Impact of the Comprehensive Care for Joint Replacement Bundled Payment Model on Postoperative Utilization of Home Health and Outpatient Physical Therapy Services.

OBJECTIVE: To study the effect of the Comprehensive Care for Joint Replacement (CJR) bundled payment program on postoperative home health and outpatient physical therapy (PT) for total hip or knee arthroplasty (THA/TKA). DESIGN: Retrospective cohort with national Medicare data (5% claims) using a difference-in-differences analysis comparing January 2013-September 2015 (before) versus October 2016-September 2019 (after). SETTING: Administrative claims from hospitals in 34 metropolitan statistical areas with mandatory CJR participation as of 2018 and 42 control metropolitan statistical areas. PARTICIPANTS: Episodes in fee-for-service Medicare beneficiaries (5% claims) undergoing elective THA (n=6327) or TKA (n=10,764) with community discharge. INTERVENTIONS: Implementation of CJR bundled payment program. MAIN OUTCOME MEASURES: Home health and outpatient PT, including any use and number of visits. RESULTS: Program implementation was associated with an increased percentage of THA episodes using home health PT (+8.0 percentage-point change; 95% CI, +3.5 to +12.6; P=.001) but a decreased per-episode number of home health PT visits for THA (-1.1; 95% CI, -1.6 to -0.6; P<.001) and TKA (-1.1; 95% CI, -1.4 to -0.7; P<.001). The program was also associated with an increased per-episode number of outpatient PT visits for TKA in the primary but not sensitivity analyses (+0.8; 95% CI, +0.1 to +1.4; P=.02). CONCLUSIONS: Findings of increased home health PT may reflect an intentional shift in care from the inpatient postacute setting to the community to decrease costs. Alternatively, the limited effect of CJR, particularly on outpatient PT, could reflect challenges with care coordination in a retrospective bundle spanning multiple care settings.

Did the Comprehensive Care for Joint Replacement Bundled Payment Program Impact Sex Disparities in Total Hip and Knee Arthroplasties?

BACKGROUND: Sex disparities have been noted across various aspects of total hip/knee arthroplasty (THA/TKA). Given incentives to standardize care, bundled payment initiatives including the Comprehensive Care for Joint Replacement (CJR) program may reduce disparities. This study aimed to assess the CJR program's impact on sex disparities in THA/TKA care and outcomes. METHODS: This retrospective cohort study included 259,673 THAs (61.7% women) and 506,311 TKAs (64.0% women) from a large national database (2013 to 2017). Sex disparities were assessed for care and outcomes related to the period (1) before surgery, (2) during hospitalization for THA/TKA, and (3) after discharge. Disparities were reported as women:men ratios. Difference-in-differences analyses estimated the impact of the CJR program on pre-existing sex disparities. RESULTS: For both THA and TKA, women were less likely than men to present with a Charlson-Deyo comorbidity index >0 (women:men ratio 0.88 to 0.92), but were more likely to require blood transfusions (women:men ratio 1.48 to 1.79) and be discharged to institutional postacute care (women:men ratio 1.50 to 1.66). Difference-in-differences models demonstrated that the CJR bundled payment program reduced sex disparities in institutional postacute care discharges (THA: -2.28%; 95% confidence interval [CI] -4.20 to -0.35%, P = .02; TKA: -2.07%; 95% CI -3.93 to -0.20%; P = .03) and THA 90-day readmissions (-1.00%, 95% CI -1.88 to -0.13%, P = .02), indicating a differential impact of CJR in women versus men for some outcomes. CONCLUSIONS: While sex disparities in THA/TKA persist, the CJR program demonstrates potential to impact such differences. Future research should focus on how potential mechanisms could be leveraged to reduce disparities.

Statistical Outcomes Guiding Periprosthetic Joint Infection Prevention and Revision Are Fragile: A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Dichotomous outcomes are frequently reported in orthopaedic research and have substantial clinical implications. This study utilizes the fragility index (FI) and fragility quotient (FQ) metrics to determine the statistical stability of outcomes reported in total joint arthroplasty randomized controlled trials (RCTs) relating to periprosthetic joint infection (PJI). METHODS: The RCTs that reported dichotomous data related to PJI published between January 1, 2010, and December 31, 2022, were evaluated. The FI and reverse FI (RFI) were defined as the number of outcome event reversals required to reverse the significance of significant and nonsignificant outcomes, respectively. The FQ was determined by dividing the FI or RFI by the respective sample size. There were 108 RCTs screened, and 17 studies included for analysis. RESULTS: A total of 58 outcome events were identified, with a median FI of 4 (interquartile range [IQR] 2 to 5) and associated FQ of 0.0417 (IQR 0.0145 to 0.0602). The 13 statistically significant outcomes had a median FI of 1 (IQR 1 to 2) and FQ of 0.00935 (IQR 0.00629 to 0.01410). The 45 nonsignificant outcomes had a median RFI of 4 (IQR 3 to 5) and FQ of 0.05 (IQR 0.0361 to 0.0723). The number of patients lost to follow-up was greater than or equal to the FI in 46.6% of outcomes. CONCLUSIONS: Statistical outcomes in RCTs analyzing PJI are fragile and may lack statistical integrity. We recommend a comprehensive fragility analysis, with the reporting of FI and FQ metrics, to aid in the interpretation of outcomes in the total joint arthroplasty literature.

