Early Discharge for Revision Total Knee and Hip Arthroplasty: Predictors of Success.

BACKGROUND: The rate of revision total joint arthroplasties is expected to increase drastically in the near future. Given the recent pandemic, there has been a general push toward early discharge. This study aimed to assess for predictors of early postoperative discharge after revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA). METHODS: There were 77 rTKA and 129 rTHA collected between January 1, 2019 and December 31, 2021. Demographic data, comorbidities, a comorbidity index, the modified frailty index (mFI-5), and surgical history were collected. The Common Procedural Terminology codes for each case were assessed. Patients were grouped into 2 cohorts, early discharge (length of stay [LOS] <24 hours) and late discharge (LOS >24 hours). RESULTS: In the rTHA cohort, age >65 years, a history of cardiac or liver disease, an mFI-5 of >1, a comorbidity index of >2.7, a surgical time >122 minutes, and the need for a transfusion were predictors of prolonged LOS. Only the presence of a surgical time of >63 minutes or an mFI-5 >1 increased patient LOS in the rTKA cohort. In both rTHA and rTKA patients, periprosthetic joint infection resulted in a late discharge for all patients, mean 4.8 and 7.1 days, respectively. Dual component revision was performed in 70.5% of rTHA. Only 27.6% of rTKA were 2-component revisions or placements of an antibiotic spacer. CONCLUSIONS: Several patient and surgical factors preclude early discharge candidacy. For rTHA, an mFI-5 of >2/5, comorbidity index of >4, or a surgical time of >122 minutes is predictive of prolonged LOS. For rTKA, an mFI-5 of >2/5, Charlson Comorbidity Index of >5, or a surgical time of >63 minutes predicts prolonged LOS.

Variation in Inflammatory Biomarkers Among Demographic Groups Significantly Affects Their Accuracy in Diagnosing Periprosthetic Joint Infection.

BACKGROUND: Diagnosis of periprosthetic joint infection (PJI) is a multistep process that involves performing various tests including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The latter two tests, despite being used at all times for PJI diagnosis, are known to be nonspecific and substantially affected by demographic characteristics, including age, gender, race, and body mass index. It is unknown how these variations affect the diagnostic utility of serological markers for PJI. METHODS: Institutional databases were queried to identify patients undergoing revision arthroplasty between 2010 and 2018, in whom preoperative serum ESR and CRP was performed. Patient demographics were collected, and patients were cross-referenced with an internal database to determine their infection status. Analyses were performed to determine how ESR and CRP varied with respect to demographic factors, including age, gender, race, and infection status. Given that patient infection status was known at the time of revision, conclusions were drawn about the effect of these variations in inflammatory markers on the diagnostic utility of ESR and CRP. RESULTS: The value of ESR increased by age was higher in females and African American race. No significant differences were observed in the value of CRP among the demographic factors, although a slight positive trend was observed with respect to age. The variation in inflammatory markers significantly affected the sensitivity, specificity, and accuracy of ESR and CRP for PJI diagnosis. CONCLUSION: Understanding how the accuracy of diagnostic tests varies with respect to demographic factors can help physicians avoid subjecting patients to unnecessary additional testing and reach more accurate diagnoses of PJI.

Which Socioeconomic Factors Affect Outcomes Following Total Hip and Knee Arthroplasty?

BACKGROUND: Studies have shown that lower socioeconomic status may result in adverse outcomes following total hip (THA) and total knee arthroplasty (TKA). The optimal method of defining socioeconomic status, however, continues to be debated. The purpose of this study is to determine which socioeconomic variables are associated with poor outcomes following THA and TKA. METHODS: We reviewed a consecutive series of 2770 primary THA and TKA patients from 2015 to 2018. Utilizing census data based upon the patient's ZIP code, we extracted poverty, unemployment, high school graduation, and vehicle possession rates. We collected demographics, comorbidities, discharge disposition, 90-day readmissions, and postoperative functional outcome scores for each patient. We then performed a multivariate regression analysis to identify the effect of each socioeconomic variable on postoperative outcomes. RESULTS: Patients from areas with high unemployment (P = .008) and low high school graduation rates (P = .019) had a higher age-adjusted Charlson Comorbidity Index. High poverty levels, high unemployment, lower high school graduation rate, and lower vehicle possession rates did not have a significant effect on functional outcomes (all P > .05). In the multivariate analysis, no socioeconomic variable demonstrated an increased rate of rehabilitation discharge, revision, or readmission (all P > .05). CONCLUSION: Patients undergoing THA and TKA from areas with high unemployment and lower educational levels do have more medical comorbidities. However, none of the 4 socioeconomic variables studied are independently associated with higher rates of readmission, discharge to rehabilitation, or worse functional outcomes. Patients from disadvantaged areas should not be denied access to arthroplasty care based on socioeconomic status alone.

