Who Should Not Undergo Short Stay Hip and Knee Arthroplasty? Risk Factors Associated With Major Medical Complications Following Primary Total Joint Arthroplasty

Efficacy and Safety of a Patient Selection Tool for Predicted Discharge at an Ambulatory Surgical Center: A Pilot Study

Background

There is a paucity of validated risk stratification tools to assess which patients can safely and predictably undergo outpatient total hip (THA) or knee arthroplasty (TKA) in an ambulatory surgery center (ASC).

Methods

Our novel patient selection tool was prospectively applied to 190 consecutive primary THA and TKA performed by a single surgeon at a single ASC. We identified the proportion of patients discharged home the same day, those requiring a one-night stay, or those with failed discharge within 23 hours. A retrospective chart review was performed to determine if any demographic parameters were risk factors for an overnight stay.

Results

Overall, 190 (100%) patients selected for outpatient THA and TKA were discharged home within 23 hours. One hundred and four patients (55%) were discharged the same day of surgery, whereas 86 (45%) required overnight stay and were discharged on postoperative day 1. Female sex (odds ratio [OR]: 4.1, 95% confidence interval [CI]: 2.0-8.2, P < .001), THA (OR: 2.5, 95% CI: 1.1-5.5, P = .022), and heavier body mass index (OR: 1.0, 95% CI: 1.0-1.2, P = .022) were identified as independent risk factors for staying overnight in the ASC.

Conclusions

In this pilot study, we found that 100% of outpatient THA and TKA-eligible patients were able to be discharged home by postoperative day 1. Additionally, we found that this selection tool is safe and effective at predicting short-stay discharge in an ASC.

Ten Year Experience With Same Day Discharge Outpatient Total Hip Arthroplasty: Patient Demographics Changed, but Safe Outcomes Were Maintained

BACKGROUND

This study aimed to characterize changes in patient demographics and outcomes for same-day discharge total hip arthroplasty (THA) over a 10-year period at a single orthopaedic specialty hospital.

METHODS

A consecutive series of 1,654 patients between 2013 and 2022 who underwent unilateral THA and were discharged on the same calendar day were retrospectively reviewed. Patient demographics, including age, sex, body mass index (BMI), age-adjusted Charlson Comorbidity Index, and American Society of Anesthesiologists (ASA), were collected. Readmissions, complications, and unplanned visits were recorded for 90 days postoperatively. In order to compare the demographics of patients over time, patients were divided into 3 groups: Time Group A (2013 to 2016), Time Group B (2017 to 2019), and Time Group C (2020 to 2022).

RESULTS

The mean age, BMI, ASA score, and CCI increased significantly across each time group. Age increased from 57 years (range, 23 to 77) to 60 years (range, 20 to 87). The BMI increased from 28.1 (range, 18 to 41) to 29.4 (range, 18 to 47). The percentage of patients aged > 70 years almost doubled over time, as did the percentage of patients who had a BMI > 35. Overall complications increased from 3.44 to 6.82%, reflective of the changing health status of patients. Readmissions increased from 0.57 to 1.70% over time. Despite this, there were no readmissions for any patient within the first 24 hours of surgery.

CONCLUSIONS

Our study has 3 important findings. We identified a worsening patient demographic over time with an increasing percentage of patients of advanced age and higher BMI, ASA, and age-adjusted Charlson Comorbidity Index. Also, there was also an increase in readmissions, complications, and unplanned visits. In addition, despite this worsening patient demographic, there were no readmissions within 24 hours and a low rate of readmissions or unplanned visits within the first 48 hours across all time periods, suggesting that same-day discharge-THA continues to be safe in properly selected patients.

Readmission rate and early complications in patients undergoing total knee arthroplasty: A retrospective study

BACKGROUND

Total knee arthroplasty (TKA) can improve pain, quality of life, and functional outcomes. Although uncommon, postoperative complications are extremely consequential and thus must be carefully tracked and communicated to patients to assist their decision-making before surgery. Identification of the risk factors for complications and readmissions after TKA, taking into account common causes, temporal trends, and risk variables that can be changed or left unmodified, will benefit this process.

AIM

To assess readmission rates, early complications and their causes after TKA at 30 days and 90 days post-surgery.

METHODS

This was a prospective and retrospective study of 633 patients who underwent TKA at our hospital between January 1, 2017, and February 28, 2022. Of the 633 patients, 28 were not contactable, leaving 609 who met the inclusion criteria. Both inpatient and outpatient hospital records were retrieved, and observations were noted in the data collection forms.

RESULTS

Following TKA, the 30-day and 90-day readmission rates were determined to be 1.1% (n = 7) and 1.8% (n = 11), respectively. The unplanned visit rate at 30 days following TKA was 2.6% (n = 16) and at 90 days was 4.6% (n = 28). At 90 days, the unplanned readmission rate was 1.4% (n = 9). Reasons for readmissions included medical (27.2%, n = 3) and surgical (72.7%, n = 8). Unplanned readmissions and visits within 90 days of follow-up did not substantially differ by age group (P = 0.922), body mass index (BMI) (P = 0.633), unilateral vs bilateral TKA (P = 0.696), or patient comorbidity status (30-day P = 0.171 and 90-day P = 0.813). Reoperation rates after TKA were 0.66% (n = 4) at 30 days and 1.15% (n = 8) at 90 days. The average length of stay was 6.53 days.

CONCLUSION

In this study, there was a low readmission rate following TKA. There was no significant correlation between readmission rate and patient factors such as age, BMI, and co-morbidity status.

Risk Factors for Return to the Emergency Department and Readmission After Same-Day Discharge Total Joint Arthroplasty

BACKGROUND

Same-day discharge (SDD) after total joint arthroplasty (TJA) is safe and cost effective. However, benefits may be offset by the potential cost of emergency department (ED) visits and readmissions. We identified risk factors for return to the ED and readmission in patients who underwent SDD and inpatient (IP) stays after TJA.

METHODS

We performed a retrospective review of patients who underwent primary TJA at an academic institution over the course of one year. There were 1,708 consecutive TJAs (721 THA [total hip arthroplasty] and 987 TKA [total knee arthroplasty]) included. A SDD occurred after 1,199 (70%) TJAs, 523 THAs, and 676 TKAs. We compared the demographics and comorbidities of patients who have SDD or IP who stayed following TJA. We documented rates of return to the ED or readmission within 90 days of surgery. Cohorts were compared using the Student's t-test or Chi-square test. Significant findings were those with P value < .05.

RESULTS

The SDD cohort had a significantly higher rate of young, non-White men who had a lower body mass index and fewer comorbidities than the IP cohort. Rates of return to ED and readmission were similar between SDD and IP cohorts after TJA and similar between THA and TKA. Factors that significantly influenced return to ED included a higher American Society of Anaesthesiologists score (SDD, IP), a higher Charlson Comorbidity Index score (SDD, IP), a lower body mass index (IP), and a psychological diagnosis (SDD, IP). Factors that significantly influenced readmission rates included a higher American Society of Anaesthesiologists score (SDD), older age (SDD), and psychological diagnosis (SDD, IP).

CONCLUSIONS

Patients who discharged the same day after primary TJA have similar rates of return to the ED and readmission as those admitted as an IP. Patients who had a psychological diagnosis, and particularly a diagnosis of depression, are at higher risk for return to the ED and readmission after primary TJA, regardless of discharge the same-day or IP admission. Improved measures that attempt to further treat and optimize this patient population could reduce unnecessary postoperative ED visits.

Assessing social disparities in inpatient vs. outpatient arthroplasty: a in-state database analysis

INTRODUCTION

Given the growing emphasis on patient outcomes, including postoperative complications, in total joint arthroplasty (TJA), investigating the rise of outpatient arthroplasty is warranted. Concerns exist over the safety of discharging patients home on the same day due to increased readmission and complication rates. However, psychological benefits and lower costs provide an incentive for outpatient arthroplasty. The influence of social determinants of health disparities on outpatient arthroplasty remains unexplored. One metric that assesses social disparities, including the following individual components: socioeconomic status, household composition, minority status, and housing and transportation, is the Social Vulnerability Index (SVI). As such, we aimed to compare: (1) mean overall SVI and mean SVI for each component and (2) risk factors for total complications between patients undergoing inpatient and outpatient arthroplasty.

METHODS

Patients who underwent TJA between January 1, 2022 and December 31, 2022 were identified. Data were drawn from the Maryland State Inpatient Database (SID). A total of 7817 patients had TJA within this time period. Patients were divided into inpatient arthroplasty (n = 1429) and outpatient arthroplasty (n = 6338). The mean SVI was compared between inpatient and outpatient procedures for each themed score. The SVI identifies communities that may need support cause by external stresses on human health based on four themed scores: socioeconomic status; household composition and disability; minority status and language; and housing and transportation. The SVI uses the United States Census data to rank census tracts for each individual theme, as well as an overall social vulnerability score. The higher the SVI, the more social vulnerability, or resources needed to thrive in that area. Multivariate logistic regression analyses were performed to identify independent risk factors for total complications following TJA after controlling for risk factors and patient comorbidities. Total complications included: infection, aseptic loosening, dislocation, arthrofibrosis, mechanical complication, pain, and periprosthetic fracture.

RESULTS

Patients who had inpatient arthroplasty had higher overall SVI scores (0.45 vs. 0.42, P < 0.001). The SVI scores were higher for patients who had inpatient arthroplasty for socioeconomic status (0.36 vs. 0.32, P < 0.001), minority status and language (0.76 vs. 0.74, P < 0.001), and housing and transportation (0.53 vs. 0.50, P < 0.001) compared to outpatient arthroplasty, respectively. There was no difference between inpatient and outpatient arthroplasty for household composition and disability (0.41 vs. 0.41, P = 0.99). When controlling for comorbidities, inpatient arthroplasty [Odds Ratio (OR) 1.91, 95% Confidence Interval (CI) 1.23-2.95, P = 0.004], hypertension (OR 2.11, 95% CI 1.23-3.62, P = 0.007), and housing and transportation (OR 2.00, 95% CI 1.17-3.42, P = 0.012) were independent risk factors for total complications.