Prior COVID-19 and Venous Thromboembolism Risk in Total Joint Arthroplasty in Patients Over 65 Years of Age.

BACKGROUND: The COVID-19 pandemic has been associated with increased risks of venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE). However, there is limited literature investigating prothrombotic states and complications after total hip arthroplasty (THA) and total knee arthroplasty (TKA). We investigated (1) trends in VTE, PE, and DVT rates post-THA and TKA from 2016 to 2019 compared to 2020 to 2021 and (2) associations between prior COVID-19 diagnosis and VTE, PE, and DVT. METHODS: A national dataset was queried for elective THA and TKA cases from 2016 to 2021. We first assessed trends in 90-day VTE prevalence between 2016 to 2019 and 2020 to 2021. Second, we investigated associations between previous COVID-19 and 90-day VTE with regression models. RESULTS: From 2016 to 2021, a total of 2,422,051 cases had an annual decreasing VTE prevalence from 2.2 to 1.9% (THA) and 2.5 to 2.2% (TKA). This was evident for both PE and DVT (all trend tests P < .001). After adjusting for covariates (including vaccination status), prior COVID-19 was associated with significantly increased odds of developing VTE in TKA patients (odds ratio 1.2, 95% confidence interval 1.1 to 1.4, P = .007), but not DVT or PE (P > .05). There were no significant associations between prior COVID-19 and VTE, DVT, or PE after THA (P > .05). CONCLUSIONS: Our study suggests that a previous diagnosis of COVID-19 is associated with increased odds of VTE, but not DVT or PE, in TKA patients. Ongoing data monitoring is needed given our effect estimates, emerging COVID-19 variants, and evolving vaccination rates.

Oral Postoperative Antibiotic Prophylaxis for Outpatient Total Hip and Knee Arthroplasty: Describing Current Practices.

BACKGROUND: Despite an increase in outpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA), large-scale data are lacking on current practice for antibiotic prophylaxis prescribing. We aimed to describe current oral antibiotic prophylaxis practices nationally for outpatient THA and TKA. METHODS: This nationwide retrospective cohort study included primary outpatient THA or TKA procedures in patients aged 18 to 64 years from 2018 to 2021 using a national claims database. Oral antibiotic prescriptions filled perioperatively (defined as 5 days before to 3 days after surgery) were extracted; these were categorized and assumed to represent postoperative prophylaxis. Multivariable logistic regression measured associations between patient and surgery characteristics and perioperative oral antibiotic prophylaxis. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) are reported. RESULTS: Oral antibiotic prescriptions were filled in 16.5% of 73,015 outpatient THA and TKA (18.4% of 24,857 THAs, 15.5% of 48,158 TKAs) procedures. Prescriptions were most often for cephalosporins (74.3%), with cephalexin (52.8%), and cefadroxil (19.1%) being the most common. Non-cephalosporin antibiotics prescribed were mainly clindamycin (6.8%), sulfamethoxazole-trimethoprim (6.7%), and doxycycline (6.2%). The odds of receiving oral antibiotic prophylaxis were higher for THA compared to TKA (OR 1.13, 95% CI 1.09 to 1.18, P < .001) and in the presence of obesity, diabetes, and autoimmune conditions (OR 1.08 to 1.13, P < .001 to .01). Ambulatory surgery center procedures also had significantly increased odds of prophylaxis compared to hospital-based outpatient surgeries (OR 2.62, 95% CI 2.51 to 2.73, P < .001). Additionally, regional and time-based variations were noted. CONCLUSIONS: Perioperative oral antibiotic prophylaxis prescriptions were filled in only 16.5% of outpatient THA and TKA cases, with variation in the type of antibiotic prescribed. The receipt of any prophylaxis and specific medications was associated with demographic, clinical, and procedure-related characteristics. Follow-up research will evaluate associations with infection risk reduction.

Characteristics and Quality of Online Searches for Direct Anterior Versus Posterior Approach for Total Hip Arthroplasty.