Is the New Outpatient Prospective Payment System Classification for Outpatient Total Knee Arthroplasty Appropriate?

BACKGROUND: In 2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the inpatient-only list, resulting in payment through the Outpatient Prospective Payment System with an average $3157 reduction. The purpose of this study is to determine if the reimbursement is justified by comparing the difference in facility costs between inpatient and outpatient TKAs. METHODS: We identified 4496 consecutive primary TKA procedures performed at 2 hospitals from 2015 to 2019. Itemized facility costs were calculated using a time-driven activity-based costing algorithm. Outpatient procedures were defined as those with a length of stay of less than 2 midnights (3851, 86%). Patient demographics, comorbidities, and itemized costs were compared between groups. A multivariate regression analysis was performed to determine the independent effect of outpatient status on true facility costs. RESULTS: Outpatient TKA patients had lower mean postoperative personnel costs ($1809 vs $947, P < .001), supply costs ($4347 vs $4229, P < .001), and overall total facility costs ($7371 vs $6937, P < .001) than inpatient TKA patients. Controlling for a younger patient cohort with fewer medical comorbidities, outpatient status was associated with a reduction in total facility costs of $972 (95% confidence interval $883-$1060, P < .001) compared to inpatient TKA. CONCLUSION: Outpatient TKA costs hospitals nearly $1000 per patient less than inpatient TKA, yet the average difference in Medicare reimbursement for an outpatient procedure is $3157 less per patient. Centers for Medicare and Medicaid Services should reconsider the Outpatient Prospective Payment System classification of TKA to better incentivize surgeons to perform TKA as a lower cost outpatient procedure when safe and appropriate.

The Impact of Author Financial Conflicts on Robotic-Assisted Joint Arthroplasty Research.

BACKGROUND: Recent studies have suggested clinical superiority with robotic-assisted arthroplasty compared to traditional techniques. However, concerns exist regarding the author's financial conflicts of interest (COI), which may influence research outcomes. This study aimed to determine whether COI relating to robotic-assisted arthroplasty influences the results of published outcomes following total hip (THA), total knee (TKA), and unicompartmental knee arthroplasty (UKA). METHODS: We performed a systematic review to identify all studies evaluating the use of robotics in THA, TKA, and UKA. An author's financial COI was identified if they reported a relevant disclosure through the American Academy of Orthopedic Surgeons or within the study article. We then queried the Open Payments website to record all payments made from a robotic company in the year prior to publication. Each study was categorized as either favoring robotics (n = 42), neutral (n = 10), or favoring traditional techniques (n = 2). We then compared the number of conflicted authors, journal impact factor, level of evidence, and mean annual industry payment to each author. RESULTS: Of the 54 studies meeting inclusion criteria, 49 (91%) had an author financial COI. Conflicted studies were more likely to report favorable results of robotics than nonconflicted studies. When compared to studies favoring conventional techniques, those demonstrating favorable robotics outcomes had a higher number of conflicted authors and a higher mean industry payment per author. There was no difference in the level of evidence or journal impact factor. DISCUSSION: Nearly all studies comparing robotic THA, TKA, and UKA to conventional techniques involve financially conflicted authors. Further studies without COI may provide unbiased results.

Amount of CMS Reduction in Facility Reimbursement Following Removal of Total Hip Arthroplasty From the Inpatient-Only List Far Exceeds Reduction in Actual Care Cost.

