Reimbursement and Complications in Outpatient vs Inpatient Unicompartmental Arthroplasty

The safety and efficacy of unicompartmental knee arthroplasty in outpatient surgical centers: A systematic review and meta-analysis

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is an effective treatment method for knee osteoarthritis. With the development and implementation of enhanced recovery after surgery, UKA is now increasingly performed in outpatient surgical centers. However, there is ongoing debate regarding the safety and effectiveness of performing UKA in outpatient settings.

METHODS

The search was performed to retrieve randomized controlled trials and cohort studies on outpatient UKA from PubMed, Cochrane Library, EMbase, CNKI, and WanFangData databases. The search was conducted from the inception of the databases until August 31, 2023. After independent screening, data extraction, and risk of bias evaluation by two researchers, meta-analysis was performed using RevMan 5.4 software.

RESULTS

A total of eight studies involving 18,411 patients were included. The results showed that the postoperative transfusion rate in the outpatient group was lower than that in the inpatient group [OR = 0.36, 95%CI (0.24, 0.54), p < 0.00001], and the difference was statistically significant. However, there was no significant difference between the two groups in terms of readmission rate, reoperation rate, surgical site infection, and periprosthetic fracture. The differences were not statistically significant.

CONCLUSION

Compared to the traditional inpatient route, the blood transfusion rate for single-condyle replacement in the outpatient operation center is lower, and there is no significant difference in readmission rate, reoperation rate, surgical site infection, and periprosthesis fracture. The outpatient approach to UKA is safe, feasible, and highly satisfactory for patients. However, the results have certain limitations, and a rigorous preoperative complication risk assessment can minimize the risk of UKA in outpatient surgery centers.

TRIAL REGISTRATION

PROSPERO number CRD42023405373.

Is Discharge Within a Day Following Total Hip Arthroplasty Safe in the Septuagenarian and Octogenarian Population? A Propensity-Matched Cohort Study

BACKGROUND

Limited data exists on whether patients older than 70 can safely be discharged within a day (rapid discharge (RD)) following primary total hip arthroplasty (THA). The purpose of this study was to compare perioperative complications and readmission rates associated with RD in patients ≥70 years compared to longer lengths of stay following THA.

METHODS

A retrospective, propensity-matched cohort study was conducted using the National Surgical Quality Improvement Program database from 2006 to 2020. Patients ≥70 years undergoing RD following THA were propensity matched to patients ≥70 years who had longer hospital stays (nonrapid discharge). Sub-analyses were performed for septuagenarians and octogenarians. Following 1:1 matching, multivariate analyses were performed to compare perioperative complications and readmissions. Following propensity matching, both groups contained 2,192 patients.

RESULTS

The RD patients were found to have shorter operative times (P < .001), less bleeding complications (P < .001), and were more likely to have home discharges (P < .001). The 2 cohorts did not differ in the remaining complications or 30-day postoperative period readmissions among all patients and when evaluating septuagenarians and octogenarians.

CONCLUSION

Patients ≥70 years undergoing RD following THA had comparable complication and readmission rates to patients older than 70 undergoing nonrapid discharge. Furthermore, RD patients were more likely to have home discharges and have shorter operations with less bleeding complications. Septuagenarians receiving RD were more likely to have an unplanned readmission. These data suggest that RD following THA can be performed safely in select patients older than 70.

Day-case hip and knee arthroplasty: stages of care and the development of an institutional pathway

Day-case, or outpatient, arthroplasty is growing and has been adopted in healthcare systems because of its cost-effectiveness. A number of studies that reported on day-case total hip arthroplasty, total knee arthroplasty and unicompartmental knee arthroplasty have shown that they can be performed successfully in a select group of patients. However, safety remains a concern, as a clear pathway, including discharge criteria, is not well described in the literature. This article outlines the stages of care involved in day-case hip and knee arthroplasty and gives insights from University College London Hospital's own evidence-based day-case arthroplasty pathway.

Unicompartmental Knee Arthroplasty Is Cost-Effective in an Outpatient Setting

INTRODUCTION

Increasingly, unicompartmental knee arthroplasty (UKA) is being performed on an outpatient basis, with the growing utilization of ambulatory surgery centers (ASCs). The purpose of this study was to compare the costs of UKAs performed in an ASC to UKAs done in a hospital, either on an outpatient or inpatient basis.

