and 21% were SHAs. Osteoarthritis was the primary diagnosis code in 91% of TSAs, 37% of SHAs, and 45% of RSAs. A primary diagnosis of osteoarthritis with no secondary code for rotator cuff tear was found in 22% of patients undergoing RSA. The mean length of stay for RSA (2.6 days; SD, 2.1 days) was longer than that for TSA (2.1 days; SD, 1.5 days) and shorter than that for SHA (3.5 days; SD, 3.6 days) (P.001). Lower-volume surgeons (10 arthroplasties per year) performed most shoulder arthroplasties: 57% of RSAs, 65% of TSAs, and 97% of SHAs. Seventy percent of RSAs were implanted by surgeons who performed more RSAs than TSAs and SHAs combined.RSA is performed with similar frequency to TSA and almost twice as much as SHA in the Medicare population. Lower-volume surgeons perform most RSAs, and a majority of surgeons perform more RSAs than all anatomic shoulder arthroplasties combined.

To further evaluate the relationship between steroid injections and osteoporotic fracture risk, we analyzed Medicare administrative claims data on both large-joint steroid injections (LJSIs) into knee and hip and transforaminal steroid injections (TSIs), as well as osteoporotic hip and wrist fractures. Our hypothesis was that a systemic effect of steroid injections would increase fracture risk in all skeletal locations regardless of injection site, whereas a local effect would produce a disproportionate increased risk of spine fracture with spine injection. Patients treated with an LJSI, a TSI, or an epidural steroid injection (ESI) were identified from 5% Medicare claims data. Patients under age 65 years and patients with prior osteoporotic fracture were excluded. Analyses were performed to determine fracture risk (adjusted hazard ratio) for each type of injection. Analysis of the Medicare data revealed that ESIs were associated with decreased osteoporotic spine fracture risk, but the effect was small and might not be clinically relevant. ESIs did not influence osteoporotic hip or wrist fracture risk, but LJSIs reduced the risk.

STUDY DESIGN Cervical decompression (CD) and cervical fusion (CF) patients in 5% Medicare Part B claims data. OBJECTIVE Evaluate the complication rate and associated risk factors after cervical spine surgery using a national sample of elderly patients. SUMMARY OF BACKGROUND DATA The number of cervical spine procedures in the United States has risen along with associated hospital costs. Postoperative complications lead to longer hospitalizations and greater costs. METHODS Demographic information and postoperative complications (90 days) were evaluated. Multivariate Cox regression was used to evaluate the risk factors for the complications, while adjusting for age, socioeconomic status, Charlson comorbidity index, race, census region, sex, and year of surgery. RESULTS Between 2010 and 2012, 1519 CD and 1273 CF Medicare patients were identified in the dataset. Respiratory complications (CD: 12.1% and CF: 14.6%), urinary retention (CD: 8.2% and CF: 9.1%), acute delirium (CD: 5.3% and CF: 6.0%), and nausea/vomiting (CD: 2.8% and CF: 3.1%) were the most commonly diagnosed complications. All other complications had an incidence of less than 1.5%. Older patients had higher risks of respiratory complications for both procedures, and CD patients with Charlson scores of 1 to 2 and 5+ were also at higher risk of respiratory complications. Males (P

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. (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? 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. 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). 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 III, therapeutic study.

Background: Few studies have explored the role of the National Health Expenditure and macroeconomics on the utilization of total joint replacement. The economic downturn has raised questions about the sustainability of growth for total joint replacement in the future. Previous projections of total joint replacement demand in the United States were based on data up to 2003 using a statistical methodology that neglected macroeconomic factors, such as the National Health Expenditure. Methods: Data from the Nationwide Inpatient Sample (1993 to 2010) were used with United States Census and National Health Expenditure data to quantify historical trends in total joint replacement rates, including the two economic downturns in the 2000s. Primary and revision hip and knee arthroplasty were identified using codes from the International Classification of Diseases, Ninth Revision, Clinical Modification. Projections in total joint replacement were estimated using a regression model incorporating the growth in population and rate of arthroplasties from 1993 to 2010 as a function of age, sex, race, and census region using the National Health Expenditure as the independent variable. The regression model was used in conjunction with government projections of National Health Expenditure from 2011 to 2021 to estimate future arthroplasty rates in subpopulations of the United States and to derive national estimates. Results: The growth trend for the incidence of joint arthroplasty, for the overall United States population as well as for the United States workforce, was insensitive to economic downturns. From 2009 to 2010, the total number of procedures increased by 6.0% for primary total hip arthroplasty, 6.1% for primary total knee arthroplasty, 10.8% for revision total hip arthroplasty, and 13.5% for revision total knee arthroplasty. The National Health Expenditure model projections for primary hip replacement in 2020 were higher than a previously projected model, whereas the current model estimates for total knee arthroplasty were lower. Conclusions: Economic downturns in the 2000s did not substantially influence the national growth trends for hip and knee arthroplasty in the United States. These latest updated projections provide a basis for surgeons, hospitals, payers, and policy makers to plan for the future demand for total joint replacement surgery.