BACKGROUND: Starting in 2020, Centers for Medicare and Medicaid Services (CMS) removed total hip arthroplasty (THA) from the inpatient-only list, resulting in an average of $1637 per case reduction in facility reimbursement. The purpose of this study is to determine whether the reduction in reimbursement is justified by comparing the difference in true facility costs between inpatient and outpatient THA. METHODS: We identified a consecutive series of 5271 primary THA procedures from 2015 to 2019. Itemized procedural costs were calculated using a time-driven activity-based costing algorithm. Outpatient procedures were defined as those with less than a 24-hour length of stay. We compared patient demographics, comorbidities, and itemized costs between inpatient and outpatient procedures. A multivariate analysis was performed to determine the independent effect of outpatient status on true facility costs. RESULTS: There were 783 (14.9%) outpatient THA procedures. The outpatient THA procedures incurred lower mean personnel ($1428 vs $2226, P < .001), supply ($4713 vs $4739, P < .001), and overall facility costs ($6141 vs $6595, P < .001) when compared with the same THA procedures done inpatient. When controlling for confounding variables, outpatient status was associated with a reduction in total facility costs of $825 (95% confidence interval, $734-$916, P < .001). CONCLUSION: The reduction in CMS reimbursement far exceeds the $825 per-patient cost savings that can be achieved by a facility by performing THA as an outpatient. CMS should reconsider the Outpatient Prospective Payment System classification of THA to better incentivize surgeons to perform THA as a lower-cost outpatient procedure when safe and appropriate.

Target Price Adjustment for Hip Fractures Is Not Sufficient in the Bundled Payments for Care Improvement Initiative.

BACKGROUND: Under the Bundled Payments for Care Improvement (BPCI) initiative, the Centers for Medicare and Medicaid Services (CMS) adjusts the target price for total hip arthroplasty (THA) based upon the historical proportion of fracture cases. Concerns exist that hospitals that care for hip fracture patients may be penalized in BPCI. The purpose of this study is to compare the episode-of-care (EOC) costs of hip fracture patients to elective THA patients. METHODS: We reviewed a consecutive series of 4096 THA patients from 2015 to 2018. Patients were grouped into elective THA (n = 3686), fracture THA (n = 176), and hemiarthroplasty (n = 274). Using CMS claims data, we compared EOC costs, postacute care costs, and performance against the target price between the groups. To control for confounding variables, we performed a multivariate analysis to identify the effect of hip fracture diagnosis on costs. RESULTS: Elective THA patients had lower EOC ($18,200 vs $42,605 vs $38,371; P < .001) and postacute care costs ($4477 vs $28,093 vs $23,217; P < .001) than both hemiarthroplasty and THA for fracture. Patients undergoing arthroplasty for fracture lost an average of $23,122 (vs $1648 profit for elective THA; P < .001) with 91% of cases exceeding the target price (vs 20% for elective THA; P < .001). In multivariate analysis, patients undergoing arthroplasty for fracture had higher EOC costs by $19,492 (P < .001). CONCLUSION: Patients undergoing arthroplasty for fracture cost over twice as much as elective THA patients. CMS should change their methodology or exclude fracture patients from BPCI, particularly during the COVID-19 pandemic.

Gastrointestinal Complications Following Total Joint Arthroplasty Are Rare but Have Severe Consequences.

BACKGROUND: Gastrointestinal (GI) complications following total joint arthroplasty (TJA) are rare, but can result in substantial morbidity and mortality, especially when intervention is required. The purpose of this study is to identify modifiable risk factors for the development of GI complications and determine their impact on short-term outcomes following TJA. METHODS: We queried patients who underwent primary TJA at a single academic center from 2009 through 2018 and collected data on demographics, comorbidities, operative and perioperative details, and short-term outcomes. Patients who suffered at least one GI complication during the same hospitalization as their TJA were identified. The type of GI complication and intervention performed, if necessary, was recorded. Variables that independently affected the risk of GI complication were identified. Multivariate regression was performed to determine the effect suffering a GI complication had on outcomes. RESULTS: Of 17,402 patients, 106 (0.6%) suffered a GI complication. Constipation/obstruction, followed by diarrhea/malabsorption, hemorrhage, and Clostridium difficile were the most commonly reported complications. Patients suffering a GI complication were significantly older (68.5 vs 63.7, P < .001), less likely to use alcohol (49% vs 65%, P = .008), and had higher incidences of 8 of the 16 comorbidities analyzed (all P < .05). Patients with GI complications had greater lengths of stay (13.2 vs 2.3 days, P < .001), discharge to facility rates (58% vs 16%, P < .001), and in-hospital mortality rates (1.9% vs 0.1%, P = .002). CONCLUSION: Patients suffering a GI complication following TJA require longer hospital stays and greater post-acute care resources and have a substantially higher risk of mortality.