BACKGROUND: Online resources are important for patient self-education and reflect public interest. We described commonly asked questions regarding the direct anterior versus posterior approach (DAA, PA) to total hip arthroplasty (THA) and the quality of associated websites. METHODS: We extracted the top 200 questions and websites in Google's "People Also Ask" section for 8 queries on January 8, 2023, and grouped websites and questions into DAA, PA, or comparison. Questions were categorized using Rothwell's classification (fact, policy, value) and THA-relevant subtopics. Websites were evaluated by information source, Journal of the American Medical Association Benchmark Criteria (credibility), DISCERN survey (information quality), and readability. RESULTS: We included 429 question/website combinations (questions: 52.2% DAA, 21.2% PA, 26.6% comparison; websites: 39.0% DAA, 11.0% PA, 9.6% comparison). Per Rothwell's classification, 56.2% of questions were fact, 31.7% value, 10.0% policy, and 2.1% unrelated. The THA-specific question subtopics differed between DAA and PA (P < .001), specifically for recovery timeline (DAA 20.5%, PA 37.4%), indications/management (DAA 13.4%, PA 1.1%), and technical details (DAA 13.8%, PA 5.5%). Information sources differed between DAA (61.7% medical practice/surgeon) and PA websites (44.7% government; P < .001). The median Journal of the American Medical Association Benchmark score was 1 (limited credibility, interquartile range 1 to 2), with the lowest scores for DAA websites (P < .001). The median DISCERN score was 55 ("good" quality, interquartile range 43 to 65), with the highest scores for comparison websites (P < .001). Median Flesch-Kincaid Grade Level scores were 12th grade level for both DAA and PA (P = .94). CONCLUSIONS: Patients' informational interests can guide counseling. Internet searches that explicitly compare THA approaches yielded websites that provide higher-quality information. Providers may also advise patients that physician websites and websites only describing the DAA may have less balanced perspectives, and limited information regarding surgical approaches is available from social media resources.

Relationships Between Preoperative Mental Health and Improvements in Patient-Reported Outcomes After Total Hip and Knee Arthroplasty.

BACKGROUND: Poor preoperative mental health has been associated with worse outcomes after total hip (THA) and total knee arthroplasty (TKA). To fully understand these relationships, we assessed post-THA and post-TKA improvements in patient-reported mental and joint health by preoperative mental health groups. METHODS: Elective cases (367 THA, 462 TKA) were subgrouped by low (<25th percentile), middle (25th-74th), and high (≥75th) preoperative mental health, using Veterans RAND 12-Item Health Survey Mental Component Summary (MCS) scores. In each subgroup, we assessed the relationship between preoperative MCS and 1-year postoperative change in mental and joint health. Pairwise comparisons and multivariable regression models were applied for THA and TKA separately. RESULTS: Median postoperative mental health change was +14.0 points for the low-MCS THA group, +11.1 low-TKA, +2.0 middle-THA and TKA, -4.0 high-THA, and -4.9 high-TKA (between-group differences P < .001). All MCS groups had improved median joint health scores, without significant between-group differences. Preoperative mental health was negatively associated with mental health improvements in all groups (B = -0.94 - -0.68, P < .001-P = .01) but with improvements in joint health only in the low-THA group (B = -0.74, P = .02). Improvements in mental and joint health were positively associated for low and middle (B = 0.61-0.87, P < .001), but not for high-MCS groups, with this relationship differing for the low versus high group. CONCLUSION: Patients who have low preoperative mental health experienced greater postoperative mental health improvement and similar joint health improvement compared to patients who have high preoperative mental health. Findings can guide subgroup-targeted surgical decision-making and preoperative counseling.

Did the COVID-19 Pandemic Coincide With an Increase in Osteonecrosis as Indication for Total Hip Arthroplasty in Older Patients?

BACKGROUND: Osteonecrosis of the femoral head is a common indication for total hip arthroplasty (THA). It is unclear to what extent the COVID-19 pandemic has impacted its incidence. Theoretically, the combination of microvascular thromboses and corticosteroid use in patients who have COVID-19 may increase the risk of osteonecrosis. We aimed to (1) assess recent osteonecrosis trends and (2) investigate if a history of COVID-19 diagnosis is associated with osteonecrosis. METHODS: This retrospective cohort study utilized a large national database between 2016 and 2021. Osteonecrosis incidence in 2016 to 2019 was compared to 2020 to 2021. Secondly, utilizing a cohort from April 2020 through December 2021, we investigated whether a prior COVID-19 diagnosis was associated with osteonecrosis. For both comparisons, Chi-square tests were applied. RESULTS: Among 1,127,796 THAs performed between 2016 and 2021, we found an osteonecrosis incidence of 1.6% (n = 5,812) in 2020 to 2021 compared to 1.4% (n = 10,974) in 2016 to 2019; P < .0001. Furthermore, using April 2020 to December 2021 data from 248,183 THAs, we found that osteonecrosis was more common among those who had a history of COVID-19 (3.9%; 130 of 3,313) compared to patients who had no COVID-19 history (3.0%; 7,266 of 244,870); P = .001). CONCLUSION: Osteonecrosis incidence was higher in 2020 to 2021 compared to previous years and a previous COVID-19 diagnosis was associated with a greater likelihood of osteonecrosis. These findings suggest a role of the COVID-19 pandemic on an increased osteonecrosis incidence. Continued monitoring is necessary to fully understand the impact of the COVID-19 pandemic on THA care and outcomes.

Racial Differences in Manipulation Under Anesthesia Rates Following Total Knee Arthroplasty.

