Predictive factors of length of hospital stay after primary total knee arthroplasty

Can machine learning models predict prolonged length of hospital stay following primary total knee arthroplasty based on a national patient cohort data?

INTRODUCTION

The total length of stay (LOS) is one of the biggest determinators of overall care costs associated with total knee arthroplasty (TKA). An accurate prediction of LOS could aid in optimizing discharge strategy for patients in need and diminishing healthcare expenditure. The aim of this study was to predict LOS following TKA using machine learning models developed on a national-scale patient cohort.

METHODS

The ACS-NSQIP database was queried to acquire 267,966 TKA cases from 2013 to 2020. Four machine learning models-artificial neural network (ANN), random forest, histogram-based gradient boosting, and k-nearest neighbor were trained and tested on the dataset for the prediction of prolonged LOS (LOS exceeded the 75th of all values in the cohort). The model performance was assessed by discrimination (area under the receiver operating characteristic curve [AUC]), calibration, and clinical utility.

RESULTS

ANN delivered the best performance among the four models. ANN distinguished prolonged LOS in the study cohort with an AUC of 0.71 and accurately predicted the probability of prolonged LOS for individual patients (calibration slope: 0.82; calibration intercept: 0.03; Brier score: 0.089). All models demonstrated clinical utility by generating positive net benefits in decision curve analyses. Operation time, pre-operative transfusion, pre-operative laboratory tests (hematocrit, platelet count, and white blood cell count), and BMI were the strongest predictors of prolonged LOS.

CONCLUSION

ANN demonstrated modest discrimination capacity and excellent performance in calibration and clinical utility for the prediction of prolonged LOS following TKA. Clinical application of the machine learning models has the potential to improve care coordination and discharge planning for patients at high risk of extended hospitalization after surgery. Incorporating more relevant patient factors may further increase the models' prediction strength.

The Surgical Timing and Prognoses of Elderly Patients with Hip Fractures: A Retrospective Analysis

Background

Guidelines exist for the surgical treatment of hip fractures, but the association between the surgical timing and the incidence of postoperative complications and other important outcomes in elderly patients with hip fracture remains controversial.

Objective

This study aims to explore the association between the surgical timing and the prognoses in elderly patients with hip fracture.

Methods

A total of 701 elderly patients (age ≥ 65 years) with hip fractures who were treated in our hospital from June 2020 to June 2021 were selected. Patients who underwent surgery within 2 d of admission were assigned to the early surgery group, and those who underwent surgery after 2 d of admission were assigned to the delayed surgery group. The prognosis indices of the patients in the two groups were recorded and compared.

Results

The length of postoperative hospitalisation in the early surgery group was significantly lower than that in the delayed surgery group (P < 0.001). The European quality of life questionnaire (EQ-5D) utility in the delayed surgery group was significantly lower than that in the early surgery group at 30 days and 6 months after operation (P<0.05). Compared with the delayed surgery group, the incidence of pulmonary infection, urinary tract infection (UTI) and deep vein thrombosis (DVT) in the early surgery group were significantly lower. There were no significant differences between the two groups in terms of mortality and excellent rates of the HHS at six months after the operation. In addition, the early surgery group had a lower readmission rate than the delayed surgery group [34 (9.5%) vs 56 (16.3%), P = 0.008].

Conclusion

Earlier surgery can reduce the incidence of pulmonary infections, UTI, DVT and readmission rate among elderly patients with hip fractures, shorten postoperative hospitalisation.

Validation of the Nottingham Hip Fracture Score in Predicting Postoperative Outcomes Following Hip Fracture Surgery

OBJECTIVE

Although several prognostic models have been developed for patients who underwent hip fracture surgery, their preoperative performance was insufficiently validated. We aimed to verify the effectiveness of the Nottingham Hip Fracture Score (NHFS) for predicting postoperative outcomes following hip fracture surgery.

METHODS

This was a single-center and retrospective analysis. A total of 702 elderly patients with hip fractures (age ≥ 65 years old) who received treatment in our hospital from June 2020 to August 2021 were selected as the research participants. They were divided into the survival group and the death group based on their survival 30 days after surgery. The multivariate logistic regression model was used to identify the independent risk factors for the 30-day mortality after surgery. The NHFS and American Society of Anaesthesiologists (ASA) grades were used to construct these models, and a receiver operating characteristic curve was plotted to assess their diagnostic significance. A correlation analysis was performed between NHFS and length of hospitalization and mobility 3 months after surgery.

RESULTS

There were significant differences in the age, albumin level, NHFS, and ASA grade between both groups (p < 0.05). The length of hospitalization in the death group was longer than the survival group (p < 0.05). The perioperative blood transfusion and postoperative ICU transfer rates in the death group were higher than in the survival group (p < 0.05). The death group's incidence of pulmonary infections, urinary tract infections, cardiovascular events, pressure ulcers, stress ulcers with bleeding, and intestinal obstruction was higher than the survival group (p < 0.05). The NHFS and ASA III were independent risk factors for the 30-day mortality after surgery, regardless of age and albumin level (p < 0.05). The area under the curve (AUC) of the NHFS and ASA grade for predicting the 30-day mortality after surgery was 0.791 (95% confidence interval [CI] 0.709-0.873, p < 0.05) and 0.621 (95% CI 0.477-0.764, p > 0.05), respectively. The NHFS positively correlated with hospitalization length and mobility grade 3 months after surgery (p < 0.05).

CONCLUSION

The NHFS demonstrated a better predictive performance than the ASA score for the 30-day mortality after surgery and positively correlated with the hospitalization length and postoperative activity limitation in elderly patients with hip fractures.