Can Prior Episode-of-Care Costs Predict the Future? Identifying High-Cost Outliers for Subsequent Total Hip and Knee Arthroplasty.

BACKGROUND: It remains unknown if a patient's prior episode-of-care (EOC) costs for total hip (THA) or knee (TKA) arthroplasty procedure can be used to predict subsequent costs for future procedures. The purpose of this study is to evaluate whether there is a correlation between the EOC costs for a patient's index and subsequent THA or TKA. METHODS: We reviewed a consecutive series of 11,599 THA and TKA Medicare patients from 2015 to 2019 and identified all patients who underwent a subsequent THA and TKA during the study period. We collected demographics, comorbidities, short-term outcomes, and 90-day EOC claims costs. A multivariate analysis was performed to identify whether prior high-EOC costs were predictive of high costs for the subsequent procedure. RESULTS: Of the 774 patients (6.7%) who underwent a subsequent THA or TKA, there was no difference in readmissions (4% vs 5%, P = .70), rate of discharge to a skilled nursing facility (SNF) (15% vs 15%, P = .89), and mean costs ($18,534 vs $18,532, P = .99) between EOCs. High-cost patients for the initial TKA or THA were more likely to be high cost for subsequent procedure (odds ratio 14.33, P < .01). Repeat high-cost patients were more likely to discharge to an SNF for their first and second EOC compared to normative-cost patients (P < .01). CONCLUSION: High-cost patients for their initial THA or TKA are likely to be high cost for a subsequent procedure, secondary to a high rate of SNF utilization. Efforts to reduce costs in repeat high-cost patients should focus on addressing post-operative needs pre-operatively to facilitate safe discharge home.

The Frequency, Reasoning, and Impact of Repeated Radiographs at the Initial Orthopedic Arthroplasty Visit.

BACKGROUND: Patients presenting to an orthopedic clinic with joint pain often seek prior care and imaging before consultation. It is unknown how often orthopedic surgeons must repeat imaging and whether repeat imaging has an impact on diagnosis or management. The purpose of this study was to determine the frequency, reason, and impact of repeating radiographs in outpatient orthopedic clinics. METHODS: Patients ≥18 years of age presenting with hip and/or knee pain were prospectively enrolled at five arthroplasty clinics from January 2019 until June 2020. Before the initial visit, surveys were distributed to patients regarding the reason for their visit, prior care, and prior diagnostic imaging. At the conclusion of the visit, surgeons reported if repeat radiographs were obtained, and if so, surgeons documented the views ordered, the reasoning for new films, and if diagnosis or management changed as a result. Patients were grouped based on repeat imaging status, and of those with repeat imaging, subgroup analysis compared patients based on if management changed. RESULTS: Of 292 patients, 256 (88%) had radiographs before their office visit, and 167 (65%) obtained repeat radiographs. Radiographs were most commonly repeated if they were inaccessible (47%), followed by if they were non-weight-bearing (40%). Repeated radiographs changed the diagnosis in 40% of patients and changed management in 22% of patients. CONCLUSION: Most patients underwent repeat radiography at their orthopedic visit. The primary reasons were owing to accessibility or the patient being non-weight-bearing. Repeat radiographs changed management in almost one-quarter of patients.

Despite Equivalent Medicare Reimbursement, Facility Costs for Outpatient Total Knee Arthroplasty Are Higher Than Unicompartmental Knee Arthroplasty.