METHODS

This study involved three matched groups, each with 50 consecutive patients, undergoing UKA either on an outpatient basis in an ASC or a community hospital, or who were admitted overnight to the same community hospital. Identical perioperative analgesic regimens and care protocols were used in each group. The primary outcomes evaluated included direct facility costs. Secondary outcomes were postoperative complications and readmissions.

RESULTS

Average age, gender ratio, and comorbidities were similar in all three cohorts. Only two patients in the study experienced complications and these were without secondary adverse consequences. Mean costs were substantially reduced when UKAs were performed in an ASC ($9,025) compared to a community hospital on either an outpatient ($12,032) or inpatient basis ($14,542).

CONCLUSION

UKA can be safely performed in the outpatient setting, in appropriately selected patients, at substantial cost savings, particularly when performed in an ASC.

Cost-effectiveness of Same-day Discharge Surgery for Primary Total Hip Arthroplasty: A Pragmatic Randomized Controlled Study

Background

Total hip arthroplasty (THA) causes a great medical burden globally, and the same-day discharge (SDD) method has previously been considered to be cost saving. However, a standard cost-effectiveness analysis (CEA) in a randomized controlled trial (RCT) is needed to evaluated the benefits of SDD when performing THA from the perspective of both economic and clinical outcomes.

Methods

Eighty-four participants undergoing primary THA were randomized to either the SDD group or the inpatient group. Outcomes were assessed by an independent orthopedist who was not in the surgical team, using the Oxford Hip Score (OHS), EuroQol 5D (EQ-5D), SF-36 scores and the quality-adjusted life years (QALYs). All the cost information was also collected.

Results

The mean stay of patients in the SDD group was 21.70 ± 3.45 h, while the inpatient group was 78.15 ± 26.36 h. This trial did not detect any significant differences in OHS and QALYs. The total cost in the SDD group was significantly lower than that in the inpatient group (¥69,771.27 ± 6,608.00 vs. ¥80,666.17 ± 8,421.96, p < 0.001). From the perspective of total cost, when measuring OHS, the incremental effect was -0.12 and the incremental cost was -¥10,894.90. The mean incremental cost-effectiveness ratio (ICER) was 90,790.83. When measuring QALYs, the incremental effect was 0.02, and the ICER was negative. Sensitivity analysis produced similar results.

Conclusions

SDD has an acceptable likelihood of being more cost-effective than the traditional inpatient option. After conducting cost-utility analysis, SDD resulted in better QALYs, while significantly reducing the total cost.

Centers for Medicare & Medicaid Services' 2018 Removal of Total Knee Arthroplasty From the Inpatient-only List Led to Broad Changes in Hospital Length of Stays

INTRODUCTION

Centers for Medicare & Medicaid Services (CMS) removed total knee arthroplasty (TKA) from the "inpatient-only" list from January 1, 2018. The impact of this change on actual hospital length of stay (LOS) and patient coding is of interest.

METHODS

Patients undergoing TKA were abstracted from the 2015 to 2018 National Surgical Quality Improvement Program database. Patient characterization as "inpatient" or "outpatient" and actual LOS were assessed. Ordinal and categorical data comparisons were done with Pearson chi-squared tests. Continuous variables were tested for normality, and nonparametric analyses were conducted using the Mann-Whitney test. Significance was set at P < 0.05.

RESULTS

In total, 125,613 TKA patients from 2017 to 2018 were identified (232,269 TKA patients from 2015 to 2018). Most patients undergoing TKA were of Medicare eligibility (≥65 years old; 60.78% in 2017 and 62.42% in 2018). Overall, LOS decreased significantly from 2017 to 2018 (2.31 ± 1.56 days versus 2.05 ± 1.57 days; P < 0.001), and more patients were discharged the same day (5.09% versus 2.28%; P < 0.001). In 2017, patients were coded as "outpatient" 1.66% of the time (those with LOS = 0 days were 22.85%, LOS = 1 day were 1.80%, LOS = 2 days were 0.79%, and LOS ≥3 days were 0.85%). In 2018, patients were coded as "outpatient" 17.14% of the time (those with LOS = 0 days were 78.2%, LOS = 1 day were 29.75%, LOS = 2 days were 6.96%, and LOS ≥3 days were 3.05%). This represented a significant change for each LOS day (P < 0.001). These results remained true when stratifying by Medicare eligibility (P < 0.001 for those <65 years old and those ≥65 years old).