BackgroundPatient, surgeon, health system, and device factors are all known to influence outcomes in total knee arthroplasty (TKA). However, patient-related factors associated with an increased risk of early failure are not well understood, particularly in elderly patients.Questions/purposesThe purpose of this study was to identify specific comorbid conditions associated with increased risk of early revision in Medicare patients undergoing TKA.MethodsA total of 117,903 Medicare patients who underwent primary TKA between 1998 and 2010 were identified from the Medicare 5% national sample administrative database and used to determine the relative risk of revision within 12 months after primary TKA as a function of baseline medical comorbidities. Cox regression was used to evaluate the impact of 29 comorbid conditions on risk of early failure controlling for age, sex, race, census region, socioeconomic status, and all other baseline comorbidities.ResultsThe most significant independent risk factors for revision TKA within 12 months were chronic pulmonary disease, depression, alcohol abuse, drug abuse, renal disease, hemiplegia or paraplegia, and obesity.ConclusionsThis information could be valuable to patients and their surgeons when making shared medical decisions regarding elective TKA and for risk-stratifying publicly reported outcomes in Medicare patients undergoing TKA.

The purpose of this study is to compare the differences in downstream cost and health outcomes between Medicare hip OA patients who undergo total hip arthroplasty (THA) and those who do not. All OA patients in the Medicare 5% sample (1998–2009) were separated into non-THA and THA groups. Differences in costs and risk ratios for mortality and new disease diagnoses were adjusted using logistic regression for age, sex, race, socioeconomic status, region, and Charlson score. Mortality, heart failure, depression, and diabetes were all reduced in the THA group, though there was an increased risk for atherosclerosis in the short term. The potential for selection bias was investigated with two separate propensity score analyses. This study demonstrates the potential benefit of THA in reducing mortality and improving aspects of overall health in OA patients.

The purpose of the current study is to identify patients who are at high risk for rehospitalization, revision, complications, and mortality after outpatient and short-stay total knee arthroplasty (TKA). The Medicare 5% limited data set sample was used to identify patients with a TKA procedure who were treated in an outpatient setting or who were discharged within 1 or 2 days in the hospital setting. Rehospitalization risk increased with higher Charlson score (i.e., poorer health status), older patients, inpatients (vs. outpatients), patients not receiving a femoral nerve block, earlier (vs. recent) year of surgery, and those with a recent history of heart failure. The findings of this study suggest that existing comorbidities, particularly heart failure, have the greatest effect on event risk after outpatient and short-stay TKA. The information obtained from this study should assist with patient selection for TKA performed on an outpatient basis.

