Outpatient Lower Extremity Total Joint Arthroplasty: Where Are We Heading?

A comparison of functional outcomes following inpatient versus outpatient hip or knee arthroplasty

Background

The length of hospital stay after lower limb arthroplasty has rapidly decreased in the last decade, largely in part due to the rise of improved perioperative protocols, but also as a response to the increased economic demand associated with the rapid growth in hip and knee arthroplasty procedures. In line with this, the development of a new pathway after lower limb arthroplasty that allows for the surgery to be performed in an outpatient setting and permits for same-day discharge after the procedure is increasingly being offered. Although costs and complications between the inpatient and outpatient models have been compared, there appears to be little known about the effects on a patient’s physical function after undergoing hip or knee outpatient arthroplasty. Therefore, this systematic review aims to explore the available evidence for the effect on functional outcomes following inpatient versus outpatient hip or knee arthroplasty.

Methods

This systematic review adhered to the PRISMA guidelines and was prospectively registered (https://osf.io/8bfae/). An electronic search of three online databases (PubMed, CINAHL and EMBASE) was conducted to identify eligible studies. All studies investigating inpatient and outpatient comparator groups, for a population of patients undergoing hip or knee arthroplasty, that assessed one or more functional outcomes, were included. A methodological quality appraisal was undertaken for the final studies contained in this review. A narrative synthesis of results is described along with quantitative outcomes presented in tables and figures.

Results

A total of seven studies containing 1,876 participants were included in this review. Four studies assessed a THA population, two assessed TKA and one assessed both. Functional outcomes varied, with 20 different functional outcomes utilised, of which 18 were patient-reported tools. Results of functional outcomes offered mixed support for both inpatient and outpatient pathways.

Conclusions

The results of this review suggest that outpatient or inpatient pathway selection for hip or knee arthroplasty should not be based on the superiority of functional outcomes alone. However, given there is growing evidence in support of an outpatient pathway in select patients with respect to cost savings and without any increase in complications, it could be proposed that an equivalency of post-operative function between the two settings makes same-day discharge favourable.

Publicly registered with Open Science Framework (https://osf.io/8bfae/).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03270-7.

Short-Stay Arthroplasty is Not Associated With Increased Risk of 90-Day Hospital Returns

BACKGROUND

With the removal of total hip arthroplasty (THA) and total knee arthroplasty (TKA) from the inpatient-only list, medical centers are faced with challenging transitions to outpatient surgery. We investigated if short-stay arthroplasty, defined as length of stay (LOS) <24 hours, would influence 90-day readmissions and emergency department (ED) visits at a tertiary referral center.

METHODS

The institutional database was retrospectively queried for primary TKAs and THAs from July 2015 to January 2018, resulting in 2,217 patients (1,361 TKA and 856 THA). Patient demographics, including age, gender, body mass index, and American Society of Anesthesiologists score were collected. LOS, disposition, cost of care, 90-day ED visits, and readmissions were identified through the institutional database using electronic medical record data. Univariable and multivariable models were used to evaluate rates of 90-day readmissions and ED visits based on LOS <24 hours vs ≥24 hours.

RESULTS

LOS <24 h was associated with significant decreases in 90-day ED visits (P = .003) and readmissions (P = .002). After controlling for potential confounding variables with a multivariable model, a significant decrease in ED visits (P = .034) remained in the THA cohort alone. Within TKA and THA cohorts, LOS <24 h was associated with lower costs (P < .001). Eighteen percent of patients with ≥24 h LOS were discharged to skilled nursing or rehabilitation facilities.

CONCLUSION

In this cohort, LOS <24 hours was associated with decreased 90-day readmissions, ED visits, and costs. With the goal of minimizing costs and maintaining patient safety while efficiently using resources, outpatient and short-stay arthroplasty are valuable, feasible options in tertiary academic centers.

Outpatient Simultaneous Bilateral Total Knee Arthroplasty: Is It Safe?

BACKGROUND

It is currently unknown if simultaneous bilateral total knee arthroplasty (si-BTKA) can also be safely performed in the outpatient setting. The primary aim of this study was to compare 30-day postoperative complication rates between outpatient and inpatient si-BTKA.

METHODS

Adults undergoing simultaneous bilateral total knee arthroplasty (si-BTKA) from 2015-2019 were queried using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Our primary analysis compared the rates of complications between outpatient si-BTKA and inpatient si-BTKA using bivariate comparisons and multivariable logistic regression of outpatient and inpatient cases controlling for differences in baseline demographics and comorbidities.

RESULTS

From 2015 to 2019, the utilization of outpatient si-BTKA increased from 0.6% to 10.5%. Outpatient si-BTKA were found to have significantly lower odds of any complication (OR = 0.49), minor complication (OR = 0.50), and postoperative transfusion (OR = 0.66) compared to inpatient cases. Outpatient si-BTKA also had a significantly shorter operative time.

CONCLUSION

Compared to inpatient si-BTKA, patients who undergo outpatient si-BTKA do not demonstrate increased rates of any complication, severe complications, and minor complications within 30-days postoperatively. Further insight is needed on the effect of outpatient si-BTKA on long-term outcomes.