DISCUSSION

After the 2018 removal of TKA from the CMS "inpatient-only" list, patients were more likely to be discharged the same day and be considered "outpatients." Patients with more prolonged LOS and those younger than 65 years were more likely to have been coded as "outpatient" in 2018 compared with 2017. These data demonstrate that national changes in CMS policies can have broad impact on overall practice patterns.

LEVEL OF EVIDENCE

Retrospective cohort study.

Fewer Adverse Events Following Outpatient Compared with Inpatient Unicompartmental Knee Arthroplasty

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is a common procedure for unicompartmental knee arthritis, often resulting in pain relief and improved function. The demand for total knee arthroplasty in the U.S. is projected to grow 85% between 2014 and 2030, and the volume of UKA procedures is growing 3 to 6 times faster than that of total knee arthroplasty. The purpose of the present study was to examine the safety of outpatient and inpatient UKA and to investigate changes over time as outpatient procedures were performed more frequently.

METHODS

Patients who underwent UKA from 2005 to 2018 as part of the National Surgical Quality Improvement Program were identified. Patients were divided into an early cohort (5,555 patients from 2005 to 2015) and late cohort (5,627 patients from 2016 to 2018). Outpatient status was defined as discharge on the day of surgery. Adverse events within 30 days postoperatively were compared, with adjustment for baseline characteristics with use of standard multivariate regression and propensity-score-matching techniques.

RESULTS

Among the 5,555 cases in the early cohort, the rate of surgical-site infection was lower for inpatient (0.84%) compared with outpatient UKA (1.69%; adjusted relative risk [RR] for inpatient, 0.5; 95% confidence interval [CI], 0.2 to 1.0; p = 0.045); no other significant differences were identified. Among the 5,627 cases in the late cohort, inpatient UKA had higher rates of any complication (2.53% compared with 0.95% for outpatient UKA; adjusted RR for inpatient, 2.5; 95% CI, 1.4 to 4.3; p = 0.001) and readmission (1.81% compared with 0.88% for outpatient UKA; adjusted RR for inpatient, 2.0; 95% CI, 1.1 to 3.5; p = 0.023). In the propensity-score-matched comparison for the late cohort, inpatient UKA had a higher rate of any complication (RR for inpatient, 2.0; 95% CI, 1.0 to 4.0; p = 0.049) and return to the operating room (RR for inpatient, 4.3; 95% CI, 1.4 to 12.6; p = 0.009). Although the rate of readmission was almost twice as high among inpatients (1.67% compared with 0.84% for outpatients; RR for inpatient, 2.0; 95% CI, 1.0 to 4.1; p = 0.059), this difference did not reach significance with the sample size studied. There was a significant reduction in the overall rate of complications over time (3.44% in the early cohort compared with 2.11% in the late cohort; adjusted RR for late cohort, 0.7; 95% CI, 0.5 to 0.8; p = 0.001), with a more than fourfold reduction among outpatients (3.95% in the early cohort compared with 0.95% in the late cohort; adjusted RR for late cohort, 0.3; 95% CI, 0.1 to 0.5; p < 0.001).

CONCLUSIONS

Outpatient UKA was associated with a lower risk of complications compared with inpatient UKA when contemporary data are examined. We identified a dramatic reduction in complications across the early and late cohorts, suggesting an improvement in quality over time, with the largest improvements seen among outpatients. This shift may represent changes in patient selection or improvements in perioperative protocols.

LEVEL OF EVIDENCE

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

Day-case unicompartmental knee arthroplasty: a literature review and development of a novel hospital pathway

INTRODUCTION

We have seen unparalleled changes in our healthcare systems globally as a result of the COVID-19 pandemic. As we strive to regenerate our full capacity elective services in order to contest the increasing demand for lower limb arthroplasty, this pandemic has allowed us a rare opportunity to revise and develop novel elective arthroplasty pathways intended to improve patient care and advance healthcare efficiency. We present an extensive evidence-based review of the approaches used to achieve day-case unicompartmental arthroplasty (UKA) as well as the development of a day-case UKA care pathway in a UK NHS institution based on the evidence provided in the literature.