CONCLUSION

Inpatient arthroplasty was associated with increased social disparities across several components of deprivation as well as an independent risk factor total complications following TJA. To the best of our knowledge, this study is the first to examine the negative repercussions of inpatient arthroplasty through the lens of social disparities and can target specific areas for intervention.

Patients With Moderate to Severe Liver Cirrhosis Have Significantly Higher Short-Term Complication Rates Following Total Knee Arthroplasty: A Retrospective Cohort Study

BACKGROUND

Liver cirrhosis is associated with increased perioperative morbidity. Our study used the Model for End-Stage Liver Disease (MELD) score to assess the impact of cirrhosis severity on postoperative outcomes following total knee arthroplasty (TKA).

METHODS

A retrospective review identified 59 patients with liver cirrhosis who underwent primary TKA at a large, urban, academic center from January 2013 to August 2022. Cirrhosis was categorized as mild (MELD < 10; n = 47) or moderate-severe (MELD ≥ 10; n = 12). Modified Clavien-Dindo classification was used to grade complications, where grade 2+ denoted significant intervention. Hospital length of stay, nonhome discharge, and mortality were collected. A 1:1 propensity matching was used to control for demographics and selected comorbidities.

RESULTS

Moderate-severe cirrhosis was associated with significantly higher rates of intrahospital overall (58.33 versus 16.67%, P = .036) complications, 30-day overall complications (75 versus 33.33%, P = .042), and 90-day overall complications (75 versus 33.33%, P = .042) when compared to matched mild cirrhosis patients. Compared to matched noncirrhotic controls, mild cirrhosis patients had no significant increase in complication rate or other outcomes (P > .05).

CONCLUSIONS

Patients with moderate-severe liver cirrhosis are at risk of short-term complications following primary TKA. Patients with mild cirrhosis have comparable outcomes to matched noncirrhotic patients. Surgeons can use MELD score prior to scheduling TKA to determine which patients require optimization or higher levels of perioperative care.

Complete Blood Count Ratios Predict Adverse Events After Total Joint Arthroplasty

INTRODUCTION

Complete blood count-based ratios (CBRs), including neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) are biomarkers associated with the proinflammatory surgical stress response. This study sought to determine whether preoperative CBRs are associated with postoperative complications, protracted hospital length of stay (LOS), and mortality after total joint arthroplasty, as well as establish threshold values for these outcomes for use in future investigations.

METHODS

The Premier Healthcare Database was retrospectively queried for adult patients who underwent primary elective total hip arthroplasty or total knee arthroplasty (TKA). Approximate cut-point values for CBRs were identified by bootstrap simulation using the Youden index. Multivariable adjusted restricted cubic spline models using the predicted cut-point value as the threshold for odds of outcomes were created to identify a final threshold value associated with increased adjusted odds ratio (aOR) of study outcomes.

RESULTS

A total of 32,868 total joint arthroplasties (THA: 12,807, TKA: 20,061) were identified. All measures predicted odds of aggregate postoperative complications (THA: NLR TV: 4.60 [aOR = 2.35], PLR TV: 163.4 [aOR = 1.32], MLR TV: 0.40 [aOR = 2.02], SII TV: 977.00 [aOR = 1.54]; TKA: NLR TV: 3.7 [aOR = 1.69], MLR TV: 0.41 [aOR = 1.62], PLR TV: 205.10 [aOR = 1.43], SII TV: 1,013.10 [aOR = 1.62]; all P < 0.05). A MLR > 0.40 [aOR = 1.54] P < 0.001) was associated with LOS ≥3 days after total hip arthroplasty while an NLR > 13.1 [aOR = 1.38] and an MLR > 0.41[aOR = 1.29] were associated with LOS ≥3 days after total knee arthroplasty (both P < 0.001). No association between inflammatory markers and inpatient mortality was observed.

CONCLUSION

Given CBRs' ability to both predict outcomes and identify patients with a proinflammatory phenotype, the findings of this study provide a framework for future investigations aimed at identifying and treating high-risk patients with immune-modulating therapies. Continued work to validate these findings by applying TVs to interventional clinical trials is needed before wide clinical adoption.

The five times sit-to-stand test predicts same-day discharge for outpatients undergoing total joint arthroplasty

PURPOSE

To examine whether a patient's pre-operatively administered five times sit-to-stand (FTSTS) test score, when used alone or when combined with previously established predictors, relates to same-day discharge (SDD) after total knee or hip arthroplasty.

METHODS

This study utilized a multivariate, retrospective, observational design. Electronic medical record data for included participants were used to analyze the relationship between the patient factors (including the novel FTSTS variable) and the SDD outcome. Univariate and multiple variable regression modeling was undertaken to understand the strength of the relationship between the independent variables with the dependent variable. Receiver operating curve (ROC) analysis was performed to determine the area under the curve (AUC) for the novel model. Cut score analysis was performed to establish the score which has the greatest utility for stratifying patients based upon their likelihood of achieving SDD.

RESULTS

All independent variables related to the SDD outcome with varying effect sizes. The dichotomized FTSTS score related to the SDD outcome with medium effect (Exp(B) = 2.56). The score of 13.6 s was established as the point where the test was most highly sensitive and specific. The combined model including all included patient characteristics had a classification accuracy of 64.7% and an area under the curve score of .724.

CONCLUSION

The FTSTS score had higher predictive accuracy than all other stand-alone patient characteristics for the SDD outcome.

The association of congestive heart failure on in-hospital lengths of stay, morbidity, and financial burden following primary total knee arthroplasty

BACKGROUND

Current literature states that 6.2 million adults in the United States are living with heart failure. Studies investigating the impact of congestive heart failure (CHF) following primary total knee arthroplasty (TKA) are scarce. Hence, this research aimed to investigate whether individuals with congestive heart failure (CHF) undergoing primary total knee arthroplasty (TKA) experience: (1) longer durations of in-hospital stay; (2) increased incidences of health complications; and (3) a higher financial load.

METHODS

A retrospective query using the 100% Parts A and B of the Medicare claims was performed. Cohorts of interest were identified using International Classification of Disease, Ninth Revision (ICD-9) and Current Procedural Terminology. Inclusion criteria for the study group consisted of patients with CHF undergoing primary TKA, whereas patients without CHF undergoing primary TKA served as the comparison cohort.

RESULTS

The query yielded 1,101,169 patients (CHF = 183,540; case-matched = 917,629). Patients with CHF had longer in-hospital LOS (5- vs. 4-days) and a higher incidence and odds of developing 90-day medical complications (49.22% vs. 7.45%) following primary TKA. CHF patients incurred higher day of surgery and total global ninety-day episode of care costs compared to their matched counterparts.

CONCLUSION

This study illustrated those patients with preexisting CHF undergoing a primary TKA have longer in-hospital lengths of stay and higher rates of morbidity and financial burden. With the increasing prevalence of CHF worldwide, orthopedists and other healthcare professionals can utilize the information provided in this study to educate patients and establish comprehensive treatment plans to help mitigate postoperative effects associated with CHF.

Outpatient Total Knee Arthroplasty From a Stand-Alone Surgery Center: Safe as the Hospital?

BACKGROUND

Literature suggests that outpatient arthroplasty may result in low rates of complications and readmissions. There is, however, a dearth of information on the relative safety of total knee arthroplasty (TKA) performed at stand-alone ambulatory surgery centers (ASCs) versus hospital outpatient (HOP) settings. We aimed to compare safety profiles and 90-day adverse events of these 2 cohorts.

METHODS

Prospectively collected data were reviewed on all patients who underwent outpatient TKA from 2015 to 2022. The ASC and HOP groups were compared, and differences in demographics, complications, reoperations, revisions, readmissions, and emergency department (ED) visits within 90 days of surgery were analyzed. There were 4 surgeons who performed 4,307 TKAs during the study period, including 740 outpatient cases (ASC = 157; HOP = 583). The ASC patients were younger than HOP patients (ASC = 61 versus HOP = 65; P < .001). Body mass index and sex did not differ significantly between groups.

RESULTS

Within 90 days, 44 (6%) complications occurred. No differences were observed between groups in rates of 90-day complications (ASC = 9 of 157, 5.7% versus HOP = 35 of 583, 6.0%; P = .899), reoperations (ASC = 2 of 157, 1.3% versus HOP = 3 of 583, 0.5%; P = .303), revisions (ASC = 0 of 157 versus HOP = 3 of 583, 0.5%; P = 1), readmissions (ASC = 3 of 157, 1.9% versus HOP = 8 of 583, 1.4%; P = .625), and ED visits (ASC = 1 of 157, 0.6% versus HOP = 3 of 583, 0.5%; P = .853).

CONCLUSION

These results suggest that in appropriately selected patients, outpatient TKA can be safely performed in both ASC and HOP settings with similar low rates of 90-day complications, reoperations, revisions, readmissions, and ED visits.

Total joint replacement in ambulatory surgery

Total joint arthroplasty is one of the most commonly performed surgical procedures in the United States, and projected numbers are expected to double in the next ten years. From 2018 to 2020, total hip and knee arthroplasty were removed from the United States' Center for Medicare and Medicaid Services "inpatient-only" list, accelerating this migration to the ambulatory setting. Appropriate patient selection, including age, body mass index, comorbidities, and adequate social support, is critical for successful ambulatory total joint arthroplasty. General anesthesia and neuraxial anesthesia are both safe and effective anesthetic choices, and recent studies in this population have found no difference in outcomes. Multimodal analgesia, including acetaminophen, nonsteroidal anti-inflammatory drugs, local infiltration analgesia, and peripheral nerve blocks, is the foundation for adequate pain control. Common reasons for "failure to launch" include postoperative urinary retention, postoperative nausea and vomiting, inadequate analgesia, and hypotension.