Artificial neural network prediction of same-day discharge following primary total knee arthroplasty based on preoperative and intraoperative variables

AIMS

This study used an artificial neural network (ANN) model to determine the most important pre- and perioperative variables to predict same-day discharge in patients undergoing total knee arthroplasty (TKA).

METHODS

Data for this study were collected from the National Surgery Quality Improvement Program (NSQIP) database from the year 2018. Patients who received a primary, elective, unilateral TKA with a diagnosis of primary osteoarthritis were included. Demographic, preoperative, and intraoperative variables were analyzed. The ANN model was compared to a logistic regression model, which is a conventional machine-learning algorithm. Variables collected from 28,742 patients were analyzed based on their contribution to hospital length of stay.

RESULTS

The predictability of the ANN model, area under the curve (AUC) = 0.801, was similar to the logistic regression model (AUC = 0.796) and identified certain variables as important factors to predict same-day discharge. The ten most important factors favouring same-day discharge in the ANN model include preoperative sodium, preoperative international normalized ratio, BMI, age, anaesthesia type, operating time, dyspnoea status, functional status, race, anaemia status, and chronic obstructive pulmonary disease (COPD). Six of these variables were also found to be significant on logistic regression analysis.

CONCLUSION

Both ANN modelling and logistic regression analysis revealed clinically important factors in predicting patients who can undergo safely undergo same-day discharge from an outpatient TKA. The ANN model provides a beneficial approach to help determine which perioperative factors can predict same-day discharge as of 2018 perioperative recovery protocols. Cite this article: Bone Joint J 2021;103-B(8):1358-1366.

Can an outpatient risk assessment tool predict who needs postoperative haemoglobin monitoring?

AIMS

Recent improvements in surgical technique and perioperative blood management after total joint replacement (TJR) have decreased rates of transfusion. However, as many surgeons transition to outpatient TJR, obtaining routine postoperative blood tests becomes more challenging. Therefore, we sought to determine if a preoperative outpatient assessment tool that stratifies patients based on numerous medical comorbidities could predict who required postoperative haemoglobin (Hb) measurement.

METHODS

We performed a prospective study of consecutive unilateral primary total knee arthroplasties (TKAs) and total hip arthroplasties (THAs) performed at a single institution. Prospectively collected data included preoperative and postoperative Hb levels, need for blood transfusion, length of hospital stay, and Outpatient Arthroplasty Risk Assessment (OARA) score.

RESULTS

A total of 504 patients met inclusion criteria. Mean age at time of arthroplasty was 65.3 years (SD 10.2). Of the patients, 216 (42.9%) were THAs and 288 (57.1%) were TKAs. Six patients required a blood transfusion postoperatively (1.19%). Transfusion after surgery was associated with lower postoperative day 1 Hb (median of 8.5 (interquartile range (IQR) 7.9 to 8.6) vs 11.3 (IQR 10.4 to 12.2); p < 0.001), longer length of stay (1 day (IQR 1 to 1) vs 2 days (IQR 2 to 3); p < 0.001), higher OARA score (median of 60.0 (IQR 40 to 75) vs 5.0 (IQR 0-35); p = 0.001), and total hip arthroplasty (p < 0.001). All patients who received a transfusion had an OARA score > 34; however, this did not reach statistical significance as a screening threshold.

CONCLUSION

Risk of blood transfusion after primary TJR was uncommon in our series, with an incidence of 1.19%. Transfusion was associated with OARA scores > 60. The OARA score, not American Society of Anesthesiologists grade, reliably identified patients at risk for postoperative blood transfusion. Selective Hb monitoring may result in substantial cost savings in the era of cost containment. Cite this article: Bone Joint J 2021;103-B(1):65-70.

The Most Significant Risk Factors for Urinary Retention in Fast-track Total Joint Arthroplasty are Iatrogenic

BACKGROUND

Postoperative urinary retention (POUR) remains a common complication after total joint arthroplasty (TJA). The objective of this study was to determine the incidence and risk factors for POUR in fast-track TJA emphasizing rapid mobilization, multimodal analgesia, and shorter hospital stay.

METHODS

Our institutional joint registry was queried for patients who underwent primary TJA between January 2016 and November 2017. The primary outcome was the development of POUR. A panel of demographic, intraoperative, and postoperative variables was investigated. Multivariable regression analyses were performed to control for possible confounding factors.

RESULTS

One hundred eighty-seven patients who underwent total hip arthroplasty (THA) and 191 patients who underwent total knee arthroplasty (TKA) were included in the study. Forty percent of TKA and 36% of THA patients developed POUR requiring bladder catheterization. Among THA patients, POUR was significantly associated with age >60 years, intraoperative fluid volume >1350 mL, and intraoperative placement of an indwelling bladder catheter (P = .016, P = .035, and P < .001, respectively). Among TKA patients, POUR was only significantly associated with intraoperative indwelling bladder catheter placement (P < .001).

CONCLUSION

The most significant risk factors for POUR in modern-day fast-track TJA are iatrogenic. Routine intraoperative placement of an indwelling bladder catheter and fluid administration exceeding 1350 mL, especially in patients older than 60 years, are discouraged.