BACKGROUND: With the recent removal of total knee arthroplasty (TKA) from the Centers for Medicare and Medicaid Services (CMS) Inpatient Only list, facility reimbursement for outpatient TKA now falls under the Outpatient Prospective Payment System at the same rate as unicompartmental knee arthroplasty (UKA). The purpose of this study was to compare true facility costs of patients undergoing outpatient TKA with those undergoing UKA. METHODS: We reviewed a consecutive series of 2310 outpatient TKA and 231 UKA patients from 2018 to 2019. Outpatient status was defined as a hospital stay of less than 2 midnights. Facility costs were calculated using a time-driven, activity-based costing algorithm. Implants, supplies, medications, and personnel costs were compared between outpatient TKA and UKA patients. A multivariate analysis was performed to control for confounding medical and demographic variables. RESULTS: When compared with patients undergoing UKA, outpatient TKA patients had higher implant costs ($3403 vs $3081; P < .001) and overall hospital costs ($6350 vs $5594; P < .001). Outpatient TKA patients had a greater length of stay (1.2 vs 0.5 days; P < .001) and greater postoperative personnel costs ($783 vs $166; P < .001) than UKA patients. When controlling for comorbidities, outpatient TKA was associated with a $803 (P < .001) increase in overall facility costs compared with UKA. CONCLUSION: Despite equivalent reimbursement from CMS as UKA, outpatient TKA has increased facility costs to the hospital. Although implant costs can vary greatly by institution, CMS should consider appropriately reimbursing outpatient TKA for the additional personnel costs when compared with UKA.

Are We at the Bottom? BPCI Programs Now Disincentivize Providers Who Maintain Quality Despite Caring for Increasingly Complex Patients.

BACKGROUND: The Bundled Payments for Care Improvement (BPCI) initiative has been successful at reducing Medicare costs after total joint arthroplasty (TJA). Target pricing is based on each institution's historical performance and is periodically reset. The purpose of this study was to examine the performance of our BPCI program accounting for patient complexity, quality, and resource utilization. METHODS: We reviewed a consecutive series of 9195 Medicare patients undergoing primary TJA from 2015 to 2018. Demographics, comorbidities, and readmissions by year were compared. We then examined 90-day episode-of-care costs, changes in target price, and financial margins during the duration of the BPCI program using Medicare claims data. RESULTS: Patients undergoing TJA in 2018 had a higher prevalence of diabetes and cardiac disease (all P < .001) as compared with those in 2015. From 2015 to 2018, there was a decrease in the rate of discharge to rehabilitation facilities (23% vs 14%, P < .001) and length of stay (2.1 vs 1.7 days, P < .001) with no difference in readmissions (6% vs 6%, P = .945). There was a reduction in postacute care costs ($6076 vs $4,890, P < .001) and 90-day episode-of-care costs ($19,954 vs $18,449, P < .001). However, the target price also decreased ($22,280 vs $18,971, P < .001), and the per-patient margin diminished ($2683 vs $522, P < .001). CONCLUSION: Surgeons have maintained quality of care at a reduced cost despite increasing patient complexity. The target price adjustments resulted in declining margins during the course of our BPCI experience. Policy makers should consider changes to target price methodology to encourage participation in these successful cost-saving programs.

Association of Perioperative Red Blood Cell Transfusion With Symptomatic Venous Thromboembolism Following Total Hip and Knee Arthroplasty.

BACKGROUND: Prior registry data suggest that perioperative red blood cell (RBC) transfusion may increase the incidence of venous thromboembolism (VTE) in patients status post surgery. However, there are limited data that explore VTE risk after perioperative transfusion in the setting of primary total joint arthroplasty (TJA). Our aim is to investigate the association between perioperative RBC transfusion and the development of symptomatic VTE after adjusting for confounding variables. METHODS: We retrospectively reviewed all patients undergoing primary TJA at a single institution from 2001 to 2016. The primary outcome was development of symptomatic VTE (deep vein thrombosis or pulmonary embolism) up to 90 days following primary TJA. To identify the association between RBC transfusion and development of VTE, univariate and multivariate analyses were used, as well as a sensitivity analysis using propensity score matching based on patient comorbidities. RESULTS: Of the 29,003 patients who underwent TJA, 2500 (8.62%) received RBC transfusion perioperatively and 302 (1.04%) developed a postoperative VTE within 90 days of surgery. While univariate analysis did suggest a slightly increased incidence of VTE in association with RBC transfusion (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.09-2.16), this difference was eliminated when multivariate analysis (OR, 0.42; 95% CI, 0.12-1.39) and propensity score matching (propensity-matched OR, 1.2; 95% CI, 0.7-1.8) were employed. CONCLUSION: Perioperative RBC transfusion does not significantly increase the incidence of symptomatic VTE following primary TJA in the 90-day postoperative period after adjustment for host VTE risk scores and other confounding variables. Perioperative RBC transfusion may be safely administered if indicated following total hip and knee arthroplasty.