BACKGROUND: Despite the extensive literature on racial disparities in care and outcomes after total knee arthroplasty (TKA), data on manipulation under anesthesia (MUA) is lacking. We aimed to determine (1) the relationship between race and rate of (and time to) MUA after TKA, and (2) annual trends in racial differences in MUA from 2013 to 2018. METHODS: This retrospective cohort study (using 2013-2018 Medicare Limited Data Set claims data) included 836,054 primary TKA patients. The primary outcome was MUA <1 year after TKA; time from TKA to MUA in days was also recorded. A mixed-effects multivariable model measured the association between race (White, Black, Other) and odds of MUA. Odds ratios (OR) and 95% confidence intervals (CI) were reported. A Cochran Armitage Trend test was conducted to assess MUA trends over time, stratified by race. RESULTS: MUA after TKA occurred in 1.7%, 3.2% and 2.1% of White, Black, and Other race categories, respectively (SMD = 0.07). After adjustment for covariates, (Black vs White) patients had increased odds of requiring an MUA after TKA: odds ratio (OR) 1.97, 95% confidence intervals (CI) 1.86-2.10, P < .0001. Moreover, White (compared to Black) patients had significantly shorter time to MUA after TKA: 60 days (interquartile range [IQR] 46-88) versus 64 days (interquartile range [IQR] 47-96); P < .0001. These disparities persisted from 2013 through 2018. CONCLUSION: Continued racial differences exist for rates and timing of MUA following TKA signifying the continued need for efforts aimed toward understanding and eliminating inequalities that exist in total joint arthroplasty (TJA) care.

Evaluating Resource Utilization for In-Person and Virtual Joint Classes in Total Joint Arthroplasty: An Analysis of Attendance Patterns at a Large Metropolitan Health System.

BACKGROUND: Provider-run "joint classes" educate total joint arthroplasty (TJA) patients on how to best prepare for surgery and maximize recovery. There is no research on potential healthcare inequities in the context of joint classes or on the impact of the recent shift toward telehealth due to coronavirus disease 2019 (COVID-19). Using data from a large metropolitan health system, we aimed to (1) identify demographic patterns in prepandemic joint class attendance and (2) understand the impact of telehealth on attendance. METHODS: We included data on 3,090 TJA patients from three centers, each with a separately operated joint class. Attendance patterns were assessed prepandemic and after the resumption of elective surgeries when classes transitioned to telehealth. Statistical testing included standardized differences (SD > 0.1 indicates significance) and a multivariate linear regression. RESULTS: The in-person and telehealth attendance rates were 69.9% and 69.2%, respectively. Joint class attendance was significantly higher for non-White, Hispanic, non-English primary language, Medicaid, and Medicare patients (all SD > 0.1). Age was a determinant of attendance for telehealth (SD > 0.1) but not for in-person (SD = 0.04). Contrastingly, physical distance from hospital was significant for in-person (SD > 0.1) but not for telehealth (SD = 0.06). On a multivariate analysis, distance from hospital (P < .05) and telehealth (P < .0001) were predictors of failed class attendance. CONCLUSION: This work highlights the relative importance of joint classes in specific subgroups of patients. Although telehealth attendance was lower, telehealth alleviated barriers to access related to physical distance but increased barriers for older patients. These results can guide providers on preoperative education and the implementation of telehealth.

Safety of Tranexamic Acid in Hip and Knee Arthroplasty in High-risk Patients.

BACKGROUND: With increasing use of tranexamic acid in total hip and knee arthroplasties, safety concerns remain. Using national claims data, this study examined tranexamic acid use in patients with preexisting comorbidities. The hypothesis was that tranexamic acid use is not associated with increased complication risk in hip and knee arthroplasty patients with comorbidities. METHODS: Among 765,011 total hip/knee arthroplasties (2013 to 2016, Premier Healthcare claims), tranexamic acid use was assessed in three high-risk groups: group I with patients with a history of venous thromboembolism, myocardial infarction, seizures, or ischemic stroke/transient ischemic attack (n = 27,890); group II with renal disease (n = 44,608); and group III with atrial fibrillation (n = 45,952). The coprimary outcomes were blood transfusion and new-onset "composite complications" (venous thromboembolism, myocardial infarction, seizures, and ischemic stroke/transient ischemic attack). Associations between tranexamic acid use and outcomes were measured separately by high-risk group. The odds ratios and Bonferroni-adjusted 99.9% CIs are reported. RESULTS: Overall, 404,974 patients (52.9%) received tranexamic acid, with similar frequencies across high-risk groups I (13,004 of 27,890 [46.6%]), II (22,424 of 44,608 [50.3%]), and III (22,379 of 45,952 [48.7%]). Tranexamic acid use was associated with decreased odds of blood transfusion in high-risk groups I (721 of 13,004 [5.5%] vs. 2,293 of 14,886 [15.4%]; odds ratio, 0.307; 99.9% CI, 0.258 to 0.366), group II (2,045 of 22,424 [9.1%] vs. 5,159 of 22,184 [23.3%]; odds ratio, 0.315; 99.9% CI, 0.263 to 0.378), and group III (1,325 of 22,379 [5.9%] vs. 3,773 of 23,573 [16.0%]; odds ratio, 0.321; 99.9% CI, 0.266 to 0.389); all adjusted comparisons P < 0.001. No increased odds of composite complications were observed in high-risk group I (129 of 13,004 [1.0%] vs. 239 of 14,886 [1.6%]; odds ratio, 0.89, 99.9% CI, 0.49 to 1.59), group II (238 of 22,424 [1.1%] vs. 369 of 22,184 [1.7%]; odds ratio, 0.98; 99.9% CI, 0.58 to 1.67), and group III (187 of 22,379 [0.8%] vs. 290 of 23,573 [1.2%]; odds ratio, 0.93; 99.9% CI, 0.54 to 1.61); all adjusted comparisons P > 0.999. CONCLUSIONS: Although effective in reducing blood transfusions, tranexamic acid is not associated with increased complications, irrespective of patient high-risk status at baseline.