Associations of discharge destination and length of stay in lower extremity free flap reconstruction

Patients with lower extremity defects requiring free flap reconstruction often have difficult postoperative courses with prolonged length of stay and need for transfer to a post-acute care facility. The primary aim of this study was to determine associations of preoperative and perioperative variables with length of stay and discharge destination in patients undergoing lower extremity free flap reconstruction. The secondary aim was to determine associations of various complications with their discharge destination. The 2011- 2017 NSQIP database was queried for CPT codes for free flap procedures and ICD-9/ICD-10 codes for lower extremities. Univariate and multivariate analyses were used to determine associations of preoperative and perioperative variables with length of stay and discharge destination in patients undergoing lower extremity free flap reconstruction and associations of complications with their discharge destination. A total of 420 patients were identified who underwent lower extremity reconstruction in 2011-2017. Of 79.8% were discharged home and 21.2% were discharged to destinations other than home. On multivariate analysis, female gender, age > 55, ASA class > 2 and dependent functional status were found to have independent associations with discharge to post-acute care facilities. ASA classification greater than 2, active smoking, and discharge to a post-acute care facility all were independently associated with prolonged length of stay. Increased length of stay and discharge to post-acute care facility are closely associated. Understanding variables that influence length of stay and need for discharge to post-acute care facilities can help identify patients that may be triaged through appropriate interventions and expectation management.

Key Components, Current Practice and Clinical Outcomes of ERAS Programs in Patients Undergoing Orthopedic Surgery: A Systematic Review

Enhanced recovery after surgery (ERAS) protocols have led to improvements in outcomes in several surgical fields, through multimodal optimization of patient pathways, reductions in complications, improved patient experiences and reductions in the length of stay. However, their use has not been uniformly recognized in all orthopedic fields, and there is still no consensus on the best implementation process. Here, we evaluated pre-, peri-, and post-operative key elements and clinical evidence of ERAS protocols, measurements, and associated outcomes in patients undergoing different orthopedic surgical procedures. A systematic literature search on PubMed, Scopus, and Web of Science Core Collection databases was conducted to identify clinical studies, from 2012 to 2022. Out of the 1154 studies retrieved, 174 (25 on spine surgery, 4 on thorax surgery, 2 on elbow surgery and 143 on hip and/or knee surgery) were considered eligible for this review. Results showed that ERAS protocols improve the recovery from orthopedic surgery, decreasing the length of hospital stays (LOS) and the readmission rates. Comparative studies between ERAS and non-ERAS protocols also showed improvement in patient pain scores, satisfaction, and range of motion. Although ERAS protocols in orthopedic surgery are safe and effective, future studies focusing on specific ERAS elements, in particular for elbow, thorax and spine, are mandatory to optimize the protocols.

Length of Hospital Stay after Total Knee Arthroplasty: A Correlation Study on 1200 Patients

In countries with a high average population age, total knee arthroplasty is still carried out in an inpatient setting. The roadmap to performing major surgery on an outpatient basis passes through the understanding of those perioperative features that correlate with higher lengths of hospital stay (LOS). A retrospective database of 1200 patients was reviewed for retrieving preoperative and perioperative factors including anthropometric and demographic data, comorbidities, preoperative laboratory assessment, and surgical time. Considering the LOS as a discrete series, data were analyzed by means of logistic regression with multiple univariate and multivariate models. The results showed a median length of hospital stay of 3 (IQR 3, 4) days. According to multiple univariate analysis, arterial hypertension (p = 0.008), diabetes mellitus (p = 0.028), CCI score (p < 0.001), ASA score (p = 0.006), surgical time (p < 0.001) and intraoperative blood loss (p < 0.001) were significantly associated with the duration of hospital stay in days. Moreover, preoperative hemoglobin value was inversely correlated to the LOS (p = 0.008). Multivariate analysis showed a significant correlation between LOS and surgical time and intraoperative blood loss. Many factors influence the permanence of the inpatient and acting on those variables, by stabilizing comorbidities and optimizing laboratory values, may reduce the overall healthcare burden.

Construction and Comparison of Predictive Models for Length of Stay after Total Knee Arthroplasty: Regression Model and Machine Learning Analysis Based on 1,826 Cases in a Single Singapore Center

The purpose of this study was to develop a predictive model for length of stay (LOS) after total knee arthroplasty (TKA). Between 2013 and 2014, 1,826 patients who underwent TKA from a single Singapore center were enrolled in the study after qualification. Demographics of patients with normal and prolonged LOS were analyzed. The risk variables that could affect LOS were identified by univariate analysis. Predictive models for LOS after TKA by logistic regression or machine learning were constructed and compared. The univariate analysis showed that age, American Society of Anesthesiologist level, diabetes, ischemic heart disease, congestive heart failure, general anesthesia, and operation duration were risk factors that could affect LOS (p < 0.05). Comparing with logistic regression models, the machine learning model with all variables was the best model to predict LOS after TKA, of whose area of operator characteristic curve was 0.738. Machine learning algorithms improved the predictive performance of LOS prediction models for TKA patients.

High range of motion in the first ten postoperative days after TKA does not predict superior outcome in the long run

INTRODUCTION

To retrospectively investigate the early postoperative range of motion (ROM) (days 4, 7, 10) after total knee arthroplasty (TKA) and to test for associations (a) with long-term outcome in terms of ROM and (b) with a disease-specific knee score.

MATERIALS AND METHODS

A retrospective analysis was performed in patients with previous primary TKA. Data taken from the medical records were ROM from preoperative and postoperative days 4, 7 and 10 and 1 year. As patient-reported outcome the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC Score) was taken from preoperative and one year after TKA.