From Winners to Losers: The Methodology of Bundled Payments for Care Improvement Advanced Disincentivizes Participation in Bundled Payment Programs.

BACKGROUND: The Bundled Payments for Care Improvement (BPCI) initiative improved quality and reduced costs following total hip (THA) and knee arthroplasty (TKA). In October 2018, the BPCI-Advanced program was implemented. The purpose of this study is to compare the quality metrics and performance between our institution's participation in the BPCI program with the BPCI-Advanced initiative. METHODS: We reviewed a consecutive series of Medicare primary THA and TKA patients. Demographics, medical comorbidities, discharge disposition, readmission, and complication rates were compared between BPCI and BPCI-Advanced groups. Medicare claims data were used to compare episode-of-care costs, target price, and margin per patient between the cohorts. RESULTS: Compared to BPCI patients (n = 9222), BPCI-Advanced patients (n = 2430) had lower rates of readmission (5.8% vs 3.8%, P = .001) and higher rate of discharge to home (72% vs 78%, P < .001) with similar rates of complications (4% vs 4%, P = .216). Medical comorbidities were similar between groups. BPCI-Advanced patients had higher episode-of-care costs ($22,044 vs $18,440, P < .001) and a higher mean target price ($21,154 vs $20,277, P < .001). BPCI-Advanced patients had a reduced per-patient margin compared to BPCI ($890 loss vs $1459 gain, P < .001), resulting in a $2,138,670 loss in the first three-quarters of program participation. CONCLUSION: Despite marked improvements in quality metrics, our institution suffered a substantial loss through BPCI-Advanced secondary to methodological changes within the program, such as the exclusion of outpatient TKAs, facility-specific target pricing, and the elimination of different risk tracks for institutions. Medicare should consider adjustments to this program to keep surgeons participating in alternative payment models.

Staging Total Hip and Knee Arthroplasty Procedures Within 90 Days Increases Costs in Bundled Payment Programs.

BACKGROUND: Under current Medicare bundled payment programs, when a patient undergoes a subsequent elective procedure within the 90-day episode-of-care, the first procedure is excluded from the bundle and a new episode-of-care initiated. The purpose of this study was to determine if staging bilateral total hip (THA) and total knee arthroplasty (TKA) procedures within 90 days have an effect on bundled episode-of-care costs. METHODS: We reviewed a consecutive series of Medicare patients undergoing staged primary THA and TKA from 2015-2019. Patients who underwent a prior procedure within 90 days were compared to those who had undergone a procedure 90-120 days prior. We then performed a multivariate analysis to identify the independent effect of staging timeframe on costs and outcomes. RESULTS: Of the 136 patients undergoing a staged bilateral THA or TKA, 48 patients underwent staged procedures within 90 days (35%) and 88 patients between 91-120 days (65%). There were no significant differences observed for demographics, comorbidities, complications, readmissions, or discharge disposition (all P > .05). Patients undergoing a staged procedure within 90 days had increased episode-of-care costs by $2021 (95% CI $11-$4032, P = .049), increased postacute care costs by $2019 (95% CI $66-$3971, P < .001), and reduced per-patient margin by $2868 (95% CI-$866-$4869, P = .005). DISCUSSION: Patients undergoing staged bilateral THA or TKA within 90 days have increased episode-of-care costs compared to those undergoing a staged procedure from 91-120 days. Since patients may still not be fully recovered from the first procedure, CMS should address the inappropriate allocation of costs to ensure institutions are not penalized.

Risk Factors and Effect of Acute Kidney Injury on Outcomes Following Total Hip and Knee Arthroplasty.