Enhanced Recovery After Surgery Protocols in Lower Extremity Joint Arthroplasty: Using Observational Data to Identify the Optimal Combination of Components.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocols are increasingly used in orthopedic surgery. Data are lacking on which combinations of ERAS components are (1) the most commonly used and (2) the most effective in terms of outcomes. METHODS: This retrospective cohort study utilized claims data (Premier Healthcare, n = 1,539,432 total joint arthroplasties, 2006-2016). Eight ERAS components were defined: (A) regional anesthesia, (B) multimodal analgesia, (C) tranexamic acid, (D) antiemetics on day of surgery, (E) early physical therapy, and avoidance of (F) urinary catheters, (G) patient-controlled analgesia, and (H) drains. Outcomes were length of stay, "any complication," and hospitalization cost. Mixed-effects models measured associations between the most common ERAS combinations and outcomes. Odds ratios (ORs) and 95% confidence intervals (CIs) are reported. RESULTS: In 2006-2012 and 2013-2016, the most common ERAS combinations were B/D/E/F/G/H (20%, n = 172,397) and B/C/D/E/F/G/H (17%, n = 120,266), respectively. The only difference between the most commonly used ERAS combinations over the years is the addition of C (addition of tranexamic acid to the protocol). The most pronounced beneficial effects in 2006-2012 were seen for combination A/B/D/E/F/G/H (6% of cases vs less prevalent ERAS combinations) for the outcome of "any complication" (OR 0.87, CI 0.83-0.91, P < .0001). In 2013-2016, the strongest effects were seen for combination B/C/D/E/F/G/H (17% of cases) also for the outcome of "any complication" (OR 0.86, CI 0.83-0.89, P < .0001). Relatively minor differences existed between ERAS protocols for the other outcomes. CONCLUSION: Despite varying ERAS protocols, maximum benefits in terms of complication reduction differed minimally. Further study may elucidate the balance between an increasing number of ERAS components and incremental benefits realized. LEVEL OF EVIDENCE: III.

Metric Selection, Metric Targets, and Risk Adjustment Should be Considered in the Design of Gainsharing Models for Bundled Payment Programs in Total Joint Arthroplasty.

BACKGROUND: Under bundled payment models, gainsharing presents an important mechanism to ensure engagement and reward innovation. We hypothesized that metric selection, metric targets, and risk adjustment would impact surgeons' performance in gainsharing models. METHODS: Patients undergoing total joint arthroplasty at an urban health system from 2017 to September 2018 were included. Gainsharing metrics included the following: length of stay, % discharge-to-home, 90-day readmission rate, % of patients with episode spend under target price, and % of patients with patient-reported outcomes (PROs) collected. Four scenarios were created to evaluate how metric selection/adjustment impacted surgeons' performance designation: scenario 1 used "aspirational targets" (>60th percentile), scenario 2 used "acceptable targets" (>50th percentile), scenario 3 risk-adjusted surgeon performance prior to comparing aspirational targets, and scenario 4 included a PRO collection metric. Number of metrics achieved determined performance tier, with higher tiers getting a greater share of the gainsharing pool. RESULTS: In total, 2776 patients treated by 12 surgeons met inclusion criteria (mean length of stay 3.0 days, readmission rate 4.0%, discharge-to-home 74%, episode spend under target price 85%, PRO collection 56%). Lowering of metric targets (scenario 1 vs. 2) resulted in a 75% increase in the number of high performers and 98% of the gainsharing pool being eligible for distribution. Risk adjustment (scenario 3) caused 50% of providers to move to higher performance tiers and potential payments to increase by 28%. Adding the PRO metric did not change performance. CONCLUSION: Quality metric/target selection and risk adjustment profoundly impact surgeons' performance in gainsharing contracts. This impacts how successful these contracts can be in driving innovation and dis-incentivizing the "cherry picking" of patients. LEVEL OF EVIDENCE: Level III.