Current Trends and Future Directions for Outpatient Total Joint Arthroplasty: A Review of the Anesthesia Choices and Analgesic Options

The aging population and the obesity epidemic have led to an increased rate of joint arthroplasty procedures, specifically total knee arthroplasty and total hip arthroplasty. These surgeries are associated with increased hospital length of stay and, consequently, higher costs. Despite the benefits of outpatient surgery, only a small percentage of total joint arthroplasties (TJAs) are done in this manner. We reviewed the most up-to-date trends for outpatient TJA and discussed essential factors for a successful outpatient program, including the proper patient selection process and best available anesthetic and analgesic options, along with their risks and benefits. Risk stratification tools, such as the Outpatient Arthroplasty Risk Assessment, are helpful for predicting outcomes regarding outpatient TJA, and neuraxial anesthesia should be considered to minimize complications and facilitate early discharge. A multimodal analgesia regimen could be effective for pain management in outpatient TJA, and the currently recommended peripheral nerve blocks for total hip arthroplasty and total knee arthroplasty are the fascia iliaca compartment block and adductor canal block, respectively. However, blocks should be carefully considered for outpatient procedures. Enhanced recovery after surgery (ERAS) protocols help to guide perioperative care teams and allow for improved patient recovery, decreased length of stay, and increased patient satisfaction.

An Update on the Management and Optimization of the Patient with Morbid Obesity Undergoing Hip or Knee Arthroplasty

The prevalence of obesity in the United States is at a record high of 42%. In 1999, the Centers for Disease Control and Prevention recognized the obesity epidemic as a national problem, spurring the first generation of interventions for obesity prevention and control. Despite billions of dollars in funding, legislative changes, and public health initiatives, the trajectory of American obesity has not waivered. Obesity is also strongly associated with the development of osteoarthritis. The growing population of young, obese, and sick patients presents a unique dilemma for orthopedic surgeons performing joint replacement, as obesity levels and the demand for joint replacement are only expected to rise further.

Are Patients Being Appropriately Selected for Same-Day Discharge Total Knee Arthroplasty?

BACKGROUND

Decreased cost associated with same-day discharge (SDD) total knee arthroplasty (TKA) has led to an increased interest in this topic. The purpose of this study is to investigate whether there is a population of TKA patients in which SDD has similar rates of 30-day complications compared to patients discharged on postoperative day 1 or 2.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2018, 6,327 TKA patients who had a SDD (length of stay [LOS] = 0) were matched to TKA patients who had an LOS of 1 or 2 days. All SDD patients were successfully matched 1:1 using the morbidity probability variable (a composite variable of demographics, comorbidities, and laboratory values). Patients were divided into quartiles based on their morbidity probability. Bivariate logistic regressions were then used to compare any complication and major complication rates in the SDD quartiles to the corresponding quartiles with an LOS of 1 or 2 days.

RESULTS

When comparing the 1st quartiles (healthiest), there was no difference between the cohorts in any complication (odds ratio [OR] = 0.960, 95% CI 0.552-1.670, P = .866) and major complications (OR = 0.999, 95% CI = 0.448-2.231, P = .999). The same was observed in quartile 2 (any complications: OR = 1.161, 95% CI = 0.720-1.874, P = .540). Comparing the third quartiles, there was an increase in all complications with SDD (OR = 1.784, 95% CI = 1.125-2.829, P = .014), but no difference in major complications (OR = 1.635, 95% CI = 0.874-3.061, P = .124). Comparing the fourth quartiles (least healthy), there was an increase in all complications (OR = 1.384, 95% CI = 1.013-1.892, P = .042) and major complications (OR = 1.711, 95% CI = 1.048-2.793, P = .032) with SDD.

CONCLUSION

The unhealthiest 50% of patients in this study who underwent SDD TKA were at an increased risk of having any complication, calling into question the current state of patient selection for SDD TKA.

LEVEL OF EVIDENCE

III.

Chronic Obstructive Pulmonary Disease is Associated With Serious Infection and Venous Thromboembolism in Patients Undergoing Hip or Knee Arthroplasties: A Meta-Analysis of Observational Studies

BACKGROUND

Although previous studies evaluated postoperative outcomes of arthroplasty patients with chronic obstructive pulmonary disease (COPD), no meta-analysis has been conducted.

METHODS

An electronic search was conducted on PubMed, Embase, and Cochrane Library databases to identify relevant studies published from inception to May 1, 2022. To assess the impact of COPD on postoperative outcomes, the odds ratios and 95% confidence intervals were calculated; pooled results were calculated using a random effects model. Sensitivity and subgroup analyses were carried out according to surgical type and statistical method. A total of 11 retrospective cohort studies involving patients with COPD who underwent hip or knee arthroplasties were included in the meta-analysis. There were 195,444 patients with COPD and 1,592,908 patients without COPD.

RESULTS

A pooled analysis showed that the COPD group was at higher risk for mortality, readmission, pneumonia, sepsis, septic shock, and surgical site infection within 30 days following hip arthroplasties than the non-COPD group. Moreover, COPD patients were more likely to experience mortality, readmission, pneumonia, sepsis, septic shock, and surgical site infection 30 days after knee arthroplasties.

CONCLUSION

In this study, coexisting COPD was associated with worse outcomes in patients with lower extremity joint arthroplasties. The findings highlighted the importance of preoperative optimization and proactive interventions for COPD in the perioperative period.

Hospital Revenue, Cost, and Contribution Margin in Inpatient Versus Outpatient Primary Total Joint Arthroplasty

BACKGROUND

Removal of primary total knee arthroplasty (TKA) and primary total hip arthroplasty (THA) from the inpatient-only list has financial implications for both patients and institutions. The aim of this study was to evaluate and compare financial parameters between patients designated for inpatient versus outpatient total joint arthroplasty.

METHODS

We reviewed all patients who underwent TKA or THA after these procedures were removed from the inpatient-only list. Patients were statistical significance into cohorts based on inpatient or outpatient status, procedure type, and insurance type. This included 5,284 patients, of which 4,279 were designated inpatient while 1,005 were designated outpatient. Patient demographic, perioperative, and financial data including per patient revenues, total and direct costs, and contribution margins (CMs) were collected. Data were compared using t-tests and Chi-squared tests.

RESULTS

Among Medicare patients receiving THA, CM was 89.1% lower for the inpatient cohort when compared to outpatient (P < .001), although there was no statistical significance difference between cohorts for TKA (P = .501). Among patients covered by Medicaid or Government-managed plans, CM was 120.8% higher for inpatients receiving THA (P < .001) when compared to outpatients and 136.3% higher for inpatients receiving TKA (P < .001).

CONCLUSION

Our analyses showed that recent costs associated with inpatient stay inconsistently match or outpace additional revenue, causing CM to vary drastically depending on insurance and procedure type. For Medicare patients receiving THA, inpatient surgery is financially disincentivized leaving this vulnerable patient population at a risk of losing access to care.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Characterizing Intraoperative Vasopressor Use in Total Knee Arthroplasty: A Retrospective Cohort Study

Preoperative optimization and protocols for joint replacement care pathways have led to decreased length of stay (LOS)and narcotic use, and are increasingly important in delivering quality, cost savings, and shifting appropriate cases to an outpatient setting. The intraoperative use of vasopressors is independently associated with increased LOS and risk of adverse postoperative events including death, and in total hip arthroplasty, there is an increased risk for intensive care unit (ICU) admission. Our aim is to characterize the patient characteristics associated with vasopressor use specifically in total knee arthroplasty (TKA). We retrospectively reviewed the electronic medical records of a cohort of patients who underwent inpatient primary TKA at a single academic hospital from January 1, 2017 to December 31, 2018. Demographics, comorbidities, perioperative factors, and intraoperative medication administration were compared with multivariate regression to identify patients who may require intraoperative vasopressors. Out of these, 748 patients underwent TKA, 439 patients required intraoperative vasopressors, while 307 did not. Significant independent predictors of vasopressor use were older age (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.03-1.08) and history of a prior cerebrovascular accident (CVA; OR = 11.80, CI: 1.48-93.81). While not significant, male sex (OR = 0.72, CI: 0.50-1.04) and regional anesthesia (OR = 0.64, CI: 0.40-1.05) were nearing significance as negative independent predictors of vasopressor use. In a secondary analysis, we did not observe an increase in complications attributable to vasopressor administration intraoperatively. In conclusion, nearly 59% of patients undergoing TKA received intraoperative vasopressor support. History of stroke and older age were significantly associated with increased intraoperative vasopressor use. As the first study to examine vasopressor usage in a TKA patient population, we believe that understanding the association between patient characteristics and intraoperative vasopressor support will help orthopaedic surgeons select the appropriate surgical setting during preoperative optimization.

Identifying Risk Factors for Complication and Readmission with Same-Day Discharge Arthroplasty

BACKGROUND

The COVID-19 pandemic caused a surge of same-day discharge (SDD) for total joint arthroplasty. However, SDD may not be beneficial for all patients. Therefore, continued investigation into the safety of SDD is necessary as well as risk stratification for improved patient outcomes.

METHODS

This retrospective cohort study examined 31,851 elective SDD hip and knee arthroplasties from 2016 to 2020 in a large national database. Logistic regression models were used to identify patient variables and preoperative comorbidities that contribute to postoperative complication or readmission with SDD. Adjusted odds ratios (AOR) and 95% confidence intervals (CI) were calculated.

RESULTS

SDD increased from 1.4% in 2016 to 14.6% in 2020. SDD is associated with lower odds of readmission (AOR: 0.994, CI: 0.992-0.996) and postoperative complications (AOR: 0.998, CI: 0.997-1.000). Patients who have preoperative dyspnea (AOR: 1.03, CI: 1.02-1.04, P < .001), chronic obstructive pulmonary disease (AOR: 1.02, CI: 1.01-1.03, P = .002), and hypoalbuminemia (AOR: 1.02, CI: 1.00-1.03, P < .001), had higher odds of postoperative complications. Patients who had preoperative dyspnea (AOR: 1.02, CI: 1.01-1.03), hypertension (AOR: 1.01, CI: 1.01-1.03, P = .003), chronic corticosteroid use (AOR: 1.02, CI: 1.01-1.03, P < .001), bleeding disorder (AOR: 1.02; CI: 1.01-1.03, P < .001), and hypoalbuminemia (AOR: 1.01, CI: 1.00-1.02, P = .038), had higher odds of readmission.

