Analyzing the Burden of Revision Total Knee Arthroplasty in the United States between 2009 and 2016.

As the number of total knee arthroplasties (TKAs) increases, it is reasonable to expect the number of revision TKAs (rTKAs) to rise in parallel. The patient-related and societal burdens of rTKA are poorly understood. Therefore, the purpose of this study was to determine temporal changes in: (1) the incidence of rTKA; (2) patient and hospital characteristics; (3) complications, hospital lengths of stay (LOSs), and discharge dispositions; and (4) costs, charges, and payer types. All patients who underwent rTKA between 2009 and 2016 were identified from the National Inpatient Sample database using International Classification of Diseases, Ninth Revision and Tenth Revision codes and were studied. Univariate analyses were performed to compare the incidence of rTKA, patient and hospital characteristics, LOS and discharge dispositions, as well as costs, charges, and payer types. A multivariate logistic regression model was built to compare the odds of complications in 2009 and 2016. Over our study period, there was a 4.3% decrease in the incidence of rTKA. The mean age of patients who underwent rTKA was 65 years and a majority were female (58%). Mean hospital LOS decreased from 4.1 days in 2009 to 3.3 days in 2016 (p < 0.001). The rate of several complications decreased significantly over our study period including myocardial infarction, cardiac arrest, transfusion, pneumonia, urinary tract infection, and mortality. A significantly lower percentage of rTKA patients were discharged to a skilled nursing facility in 2016 (26.5%) compared with 2009 (31.6%; p < 0.001). There was an 18.7% increase in the mean costs, and a 43.3% increase in the mean charges (p < 0.001). Over the study period, there was a decrease in the incidence of rTKAs. Despite potential improvements in primary TKA, the burden associated with rTKA remains large. This report can be used to help educate medical providers about outcomes that may result from a primary and/or revised TKA.

Impact of Parkinson's Disease on Complications, Readmission Rates, and Costs of Care following Primary Total Knee Arthroplasty.

Large-scale studies evaluating the effects of Parkinson's disease (PD) on primary total knee arthroplasty (TKA) are limited. The purpose of this study was to determine if PD patients undergoing primary TKA have increased: (1) medical complications; (2) implant-related complications; (3) readmission rates; and (4) costs. A query was performed using an administrative claims database. The study group consisted of all patients undergoing primary TKA who had a history of PD. Matched non-PD patients undergoing primary TKA served as a control group. The query yielded 72,326 patients (PD = 18,082; matching cohort = 54,244). Pearson's chi-square tests, logistic regression analyses, and Welch's t-tests were used to test for significance between the cohorts. Primary TKA patients who had PD were found to have greater incidences and odds of medical complications (4.21 vs. 1.24%; odds ratio [OR]: 3.50, 95% confidence interval [CI]: 3.15-3.89, p < 0.0001) and implant-related complications (5.09 vs. 3.15%; OR: 1.64, 95% CI: 1.51-1.79, p < 0.0001) compared with the matching cohort. Additionally, the rates and odds of 90-day readmission were higher (16.29 vs. 12.66%; OR:1.34, p < 0.0001) and episodes of care costs were significantly greater ($17,105.43 vs. $15,252.34, p < 0.0001) in patients who had PD. Results demonstrate that PD patients undergoing primary TKA had higher incidences of medical and implant-related complications. They also had increased 90-day readmission rates and costs compared with controls. The findings of this study should be used in risk stratification and should inform physician-patient discussion but should not be arbitrarily used to deny access to care.

Cost Analysis of Medicare Patients with Varying Complexities Who Underwent Total Knee Arthroplasty.

The effort to reduce overall healthcare costs may affect more complex patients, as their pre- and postoperative care can be substantially involved. Therefore, the purpose of this study was to use a large nationwide insurance database to compare (1) costs, (2) reimbursements, and (3) net losses of 90-day episodes of care (EOC) for total knee arthroplasty (TKA) patients according to Elixhauser's Comorbidity Index (ECI) scores. All TKAs performed between 2005 and 2014 in the Medicare Standard Analytic Files were extracted from the database and stratified based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort and control cohort were matched based on age and sex, resulting in a total of 715,398 patients included for analysis. Total EOC costs, reimbursements, and total net losses (defined as total EOC costs minus total EOC reimbursements) were compared between the cohorts. Overall, total EOC costs increased with ECI. For example, compared with the matched ECI 1 cohorts, the total EOC costs for ECI 5 patients ($56,589.19 vs. $51,747.54) were significantly greater (p < 0.01). Although reimbursements increased with increasing ECI, so did net losses. The net losses for ECI 5 patients were greater than that for ECI 1 patients ($42,309.39 vs. $40,007.82). The bundled payments for care improvement (BPCI) and comprehensive care for joint replacement (CJR) are alternative payment models that might de-incentivize treatment of more complex patients. Our study found that despite increasing reimbursements, overall costs, and therefore net losses, were greater for more complex patients with higher ECI scores.