BACKGROUND: Development of acute kidney injury (AKI) following primary total joint arthroplasty (TJA) is a potentially avoidable complication associated with negative outcomes including discharge to facilities and mortality. Few studies have identified modifiable risk factors or strategies that the surgeon may use to reduce this risk. METHODS: We identified all patients undergoing primary TJA at a single hospital from 2005 to 2017, and collected patient demographics, comorbidities, short-term outcomes, as well as perioperative laboratory results. We defined AKI as an increase in creatinine levels by 50% or 0.3 points. We compared demographics, comorbidities, and outcomes between patients who developed AKI and those who did not. Multivariate regressions identified the independent effect of AKI on outcomes. A stochastic gradient boosting model was constructed to predict AKI. RESULTS: In total, 814 (3.9%) of 20,800 patients developed AKI. AKI independently increased length of stay by 0.26 days (95% confidence interval [CI] 0.14-0.38, P < .001), in-hospital complication risk (odds ratio = 1.73, 95% CI 1.45-2.07, P < .001), and discharge to facility risk (odds ratio = 1.26, 95% CI 1.05-1.53, P = .012). Forty-one predictive variables were included in the predictive model, with important potentially modifiable variables including body mass index, perioperative hemoglobin levels, surgery duration, and operative fluids administered. The final predictive model demonstrated excellent performance with a c-statistic of 0.967. CONCLUSION: Our results confirm that AKI has adverse effects on outcome metrics including length of stay, discharge, and complications. Although many risk factors are nonmodifiable, maintaining adequate renal perfusion through optimizing preoperative hemoglobin, sufficient fluid resuscitation, and reducing blood loss, such as through the use of tranexamic acid, may aid in mitigating this risk.

A Postdischarge Multimodal Pain Management Cocktail Following Total Knee Arthroplasty Reduces Opioid Consumption in the 30-Day Postoperative Period: A Group-Randomized Trial.

BACKGROUND: Traditional pain management after total knee arthroplasty (TKA) relies heavily on opioids. Although there is evidence that in-hospital multimodal pain management (MMPM) is more effective than opioid-only (OO) analgesia, there has been little focus on postdischarge pain management. The hypothesis of this study was that MMPM after TKA would reduce pain scores and opioid consumption in the 30-day period after hospital discharge. METHODS: This is a prospective, 2-group, comparative study with a provider cross-over design comparing a 30-day OO prn regimen with a MMPM regimen and opioid medications prn. The primary outcome measure was visual analog scale pain score and opioid-related side effects. Secondary outcome measures included morphine milligram equivalents consumed, failure of the protocol, and opioid refills. RESULTS: There were 216 patients included in the trial, with final data available for 143. There was no clinically meaningful difference in visual analog scale score between the 2 groups at any time. Average opioid consumption at 30 days was 582.5 and 386.4 morphine milligram equivalents for the OO and MMPM cohorts, respectively (P = .0006). Average number of opioid pills consumed at 30 days was 91.8 and 60.4 for OO and MMPM cohorts, respectively (P = .0004). CONCLUSION: A 30-day postdischarge multimodal pain regimen reduced opioid use after TKA while maintaining a similar level of pain control as the OO regimen. OO regimens are at an increased risk of needing additional medications to control pain. LEVEL OF EVIDENCE: Level II. REGISTRY NAME: www.clinicaltrials.gov. TRIAL NUMBER: NCT04003350.

The Use of Cementless Components Does Not Significantly Increase Procedural Costs in Total Knee Arthroplasty.

BACKGROUND: Modern cementless total knee arthroplasty (TKA) designs have shown promising early clinical success; however, concerns exist regarding the higher cost of the cementless implants. The purpose of this study is to evaluate the total facility cost of cementless vs traditional cemented TKA along with the effect of cementless fixation on short-term outcomes. METHODS: We reviewed a consecutive series of patients between 2015 and 2017 who underwent either cementless or cemented primary TKA. Itemized facility costs were calculated for every procedure using a time-driven activity-based costing algorithm. Controlling for demographic variables and medical comorbidities, we performed a multivariate analysis to identify independent risk factors for facility costs following TKA. Short-term outcome metrics including complications, readmissions, and patient-reported outcomes were compared between groups. RESULTS: Among the 2426 primary TKA patients in this study, 119 (4.91%) were performed using cementless implants. When compared to cemented TKA, cementless TKA patients had higher implant costs ($3047.80 vs $2808.73, P < .0001), but lower supply costs ($639.49 vs $815.57, P < .0001) and lower operating room personnel costs ($982.01 vs $1238.26, P < .0001). When controlling for confounding variables, cementless fixation did not have a significant effect on total facility cost or outcomes. CONCLUSION: In conclusion, the use of cementless TKA implants did not significantly increase total procedural costs when compared to traditional cemented TKA components at our institution. Our data suggest that the increased cost of a cementless implant is recouped through savings in cost of cement and supplies, as well as shorter operative times. The authors encourage investigators at other institutions to use the authors' methodology to evaluate (preferably in a prospective manner) whether the findings from this study can be corroborated.