CONCLUSION

SDD is safe with certain comorbidities. Preoperative screening for cardiopulmonary comorbidities (eg, dyspnea, hypertension, and chronic obstructive pulmonary disease), chronic corticosteroid use, bleeding disorder, and hypoalbuminemia may improve SDD outcomes.

Over Half of All Medicare Total Knee Arthroplasty Patients Are Now Classified as an Outpatient-Three-Year Impact of the Removal From the Inpatient-Only List

BACKGROUND

In 2018, Centers for Medicare & Medicaid Services removed total knee arthroplasty (TKA) from its inpatient-only list, triggering many unintended consequences. The purpose of this study was to determine how the impact of TKA removal affected the number of outpatient TKA patients, which patients were being labeled outpatient, and how outpatient classification affected discharge location and readmission rates.

METHODS

Using a large administrative claims database, we reviewed a consecutive series of 216,365 primary TKA Medicare patients from 2015 to 2020. Patients who had an inpatient status (n = 63,356) were compared to patients who had an outpatient status (n = 38,510) from 2018 to 2020 based on demographics, comorbidities, discharge dispositions, and readmissions.

RESULTS

In 2015, only 1.8% of TKA patients were designated as outpatients, but by 2020, 57.2% of Medicare TKA patients were classified as outpatients. A majority of patients (72%) who had an outpatient designation remained in the hospital for >24 hours (average length of stay was 2.7 days). Patients who had an outpatient status were discharged to skilled nursing facilities more frequently than patients who had an inpatient status (3.1 versus 2.0%, P < .001) with increased emergency visits (5.1 versus 3.9%, P < .001) and 90-day readmissions (2.2 versus 0.9%, P < .001).

CONCLUSION

Over half of all Medicare TKA patients are being classified as outpatients 3 years following the policy to remove TKA from the inpatient-only list. Patients designated as outpatients had higher readmissions than those designated as inpatients. This policy should be re-evaluated in the context of failure to demonstrate safer discharge of Medicare patients who undergo TKA.

Outcomes and Cost Analysis of a Surgical Care Unit for Outpatient Total Joint Arthroplasties Performed at a Tertiary Academic Center

Background

Methods

Results

Conclusions

Comparative Analysis of Outcomes in Medicare-Eligible Patients with a Hospital Stay Less than Two-Midnights versus Longer Length of Stay following Total Knee Arthroplasty: Implications for Inpatient-Outpatient Designation

The Centers for Medicaid and Medicare Services (CMS) removed primary total knee arthroplasty (TKA) from the inpatient-only list in January 2018. This study aims to compare outcomes in Medicare-aged patients who underwent primary TKA and had an in-hospital stay spanning less than two-midnights to those with a length of stay greater than or equal to two-midnights. We retrospectively reviewed 4,138 patients ages ≥65 who underwent primary TKA from 2016 to 2020. Two cohorts were established based on length of stay (LOS), those with an LOS <2 midnights were labeled outpatient and those with an LOS ≥2 midnights were labeled inpatient as per CMS designation. Demographic, clinical data, knee injury and osteoarthritis outcome score for joint replacement (KOOS, JR), and veterans RAND 12 physical and mental components (VR-12 PCS & MCS) were collected. Demographic differences were assessed with Chi-square and independent sample t-tests. Clinical data and KOOS, JR and VR-12 PCS and MCS scores were compared by using multilinear regression analysis, controlling for demographic differences. There were 841 (20%) patients with a LOS < 2 midnights and 3,297 (80%) patients with a LOS ≥ 2 midnights. Patients with a LOS < 2 midnights were significantly younger (71.70 vs. 73.06; p < 0.001), more likely male (42.1 vs. 25.7%; p < 0.001), Caucasian (68.8 vs. 57.7%; p <0.001), have lower BMI (30.80 vs. 31.92; p < 0.001), Charlson Comorbidity Index (CCI; 4.62 vs. 4.96; p < 0.001), and American Society of Anesthesiologists (ASA) class II or higher (p < 0.001). These patients were more likely to be discharged home compared to patients with LOS ≥ 2 midnights (95.8 vs. 73.1%; p < 0.001). Patients who stayed ≥ 2 midnights reported lower patient-reported outcome scores at all time-periods (preoperatively, 3 months and 1 year), but these differences did not exceed the minimum clinically important difference. Mean improvement preoperatively to 1 year postoperatively in KOOS, JR (22.53 vs. 25.89; p < 0.001), and VR-12 PCS (12.16 vs. 11.49; p = 0.002) was statistically higher for patients who stayed < 2 midnights, though these differences were not clinically significant. All-cause ED visits (p = 0.167), 90-day all-cause readmissions (p = 0.069) and revision (p = 0.277) did not statistically differ between the two cohorts. TKA patients classified as outpatient had similar quality metrics and saw similar clinical improvement following TKA with respect to most patient reported outcome measures, although they were demographically different. Outpatient classification is more likely to be assigned to younger males with higher functional scores, lower BMI, CCI, and ASA class compared with inpatients. This Retrospective Cohort Study shows level III evidence.

Predicting Total Knee Arthroplasty Outpatient Discharge: Surgeons versus Insurance Companies

BACKGROUND

Insurance companies are increasingly making unilateral determinations of admission status for primary total knee arthroplasty (TKA). These determinations may differ from those based on surgeon-derived criteria for outpatient knee replacement. The goal of this study is to determine if insurance company determinations of outpatient status are as reliable as surgeon-derived criteria in predicting outpatient discharge after TKA.

METHODS

We retrospectively reviewed 709 patients who were preoperatively authorized for outpatient TKA. Patients were stratified into 2 groups: "outpatient per surgeon" (appropriate for outpatient surgery per institutional protocols) or "outpatient per insurance" (appropriate for inpatient surgery per institutional protocols but denied inpatient status by insurance). The primary endpoint of this study was the conversion rate of outpatient to inpatient stay. Univariate logistic regression was performed to compare the odds of conversion to inpatient stay between outpatient per surgeon and outpatient per insurance procedures and other covariates.

RESULTS

The cohort included 434 outpatient per insurance (61.2%) and 275 outpatient per surgeon (38.8%) patients. Surgeons accurately predicted outpatients' discharge 92.0% of the time, while insurance companies did so 81.3% of time (P < .001). Outpatient per insurance procedures (odds ratio [OR] 2.20, P = .003) and body mass index >35 kg/m² (OR 1.82, P = .026) had higher odds of being converted to inpatient. Males had higher odds (OR 1.52, P < .001) of being discharged as outpatient.

CONCLUSION

Determining inpatient versus outpatient status is a complex decision involving both clinical and social factors. Surgeons accurately predicted outpatient discharge 92% of the time. Moreover, outpatient per insurance procedures were twice as likely to be converted to inpatient status. Therefore, insurance companies should leave deciding admission status up to both the patient and surgeon.

Same-Day Outpatient Lower-Extremity Joint Replacement: A Critical Analysis Review

➢ The economics of transitioning total joint arthroplasty (TJA) to standalone ambulatory surgery centers (ASCs) should not be capitalized on at the expense of patient safety in the absence of established superior patient outcomes. ➢ Proper patient selection is essential to maximizing safety and avoiding complications resulting in readmission. ➢ Ambulatory TJA programs should focus on reducing complications frequently associated with delays in discharge. ➢ The transition from hospital-based TJA to ASC-based TJA has substantial financial implications for the hospital, payer, patient, and surgeon.

Black and Hispanic Patients Do Not Stay Longer After Primary Total Knee Arthroplasty: Results From an Urban Center Serving a Predominantly Minority Cohort

INTRODUCTION

Previous reports identified minority race/ethnicity to be an independent risk factor for prolonged length of stay (LOS); however, these cohorts consisted of predominantly White patients. This study sought to evaluate minority status as an independent risk factor for prolonged LOS after primary total knee arthroplasty (TKA) in a predominantly Hispanic and Black cohort.

METHODS

This was a retrospective study using an institutional database of patients who underwent primary TKA between the years 2016 and 2019. Demographic and socioeconomic data, smoking, body mass index (BMI), medical comorbidities, discharge disposition, and 30-day readmission rates were collected. Patients were first categorized into racial/ethnic groups (Hispanic, Black, or White). An univariate analysis was performed comparing patient characteristics between racial/ethnic groups using the Wilcoxon rank sum, chi-squared, and Fisher exact tests. We then categorized patients into two groups-normal LOS (discharged on postoperative day 1 to 2) and prolonged LOS (discharged after postoperative day 2). An univariate analysis was again performed comparing patient characteristics between LOS groups using Wilcoxon rank sum, chi-squared, and Fisher exact tests. After identifying risk factors markedly associated with LOS, a multivariate logistic regression analysis was performed to identify independent risk factors for prolonged LOS.

RESULTS

A total of 3,093 patients were included-47.9% Hispanic and 38.3% Black. Mean LOS was 2.9 ± 1.6 days. An univariate analysis found race/ethnicity, age, low socioeconomic status (SES), discharge disposition, insurance type, weekday of surgery, BMI >40, smoking, increased American Society of Anesthesiologists (ASA)/Charlson Comorbidity Index (CCI) and several medical comorbidities to be associated with prolonged LOS (P < 0.05). A multivariate logistic regression analysis found Black and Hispanic patients were less likely to have prolonged LOS after adjusting for associated risk factors. White race/ethnicity, nonhome discharge, low SES, weekday of surgery, smoking, BMI >40, and increased ASA and CCI were identified as independent risk factors for prolonged LOS (P < 0.05). The overall 30-day readmission rate was 3.6%, with no notable difference between racial/ethnic and LOS groups (P = 0.98 and P = 0.78).