BACKGROUND CONTEXT Low back pain (LBP) has a costly economic and societal burden, especially when considering the costs related to disability and loss of work productivity (indirect costs), as well as nonsurgical and surgical interventions (direct costs), such as lumbar fusion. PURPOSE We sought to determine the 3 years health care utilization and direct costs of patients with LBP diagnosis, with stratification based on the occurrence of lumbar fusion surgery. We hypothesized that the economic burden of LBP patients is significant and medical resource utilization and costs are greater for LBP patients who undergo 1-2 level lumbar fusion. STUDY DESIGN/SETTING Retrospective cohort analysis. PATIENT SAMPLE A total of 852,111 LBP patients, of which 10,224 received one or two level spinal fusions within 3 years following the LBP diagnosis. OUTCOME MEASURES Utilization and costs of medical resources and outpatient analgesic medications in a 3-year period. METHODS A claims database of privately-insured patients from October 2011 to September 2016 was used to evaluate medical and outpatient analgesic medication claims associated with LBP. The utilization and costs were compared between the LBP patients with and without 1- or 2-level spinal fusion. RESULTS The cohort of 852,111 LBP patients accrued $4.23 billion ($497 million per 100,000 persons) in direct health care costs over 3 years. The most commonly used medical resources were physician office visits (90.5%), hospital outpatient encounters (42.1%) and spine x-rays (41.9%). However, in terms of costs, the largest contributors were hospital inpatient costs (32.5%), physician office costs (23.5%), and hospital outpatient costs (20.8%). 69.1% of LBP patients filled analgesic medication prescriptions with opiate agonists being the most frequent (42.3%), followed by NSAIDs (36.7%), and anti-depressants (25.3%). Patients who received one- or two-level spinal fusions used medical resources and filled outpatient analgesic medication prescriptions more frequently and had higher direct costs (average $69,204 vs. $4,186, p CONCLUSIONS The cost of managing LBP is substantial, both for those who receive spinal fusions and for non-fusion patients. The 3-year direct economic burden for LBP patients with fusions was estimated to be $707.5 million (equivalent to $6.9 billion per 100,000 fusion patients). Including indirect cost estimates, the 3-year societal burden in this cohort of non-fusion LBP patients was estimated to range from $8,372 to $28,883 per patient (equivalent to $837 million to $2.9 billion per 100,000 LBP patients). FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Opioids are the most common class of analgesic medication prescribed for chronic low back pain (LBP), although their long-term efficacy is unclear. Complications of opioid use for LBP include addiction and overdose related mortality, which have risen in parallel with increased prescription rates. PURPOSE The purpose of this study was to evaluate opioid usage patterns for LBP patients with and without spinal fusion surgery, including long-term prescriptions postfusion. STUDY DESIGN/SETTING Retrospective cohort analysis based on claims data of outpatient pharmaceutical prescriptions from privately insured patients (Truven MarketScan data). PATIENT SAMPLE A total of 852,111 patients with a LBP diagnosis between October 2011 and September 2013 were identified and followed for 3 years. OUTCOME MEASURES Utilization and cost of opioid prescriptions; number of prescriptions, number of days of supply, average wholesale price, ingredient cost, and total payment; morphine milligram equivalents (MME) and number of days that exceeded 50 or 90 MME. METHODS The 3-year utilization, cost and MME of opioid prescriptions were evaluated for LBP patients with and without one or two level lumbar fusion. For those with fusion, opioid prescriptions before and after fusion, as well as prescriptions use 3, 6 and 12 months following fusion surgery, were analyzed. RESULTS Roughly two-thirds of the LBP patients (69.1%) filled analgesic medication, with opiate agonists being the most common class of drug. 31.0% of LBP patients had opioid prescriptions within the first 6 months of initial diagnosis, which increased to 42.1% within 3 years. During the 3 years, LBP patients filled opioid dosage of 50+ MME/day for an average of almost 2 months (53 +/− 149 days) and opioid dosage of 90+ MME/day for an average of almost a month (34 +/− 124 days) per patient. More than twice as many fusion as non fusion patients filled opioids prescriptions (87.2% vs. 41.5%, p CONCLUSIONS The opioid burden in the LBP population is high and is further elevated in those who subsequently undergo fusion surgery. Long-term opioid prescriptions persisted for a quarter of fusion patients 12 months postsurgery. Efforts to identify efficacious alternative therapies to treat LBP may reduce societal burden of chronic opioid use. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

The article Were VCF patients at higher risk of mortality following the 2009 publication of the vertebroplasty “sham” trials?, written by K. L. Ong, D. P. Beall, M. Frohbergh, E. Lau, and J. A. Hirsch was originally published electronically on the publisher’s internet portal.

BackgroundPatient, surgeon, health system, and device factors are all known to influence outcomes in THA. However, patient-related factors associated with an increased risk of early failure are poorly understood, particularly in elderly patients.Questions/purposesWe identified specific demographic and clinical characteristics associated with increased risk of early revision in Medicare patients with THA.MethodsThe Medicare 5% national sample administrative database was used to calculate the relative risk of revision within 12 months following primary THA as a function of baseline medical comorbidities in 56,030 Medicare patients who underwent primary THA between 1998 and 2010. The impact of 29 comorbid conditions on risk of early revision was examined using Cox regression, controlling for age, sex, race, US Census region, socioeconomic status, and all other baseline comorbidities.ResultsDepression, rheumatologic disease, psychoses, renal disease, chronic urinary tract infection, and congestive heart failure were associated with revision THA within 12 months of the index arthroplasty (p ≤ 0.038 for all comparisons; risk factors listed in order of significance).ConclusionsThis information is important when counseling elderly patients with THA regarding the risk of early failure and for risk stratifying publicly reported outcomes in Medicare patients with THA.