Comparison Study of Patient Demographics, Risk Factors, and Lengths of Stay for Postoperative Ileus After Primary Total Knee Arthroplasty.

BACKGROUND: Postoperative ileus is a potential complication after orthopedic surgery, which has not been well studied after total knee arthroplasty (TKA). The aims of this study were to analyze rates of postoperative ileus; patient demographic profiles; in-hospital lengths of stay (LOS); and patient-related risk factors for postoperative ileus after primary TKA. METHODS: A query was performed from January 1, 2005 to March 31, 2014 using the Medicare Standard Analytical Files. Patients who underwent primary TKA and developed postoperative ileus within 3 days after their index procedure were identified. Patients who did not develop ileus represented controls. Primary outcomes analyzed and compared included patient demographics, risk factors, and in-hospital LOS. A P value less than .05 was considered statistically significant. RESULTS: Ileus patients were older, more likely to be male, and had higher Elixhauser-Comorbidity Index scores (8 vs 6; P < .0001) compared with controls. Male patients (odds ratio [OR], 2.12; P < .0001), patients with preoperative electrolyte/fluid imbalance (OR, 3.40; P < .001), patients older than 70 years (OR, 1.62-2.33; P < .015), and body mass indices greater than 30 kg/m2 (OR, 1.79-2.00; P < .001) were at the greatest risk of developing ileus. In addition, ileus patients had significantly longer in-hospital LOS (5.42 vs 3.22 days; P < .001). CONCLUSION: The study demonstrated differences in patient demographics, patient-related risk factors, and an increased in-hospital LOS for ileus patients after primary TKA. The study is important as it can allow orthopedists to properly identify and optimize patients with certain risk factors to potentially mitigate this adverse event from occurring.

Isolated Polyethylene Exchange With Increased Constraint Is Comparable to Component Revision TKA for Instability in Properly Selected Patients.

BACKGROUND: Symptomatic instability following total knee arthroplasty (TKA) is a leading cause of early failure. Most reports recommend component revision as the preferred treatment because of poor outcomes and high failure rates with isolated tibial polyethylene insert exchange (ITPIE). However, these ideas have not been tested in modern implant systems that allow insert constraint to be increased. METHODS: We retrospectively reviewed 90 consecutive patients with minimum 2-year (mean 3.7 years) follow-up who underwent revision TKA for instability at a single institution. Mean age was 62.0 years (range, 41 to 83 years), and 73% of patients were women. Forty percent of patients were treated with ITPIE when standardized preoperative and intraoperative criteria were met; 60% underwent revision of one or both components when these criteria were not met. RESULTS: Patients experienced significant improvements in Knee Society (KS) knee (48.4 to 82.6; P < .001) and function (49.0 to 81.0; P < .001) scores. There were no significant differences in improvements in KS knee scores (38.1 vs 33.1; P = .18), KS function scores (36.0 vs 34.0; P = .63), or arc of motion (5° vs 6°; P = .88) between those treated with ITPIE and component revision. Failure rates were 19.4% in the ITPIE group vs 18.5% in the component revision group (odds ratio, 1.06; P = .91). Re-revision rates were significantly lower (6.3% vs 30.8%; odds ratio, 0.15; P = .004) when polyethylene insert constraint was increased. CONCLUSION: In selected patients, ITPIE is not inferior to component revision at addressing symptomatic instability following TKA. Degree of constraint should be increased whenever possible during revision surgery for instability.

Variation in Treatment Patterns Correlate With Resource Utilization in the 30-Day Episode of Care of Displaced Femoral Neck Fractures.

BACKGROUND: We evaluated which treatment decisions in the management of displaced femoral neck fractures (FNFs) may associate with measures of resource utilization relevant to a value-based episode-of-care model. METHODS: A total of 1139 FNFs treated with hip arthroplasty at 7 hospitals were retrospectively reviewed. Treatment choices were procedure (hemiarthroplasty vs total hip arthroplasty [THA]), surgeon training status, admitting service, and time to surgery. Dependent variables were length of stay, discharge disposition, 30-day readmission, and in-hospital mortality. Variation across hospitals was evaluated with analysis of variance and chi-square tests. Treatment choices were evaluated for the dependent variables of interest with univariable and multivariable regression. RESULTS: There was significant variation between hospitals regarding proportion of cases treated with THA (range = 3.0%-73.2%, P < .001), proportion treated by arthroplasty fellowship-trained surgeons (range = 0%-74.9%, P < .001), proportion admitted to the orthopedic service (range = 2.8%-91.3%, P < .001), mean time to surgery (range = 0.9-2.1 days, P < .001), and proportion of discharge home (range = 63.9%-97.8%, P < .001). Multivariable analysis adjusting for age, gender, and Charlson Comorbidity Index demonstrated correlations between (1) decreased length of stay and admission to orthopedics (B = -1.256, P < .001); (2) lower 30-day readmission and THA (odds ratio [OR] = .376, P = .004), and (3) decreased discharge to a care facility and admission to orthopedics (OR = 0.402, P = <.001), THA (OR = 0.435, P = .002), and treatment by an arthroplasty fellowship-trained surgeon (OR = 0.572, P = .016). None of the treatment variables tested associated with in-hospital mortality. CONCLUSION: We observed significant variation in the treatment of displaced FNF patients across 7 hospitals and identified treatment choices that associated with resource utilization within the episode of care. Future, prospective study is necessary to understand whether care pathways that adapt some combination of these characteristics may result in more value-based care.