CONCLUSION

In contrast to previous reports, our study found that after adjusting for associated risk factors, minority patients do not have prolonged LOS after primary TKA in an urban, socioeconomically disadvantaged, predominantly minority patient cohort. White race/ethnicity, nonhome discharge, low SES, weekday of surgery, smoking, BMI >40, increased CCI, and ASA were all found to be independent risk factors for prolonged LOS. These findings highlight the need to further investigate the role of race/ethnicity on LOS after primary TKA using large-scale, randomized controlled trials with equally represented patient cohorts.

Tempering Expectations for Outpatient Total Knee Arthroplasty for Patients Over 70

BACKGROUND

Total knee arthroplasty (TKA) is now considered an outpatient procedure, yet advanced age impacts patients' ability to achieve outpatient discharge. Therefore, the purpose of this study is to determine the rate of successful outpatient discharge for TKA patients above 70 years of age and identify potential barriers to success.

METHODS

This retrospective review included 352 unilateral TKA patients. The rapid discharge protocol was followed for all patients with the intention of discharge within a 24-hour period. Successful outpatient discharge was classified as ≤24-hour stay and failure was any stay exceeding a 24-hour period in the hospital. Univariate logistic regressions were performed to determine the influence of independent variables on discharge status for all patients and only patients >70 years old.

RESULTS

Overall, 46 patients (13%) failed to achieve outpatient discharge, with 35 (76%) patients being ≥70 years old. For patients ≥70, age was not a predictive variable for failure to achieve outpatient discharge (P = .484). However, being female (odds ratio 3.273, 95% confidence interval 1.286-8.325, P = .013) and the use of an assistive walking device (odds ratio 3.031, 95% confidence interval 1.387-6.625, P = .005) remained independent contributors to prolonged hospital stay.

CONCLUSION

With patients ≥70 years old more likely to require >24-hour stays, age should be an evaluated metric for justifying higher levels of reimbursement. Although TKA is now considered an outpatient procedure, greater consideration should be given to patients ≥70 years old for higher levels of reimbursement as outpatient discharge is less likely to be successful.

Recent Increases in Outpatient Total Hip Arthroplasty Have Not Increased Early Complications

BACKGROUND

Outpatient total hip arthroplasty (THA) has increased in recent years. Recent regulatory changes may allow and incentivize outpatient THA in more patients; however, there are concerns regarding safety. The purpose of this study is to assess early complications in outpatient THA compared to longer hospitalization.

METHODS

We identified patients undergoing primary THA in the National Surgical Quality Improvement Program database between 2015 and 2018. Patients were stratified by length of stay (LOS): 0 days (LOS 0), 1-2 days, and ≥3 days. Thirty-day rates of any complication, wound complications, readmissions, and reoperation were assessed. Multivariate analysis was performed.

RESULTS

In total, 4813 (4%) patients underwent outpatient THA, 84,627 (64%) had LOS of 1-2 days, and 42,293 (32%) had LOS ≥3 days. LOS 0 patients were younger, had lower body mass index, and less medical comorbidities compared to those with postsurgical hospitalization. Any complication was experienced in 3.2% of the LOS 0 group, 5.3% of the LOS 1-2 group, and 15.6% for the LOS ≥3 group (P < .0001). Readmission rates were 1.6%, 2.6%, and 4.7% for the 3 groups, respectively (P < .0001). After controlling for confounding variables, patients with LOS 1-2 days had higher odds for any complication (odds ratio 1.56 [1.32-1.83) and readmission (odds ratio 1.41 [1.12-1.78]) compared to LOS 0 days. Patients with LOS ≥3 days had higher odds for complications compared to LOS 0 or 1-2 days.

CONCLUSION

Outpatient THA had lower odds for readmission or complications compared to LOS 1-2 days. Despite increased outpatient surgery, many patients had postsurgical hospitalization and, due to patient factors, this remains an integral patient of post-THA care.

Elective lower limb orthopedic arthroplasty surgery in patients with pulmonary hypertension

Patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (PH) are at increased risk when undergoing anesthesia and major surgery. Data on outcomes for elective orthopedic surgery in patients with PH are limited. A patient pathway was established to provide access to elective lower limb arthroplasty. This included assessment of orthopedic needs, fitness for anesthesia, preoperative optimization, and intra- and postoperative management. Patient data were retrospectively retrieved using patient's hospital records. Between 2012 and 2020, 29 operations (21 total hip replacements [THRs], 7 total knee replacements [TKRs], 1 total hip revision) were performed in 25 patients (mean age: 67 years). Perioperatively, 72% were treated with low-dose intravenous prostanoid. All had arterial lines, and central access and perioperative lithium dilution cardiac output monitoring was used in 86% of cases. Four patients underwent GA, 21 spinal anesthesia, and 4 CSE anesthesia. Supplemental nerve blocks were performed in all patients undergoing general, and 12 of 21 undergoing spinal anesthesia. All were managed in high dependency postoperatively. Hospital length of stay and complication rates were higher than reported in non-PH patients. Perioperative complications included hypotension requiring vasopressors (n = 10), blood transfusion (n = 7), nonorthopedic infection (n = 4), and decompensated right heart failure (n = 1). There was no associated mortality. All implants were functioning well at 6 weeks and subsequent follow-up. EmPHasis-10 quality of score decreased by 5.5 (±2.1) (p = 0.04). A dedicated multiprofessional pathway can be used to safely select and manage patients with PH through elective lower limb arthroplasty.

Enhanced Recovery After Primary Total Hip and Knee Arthroplasty: A Systematic Review

BACKGROUND

Enhanced Recovery After Surgery (ERAS) has become increasingly implemented to reduce costs, to increase efficiency, and to optimize patient outcomes after a surgical procedure. This study aimed to systematically review the effect of ERAS after primary elective total hip arthroplasty (THA) or total knee arthroplasty (TKA) on hospital length of stay, total procedure-related morbidity, and readmission.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and with guidance from the Cochrane Handbook for Systematic Reviews of Interventions. MEDLINE, Embase, and Cochrane databases were searched from inception (1946 for MEDLINE and 1974 for Embase; Cochrane is a composite of multiple databases and thus does not report a standard inception date) until January 15, 2020. Prospective nonrandomized cohort studies and randomized controlled trials comparing adult patients undergoing elective primary THA or TKA with ERAS or traditional protocols were included. Articles examining outpatient, nonelective, or revision surgical procedures were excluded. Two reviewers independently assessed the risk of bias and extracted data. The primary outcome was length of stay. The secondary outcomes included total procedure-related morbidity and readmission.

RESULTS

Of the 1,018 references identified (1,017 identified through an electronic search and 1 identified through a manual search), 9 individual studies met inclusion criteria. Data were reported from 7,789 participants, with 2,428 receiving ERAS and 5,361 receiving traditional care. Narrative synthesis was performed instead of meta-analysis, given the presence of moderate to high risk of bias, wide variation of ERAS interventions, and inconsistent methods for assessing and reporting outcomes among included studies. Adherence to ERAS protocols consistently reduced hospital length of stay. Few studies demonstrated reduced total procedure-related morbidity, and there was no significant effect on readmission rates.

CONCLUSIONS

ERAS likely reduced the length of stay after primary elective THA and TKA, with a more pronounced effect in selected healthier patient populations. We found minimal to no impact on perioperative morbidity or readmission. The quality of existing evidence was limited because of study heterogeneity and a significant risk of bias. Further high-quality research is needed to definitively assess the impact of ERAS on total joint arthroplasty.

LEVEL OF EVIDENCE

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Feasibility of Outpatient Shoulder Arthroplasty: Risk Stratification and Predictive Probability Modeling

Whether shoulder arthroplasty can be performed on an outpatient basis depends on appropriate patient selection. The purpose of this study was to identify risk factors for adverse events (AEs) following shoulder arthroplasty and to generate predictive models to improve patient selection. This was a retrospective review of prospectively collected data using a single institution shoulder arthroplasty registry as well as the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database, including subjects undergoing hemiarthroplasty, total shoulder arthroplasty (TSA), and reverse TSA. Predicted probability of suitability for same-day discharge was calculated from multivariable logistic models for different patient subgroups based on age, comorbidities, and Charlson/Deyo Index scores. A total of 2314 shoulders (2079 subjects) in the institutional registry met inclusion criteria for this study. Younger age, higher body mass index (BMI), male sex, and prior steroid injection were all significantly associated with suitability for discharge, whereas preoperative narcotic use, comorbidities (heart disease and anemia/other blood disease), and Charlson/Deyo Index score of 2 were associated with AEs that might prevent same-day discharge. Compared with TSA, reverse TSA was associated with less suitability for discharge (P=.01). On querying the ACS-NSQIP database, 15,254 patients were identified. Female sex, BMI less than 35 kg/m², American Society of Anesthesiologists class III/IV, preoperative anemia, functional dependence, low pre-operative albumin, and hemiarthroplasty were associated with unsuitability for discharge. Males 55 to 59 years old with no comorbidities nor history of narcotic use formed the lowest risk subgroup. Transfusion is the primary driver of AEs. Strategies to avoid this complication should be explored. Risk stratification will improve the ability to identify patients who can safely undergo outpatient shoulder arthroplasty. [Orthopedics. 2021;44(2):e215-e222.].

Has Removal From the Inpatient-Only List Increased Complications After Outpatient Total Knee Arthroplasty?

BACKGROUND

On 1/1/2018, the Centers for Medicare and Medicaid Services removed total knee arthroplasty (TKA) from the Inpatient-Only (IPO) list. This change allowed expansion of outpatient TKA, potentially to include older, more frail patients at greater risk for perioperative complications. The purpose of this study was to evaluate the impact of removing TKA from the IPO list on early complications.