METHODS

An extensive search of the literature was performed for articles that reported on readmission or complication rates ≥30 days postoperatively following day-case UKA.

FINDINGS

Fifteen manuscripts reporting the results of day-case UKA, defined as discharged on the same calendar day of surgery, were included in our review. Mean reported complication rates for day-case and inpatient UKA within the follow-up periods were 4.05% and 6.52%, respectively. Mean readmission rates were 2.71% and 4.36% for day-case and inpatient UKA, respectively. The mean rate of successful same-day discharge was 92.45%.

CONCLUSION

We introduce our institutional Elective Day Surgery Arthroplasty Pathway (EDSAP) founded upon the evidence presented in the literature. Stringent patient selection complimented by a well-defined day-case arthroplasty pathway is fundamental for successful commencement of day-case UKA in the NHS.

Unicompartmental Knee Arthroplasty Is Associated With a Lower Rate of Periprosthetic Joint Infection Compared to Total Knee Arthroplasty

Background

Several studies have reported lower perioperative complications with unicompartmental knee arthroplasty (UKA) than with total knee arthroplasty (TKA). However, there is a paucity of data analyzing the incidence of periprosthetic joint infection (PJI) in similar patients undergoing UKA and TKA. As such, we sought to analyze the incidence of UKA and TKA PJI in a large matched population.

Material and Methods

The Mariner data set of the PearlDiver database was queried for all patients undergoing UKA or TKA during 2010-2017. Included patients were required to have at least 2 years of database inclusion after surgery. Patients were then matched at a 1:3 ratio (UKA:TKA) on age, gender, Elixhauser Comorbidity Index, tobacco use, and obesity. Rates of PJI requiring operative intervention within 90 days and 1 year were calculated.

Results

In total, 5636 patients having undergone UKA were matched to 16,890 patients having undergone TKA. Fifteen (0.27%) after UKA and 79 (0.47%) after TKA had a PJI surgically managed within 90 days (risk ratio = 0.57, 95% confidence interval = 0.33-0.99, P = .04). Thirty (0.53%) after UKA and 136 (0.81%) after TKA had a PJI surgically managed within 1 year (risk ratio = 0.66, 95% confidence interval = 0.45-0.98, P = .04).

Conclusions

In a large group of rigorously matched patients, UKA was associated with a significantly lower rate of surgically managed PJI than TKA at 90 days and 1 year; however, the rate of PJI in both groups remained low at <1% at 90 days and 1 year.

Development of a Machine Learning Algorithm to Predict Nonroutine Discharge Following Unicompartmental Knee Arthroplasty

BACKGROUND

Reliable and effective prediction of discharge destination following unicompartmental knee arthroplasty (UKA) can optimize patient outcomes and system expenditure. The purpose of this study is to develop a machine learning algorithm that can predict nonhome discharge in patients undergoing UKA.

METHODS

A retrospective review of a prospectively collected national surgical outcomes database was performed to identify adult patients who underwent UKA from 2015 to 2019. Nonroutine discharge was defined as discharge to a location other than home. Five machine learning algorithms were developed to predict this outcome. Performance of the algorithms was assessed through discrimination, calibration, and decision curve analysis.

RESULTS

Overall, of the 7275 patients included, 263 (3.6) patients were unable to return home upon discharge following UKA. The factors determined most important for identification of candidates for nonroutine discharge were total hospital length of stay, preoperative hematocrit, body mass index, preoperative sodium, American Society of Anesthesiologists classification, gender, and functional status. The extreme boosted model achieved the best performance based on discrimination (area under the curve = 0.875), calibration, and decision curve analysis. This model was integrated into a web-based open access application able to provide both predictions and explanations.

CONCLUSION

The present model can, following appropriate external validation, be used to augment clinician decision-making in patients undergoing elective UKA. Patients with high preoperative probabilities of nonroutine discharge based on nonmodifiable risk factors should be counseled to start the insurance authorization process with case management to avoid unnecessary inpatient stay, and those with modifiable risk can attempt prehabilitation to optimize these parameters before surgery.