RESULTS

316 patients (330 knees) were available. Only negligible correlations were determined between ROM at twelve months postoperative and ROM in the early postoperative days (days 4, 7, 10). Similarly, only negligible correlations were determined between ROM in the early postoperative days (days 4, 7, 10) and the 1-year WOMAC.

CONCLUSION

From the main findings it would seem that steepness of ROM ascent in the early postoperative days is of minor importance for (a) long-term ROM and (b) long-term knee score outcome after TKA.

Factors Affecting Hospital Length of Stay following Total Knee Replacement: A Retrospective Analysis in a Regional Hospital

In an effort to reduce hospital length of stay (LoS) following total knee arthroplasty (TKA), patient management strategies have evolved over time. The aims of this study were threefold: first, to quantify the reduction in LoS for TKA in a regional hospital; second, to identify the patient, surgical and management factors associated with hospital LoS; and lastly, to assess the change in complications incidence and hospital readmission as a function of LoS. A retrospective chart review was conducted on a consecutive series of primary and revision TKAs from January 2012 to March 2018. Factors describing patient demographics, as well as preoperative, intraoperative, surgical, and postoperative management, were extracted from paper and electronic medical records by a team of reviewers. Multivariate linear regression was performed to assess the association between these factors and LoS. In total, 362 procedures were included, which were reduced to 329 admissions once simultaneous bilateral procedures were taken into account. Median LoS reduced significantly (p = 0.001) from 6 to 2 days over the period of review. A stepwise regression analysis identified patient characteristics (age, gender, comorbidities, discharge barriers), perioperative management (anesthesia type), surgical characteristics (approach, alignment method), and postoperative management (mobilization timing, postoperative narcotic use, complication prior to discharge) as factors explaining 58.3% of the variance in LoS. Representation to emergency (6%) and hospital readmission (3%) remained low for the reviewed period. Efforts to reduce hospital LoS following TKA within a regional hospital setting can be achieved over time without significant increases in the rate or severity of complications or representation to acute care and subsequent readmission. The findings establish the role of patient, surgical and management factors in the context of agreed discharge criteria between care providers.

Outpatient total knee arthroplasty leads to a higher number of complications: a meta-analysis

Background

Careful pre- and post-operative management can allow surgeons to perform outpatient TKA, making this a more affordable procedure. The aim of the present meta-analysis is to compare outpatient and inpatient TKA.

Methods

A systematic search of the literature was performed in July 2020 on PubMed, Web of Science, Cochrane library, and on the grey literature databases. The papers collected were used for a meta-analysis comparing outpatient and inpatient TKA in terms of complication and readmission rates. Risk of bias and quality of evidence were defined according to Cochrane guidelines.

Results

The literature search resulted in 4107 articles; of these, 8 articles were used for the meta-analysis. A total of 212,632 patients were included, 6607 of whom were TKA outpatients. The overall complication rate for outpatient TKAs was 16.1%, while inpatient TKAs had an overall lower complication rate of 10.5% (p = 0.003). The readmission rate was 4.9% in outpatient TKAs and 5.9% in inpatient TKAs. Only 3 studies reported the number of deaths, which accounted for 0%. The included studies presented a moderate risk of bias, and according to GRADE guidelines, the level of evidence for complications and readmissions was very low.

Conclusions

This meta-analysis documented that outpatient TKA led to an increased number of complications although there were no differences in the number of readmissions. However, future high-level studies are needed to confirm results and indications for the outpatient approach, since the studies currently available have a moderate risk of bias and a very low quality of evidence.

HIGHER RISK OF COMPLICATIONS AFTER TOTAL KNEE ARTHROPLASTY IN OCTOGENARIANS

OBJECTIVE

To evaluate the complication rate of total knee arthroplasty (TKA) in octogenarian patients and identify predictive factors.

METHODS

The study comprised 70 octogenarians and 70 non-octogenarian patients as control group, all submitted to TKA. We analyzed the medical records of these patients, seeking for complications during the first postoperative year. Regarding the risk factors, we evaluated: age, sex, race, American Society of Anesthesiologists score, body mass index, smoking, hypertension and diabetes mellitus.

RESULTS

In the control group, the incidence of complications was 7.1%. Whereas in the octogenarian group it was significantly higher, reaching 34.3% (OR 6.8; 95% CI 2.4-19.1). We found no association to sex, skin color, and comorbidities. Age is an independent risk factor for postoperative complications. Our data may help patients to acknowledge the risks of undergoing primary TKA and physicians to assess and adjust perioperative risk.

CONCLUSION

The incidence of postoperative complications is significantly higher in octogenarians. Level of Evidence III, Case-control study.

Impact of surgical instrumentation on hospital length of stay and cost of total knee arthroplasty

BACKGROUND

We aimed to analyze the impact of two different types of surgical instrumentation (conventional manual instrumentation (CI) and patient-specific instrumentation (PSI)) on length of stay (LOS) and objectify differences in cost. We hypothesized that there are no differences in the LOS and cost due to the instrumentation system used.

RESEARCH DESIGN AND METHODS

LOS was registered using inpatient admission data provided by the Institutional Management Control Department. We recorded the costs associated with each procedure that could be influenced by the use of one system or another during the in-hospital stay. We conducted a prospectively single-center cohort study of 305 TKAs. Surgery was performed with conventional CI in 122 cases and with PSI in 183 cases.

RESULTS

The mean LOS for the CI group was 4.29 days (SD 1.65) and 4.22 days (SD 1.26), for the PSI group. No significant difference among both instrumentation systems was obtained. When comparing global costs, the mean cost was slightly higher (without a significant difference) for the PSI cases (€3110.24 vs. €2852.7 for the CI cases).