METHODS

Patients undergoing TKA in the National Surgical Quality Improvement Program database were identified using CPT code 27447. Only cases with length of stay of zero days were included. Rates of 30-day complications, readmissions, and reoperation were compared before and after TKA was removed from the IPO list (2015-2017 vs 2018). The analysis was performed both with and without propensity score matching.

RESULTS

212,313 patients underwent TKA during the study period. 2466 (1.5%) were outpatient TKA in 2015-2017 and 3189 (5.6%) in 2018. After propensity matching, there were 2458 patients in each cohort. Rates of total 30-day complications were significantly lower in 2018 (3.7%) than the years TKA remained on the IPO (4.5%, P = .04). Similarly, rates of any reoperation decreased from 1.2% during 2015-2017 to 0.6% in 2018 (P = .03). There were no significant changes in rates of readmission (2.5% vs 2.2%, P = .5) or wound complications (0.8% vs 0.8%, P = 1.0).

CONCLUSION

Removal of TKA from the IPO list did not result in an increase in complications or readmissions. These data suggest, despite the regulatory change, surgeons have continued to exercise sound judgment as to what patients can safely undergo outpatient TKA.

Allergies, Preoperative Narcotic Use, and Increased Age Predict Failed Same-Day Discharge After Joint Replacement

BACKGROUND

Identifying predictors of failed same-day discharge (SDD) is critical for patient selection. We evaluated patient factors associated with failure of SDD in patients undergoing elective total joint arthroplasty (TJA) in a hospital setting.

METHODS

We retrospectively reviewed consecutive patients who underwent primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) between January 31, 2018 and February 1, 2020 by one of the 3 fellowship-trained arthroplasty surgeons. Patient demographics, comorbidities, and clinical data were collected. Analysis was performed to assess risk factors for failed SDD.

RESULTS

In total, 2615 TJAs (1425 TKAs, 1190 THAs) were performed over the study period. Two hundred seventy-one (10.4%) were SDDs (80 TKAs, 191 THAs). There were fewer TKAs than THAs (5.6% vs 16.1%, P < .001). Forty-five patients failed SDD (16.6%). Failure rates were similar in TKA and THA (18.8%, 15.7%, P = .54). The most common reasons for failure of SDD were hypotension (11, 24.4%), delayed resolution of spinal anesthesia (11, 24.4%), and nausea (5, 11.1%). Age over 70 years (P = .007), greater than 2 self-reported allergies (P < .001), and preoperative narcotic use (P = .01) were associated with failure of SDD. Gender, body mass index, American Society of Anesthesiologists class, and prior TJA were not significantly associated (P > .05).

CONCLUSION

Success of SDD was greater than 80%. Hypotension, delayed resolution of spinal anesthesia, and nausea accounted for 60% of failures of SDD. Patients >70 years, those with >2 self-reported drug allergies, or patients who used preoperative narcotics were at high risk for failure of SDD after THA or TKA.

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.

Readmission, Complication, and Disposition Calculators in Total Joint Arthroplasty: A Systemic Review

BACKGROUND

Predictive tools are useful adjuncts in surgical planning. They help guide patient selection, candidacy for inpatient vs outpatient surgery, and discharge disposition as well as predict the probability of readmissions and complications after total joint arthroplasty (TJA). Surgeons may find it difficult due to significant variation among risk calculators to decide which tool is best suited for a specific patient for optimal decision-based care. Our aim is to perform a systematic review of the literature to determine the existing post-TJA readmission calculators and compare the specific elements that comprise their formula. Second, we intend to evaluate the pros and cons of each calculator.

METHODS

Using a Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols protocol, we conducted a systematic search through 3 major databases for publications addressing TJA risk stratification tools for readmission, discharge disposition, and early complications. We excluded those manuscripts that were not comprehensive for hips and knees, did not list discharge, readmission or complication as the primary outcome, or were published outside the North America.

RESULTS

Ten publications met our criteria and were compared on their sourced data, variable types, and overall algorithm quality. Seven of these were generated with single institution data and 3 from large administrative datasets. Three tools determined readmission risk, 5 calculated discharge disposition, and 2 predicted early complications. Only 4 prediction tools were validated by external studies. Seven studies utilized preoperative data points in their risk equations while 3 utilized intraoperative or postsurgical data to delineate risk.

CONCLUSION

The extensive variation among TJA risk calculators underscores the need for tools with more individualized stratification capabilities and verification. The transition to outpatient and same-day discharge TJA may preclude or change the need for many of these calculators. Further studies are needed to develop more streamlined risk calculator tools that predict readmission and surgical complications.

Predicting short stay total hip arthroplasty by use of the timed up and go-test

Background

One of the most important steps before implementing short stay total hip arthroplasty (THA) is establishing patient criteria. Most existing criteria are mainly based on medical condition, but as physical functioning is associated with outcome after THA, we aim to evaluate the added value of a measure of physical functioning to predict short-stay THA.

Methods

We used retrospective data of 1559 patients who underwent an anterior THA procedure. Logistic regression analyses were performed to study the predictive value of preoperative variables among which preoperative physical functioning by use of the Timed Up and Go test (TUG) for short stay THA (< 36 h). The receiver operating characteristic (ROC) curve and Youden Index were used to define a cutoff point for TUG associated with short stay THA.

Results

TUG was significantly associated with LOS (OR 0.84, 95%CI 0.82–0.87) as analyzed by univariate regression analysis. In multivariate regression, a model with the TUG had a better performance with an AUC of 0.77 (95%CI 0.74–0.79) and a R² of 0.27 compared to the basic model (AUC 0.75, 95%CI 0.73–0.77, R² 0.24). Patients with a preoperative TUG less than 9.7 s had an OR of 4.01 (95%CI 3.19–5.05) of being discharged within 36 h.

Conclusions

Performance based physical functioning, measured by the TUG, is associated with short stay THA. This knowledge will help in the decision-making process for the planning and expectations in short stay THA protocols with the advantage that the TUG is a simple and fast instrument to be carried out.

Preoperative Predictors of Same-Day Discharge After Total Knee Arthroplasty

Background

In January 2020, The Centers for Medicare and Medicaid Services approved total knee arthroplasty (TKA) to be performed in ambulatory surgery centers (ASCs). This study aims to develop a predictive model for targeting appropriate patients for ASC-based TKA.

Methods

A retrospective review of 2266 patients (205 same-day discharge [SDD; 9.0%] and 2061 one-day length of stay [91.0%]) undergoing TKA at a regional medical center between July 2016 and September 2020 was conducted. Multiple logistic regression was used to evaluate predictors of SDD, as these patients represent those most likely to safely undergo TKA in an ASC.

Results

Controlling for other demographics and comorbidities, patients with the following characteristics were at reduced odds of SDD: increased age (odds ratio [OR] = 0.935, P < .001), body mass index ≥35 (OR = 0.491, P = .002), female (OR = 0.535, P < .001), nonwhite race (OR = 0.456, P = .003), primary hypertension (OR = 0.710, P = .032), ≥3 comorbidities (OR = 0.507, P = .002), American Society of Anesthesiologists score ≥3 (OR = 0.378, P < .001). The model was deemed to be of adequate fit using the Hosmer and Lemeshow test (χ² = 12.437, P = .112), and the area under the curve was found to be 0.773 indicating acceptable discrimination.

Conclusion

For patients undergoing primary TKA, increased age, body mass index ≥35, female gender, nonwhite race, primary hypertension, ≥3 comorbidities, and American Society of Anesthesiologists score ≥3 decrease the likelihood of SDD. A predictive model based on readily available patient presentation and comorbidity characteristics may aid surgeons in identifying patients that are candidates for SDD or ASC-based TKA.

Complications and Readmissions After Total Hip Replacement in Octogenarians and Nonagenarians

Introduction

As the US population ages, the need for total hip arthroplasty (THA) is predicted to increase by 174% by 2030. The purpose of our study was to examine the rate and risks of 30-day complications and unplanned readmission in patients over the age of 80 years old.

Materials and Methods

The National Surgical Quality Improvement Project database for the years 2008 to 2014 was queried for patients over the age of 80 undergoing THA. The risks of major complications, minor complications, bleeding occurrences, unplanned readmissions, and deaths over a 30-day period were examined using univariate and multivariate analyses.

Results

A total of 7730 patients were included for analysis; 324 (4.2%) patients experienced a major complication, 1944 (25.1%) patients experienced a minor complication, 1776 (22.9%) patients had a bleeding occurrence requiring transfusion, and 376 (4.9%) patients experienced an unplanned readmission to the hospital within 30 days. A total of 33 (0.4%) patient deaths were recorded within 30 days postoperatively. Patients with congestive heart failure were at increased risk for developing a major complication, odds ratio (OR) 3.618 (1.052-12.437), and postoperative death, OR 11.920 (1.362-104.322). Patients with an American Society of Anesthesiologists >2, OR: 1.351 (1.131-1.613), and an operative time greater than 120 minutes, OR: 1.346 (1.084-1.670), had increased risks of minor complications. Patients with a body mass index greater than 30 had reduced rates of minor complications, OR: 0.609 (0.486-0.763). Increased risk of unplanned readmission was seen in patients with chronic obstructive pulmonary disease, OR: 2.403 (1.324-4.359).

Discussion/Conclusion

Elderly patients undergoing THA have high complication and readmission rates. Surgeons should convey these increased risk factors and rates of complications in elective THAs to their elderly patients and work with primary care physicians to mitigate these risks.

Is Outpatient Arthroplasty Safe? A Systematic Review

BACKGROUND

Advances in perioperative care and growing demand for hospital beds have progressively reduced the length of stay in lower limb arthroplasty. Current trends in population demographics and fiscal climate have also added to this change. Individual institutions have reported good outcomes with outpatient hip and knee arthroplasty. Debate remains regarding the safety of this practice, the optimal protocol, and the applicability in different subsections of population. The primary purpose of this review is to assess the complication and reoperation rates of outpatient arthroplasty.