article i nfo There are little data that quantify the long term costs, mortality, and downstream disease after Total Knee Arthroplasty (TKA). The purpose of this study is to compare differences in cost and health outcomes between Medicare patients with OA who undergo TKA and those who avoid the procedure. The Medicare 5% sample was used to identify patients diagnosed with OA during 1997-2009. All OA patients were separated into non- arthroplasty and arthroplasty groups. Differences in costs, mortality, and new disease diagnoses were adjusted using logistic regression for age, sex, race, buy-in status, region, and Charlson score. The 7-year cumulative average Medicare payments for all treatments were $63,940 for the non-TKA group and $83,783 for the TKA group. The risk adjusted mortality hazard ratio (HR) of the TKA group ranged from 0.48 to 0.54 through seven years (all Pb0.001). The risk of heart failure in the TKA group was 40.9% at 7years (HR=0.93, Pb0.001). The results demonstrate the patients in the TKA cohort as having a lower probability of heart failure and mortality, at a total incremental cost of $19,843.

Jordana K Schmier,1 Carolyn K Hulme-Lowe,1 David W Covert,2 Edmund C Lau3 1Exponent, Inc., Health Sciences, Alexandria, VA, 2Alcon Research Ltd., Fort Worth, TX, 3Exponent, Inc., Health Sciences, Menlo Park, CA, USA Background: Endophthalmitis, which can occur after ophthalmic surgery, is an inflammation of the intraocular cavity and causes temporary or permanent vision impairment. However, little is known about the cost of treatment. The objective of this analysis was to update and expand upon the results of a previously published report that estimated the direct medical cost of treatment for endophthalmitis. Methods: Retrospective data analysis using 2010 through 2014 United States Medicare Limited Data Sets. Procedure codes were used to identify beneficiaries who underwent cataract surgery; demographic and clinical characteristics at the time of diagnosis were determined. Patients were stratified into cases (those who developed endophthalmitis) and controls (those who did not develop endophthalmitis) in the 3 months following surgery. Claims (ie, charges) and reimbursements (ie, costs) for cases and controls in the 6 months following cataract surgery were identified and compared. Results are presented in 2015 US dollars. Results: Of a total of 153,860 cataract surgery patients, 181 were diagnosed with endophthalmitis following cataract surgery, at a rate of 1.2 per 1,000. Cases were more likely to be male and less likely to be white than controls; age was similar. Total medical claims and reimbursements as well as ophthalmic claims and reimbursements were significantly higher for cases compared with controls. Total reimbursements, adjusted for age, sex, and region, were $4,893 higher (83% greater) and adjusted ophthalmic reimbursements were $3,002 higher (156% greater) for cases than for controls. Claims and reimbursements were significantly higher across all types of Medicare cost components. Conclusion: Postcataract surgery endophthalmitis is associated with a substantial cost. Successful prophylaxis with antibiotic agents would reduce the significant costs associated with treating endophthalmitis. Keywords: costs and cost analysis, endophthalmitis, eye infections, bacterial, health care costs