K-Means Clustering to Elucidate Vulnerable Subpopulations Among Medicare Patients Undergoing Total Joint Arthroplasty.

BACKGROUND: The role of preoperative laboratory values for risk stratification following joint arthroplasty is currently ambiguous. In order to improve upon existing risk stratification within joint arthroplasty, this study sought to define novel phenotypes of total hip or total knee arthroplasty patients based entirely on preoperative laboratory measures. These phenotypes ("clusters") were compared to elucidate statistically and clinically significant differences in outcomes. METHODS: A total of 134,252 patients were gathered from the National Surgical Quality Improvement Program database between 2005 and 2015. "K-means" with 3 clusters was applied using 9 preoperative laboratory values: sodium, blood urea nitrogen (BUN), creatinine, albumin, bilirubin, white blood cell count, hematocrit, platelet count, and international normalized ratio of prothrombin values (INR). Outcome measures included 30-day readmissions, severe adverse events, and discharge to nonhome. RESULTS: Cluster 2 was characterized by elevated preoperative BUN, creatinine, and INR and demonstrated almost twice the rate of adverse events (3.52% vs 2.20% and 2.22%), 30-day readmissions (6.39% vs 3.31% and 3.71%), and discharge to nonhome (47.97% vs 30.50% and 35.85%). Cluster 3 was characterized by a slightly higher risk of discharge to nonhome than cluster 1 and was overwhelmingly female (79.5% female, 35.8% discharge to nonhome). Cluster 1 represents the lowest-risk subgroup, experiencing the lowest rates of readmissions, adverse events, and discharge to nonhome. CONCLUSION: Preoperative laboratory values, namely BUN, creatinine, and INR, are useful in identifying patients at risk of adverse outcomes. This analysis supports the existing surgical literature pushing for preoperative hydration as a targeted intervention to expedite recovery.

The Cost of Poor Mental Health in Total Joint Arthroplasty.

BACKGROUND: The purpose of this analysis was to evaluate (1) the impact of depression on resource utilization and financial outcomes in bundled total joint arthroplasty (TJA) and (2) whether similar effects are seen using baseline patient-reported outcome scores. METHODS: All elective bundled TJA cases from 2017 to 2018 at an academic system in the New York City area were included. We analyzed variables associated with cost differences seen between patients with and without depression, and between patients with low (<40th percentile) and high baseline (>60th percentile) Veterans RAND 12-Item Health Survey mental component scores (MCSs). We also analyzed whether depression or low MCS could predict worse financial outcomes. RESULTS: Our population included 825 patients, 418 with patient-reported outcome scores data. Depression was associated with higher rates of skilled nursing facility (SNF) discharge (42.7% vs 36.5%, P = .04), SNF payments ($16,200 vs $12,100, P = .0002), and average total episode costs ($31,000 vs $27,000, P = .04). Depression predicted bundle cost to be greater than target price (OR 1.82, 95% CI: 1.04-.16; P = .04) and SNF payment greater than 75th percentile (OR: 1.91; 95% CI: 1.00-3.65; P < .05). Similar effects were not seen using MCS. CONCLUSION: This is the first study to determine that depression predicts bundle cost greater than target price and SNF payment greater than 75th percentile. Our results emphasize the importance of accurate preoperative assessment of mental health in optimization of care, focusing on attenuating the increased SNF payments associated with depression. As similar effects were not seen using MCS, future studies should analyze the use of validated screening tools for depression, such as the PHQ-9, for more accurate assessments of patient mental health in TJA.

Characteristics of Antibiotic Prophylaxis and Risk of Surgical Site Infections in Primary Total Hip and Knee Arthroplasty.

BACKGROUND: Despite numerous antibiotic prophylaxis options for total hip arthroplasty (THA) and total knee arthroplasty (TKA), an assessment of practice patterns and comparative effectiveness is lacking. We aimed to characterize antibiotic utilization patterns and associations with infection risk and hypothesized differences in infection risk based on regimen. METHODS: A retrospective cohort study was performed using data from 436,724 THA and 862,918 TKA (Premier Healthcare Database; 2006-2016). Main exposures were antibiotic type and duration: day of surgery only (day 0) or through postoperative day 1 (day 1). The primary outcome was surgical site infection (SSI) <30 days postoperation. Mixed-effect models measured associations between prophylaxis regimen and SSI as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: SSI prevalence was 0.21% (n = 914) for THA and 0.22% (n = 1914) for TKA. Among THA procedures, the most commonly used antibiotics were cefazolin (74.1%), vancomycin (8.4%), "other" antibiotic combinations (7.1%), vancomycin + cefazolin (5.1%), and clindamycin (3.3%). Here, 51.8% received prophylaxis on day 0 only, whereas 48.2% received prophylaxis through day 1. Similar patterns existed for TKA. Relative to cefazolin, higher SSI odds were seen with vancomycin (OR = 1.36; CI 1.09-1.71) in THA and with vancomycin (OR = 1.29; CI = 1.10-1.52), vancomycin + cefazolin (OR = 1.35; CI = 1.12-1.64), clindamycin (OR = 1.38; CI = 1.11-1.71), and "other" antibiotic combinations (OR = 1.28; CI = 1.07-1.53) in TKA. Prophylaxis duration did not alter SSI odds. Results were corroborated in sensitivity analyses. CONCLUSION: Antibiotic prophylaxis regimens other than cefazolin were associated with increased SSI risk among THA/TKA patients. These findings emphasize a modifiable intervention to mitigate infection risk.