High-Quality Skilled Nursing Facilities Are Associated With Decreased Episode-of-Care Costs Following Total Hip and Knee Arthroplasty.

BACKGROUND: With the increasing popularity of alternative payment models following total hip (THA) and knee arthroplasty (TKA), efforts have focused on reducing post-acute care (PAC) costs, particularly patients discharged to skilled nursing facilities (SNFs). The purpose of this study is to determine if preferentially discharging patients to high-quality SNFs can reduce bundled payment costs for primary THA and TKA. METHODS: At our institution, a quality improvement initiative for SNFs was implemented at the start of 2017, preferentially discharging patients to internally credentialed facilities, designated by several quality measures. Claims data from Centers for Medicare and Medicaid Services were queried to identify patients discharged to SNF following primary total joint arthroplasty. We compared costs and outcomes between patients discharged to credentialed SNF sites and those discharged to other sites. RESULTS: Between 2015 and 2018, of a consecutive series of 8778 primary THA and TKA patients, 1284 (14.6%) were discharged to an SNF. Following initiation of the program, 498 patients were discharged to an SNF, 301 (60.4%) of which were sent to a credentialed facility. Patients at credentialed facilities had significantly lower SNF costs ($11,184 vs $8198, P < .0001), PAC costs ($18,952 vs $15,148, P < .0001), and episode-of-care costs ($34,557 vs $30,831, P < .0001), with no difference in readmissions (10% vs 12%, P = .33) or complications (8% vs 6%, P = .15). Controlling for confounding variables, being discharged to a credentialed facility decreased SNF costs by $1961 (P = .0020) and PAC costs by $3126 (P = .0031) per patient. CONCLUSION: Quality improvement efforts through partnership with selective SNFs can significantly decrease PAC costs for patients undergoing primary THA and TKA.

Formal Physical Therapy Following Total Hip and Knee Arthroplasty Incurs Additional Cost Without Improving Outcomes.

BACKGROUND: Recent evidence has demonstrated that formal physical therapy (PT) may not be required for most patients undergoing total hip (THA) and knee (TKA) arthroplasty. This study compared the differences in costs and functional outcomes in patients receiving formal PT and those who did not follow primary THA and TKA. METHODS: We queried claims data from a single private insurer identifying patients who underwent primary THA or TKA from 2015 to 2017 in our practice. Demographics, comorbidities, number, and cost of PT visits in a 90-day episode of care were recorded. Outcomes were compared between patients using self-directed home exercises, home PT, outpatient PT, or both home and outpatient PT. A multivariate analysis was performed to identify significant predictors of outcomes. RESULTS: Of the 2971 patients included in analysis, patients using both services had higher 90-day PT costs (mean $2091, P < .001) than those using home PT alone ($1146), outpatient PT alone ($1356), or no formal PT ($0). Home PT had the greatest cost per visit for both private insurance patients ($177/visit) and Medicare Advantage patients ($157/visit), but patients using both home PT and outpatient PT services had the greatest overall PT cost, $2091 for private insurance and $1891 for Medicare Advantage. Patients who used home PT were at significantly higher risk of both complications (odds ratio = 3.21; 95% confidence interval, 2.1-4.9; P < .001) and readmissions (odds ratio = 3.4; 95% confidence interval, 2.1-5.5; P < .001). CONCLUSION: Participation in formal PT accounts for up to 8% of the episode of care following THA and TKA. The role of formal PT for most patients should take into account the cost-effectiveness of the intervention.