CONCLUSIONS

LOS and overall cost, in hospitals with a low annual TKA surgery volume, are unrelated to conventional or patient-specific instrumentation.

Experience-optimised fast track improves outcomes and decreases complications in total knee arthroplasty

PURPOSE

The aim of this study was to describe an advanced total knee arthroplasty (TKA) fast-track programme and determine discharge parameters during hospitalisation, as well as patient satisfaction, outcomes and complications within the first 12 months after surgery.

METHODS

This prospective study was based on patients selected consecutively for primary elective TKA, undergoing surgery between 2014 and 2017 in an established fast-track setting. Hospitalisation-related parameters were collected: demographics, body mass index (BMI), surgical time, ischaemia time, haemoglobin values, blood transfusions, length of stay, weight-bearing and stair-climbing time, opioid administration, preoperative and discharge loss of extension and maximum active flexion of the knee, visual analogue scale (VAS), 12-month follow-up satisfaction rate and range of motion, any complications, hospital re-admission and re-operation within the first 12 months. Differences were determined using t-tests.

RESULTS

A total of 704 total knee replacements implanted in 481 patients were included in the study and 223 patients had a bilateral TKA. Their mean age was 69.8 years (range 57-88 years). At the 12-month follow-up, 623 patients (88.5%) reported being satisfied or very satisfied and 15 (2.1%) were dissatisfied with their TKA, mean active flexion and loss of extension were 104.4° and 2.3°, respectively. A total of 15 complications occurred (two percent): five painful knees, three knee stiffness, three haematomas, two infections, one hospital re-admission and one deep venous thrombosis. No cases of pulmonary embolism and death related to surgery were reported.

CONCLUSION

The study reports on an advanced fast-track programme for TKA with a low incidence of surgery- and hospitalisation-related issues and complications and without any severe adverse events during the first year. On average, the fast-track programme had a short length of stay, an early recovery of weight-bearing, knee mobility, pain control and a high satisfaction rate, accompanied with an acceptable 12 month range of motion.

Perioperative predictors of prolonged length of hospital stay following total knee arthroplasty: a retrospective study from a single center in China

Background

Decreasing the length of hospital stay is an ideal course of action to appropriately allocate medical resources. The aim of this retrospective study was to identify perioperative factors that may decrease the length of hospital stay (LOS).

Methods

In this study, we collected the data on 1112 patients who underwent primary total knee arthroplasty surgery (TKAs) at our institution from Jan 1, 2011 to Nov 31, 2017. Based on the published literature, 16 potential factors (12 preoperative variables, 1 intraoperative variable, and 3 postoperative variables) were investigated. The patients requiring a hospital stay longer than the mean LOS (8 days) were defined as patients with a prolonged LOS. The factors with a P value less than 0.1 in the univariate analysis were further analysed in a multivariate model. An ordinal regression was used to determine independent risk factors for a prolonged LOS.

Results

The mean LOS was 8.3 days (±4.3), with a range of 2 to 30 days. Sixteen variables were analysed by univariate analysis, and 11 of them had p < 0.1 and were included in the multivariable model. Finally, 9 factors were found to be associated with a prolonged LOS. Among the 9 variables, 2 were surgery-related factors (operative time and intraoperative blood loss), and 3 were patient-related factors (age, ASA classification and neurological comorbidities).

Conclusion

In this study, we found that the clinical protocol, complications, the patient’s age, the ASA classification, neurological comorbidities, the operative time, the ward, intraoperative blood loss and the surgeon were all factors contributing to a prolonged LOS. In clinical practice, these factors provide important information for the surgeon and are useful for identifying patients with a high risk of a prolonged LOS.

Influence of the Maryland All-Payer Model on Primary Total Knee Arthroplasties

In 2014, Maryland received a waiver for the Global Budget Revenue (GBR) program. We evaluated GBR's impact on patient and hospital trends for total knee arthroplasty (TKA) in Maryland compared with the U.S. Specifically, we examined (1) patient characteristics, (2) inpatient course, and (3) costs and charges associated with TKAs from 2014 through 2016.

METHODS

A comparative analysis of TKA-treated patients in the Maryland State Inpatient Database (n = 36,985) versus those in the National Inpatient Sample (n = 2,117,191) was performed. Patient characteristics included race, Charlson Comorbidity Index (CCI), morbid obesity, patient income status, and primary payer. Inpatient course included length of hospital stay (LOS), discharge disposition, and complications.

RESULTS

In the Maryland TKA cohort, the proportion of minorities increased from 2014 to 2016 while the proportion of whites decreased (p = 0.001). The proportion of patients with a CCI of ≥3 decreased (p = 0.014), that of low-income patients increased (p < 0.001), and that of patients covered by Medicare or Medicaid increased (p < 0.001). In the U.S. TKA cohort, the proportion of blacks increased (p < 0.001), that of patients with a CCI score of ≥3 decreased (p < 0.001), and the proportions of low-income patients (p < 0.001) and those covered by Medicare or Medicaid increased (p < 0.001). In both Maryland and the U.S., the LOS (p < 0.001) and complication rate (p < 0.001) decreased while home-routine discharges increased (p < 0.001). Costs and charges decreased in Maryland (p < 0.001 for both) whereas charges in the U.S. increased (p < 0.001) and costs decreased (p < 0.001).

CONCLUSIONS

While the U.S. health reform and GBR achieved similar patient and hospital-specific outcomes and broader inclusion of minority patients, Maryland experienced decreased hospital charges while hospital charges increased in the U.S.