The state of Massachusetts enacted universal health insurance in 2006. However it is unknown whether the increased access to care resulted in changes to surgical use or costs.We asked the following related research questions: compared with the United States as a whole, how did the (1) number of cases (as a percentage of the overall population, to account for changes in the overall population during the time surveyed), (2) payer mix, and (3) inpatient costs for arthroplasty change in Massachusetts after introduction of health insurance reform?We analyzed the use and cost of primary THAs and TKAs in Massachusetts using the State Inpatient Database (SID) between 2002 and 2011 compared with the Nationwide Inpatient Sample (NIS) during the same years. The SID captures 100% of inpatient procedures in Massachusetts, while the NIS is a nationally representative database of inpatient procedures for the United States. The SID and NIS are publicly available data sources from the Agency for Healthcare Research and Quality, and include information regarding procedure volumes, payer mixes, and costs. Inpatient costs were defined similarly in both databases by using hospital charges and an average cost-to-charge ratio that is unique for each hospital. The incidence of arthroplasties was calculated by dividing the procedure volume by the relevant population (either for Massachusetts or the entire country) based on public data from the United States Census bureau.The incidence of THAs and TKAs performed in Massachusetts increased steadily throughout the study period, and paralleled a similar increase in the United States as a whole. In Massachusetts, the incidence of THAs increased by 59% between 2002 and 2011, and the incidence of TKAs likewise increased by 80%. The trends for the incidence in total joint arthroplasties were similar to those for Massachusetts for the United States as a whole. The period of health insurance reform in Massachusetts was associated with a greater proportion of patients covered by Medicaid, Commonwealth Care, or Health Safety Net for THAs and TKAs. By 2011, universal health insurance in Massachusetts covered 2.45% of primary THAs and 2.77% of primary TKAs. Coverage for Medicaid in Massachusetts increased from 3.23% and 3.04% of THAs and TKAs in 2002 to 4.06% and 4.34% respectively in 2011. On average, Medicaid coverage was greater for TKAs in Massachusetts than across the United States during the study period. The introduction of health insurance reform had a minimal effect on the cost of total joint arthroplasties in Massachusetts. Although the costs of total joint arthroplasties in the United States were higher than those in Massachusetts, this difference narrowed substantially from 2002 to 2011, with the Massachusetts cost trending upward and the overall United States cost trending downward.Despite extending insurance coverage to the entire state of Massachusetts, there was little change in actual utilization trends for joint replacement.The enactment of universal health insurance coverage in Massachusetts appears to have been a nonevent insofar as the use and cost of total hip and knee surgeries is concerned in the state. Factors other than health insurance reform appear to be driving the growth in demand for arthroplasties in Massachusetts and are likely to do so as well in the United States under the Affordable Care Act of 2010.

The purpose of this study was to identify the incidence and types of complications after revision total hip arthroplasty (THA) within the first year, and determine the relative risk factors for these complications and of re-revision.The sample size of 5% Medicare claims data from 1998-2011 was studied. Primary THA patients who underwent subsequent revision were identified using ICD-9-CM codes. Outcomes and complications after revision THA were assessed. Multivariate Cox regression was used to evaluate the effect of patient demographic characteristics on the adjusted complication risk for revision THA patients.Of the 64,260 primary THA patients identified between 1998 and 2011, 3555 patients (5.71%) underwent revision THA. Etiology of primary hip failure included mechanical complications such as loosening and wear (40.7%), dislocation (14.0%), and infection (11.3%). Complications after revision THA included infection and redo revision, 17.3% and 15.8% followed by venous thromboembolic disease (VTE) at 11.1%, dislocation at 5.43%, PE at 3.24%, and death at 2.11%. The rate of "new" infections after an aseptic revision was 8.13%. Patients in the 85+-year-old age group had a 100% greater adjusted risk of VTE (P.001) and 406% higher adjusted risk of death (P.001) than those in the 65-69 years-old age group. Patients with higher Charlson scores had higher adjusted risks of VTE (P.001), infection (P.001), death (P = .002), and re-revision THA (P = .011).Advanced age is a clear risk factor for VTE and mortality, but not for dislocation, infection, or re-revision. Higher Charlson index was found to be a risk factor for every complication after revision except dislocation. Greater attention is required to address the high rate of infection and re-do revision after revision THA (17.3% and 15.8%).

Background The purpose of this study was to analyze the hospital, clinical, and patient factors associated with inpatient readmission after total knee arthroplasty (TKA) in the Medicare population and to understand the primary reasons for readmission. Methods The Medicare 100% national hospital claims database was used to identify 952,593 older patients (65+) with a primary TKA in 3848 hospitals between 2010 and 2013. A multilevel logistic regression analysis with a clustered data structure was used to investigate the risk of all-cause 30- and 90-day readmission, incorporating hospital, clinical, and patient factors. Results At 30 days, readmission ranged from 0% to 22% (median, 4.9%), whereas at 90 days, readmission ranged from 0% to 32% (median, 8.6%). Geographic census region, hospital procedure volume, rural hospital location, and nonprofit ownership were the only significant hospital factors among those we studied. Evaluation of clinical factors showed use of a perioperative transfusion was associated with 13% greater risk; patients discharged to home had 25% lower risk; and surgeon volume and length of stay were also significant. These effect sizes were at least comparable to patient factors, such as age, gender, comorbidities, and socioeconomic status. The top 5 most frequently reported primary reasons for 30- or 90-day readmission in TKA were surgery and medical related: wound infection, deep infection, atrial fibrillation, cellulitis and abscess of leg, or pulmonary embolism. Conclusion The results of this study support further optimization of anti-infection measures, both intraoperative and postoperative, to reduce the broad variation in hospital readmissions.