Hospital-Specific Total Joint Arthroplasty Casemix and Patient Flows in the Era of Payment Reform: Impact on Resource Utilization Among New York State Hospitals.

BACKGROUND: Bundled payment models may lead to selection of healthier total joint arthroplasty (TJA) candidates resulting in comorbid patients being taken care of in fewer hospitals. We aimed to (1) evaluate hospital-specific TJA comorbidity burden ("casemix") over time and (2) associations with resource utilization. METHODS: This retrospective cohort study used 2011 and 2016 New York State data (n = 36,078 hip/knee arthroplasties). Comorbidity burden was estimated by the Charlson-Deyo Index; main outcomes were hospitalization cost and nonhome discharge. Hospitals were categorized into those with a decreased, stable (with a 5% buffer), or increased percentage of comorbidity-free patients (Charlson-Deyo = 0) between 2011 and 2016. Mixed-effects models measured the association between Charlson-Deyo Index category and outcomes, by hospital casemix categorization. Odds ratios and 95% confidence intervals (CIs) are reported. RESULTS: Overall, 29 (n = 8810), 37 (n = 16,297), and 46 (n = 10,971) hospitals were categorized into the decreased, stable, and increased Charlson-Deyo = 0 categories, respectively, with median annual TJA volumes of 499, 814, and 393 (P < .0001). Multivariable models demonstrated that-in hospitals with a stable patient casemix-increased patient comorbidity was associated with increased hospitalization costs (maximum 21.8%, CI 18.9-24.9, P < .0001). However, this effect was moderated (maximum 11.1%, CI 8.0-14.2) in hospitals that took on a more comorbid patient casemix. Similar patterns were observed for nonhome discharge. CONCLUSION: Most studied hospitals show an increase in comorbidity-free TJA patients, suggestive of patient selection. This redistribution of comorbid patients to select hospitals may not necessarily be a negative development as our results suggest more efficient resource utilization for comorbid patients in such hospitals.

What Are the Uses and Limitations of Time-driven Activity-based Costing in Total Joint Replacement?

BACKGROUND: With increasing emphasis on value-based payment models for primary total joint arthroplasty (TJA), there is greater need for orthopaedic surgeons and hospitals to better understand the actual costs and resource use of TJA. Time-driven activity-based costing (TDABC) is a methodology for accurate cost estimation, but its application in the TJA care pathway across institutions/regions has not yet been analyzed. QUESTIONS/PURPOSES: In this systematic review of studies applying TDABC to primary TJA, we investigated the following: (1) Is there variation in TDABC methodology and cost estimates across institutions? (2) Is a standard set of direct and indirect costs included across studies? (3) Is there a difference in cost estimates derived from TDABC and traditional hospital cost-accounting approaches? and (4) How are institutions using TDABC (process and outputs) with respect to the TJA care pathway? METHODS: A comprehensive search strategy was developed that included the keywords "TDABC," "time-driven activity-based cost," "THA," "TKA," "THR," "TKR," and "TJR" in the PubMed/MEDLINE, EMBASE, Web of Science, Ovid SP, Scopus, and ScienceDirect databases for articles published between 2004 and 2018 as well as extensive hand searching and citation mining. Relevant studies (n = 15) were screened to include THA or TKA as the focus of the TDABC model, full-text articles, TDABC-based cost estimates for TJA, and studies written in English (n = 8). Due to the heterogeneity of outcomes/methodology in TDABC studies involving TJA, quality assessment was based on each study's adherence to the seven steps delineated by Kaplan et al. in their original publication introducing TDABC in health care. RESULTS: There was substantial variation in TDABC methodology (especially in scope), adherence to the seven steps of TDABC, and data collection. Only five of eight studies incorporated indirect costs into their TDABC calculation, with notable differences in which direct and indirect expenses were included. TDABC-based cost estimates for TJA ranged from USD 7081 to USD 29,557, with variation driven by the TJA timeframe and whether implant costs were included in the costing calculation. TDABC was most frequently used to compare against traditional hospital accounting methods (n = 4), to increase operational efficiency (n = 4), to reduce wasted resources (n = 3), and to mitigate risk (n = 3). CONCLUSIONS: TDABC-based cost estimates are more granular and useful in practice than those calculated via traditional hospital accounting; however, there is a lack of standardized principles to guide TDABC implementation (especially for indirect costs) due to institutional and regional differences in TDABC application. Although TDABC methodology will likely continue to vary somewhat between studies, standardized principles are needed to guide the definition, estimation, and reporting of costs to enable detailed examination of study methodology and inputs by readers. LEVEL OF EVIDENCE: Level III, economic and decision analysis.