LEVEL OF EVIDENCE

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

Preoperative Patient Factors Affecting Length of Stay following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Total knee arthroplasty (TKA) yields substantial improvements in quality of life for patients with severe osteoarthritis. Previous research has shown that TKA outcomes are inferior in patients with certain demographic and clinical factors. Length of stay (LOS) following TKA is a major component of costs incurred by healthcare providers. It is hypothesized that patient-related factors may influence LOS following TKA. The purpose of this systematic review and meta-analysis is to investigate these factors.

METHODS

Three databases (PubMed, Embase, and OVID Medline) were searched using variants of the terms "total knee arthroplasty" and "length of stay". Studies were screened and data abstracted in duplicate. The primary outcome was the effect of prognostic variables on LOS following TKA. Meta-analysis was performed using the Review Manager (RevMan) software (version 5.3. Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014).

RESULTS

A total of 68 studies met all inclusion criteria for this review. These studies comprised 21,494,459 patients undergoing TKA with mean age 66.82 years (range, 15-95 years) and 63.8% (12,165,160 of 19,060,572 reported) females. The mean MINORS score was 7, suggesting that studies had a low quality of evidence. Mean LOS following TKA has steadily decreased over the past 4 decades, partially because of the implementation of fast-track programs. Demographic factors associated with increased LOS were age >70 years (mean difference [MD] = 0.81; 95% confidence interval [CI] = 0.38-1.24), female gender (MD = 0.32; 95% CI = 0.29-0.48), body mass index >30 (MD = 0.09; 95% CI = 0.01-0.16), and non-White race (MD = 0.20; 95% CI = 0.10-0.29). Clinical factors associated with increased LOS were American Society of Anesthesiologists score 3-4 vs 1-2 (MD = 1.12; 95% CI = 0.58 to 1.66), Charlson Comorbidity Index > 0 vs 0 (MD = 0.77; 95% CI = 0.32 to 1.22), and preoperative hemoglobin < 130 g/L (MD = 0.66; 95% CI = 0.34 to 0.98).

CONCLUSION

This systematic review and meta-analysis showed that increased age, female gender, body mass index ≥ 30, non-White race, American Society of Anesthesiologists > 2, Charlson Comorbidity Index > 0, and preoperative hemoglobin < 130 g/L were predictors of increased LOS. Mean LOS has steadily decreased over the past decades with the implementation of perioperative "fast-track" programs. Future research should investigate the benefits of preoperative risk factor modification on LOS, in addition to novel surgical approaches, anesthetic adjuvants, and physiotherapy modifications.

LEVEL OF EVIDENCE

IV, systematic review, and meta-analysis of level III and IV evidence.

Are the Cumulated Ambulation Score and Risk Assessment and Prediction Tool useful for predicting discharge destination and length of stay following total knee arthroplasty?

BACKGROUND

Postoperative management of patients undergoing total knee arthroplasty (TKA) is continually changing. Costs related to TKA are driven by implant cost, operating room cost, hospital length of stay (LOS), and rehabilitation approach. Discharges to rehabilitation centers have declined significantly in recent years.

AIM

We evaluated the usefulness of the Cumulated Ambulation Score (CAS) and Risk Assessment and Prediction Tool (RAPT) to predict discharge destination and estimate hospital LOS of patients undergoing TKA.

DESIGN

Prospective cohort study.

SETTING

University hospital inpatients.

POPULATION

Patients undergoing elective primary TKA.

METHODS

Consecutive patients were prospectively evaluated. Outcome measures were discharge destination and LOS dichotomized at the median (LOS<8 versus LOS≥8). Patients completed five outcome questionnaires and knee range of motion was measured preoperatively. RAPT was considered continuous, and also dichotomized (RAPT≤9 versus RAPT>9; RAPT9). CAS was dichotomized (CAS<11 versus CAS≥11; CAS11). Surgical technique and aftercare were similar for all patients.

RESULTS

Sixty-four patients (37 females), mean age 69.3±10.2 years were evaluated. CAS11 and discharge destination were strongly associated: 75.9% of patients with CAS≥11 were discharged home; 85.7% of patients with CAS<11 were discharged to a rehabilitation center (P<0.001). 80.7% of patients with RAPT≤9 were discharged to a rehabilitation center, versus 36.4% of patients with RAPT>9 (P=0.002). Odds ratios for discharge home were 18.9 (CAS11) and 7.3 (RAPT). CAS11 and RAPT were not related to LOS.

CONCLUSIONS

The CAS and RAPT can assist clinicians in estimating the discharge destination and developing patient care plans following TKA. However, predicting LOS with such tools alone was inaccurate.

CLINICAL REHABILITATION IMPACT

Use of the CAS and RAPT can inform discharge destination and patient care plans following TKA and has the potential to optimise resources and costs. However, due to social and organizational constraints on discharge, predicting LOS with such tools alone revealed to be inaccurate.

Continuous adductor canal blockade facilitates increased home discharge and decreased opioid consumption after total knee arthroplasty

BACKGROUND

There is a growing interest in avoiding discharging patients to rehab to maximize outcome and minimize complications after total knee arthroplasty (TKA). In addition, use of postoperative pain pathways that minimize opioid use is critical amidst the current opioid epidemic. However, the ideal pain regimen after TKA has yet to be determined.

METHODS

From July 1, 2013 to October 1, 2014 two perioperative pathways were used to address surgical pain. These included either a single shot femoral nerve block plus liposomal bupivacaine pericapsular injection (FNB + LB-PAI) or adductor canal catheter plus posterior capsule single shot block (ACC + iPACK), each with an oral analgesic protocol. Little modification occurred with regard to surgical technique, postoperative medications, or postoperative physical therapy (PT).