METHODS

We performed a systematic review of all papers reporting on 30 and/or 90-day complication rates of outpatient total hip, total knee, and unicondylar knee arthroplasty published from January 1, 2009 to November 1, 2019. Patient demographics, anesthesia, analgesic protocol, selection criteria, and reasons for failed discharge were also extracted.

RESULTS

Nineteen manuscripts with a total of 6519 operations between them were analyzed as a part of this systematic review. Mean 90-day readmission rates were 2.3% (range 0%-6%) with 1.61% (range 0%-4%) rate. Overall rate of successful same calendar day discharge was 93.4%. Nausea/dizziness was the most common reason identified (n = 45) for failure of discharge.

CONCLUSION

The patients recruited for outpatient joint arthroplasty were younger, more active, and had suffered from less medical comorbidities than the more typical lower limb arthroplasty patient. There are significant differences in the reported complications between the studies reviewed. More research is needed to establish if an outpatient program can produce similar outcomes to a fast-track program. Further research is also needed to establish the optimal perioperative protocols.

Similar Outcomes After Hospital-Based Same-Day Discharge vs Inpatient Total Hip Arthroplasty

Background

There has been increasing interest in performing primary hip and knee replacement with same-day discharge (SDD). The purpose of this study is to compare patient-reported outcome (PRO) scores, pain scores, and readmissions in patients who underwent SDD total hip arthroplasty (THA) with those in patients who underwent traditional inpatient THA.

Methods

A retrospective study was conducted on 963 patients who underwent primary THA at our institution between September 2016 and December 2018. Two cohorts were established based on whether the patient underwent SDD or traditional inpatient THA. An electronic physical engagement application was used to collect PRO scores (Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, Veterans Rand 12-Item Health Survey Physical Component Score, and Mental Component Score) and pain scores. To control for demographic variables, a multiple regression analysis of PRO scores was conducted.

Results

Four hundred fifteen (43.1%) patients in this study underwent the SDD protocol. There were significant differences between both cohorts with respect to sex, age, body mass index, American Society of Anesthesiologists score, and smoking status. The bivariate analysis revealed that the SDD cohort had a significantly greater change in the Veterans Rand 12-Item Health Survey Physical Component Score and had fewer readmissions. Both cohorts had equivalent decreases in pain scores. After controlling for demographic variables in a multivariable analysis, the SDD cohort was found to have higher PRO scores at all time points, but there were no significant differences in the change in PRO scores over time between both groups.

Conclusion

Patients in an SDD THA care pathway experienced similar improvements in PRO scores and clinically equal reduction in pain scores.

Low complication rates in outpatient total knee arthroplasty

PURPOSE

The primary purpose of this study is to report the incidence of complications associated with outpatient total knee arthroplasty (TKA). Secondarily, 2-year minimum outcomes are reported.

METHODS

Between 2013 and 2016, 928 patients underwent 1143 outpatient TKAs with the Vanguard Complete Knee System (Zimmer Biomet, Warsaw, IN). Patients were selected for outpatient surgery if they were medically optimized without a failing organ system and had sufficient support at home. Overnight stays, medical complications and early perioperative complications were assessed in this entire cohort. Two-year minimum follow-up was available on 793 patients (978 knees). Patient records were analyzed for outcome measures and revisions.

RESULTS

In 124 procedures, the patient stayed overnight for 23-h observation. Thirty-seven (3.2%) were for convenience reasons and 87 (7.6%) for medical observation. Heart disease and chronic obstructive pulmonary disease were associated with increased risk of overnight stay. Excluding manipulations, reoperation within 90 days occurred in eight (0.7%) knees. Patients with 2-year minimum follow-up had significant improvements in ROM, Knee Society Clinical, Functional and Pain scores (p < 0.005). Nine (0.8%) patients required revision. Manipulations were performed on 118 (10.3%) patients. The overall deep infection rate was 0.17% (2/1143).

CONCLUSIONS

Outpatient TKA is safe for a large proportion of patients. Certain medical co-morbidities increase the risk of overnight stay. Patients had significant improvement in ROM and outcome scores with low revision rate.

LEVEL OF EVIDENCE

III.

The Effect of Neuraxial Anesthesia on Postoperative Outcomes in Total Joint Arthroplasty With Rapid Recovery Protocols

BACKGROUND

Compared to general anesthesia (GA), neuraxial anesthesia (NA) has been associated with improved outcomes after total joint arthroplasty (TJA). We examined the impact of NA on patient outcomes in an institution with an established rapid recovery protocol.

METHODS

This is a single-institution retrospective analysis of 5914 consecutive primary TJA performed from July 2015 to June 2018. Univariate tests and multivariate regression compared length of stay (LOS), transfusion rates, hematocrit levels, discharge disposition, and emergency room returns between patients receiving GA and NA.

RESULTS

Patients receiving NA had a significantly shorter LOS (total hip arthroplasty [THA]: GA 1.74 vs NA 1.36 days, P < .001; total knee arthroplasty [TKA]: GA 1.77 vs NA 1.64 days, P < .001). Both THA and TKA patients receiving NA were less likely to require transfusion (THA: GA 5.8% vs NA 1.6%, P < .001; TKA: GA 2.5% vs NA 0.5%, P < .001) and had a higher postoperative hematocrit (THA: GA 32.50% vs NA 33.22%, P < .001; TKA GA 33.57 vs NA 34.50%, P < .001). Patients receiving NA were more likely to discharge home (THA: GA 83.4% vs NA 92.3%, P < .001; TKA: GA 83.3% vs NA 86.3%, P = .010) (THA: NA adjusted OR [aOR] 2.04, P < .001; TKA: NA aOR 1.23, P = .048) and had significantly lower rates of 90-day emergency room visits (THA: NA aOR 0.61, P = .005; TKA: NA aOR 0.74, P = .034).

CONCLUSION

NA appears to contribute to decreased LOS, short-term complications, and transfusions while facilitating home discharge following TKA and THA. These trends are consistent when controlling for patient-specific risk factors, suggesting NA may enhance outcomes for patients with increased age, body mass index, and comorbidities.

LEVEL OF EVIDENCE

Level III Retrospective Cohort Study.

No Difference in Outcomes Between Short and Longer-Stay Total Joint Arthroplasty with a Discharge Home: A Propensity Score-Matched Analysis Involving 46,660 Patients

BACKGROUND

Outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA) with a short length of hospital stay have been reported; however, most studies have not accounted for an inherent patient selection bias and discharge disposition. The purpose of this study was to utilize a propensity score to match and compare the outcomes of patients undergoing THA or TKA with short and longer lengths of stay with a discharge directly home.

METHODS

An administrative database from Ontario, Canada, which has a single-payer health-care system, was retrospectively reviewed to identify patients who underwent THA or TKA from 2008 to 2016. Patients were subsequently stratified into 2 groups based on their length of stay: short length of stay (≤2 days; thereafter referred to as short stay) and longer length of stay (>2 days; thereafter referred to as longer stay). Using a propensity score, patients who underwent short-stay THA or TKA were matched to patients who underwent longer-stay THA or TKA. Matching was based on 15 demographic, medical, and surgical factors. Our primary outcomes included postoperative complications, health-care utilization (readmission and emergency department presentation), and health-care costs.

RESULTS

Overall, 89,656 TKAs (14,645 short stays and 75,011 longer stays) and 52,610 THAs (9,426 short stays and 43,184 longer stays) were included in this study. Patients who underwent short-stay THA or TKA were significantly more likely (p < 0.05) to be younger, male, healthier, and from a higher socioeconomic status and to have undergone the procedure with a higher-volume surgeon. Over 95% of short-stay cases were successfully matched to longer-stay cases, and we found no significant difference in complications, health-care utilization, and costs between patients on the basis of the length of stay.

CONCLUSIONS

Patients undergoing short-stay THA or TKA with a discharge home were more likely to be younger, healthy, male patients from a higher socioeconomic status. Higher-volume surgeons are also more likely to perform short-stay THA or TKA. These characteristics confirm the previously held belief that a selection bias exists when comparing cohorts based on time to discharge. When comparing matched cohorts of patients who underwent short-stay and longer-stay THA or TKA, we observed no difference in outcomes, suggesting that a short stay with a discharge home in the appropriately selected patient is safe following THA or TKA.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Outcomes of Same-Day Discharge After Total Hip Arthroplasty in the Medicare Population

BACKGROUND

There is an increasing utilization of same-day discharge total hip arthroplasty (SDD THA). As the Center for Medicare and Medicaid Services considers removing THA from the inpatient-only list, there is likely to be a significant increase in the number of Medicare patients undergoing SDD THA. Thus, there is a need to report on outcomes of SDD THA in this population.

METHODS

A retrospective review was performed on 850 consecutive SDD THA patients including 161 Medicare patients. We compared failure to launch, complication, emergency department visit, and 90-day readmission rates between the Medicare and non-Medicare cohorts.

RESULTS

The Medicare group was older and had less variability in their admission diagnosis. There was no significant difference in failure to launch, complication, emergency department visit, or 90-day readmission rates between Medicare and non-Medicare groups.

CONCLUSION

The benefits of SDD THA can be safely extended to the carefully indicated and motivated Medicare patient.