The Knee Society Short Form Reduces Respondent Burden in the Assessment of Patient-reported Outcomes.

BACKGROUND: The patient's own evaluation of function and satisfaction is a fundamental component of assessing outcomes after total knee arthroplasty (TKA). The new Knee Society Knee Score was introduced in 2012 and has been shown to be a valid and reliable instrument for measuring the outcome of TKA. This score combines an objective, physician-derived component and a patient-reported component to characterize the expectations, satisfaction, and functional activities of diverse lifestyles of contemporary patients undergoing TKA. However, in the routine clinical setting, the administration and scoring of outcome measures is often resource-intensive, as the expenditure of time and budget for outcome measurement increase with the length and complexity of the instrument used, and so a short-form assessment can help to reduce the burden the assessment of outcomes. QUESTIONS/PURPOSES: The purposes of this study were (1) to develop a short-form version of the new Knee Society Knee Score; (2) to validate the short form against the full Knee Society Knee Score; and (3) to evaluate the responsiveness to treatment (TKA) of the new Knee Society short-form assessment. METHODS: To develop the short form, data from the sample of 497 patients recruited during validation of the original long form the new Knee Society Knee Score were used. The multicenter study was approved by the institutional review boards at 15 participating medical institutions within the United States and Canada. An analytic item reduction approach was applied simultaneously but separately to preoperative and postoperative patient-reported data to select a subset of items from the original form that had good measurement properties and closely reflected the scores obtained using the original form. RESULTS: Expectations and satisfaction were reflected by a single item in the newly developed short form compared with a total of five satisfaction and three expectation items in the long form. The functional activities subscale was reduced from 17 to six items. An excellent correlation was demonstrated between function scores derived from the functional activities subscale of the original long-form score (17 items) and the six-item short form (r = 0.97; p < 0.01). The sample mean difference between the two scores was less than 4 points with a SD of 6.7 points. The short form was capable of discriminating clinically different groups of patients before and after TKA with virtually the same estimated effect size as the original functional activities subscale of the new Knee Society Knee Score. CONCLUSIONS: The Knee Society Knee Score long form is still recommended for research studies and for more sensitive measurement of the outcomes of individual patients. However, for general clinical use with large patient populations, the short form is expected to improve the rate of patient completion while also being easier to administer. In this study, we found the short-form version of the Knee Society Knee Score to be practical, valid, reliable, and responsive for assessing the functional outcome of TKA.

Routine Examination of Pathology Specimens Following Knee Arthroscopy: A Cost-Effectiveness Analysis.

BACKGROUND: While the clinical value of routine pathologic examination of tissues removed during orthopaedic procedures has not been determined, limited cost-effectiveness and a low prevalence of findings that alter patient management have been previously demonstrated with arthroscopy. The purpose of this study was to examine the clinical value and cost-effectiveness of routine histological examination of knee arthroscopy specimens. METHODS: Retrospective chart analysis of 3797 consecutive knee arthroscopies by two surgeons from 2004 to 2013 at three affiliated hospitals within one health-care system was undertaken. Pathology reports regarding tissue removed during partial meniscectomies and anterior cruciate ligament reconstructions were reviewed to determine if the results altered patient care. The total costs of histological examination were estimated in 2012-adjusted U.S. dollars. The cost per health effect was determined by calculating the cost per discrepant and discordant diagnosis. RESULTS: The prevalence of concordant diagnoses was 99.3% (3769 of 3797), the prevalence of discrepant diagnoses was 0.7% (twenty-seven of 3797), and the prevalence of discordant diagnoses was 0.026% (one of 3797). The total cost of histological examinations was estimated to be $371,810. The total cost of the pathology cost per discrepant diagnosis was $13,771, and the cost per discordant diagnosis was $371,810. CONCLUSIONS: Routine pathological examination of surgical specimens from patients undergoing knee arthroscopy had limited cost-effectiveness because of the low prevalence of findings that altered patient management. Histological examination of surgical specimens from arthroscopic knee surgery did not alter patient care and increased costs. We suggest that gross and histological examination of tissue removed during knee arthroscopy should be done at the discretion of the orthopaedic surgeon rather than being mandatory.