RESULTS

Overall, 264 unilateral, primary TKA patients (146 FNB + LB-PAI, 118 ACC + iPACK) were included. ACC + iPACK patients had a shorter median length of stay (LOS, 2.0 vs 3.0, p < 0.001), more discharges home (79.7% vs 67.8%, p = 0.002), and less median opioid consumption (IV morphine equivalents, IVME, 20.0 vs 44.1, p < 0.001) than the FNB + LB-PAI group. In multivariable analysis, use of ACC + iPACK remained independently associated with shorter LOS, increased discharge home, and less IVME consumed when controlling for confounding variables. ACC + iPACK patients also had fewer opioid related adverse events (0.8 vs 5.5, p = 0.045) and a lower rate of MUA (0.8% vs 6.2%, p = 0.026).

CONCLUSIONS

We recommend ACC + iPACK with a multimodal oral analgesic protocol as the primary postoperative analgesia in enhanced recovery TKA protocols. This resulted in an easier recovery with fewer complications.

LEVEL OF EVIDENCE

Level III.

Closed suction drainage following routine primary total joint arthroplasty is associated with a higher transfusion rate and longer postoperative length of stay: a retrospective cohort study

BACKGROUND

In an enhanced recovery after surgery program, not placing a closed suction drain following routine primary total joint arthroplasty (TJA) is becoming more acceptable. However, the influence of drain use on transfusion rate and postoperative length of stay (PLOS) in TJA remains controversial. Therefore, we aimed to compare drain use with no drain in routine primary TJA to determine the differences in transfusion rate and PLOS.

METHODS

We analyzed the data from 12,992 patients undergoing primary unilateral TJA: 6325 total knee arthroplasties (TKA) and 6667 total hip arthroplasties (THA). Patients were divided into two groups according to whether they received a drain postoperatively following TKA and THA. We extracted information for transfusion and PLOS from patients' electronic health records and analyzed the data by logistic and linear regression analyses.

RESULTS

The transfusion rate and PLOS were 15.07% and 7.75 ± 3.61 days, respectively, in the drain group and 6.72% and 6.54 ± 3.32 days, respectively, in the no-drain group following TKA. The transfusion rate and PLOS were 20.53% and 7.00 ± 3.35 days, respectively, in the drain group and 13.57% and 6.07 ± 3.06 days, respectively, in the no-drain group following THA. After adjusting for the following variables: age, gender, body mass index, orthopedic diagnoses, hypertension, type 2 diabetes, coronary heart disease, chronic obstructive pulmonary disease, preoperative hemoglobin, albumin, analgesic use, anesthesia, American Society of Anesthesiologists class, tranexamic acid use, intraoperative bleeding, operative time, and tourniquet use (for TKA), drain use correlated significantly with a higher transfusion rate (risk ratio = 2.812, 95% confidence interval (CI) 2.224-3.554, P < 0.001 for TKA and risk ratio = 1.872, 95% CI 1.588-2.207, P < 0.001 for THA) and a longer PLOS (partial regression coefficient (B) = 1.099, 95% CI 0.879-1.318, P < 0.001, standard regression coefficient (B') = 0.139 for TKA; B = 0.973, 95% CI 0.695-1.051, P < 0.001, and B' = 0.115 for THA). Two groups showed no significant difference in wound complications.

CONCLUSIONS

Our findings indicated that drain use was associated with a higher transfusion rate and a longer PLOS in patients undergoing routine primary TJA. The routine use of postoperative drainage is not recommended in primary unilateral TJA.

Rapid Discharge in Total Hip Arthroplasty: Utility of the Outpatient Arthroplasty Risk Assessment Tool in Predicting Same-Day and Next-Day Discharge

BACKGROUND

Hospital length of stay is a major driver of cost in the total hip arthroplasty (THA) episode of care, and as a result, significant efforts are being made to minimize it. This study aims to assess the utility of the Outpatient Arthroplasty Risk Assessment (OARA) screening tool in accurately identifying patients for safe and early discharge after THA.

METHODS

A retrospective review was conducted on 332 consecutive patients who underwent primary THA at a single tertiary academic center. Patients were evaluated using the OARA score, a tool that has been proposed to identify patients who can safely undergo early discharge after THA. The validity of these claims was assessed by analyzing the OARA score's positive and negative predictive values for high vs low OARA scores between patients enrolled in our (1) same-day discharge (SDD) and 2) next-day discharge (NDD) pathways.

RESULTS

When comparing the utility of the OARA score in accurately predicting length of stay, the OARA score demonstrated a (1) higher, but constant, positive predictive value for discharge on postoperative day (POD) 0 for SDD (86.1%) than POD1 for NDD (35.5%) and (2) lower negative predictive value for discharge on POD0 (23.1%) for SDD than POD1 for NDD (86.1%).

CONCLUSION

The OARA score was developed to risk-stratify patients who can safely undergo SDD or NDD after THA. In this study, the OARA score was a highly predictive tool in identifying NDD patients at risk for failure of discharge by POD1.

Factors influencing postoperative length of stay in an enhanced recovery after surgery program for primary total knee arthroplasty

Background

Hospital length of stay (LOS) after primary total knee arthroplasty (TKA) has decreased obviously following the implementation of enhanced recovery after surgery (ERAS) program in the last few years. However, there are still some patients that cannot be discharged at early time for a variety of reasons, and it is necessary to explore factors leading to prolonged LOS. Therefore, the purpose of this study was to identify the complete preoperative, perioperative, and postoperative factors associated with prolonged postoperative LOS (PLOS) after primary TKA in a detailed ERAS program.