Are Histological Examinations of Arthroplasty Specimens Performed Consistently Across the Country? A Large Database Study.

BACKGROUND: It is currently unknown to what extent routine histological examination of joint arthroplasty specimens occurs across hospitals nationwide. Although this practice is neither supported nor refuted by the available evidence, given the increasing demand for joint arthroplasties, it is crucial to study overall utilization as well as its main drivers. QUESTIONS/PURPOSES: Using national data on joint replacements, we aimed to evaluate: (1) What is the current use of routine histological examination of joint arthroplasty specimens? (2) Does the use vary by geographic location and hospital characteristics? (3) Has use changed over time? METHODS: From the Premier Healthcare database (2006-2016) we included claims data from 87,667 shoulder (595 hospitals, median age 70 years, 16% nonwhite), 564,577 hip (629 hospitals, median age 65 years, 21% nonwhite), and 1,131,323 (630 hospitals, median age 66 years, 24% nonwhite) knee arthroplasties (all elective). Our study group has extensive experience with this data set, which contains information on 20% to 25% of all US hospitalizations. Included hospitals are mainly concentrated in the South (approximately 40%) with equal distributions among the Northeast, West, and Midwest (approximately 20% each). Moreover, the Premier data set has detailed billing information, which allows for evaluations of real-world clinical practice. There was no missing information on the main variables of interest for this specific study. We assessed frequency of histology examination (defined by Current Procedural Terminology codes) overall as well as by hospital characteristics (urban/rural, bed size, teaching status, arthroplasty volume), geographic region (Northeast, South, Midwest, West), and year. Given the large sample size, instead of p values, standardized differences were applied in assessing group differences where a standardized difference of > 0.1 (or 10%) was assumed to represent a meaningful difference between groups. For significance of trends, p values were applied. Percentages provided represent proportions of individual procedures. RESULTS: In most hospitals, histology testing was either rare (1%-10%, used in 187 of 595, 189 of 629, and 254 of 630 hospitals) or ubiquitous (91%-100%, used in 121 of 595, 220 of 629, and 195 of 630 hospitals) for shoulder, hip, and knee arthroplasties, respectively. Overall, histology testing occurred more often in smaller hospitals (37%-53% compared with 26%-45% in larger hospitals) and those located in the Northeast (59%-68% compared with 22%-44% in other regions) and urban areas (32%-49% compared with 20%-31% in rural areas), all with standardized differences > 10%. Histologic examination is slowly decreasing over time: from 2006 to 2016, it decreased from 34% to 30% for shoulder arthroplasty, from 50% to 45% for THAs, and from 43% to 38% for TKAs (all p < 0.001). CONCLUSIONS: Although overall use is decreasing, a substantial number of hospitals still routinely perform histology testing of arthroplasty specimens. Moreover, variation between regions and hospital types suggests that this practice is driven by a variety of factors. This is the first study addressing national utilization, which will be helpful for individual hospitals to assess how they compare with national utilization patterns. Moreover, the findings have clear implications for followup studies, which may be necessary given the exponentially growing demand for arthroplasties. LEVEL OF EVIDENCE: Level III, therapeutic study.

Antibiotic-Loaded Bone Cement in Primary Total Knee Arthroplasty: Utilization Patterns and Impact on Complications Using a National Database.

BACKGROUND: The routine usage of antibiotic-loaded bone cement (ALBC) in primary total knee arthroplasty (TKA) is controversial. Its effectiveness in reducing infection risk remains unclear while high-dose antibiotics can lead to multiple adverse effects. The purpose of this population-based study is to evaluate utilization patterns of ALBC in primary TKA and its impact on clinical outcomes. METHODS: This retrospective cohort study used data from the nationwide Premier Healthcare claims database (2006-2016). Multivariable models estimated associations between ALBC use and early postoperative infection, kidney injury, allergic reaction, hospital readmission, cost, and length of stay. RESULTS: ALBC was used in 27.2% of all primary TKAs (N = 1,184,270). Usage increased from 17.3% to 30.2% in 2006-2010, then plateaued. Study covariates differed minimally between groups, suggesting nonselective ALBC use. Utilization was lower in rural (21.4%) and higher in large (>500 beds; 29.4%) hospitals. After adjusting for relevant covariates, ALBC use was associated with significantly decreased odds for early postoperative infection (odds ratio, 0.89; confidence interval, 0.83-0.96) and increased odds for acute kidney injury (odds ratio, 1.06; confidence interval, 1.02-1.11). CONCLUSION: With utilization rates of around 30%, we found that ALBC reduced odds for early postoperative infection and increased odds for kidney injury. Strong consideration should be given for selective use of ALBC in primary TKA.