Outcomes of Same-Day Orthopedic Surgery: Are Spine Patients More Likely to Have Optimal Immediate Recovery From Outpatient Procedures?

BACKGROUND

Spinal surgery is associated with an inherently elevated risk profile, and thus far there has been limited discussion about how these outpatient spine patients are benefiting from these same-day procedures against other typical outpatient orthopedic surgeries.

METHODS

Orthopedic patients who received either inpatient or outpatient surgery were isolated in the American College of Surgeons National Surgical Quality of Improvement Program (2005-2016). Patients were stratified by type of orthopedic surgery received (spine, knee, ankle, shoulder, or hip). Mean comparisons and chi-squared tests assessed basic demographics. Perioperative complications were analyzed via regression analyses in regard to their principal inpatient or outpatient orthopedic surgery received.

RESULTS

This study included 729 480 surgical patients: 32.5% received spinal surgery, 36.5% knee, 24.1% hip, 4.9% shoulder, and 1.7%ankle. Of those who received a spinal procedure, 74.7% were inpatients (IN), and 25.3% were outpatients (OUT): knee: 96.1% IN, 3.9% OUT; hip:98.9% IN, 1.1% OUT; ankle: 29% IN, 71% OUT; and shoulder: 52.6% IN, 47.6% OUT. Hip patients were the oldest, and knee patients had the highest body mass index out of the orthopedic groups (P < .00). Spine IN patients experienced more complications than the other orthopedic groups and had the lowest OUT complications(both P < .05). This same trend of having higher IN complications than OUT complications was identified for hip, shoulder, and knee. However, ankle procedures had greater OUT procedure complications than IN (P < .05). After controlling for age, body mass index, and Charlson Comorbidity Index, IN procedures, such as knee, hip, spine, and shoulder, were significantly associated with experiencing postoperative complications. From 2006 to 2016, IN and OUT surgeries were significantly different among complications experienced for all of the orthopedic groups (P < .05) with complications decreasing for IN and OUT patients by 2016.

CONCLUSIONS

Over the past decade, spine surgery has decreased in complications for IN and OUT procedures along with IN/OUT knee, ankle, hip, and shoulder procedures, reflecting greater tolerance for risk in an outpatient setting.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Despite the increase in riskier spine procedures, complications have decreased over the years. Surgeons should aim to continue to decrease inpatient spine complications to the level of other orthopedic surgeries.

The association between surgical duration and venous thromboembolism in outpatient surgery: A propensity score adjusted prospective cohort study

Background

Outpatient surgeries account for 60–70% of all procedures. Increased surgical duration has been demonstrated to be an independent risk factor for the development of venous thromboembolism (VTEs) after inpatient surgeries. In contrast, it is currently unknown if surgical duration increases the risk of VTEs for outpatient surgeries.

Materials and methods

The 2005 through 2016 NSQIP Participant Use Data Files were queried to extract all patients scheduled for outpatient surgery. A z-score for surgical duration was calculated for each procedure to allow for standardization across surgeries of expected shorter or longer duration. The primary outcome measured was incidence of VTEs within 30 days of surgery.

Results

A total of 3474 patients out of 1,863,523 (0.19%) had a VTE. After adjusting for confounding factors, the first and fifth quintiles compared to the middle quintile had odds ratios (ORs) of 0.75 (95% CI 0.68, 0.80) and 1.43 (95% CI, 1.35%–1.52%), respectively, P < 0.001. Patients who developed VTEs were more likely to be readmitted to the hospital, OR (95%CI) of 51.9 (48.0–56.2), C statistic = 0.67.

Conclusion

Surgical duration is associated with the development of VTEs after outpatient surgery. While the overall incidence of VTE is low and does not require generalized prophylaxis, clinical practitioners should consider prophylaxis for patients undergoing outpatient surgery performed with excessive time compared to the average surgical procedure duration.

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Surgical duration is related with VTE development 30 days within outpatient surgery.

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Long outpatient surgeries resulted in a 1.43-fold increase in developing a VTE.

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Short outpatient surgeries resulted in a 25% reduction in developing a VTE.

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ENT surgery had the lowest VTE incidence while vascular surgery had the highest.

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Patients who developed VTEs were 52 times more likely to be readmitted.