Methods

In a consecutive series from July 2015 to March 2017, all patients who underwent unilateral elective primary TKA were included in the retrospective study. A PLOS greater than 3 days was considered a prolonged PLOS. Multivariable logistic regression analysis was performed to identify patient characteristics and relevant preoperative, perioperative, and postoperative variables that were associated with prolonged PLOS and postoperative complications.

Results

A total of 241 patients were included with a mean PLOS of 3.8 days. Prolonged PLOS was significantly associated with preoperative valgus deformity of the knee (OR 4.95, 95%CI 1.56–15.77, P = 0.007), increased serum level of interleukin-6 on postoperative day 1 (OR 1.01, 95%CI 1.00–1.03, P = 0.039), increased visual analogue scale pain score and serum level of C-reactive protein on postoperative day 3 (OR 2.56, 95%CI 1.28–5.13, P = 0.008; OR 1.01, 95%CI 1.00–1.03, P = 0.019), increased day to achieve 90° active knee flexion after surgery (OR 2.19, 95%CI 1.27–3.79, P = 0.005), and postoperative wound complications (OR 8.58, 95%CI 2.10–35.03, P = 0.003) and other minor complications (OR 6.04, 95%CI 2.40–15.19, P < 0.001). Preoperative pulmonary infection (OR 2.75, 95%CI 1.20–6.28, P = 0.016), American Society of Anesthesiologists score 3/4 (OR 2.14, 95%CI 1.01–4.52, P = 0.046), and utilization of catheter after surgery (OR 2.53, 95%CI 1.23–5.19, P = 0.012) were significantly associated with postoperative complications.

Conclusions

Multiple factors were associated with prolonged PLOS and postoperative complications after TKA in the ERAS program. It is important to recognize all the factors to try to maximize the use of medical resources and ultimately optimize the care of our patients.

Fast-track total knee arthroplasty improved clinical and functional outcome in the first 7 days after surgery: a randomized controlled pilot study with 5-year follow-up

INTRODUCTION

Fast-track protocols (FP) are used more and more to optimize results after total knee arthroplasty (TKA). Many studies evaluating FP in TKA concentrate on clinical outcome and medium to long-term results. Since discharge from hospital after TKA is achieved increasingly quicker worldwide using FP in an increasingly younger and active patient population, the effects of FP on functional outcome in the first days after TKA become more important. The purpose of the current study was to compare FP with a regular joint care protocol (RP), with an emphasis on the first 7 days after surgery.

MATERIALS AND METHODS

A non-blinded randomized controlled clinical pilot study was performed with 25 patients assigned to a FP group and 25 patients assigned to a RP group. Primary outcome was functional outcome, clinical outcome, pain, and complications for each day in the first week after surgery. Patients were followed up to 5 years after surgery.

RESULTS

Significantly lower VAS scores for knee pain, faster Timed-Up and Go test times and more mobility on functional tests were seen on several days in the first week in the FP group compared to the RP group. Few other significant differences were found at 2, 6 weeks, and no significant differences were found at 12 weeks and 1, 2 and 5 years after surgery.

CONCLUSIONS

Fast-track protocol for primary TKA showed significantly lower knee pain scores and improved functional outcome in the first 7 days after TKA compared to a regular protocol.

Comorbidities Have a Greater Impact Than Age Alone in the Outcomes of Octogenarian Total Knee Arthroplasty

BACKGROUND

Increasing age and various comorbidities are known risk factors for complications after total knee arthroplasty (TKA), but data on the impact of total comorbidity burden is scarce. We investigated the effect of age and total comorbidity burden on outcomes after primary TKA in octogenarians (OGs).

METHODS

A matched-pair comparison study was conducted using prospectively collected TKA registry data in a large tertiary institution. Between 2006 and 2011, consecutive OGs undergoing primary unilateral TKA, with minimum 2-year follow-up, were matched 1:1 with younger controls based on demographic and surgical variables. We compared the Charlson comorbidity index (CCI), complication rate, length of stay (LOS), 30-day readmission, and 2-year reoperation rate. Multivariate analysis was performed to determine the effects of age and CCI on each outcome.

RESULTS

There were 209 OGs and 209 controls. OGs were significantly older (mean age 82.1 vs 66.1 years, P < .001) and had higher CCI. OGs had longer mean LOS (6.3 vs 5.4 days, P = .001), and a trend for more complications and readmissions. The complication rate increased from 7.5% for CCI = 0, to 33.3% for CCI ≥3 (P = .005). The LOS increased from 5.4 days for CCI = 0, to 9.6 days for CCI ≥3 (P < .001). Multivariate analysis showed that higher CCI was an independent risk factor for complications and longer LOS, whereas age was not.

CONCLUSION

Comorbidity burden has a greater impact than age alone on TKA outcomes in OGs. Well-selected OGs remain good candidates for TKA.

The Effect of a Rapid Rehabilitation Program on Patients Undergoing Unilateral Total Knee Arthroplasty

BACKGROUND

Few studies have looked at longer term functional outcomes of rapid rehabilitation (physical therapy in the postanesthesia care unit on the day of surgery) for patients undergoing total knee arthroplasty.

PURPOSE

The purpose of this interdisciplinary study (physical therapy and nursing) was to assess the effect of a rapid rehabilitation program on inpatient length of stay (LOS) and functional recovery.

METHODS

Functional outcomes were measured by the Knee Injury Osteoarthritis Outcome Score presurgically and at 4 and 12 weeks postoperatively and by progression along a physical therapy rehabilitation pathway.