Outpatient Versus Rapid Recovery Inpatient Knee Arthroplasty: Comparison of Matched Cohorts

Increased focus on reducing the cost of total knee arthroplasty (TKA) has driven greater interest in performing the procedure in an outpatient setting. This study used exact matching to compare clinical and economic outcomes following TKA in an outpatient vs rapid recovery inpatient setting. This study used a nationally representative commercial database. Patients were grouped into 2 cohorts: same-day outpatient TKA (surgery center or hospital outpatient) or short-stay inpatient TKA ("rapid recovery"; length of stay 1 day or less). Only patients discharged home under self-care or with health care were included. Exact 1:1 matching was performed on clinical and demographic characteristics to control for potential case-selection bias by choice of care setting. Prior to matching, 969 outpatients and 8101 rapid recovery inpatients met selection criteria. The outpatient cohort was younger (median age, 58 vs 61 years), predominantly female (56% vs 51%), and less comorbid (Charlson Comorbidity Index score of 0: 84.2% vs 74.0%) vs the rapid recovery cohort. Post-match, 863 patients were available in each cohort. The outpatient cohort exhibited a significantly lower incidence of opiate use (80.4% vs 90.7%; P<.001) and minor complications (2.8% vs 5.8%; P=.002). Incidence of major complications (5.2% vs 6.7%, P=.173) and 90-day readmissions (5.1% vs 7.3%, P=.064) were equivalent. The outpatient median 90-day episode payment was $6824 lower (22%) per patient ($24,749 vs $31,573, respectively; P<.001). This study suggests that among carefully selected patients undergoing outpatient TKA, outcomes are equivalent, if not improved, at a lower payor cost compared with a rapid recovery inpatient setting. [Orthopedics. 2020; 43(1):36-41.].

Establishing a patient centered, outpatient total joint home recovery program within an integrated healthcare system

Outpatient total joint home recovery (HR) is a rapidly growing initiative being developed and employed at high volume orthopedic centers. Minimally invasive surgery, improved pain control and home health services have made HR possible. Multidisciplinary teams with members ranging from surgeons and anesthesiologists to hospital administrators, physical therapists, nurses and research analysts are necessary for success. Eligibility criteria for outpatient total joint arthroplasty will vary between medical centers. Surgeon preference in addition to medical comorbidities, social support, preoperative patient mobility and safety of the HR location are all factors to consider when selecting patients for outpatient total joint HR. As additional knowledge is gained, the next steps will be to establish 'best practices' and speciality society-endorsed guidelines for patients undergoing outpatient total joint arthroplasty.

Association between same day discharge total knee and total hip arthroplasty and risks of cardiac/pulmonary complications and readmission: a population-based observational study

OBJECTIVE

To determine if same-day discharge total knee arthroplasty (TKA) or total hip arthroplasty (THA) is not associated with increased risk of unplanned readmission and adverse outcomes within 30 days of surgery.

DESIGN

This is a population-based observational study.

SETTING

Patients from 708 participating institutions who underwent primary TKA or primary THA between 2011 and 2017 were divided into three groups by length of stay (LOS 0, 1 and 2-3 days). All patients with LOS>3 days were excluded from the current study. Regression analysis and propensity score matching were performed.

DATA SOURCES

American College of Surgeons-National Surgical Quality Improvement Programme database.

MAIN OUTCOMES AND MEASURES

Primary outcomes included unplanned readmission and cardiac/pulmonary complications within 30 days of surgery.

RESULTS

We identified 226 481 TKA (LOS 0=3118, LOS 1=31 404, and LOS 2-3=1 91 959) and 140 557 THA patients (LOS 0=2652, LOS 1=29 617, and LOS 2-3=1 08 288). There were no differences in 30-day mortality. After adjusting for relevant covariates, LOS 0 (compared with LOS 1) was associated with higher odds of cardiac/pulmonary complications in both TKA (OR 1.95, 95% CI 1.20 to 3.16; 0.67% vs 0.37%) and THA (OR 1.96, 95% CI 1.05 to 3.64; 0.57% vs 0.26%). There were no statistical differences in unplanned readmissions between LOS 0 and LOS 1 groups in TKA (2.41% vs 2.31%) and THA (1.62% vs 2.04%).

CONCLUSIONS

LOS 0 discharge after TKA and THA was associated with higher odds of cardiac/pulmonary complications compared with LOS 1 discharge. While the overall burden of complications is relatively low, until future studies can confirm or challenge our findings, a measured approach is advisable when recommending discharge of patients on the same day of surgery.

Outpatient Total Hip Arthroplasty Performed at an Ambulatory Surgery Center vs Hospital Outpatient Setting: Complications, Revisions, and Readmissions

BACKGROUND

Outpatient total hip arthroplasty (THA) utilization continues to grow. Literature suggests outpatient THA may result in low rates of complications and readmission. There are no studies comparing safety profiles of THA performed at ambulatory surgery centers (ASC) vs hospital outpatient (HOP) settings.

METHODS

Prospectively collected data were reviewed on all patients who underwent THA from 2013 to 2018. ASC and HOP subgroups were compared, investigating difference in demographics, comorbidities, American Society of Anesthesiologists subgroups, all complications, revisions, emergency department (ED) visits, and readmissions within the first 90 days of surgery. An additional subgroup analysis of patients younger than 65 years was performed.

RESULTS

Two surgeons performed 3063 THAs during the study period, including 965 outpatient cases (ASC = 335; HOP = 630). Thirty-seven (3.8%) complications occurred within 90 days. No differences were found between groups for 90-day complication rates (ASC = 13, 3.9%; HOP = 24, 3.8%; P = .48), revision rates (ASC = 0, 0%; HOP = 2, .3%; P = .30), all-cause reoperation rates (ASC = 1, 0.3%; HOP = 5, 0.8%; P = .35), ED visits (ASC = 3, 0.9%; HOP = 2, 0.3%; P = .23), or readmission rates (ASC = 2, 0.6%; HOP = 9, 1.4%; P = .25).

CONCLUSION

THA can be safely performed in both ASC and HOP settings with low 90-day postoperative complication, revision, reoperation, ED visit, and readmission rates. Based on the populations studied, we identified no statistically significant differences in rates of complications between ASC and HOP groups.

Deep Learning Preoperatively Predicts Value Metrics for Primary Total Knee Arthroplasty: Development and Validation of an Artificial Neural Network Model

BACKGROUND

The objective is to develop and validate an artificial neural network (ANN) that learns and predicts length of stay (LOS), inpatient charges, and discharge disposition before primary total knee arthroplasty (TKA). The secondary objective applied the ANN to propose a risk-based, patient-specific payment model (PSPM) commensurate with case complexity.

METHODS

Using data from 175,042 primary TKAs from the National Inpatient Sample and an institutional database, an ANN was developed to predict LOS, charges, and disposition using 15 preoperative variables. Outcome metrics included accuracy and area under the curve for a receiver operating characteristic curve. Model uncertainty was stratified by All Patient Refined comorbidity indices in establishing a risk-based PSPM.

RESULTS

The dynamic model demonstrated "learning" in the first 30 training rounds with areas under the curve of 74.8%, 82.8%, and 76.1% for LOS, charges, and discharge disposition, respectively. The PSPM demonstrated that as patient comorbidity increased, risk increased by 2.0%, 21.8%, and 82.6% for moderate, major, and severe comorbidities, respectively.

CONCLUSION

Our deep learning model demonstrated "learning" with acceptable validity, reliability, and responsiveness in predicting value metrics, offering the ability to preoperatively plan for TKA episodes of care. This model may be applied to a PSPM proposing tiered reimbursements reflecting case complexity.

Perioperative morbidity in total knee arthroplasty

Introduction

As the life expectancy and weight of patients are increasing, more old and obese patients are undergoing total knee arthroplasty (TKA). TKA may lead to several perioperative complications. These include anesthesia-related risks, exacerbation of comorbid medical issues and complications of surgical procedure. We have no studies reporting medical complications following TKA among our population. This study aimed to evaluate perioperative complications of TKA and to identify the related risk factors.

Methods

It was a monocentric retrospective including 410 observations in the local TKA registry. Data of patients operated for primary unilateral TKA during the period from January 2014 to December 2017 were reviewed. All patients had standardized protocols of anesthesia and post operative care for three days following surgery. Multivariate logistic regression was used to identify the predicting factors for complications.

Results

Incidence of perioperative complications was 37.1%. The most frequent were per operative hypotension (14.1%) and postoperative desaturation (21.7%, including pulmonary embolism in 2.4%). Multivariate logistic regression analysis identified: age ≥ 65 years (OR=1.9; p=0.006), respiratory diseases (OR=1.8; p=0.042) and general anesthesia (OR=2.8; p=0.009) as significant risk factors for any complications. Loss of autonomy (OR=4.8; p <0.001) and general anesthesia (OR=2.6; p=0.03) were significant risk factors for hypotension. Age ≥ 65 years (OR=2.6;p<0.001), female gender (OR=4.3;p=0.006) and respiratory diseases(OR=1.9;p=0.02) were associated with postoperative desaturation.

Conclusion

This study highlighted hemodynamic and respiratory complications as the most common early complications in TKA. Age ≥ 65years, general anesthesia and respiratory diseases were significant risk factors.

Bundled Care for Hip Fractures: A Machine-Learning Approach to an Untenable Patient-Specific Payment Model

OBJECTIVES

With the transition to a value-based model of care delivery, bundled payment models have been implemented with demonstrated success in elective lower extremity joint arthroplasty. Yet, hip fracture outcomes are dependent on patient-level factors that may not be optimized preoperatively due to acuity of care. The objectives of this study are to (1) develop a supervised naive Bayes machine-learning algorithm using preoperative patient data to predict length of stay and cost after hip fracture and (2) propose a patient-specific payment model to project reimbursements based on patient comorbidities.

METHODS

Using the New York Statewide Planning and Research Cooperative System database, we studied 98,562 Medicare patients who underwent operative management for hip fracture from 2009 to 2016. A naive Bayes machine-learning model was built using age, sex, ethnicity, race, type of admission, risk of mortality, and severity of illness as predictive inputs.

RESULTS

Accuracy was demonstrated at 76.5% and 79.0% for length of stay and cost, respectively. Performance was 88% for length of stay and 89% for cost. Model error analysis showed increasing model error with increasing risk of mortality, which thus increased the risk-adjusted payment for each risk of mortality.

CONCLUSIONS

Our naive Bayes machine-learning algorithm provided excellent accuracy and responsiveness in the prediction of length of stay and cost of an episode of care for hip fracture using preoperative variables. This model demonstrates that the cost of delivery of hip fracture care is dependent on largely nonmodifiable patient-specific factors, likely making bundled care an implausible payment model for hip fractures.