RESULTS

Experimental group LOS was significantly shorter than the control group (p = .0261). Multilevel regression modeling showed that KOOS and physical therapy clinical pathway score trajectories did not differ significantly between groups. Patients receiving rapid rehabilitation were 2.5 (95% CI [0.958, 6.53]) times more likely to have a positive physical therapy rehabilitation trajectory than patients in the control group.

CONCLUSION

Findings validated earlier study results in terms of LOS; however, further research is needed to assess the effect of rapid rehabilitation on longer term functional outcomes.

Should All Patients Be Included in Alternative Payment Models for Primary Total Hip Arthroplasty and Total Knee Arthroplasty?

BACKGROUND

Alternative payment models in total joint replacement incentivize cost effective health care delivery and reward reductions in length of stay (LOS), complications, and readmissions. If not adjusted for patient comorbidities, they may encourage restrictive access to health care.

METHODS

We prospectively evaluated 802 consecutive primary total hip arthroplasty and total knee arthroplasty patients evaluating comorbidities associated with increased LOS and readmissions.

RESULTS

During this 9-month period, 115 patients (14.3%) required hospitalization >3 days and 16 (1.99%) were readmitted within 90 days. Univariate analysis demonstrated that preoperative narcotic use, heart failure, stroke, chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), and liver disease were more likely to require hospitalization >3 days. In multivariate analysis, CKD and COPD were independent risk factors for LOS >3 days. A Charlson comorbidity index >5 points was associated with increased LOS and readmissions.

CONCLUSION

Patients with CKD, COPD, and Charlson comorbidity index >5 points should not be included in alternative payment model for THA and TKA.

Factors influencing length of hospital stay after primary total knee arthroplasty in a fast-track setting

PURPOSE

The goal of this study was to identify factors prior to surgery that are associated with an increased length of hospital stay after TKA using a fast-track protocol.

MATERIALS AND METHODS

In total, 879 consecutive patients who underwent primary TKA were included in this retrospective cohort study. A length of stay greater than or equal to three nights was considered an increased length of hospital stay. Univariable and multivariable generalized linear mixed models were used to identify potential factors associated with increased length of hospital stay.

RESULTS

Length of hospital stay was significantly associated with age [OR 1.01 (95 % CI 1.01-1.02); p < 0.001], gender [female vs. male, OR 1.07 (95 % CI 1.00-1.15); p = 0.04], ASA [ASA III/IV vs. ASA I, OR 1.22 (95 % CI 1.06-1.39); p = 0.005], living situation (alone vs. together, OR 1.08 (95 % CI 1.00-1.16); p = 0.04], neurological comorbidities [OR 1.14 (95 % CI 1.06-1.23); p < 0.001], musculoskeletal comorbidities [OR 0.91 (95 % CI 0.85-0.97); p = 0.005], anaesthesia [spinal vs. general, OR 0.86 (95 % CI 0.76-0.97); p = 0.02], and weekday of surgery [Thursday vs. Monday, OR 1.12 (95 % CI 1.02-1.23); p = 0.02].

CONCLUSIONS

Older age, female gender, ASA III/IV, people living alone, the presence of neurological comorbidities, general anaesthesia and surgery on Thursday were associated with an increased length of hospital stay. In clinical practice, the knowledge of factors associated with an increased length of hospital stay can be used to further optimize peri-operative protocols for patients at risk for an increased length of hospital stay after TKA.

LEVEL OF EVIDENCE

II.

Is Obesity a Risk Factor for Adverse Events After Knee Arthroscopy?

PURPOSE

To evaluate how body mass index (BMI) affects rates of 30-day complication, hospital readmissions, and mortality in patients undergoing knee arthroscopy.

METHODS

Patients undergoing knee arthroscopy procedures between 2006 and 2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Patient demographics and preoperative risk factors including BMI were analyzed for postoperative complications within 30 days. Cochran-Armitage testing was performed to detect differences in complication rates across BMI categories according to World Health Organization classification. The independent risk of BMI was assessed using multivariate regression analysis.

RESULTS

Of 41,919 patients with mean age 48 years undergoing knee arthroscopy, 20% were classified as normal weight (BMI 18.5 to 24), 35% overweight (BMI 25 to 29), 24% obese class I (BMI 30 to 34), 12% class II (BMI 35 to 40), and 9% class III (BMI ≥40). Risk of complication increased significantly with increasing BMI (normal: 1.5%, overweight: 1.6%, obese class I: 1.7%, obese class II: 1.8%, obese class III: 1.9%, P = .043). On multivariate analysis, there was no increased risk of postoperative complication directly attributed to patient BMI. Independent risk factors for medical and surgical complications after knee arthroscopy included American Society of Anesthesiologists (ASA) rating (class 4 v class 1 odds ratio [OR]: 5.39 [95% confidence interval: 3.11-9.33], P < .001), functional status for activities of daily living (dependent v independent OR: 2.13 [1.42, 3.31], P < .001), history of renal comorbidity (presence v absence OR: 5.10 [2.30, 11.29], P < .001), and previously experienced history of wound infection prior to current surgery (presence v absence OR: 4.91 [2.88, 8.39], P < .001).

CONCLUSIONS

More than 40% of knee arthroscopy patients qualify as obese. Although univariate analysis suggests that obesity is associated with increased postoperative complications within 30 days of surgery, BMI alone does not predict complications. Independent predictors of complications include patients with high ASA classification, dependent functional status, renal comorbidities, and a recent history of wound infection.

LEVEL OF EVIDENCE

Level IV, prognostic case series.