Hospital Length of Stay following Primary Total Knee Arthroplasty: Data from the Nationwide Inpatient Sample Database

Modifiable, Postoperative Risk Factors for Delayed Discharge Following Total Knee Arthroplasty: The Influence of Hypotension and Opioid Use

BACKGROUND

We sought to identify independent modifiable risk factors for delayed discharge after total knee arthroplasty (TKA) that have been previously underrepresented in the literature, particularly postoperative opioid use, postoperative laboratory abnormalities, and the frequency of hypotensive events.

METHODS

Data from 1033 patients undergoing TKA for primary osteoarthritis of the knee between June 2012 and August 2014 at an academic orthopedic specialty hospital were reviewed. Patient demographics, comorbidities, inpatient opioid medication, postoperative hypotensive events, and abnormalities in laboratory values, all occurring on postoperative day 0 or 1, were collected. Multivariate logistic regression analysis was performed to identify independent risk factors for a prolonged length of stay (LOS) >3 days.

RESULTS

The average age of patients undergoing primary TKA in our cohort was 65.9 (standard deviation, 9.1) years, and 61.7% were women. The mean LOS for all patients was 2.64 days (standard deviation, 1.14; range, 1-9). And 15.3% of patients had a LOS >3 days. On multivariate logistic regression analysis, nonmodifiable risk factors associated with a prolonged LOS included nonwhite race (odds ratio [OR], 2.01), single marital status (OR, 1.53), and increasing age (OR, 1.47). Modifiable risk factors included every 5 postoperative hypotensive events (OR, 1.31), 10-mg increases in oral morphine equivalent consumption (OR, 1.04), and postoperative laboratory abnormalities (hypocalcemia: OR, 2.15; low hemoglobin: OR, 2.63).

CONCLUSION

This study identifies potentially modifiable factors that are associated with increased LOS after TKA. Doubling down on efforts to control the narcotic use and to use opioid alternatives when possible will likely have efficacy in reducing LOS. Attempts should be made to correct laboratory abnormalities and to be cognizant of patient opioid use, age, and race when considering potential avenues to reduce LOS.

Length of Hospital Stay for Osteoarthritic Primary Hip and Knee Replacement Surgeries in New Zealand

This study aims to explore the length of stay (LOS) of publicly funded osteoarthritic primary hip and knee replacement surgeries in New Zealand. Patients with osteoarthritis who underwent publicly funded primary hip and knee replacement surgery in 2005-2017 were included. We have identified 53,439 osteoarthritic primary hip replacements and 50,072 osteoarthritic primary knee replacements. LOS has been reduced by almost 40% over the last 13 years. Logistic regression showed that women, Māori, Pacific and Asian patients, older patients, people with more comorbidities and those having opiates on discharge and patients in earlier years were more likely to have extended LOS following hip replacements and knee replacements. Regional differences were noted in LOS between the Waitemata District Health Board (DHB) compared to Tairāwhiti DHB where patients were the most likely to have a LOS of more than 5 days after hip and knee replacements. LOS after hip and knee replacements has been reduced dramatically. Women, Māori, Pacific and Asian patients, older patients and people with more comorbidities are more likely to have extended LOS. Patients dispensed opiates on discharge had a longer LOS. There are great geographical variations in LOS for primary hip and knee surgeries in New Zealand.

Successful Implementation of an Accelerated Recovery and Outpatient Total Joint Arthroplasty Program at a County Hospital

Outpatient and accelerated recovery total joint arthroplasty (TJA) programs have become standard for private and academic practices. County hospitals traditionally serve patients with limited access to TJA and psychosocial factors which create challenges for accelerated recovery. The effectiveness of such programs at a county hospital has not been reported.

Methods

In 2017, our county hospital implemented an accelerated recovery protocol for all TJA patients. This protocol consisted of standardized, preoperative medical and psychosocial optimization, perioperative spinal anesthesia, tranexamic acid and local infiltration analgesia use, postoperative emphasis on non-narcotic analgesia, and early mobilization. LOS, complications, disposition, and cost were compared between patients treated before and after protocol implementation.

Results

In 15 months, 108 primary TJA patients were treated. Compared with the previous 108 TJA patients, LOS dropped from 3.4 to 1.6 days (P < 0.001), more patients discharged home (92% versus 72%, P < 0.001), average hospitalization and procedure-specific costs decreased 24.7% and 22.1%, respectively, and were significantly fewer complications (7% versus 21%, P = 0.007).

Conclusions

Implementation of an accelerated recovery TJA program at a County Hospital is novel. This implementation requires careful patient selection and a coordinated multidisciplinary approach and is a safe and cost-effective method of delivering high-quality care to an underserved cohort.

Medicaid insurance status predicts postoperative mortality after total knee arthroplasty in state inpatient databases

Aim: Medicaid versus private primary insurance status may predict in-hospital mortality and morbidity after total knee arthroplasty (TKA). Materials & methods: Regression models were used to test our hypothesis in patients in the State Inpatient Database (SID) from five states who underwent primary TKA from January 2007 to December 2014. Results: Medicaid patients had greater odds of in-hospital mortality (odds ratio [OR]: 1.73; 95% CI: 1.01-2.95), greater odds of any postoperative complications (OR: 1.25; 95% CI: 1.18-1.33), experience longer lengths of stay (OR: 1.09; 95% CI: 1.08-1.10) and higher total charges (OR: 1.03; 95% CI: 1.02-1.04). Conclusion: Medicaid insurance status is associated with higher in-hospital mortality and morbidity in patients after TKA compared with private insurance.

PT Achievement in Public Hospitals and Its Effect on Outcomes

The demand for TKA continues to rise within the United States, while increasing quality measures and cost containment became the basis of reimbursement for hospital systems. Length of stay is a major driver in the cost of TKA. Early mobilization with physical therapy has been shown to increase range of motion and decrease complications, but with mixed results in regards to length of stay. We postulate that initiating physical therapy on post-operative day zero will decrease length of stay in an urban public hospital. Retrospective chart review was performed at a large, urban, public academic medical center to identify patients who have had a primary TKA over the course of a 3-year period. Groups who underwent post-operative day zero therapy were compared with those who initiated physical therapy on post-operative day one. Length of stay was the primary outcome. Patient demographic characteristics and discharge disposition were also collected. There were 98 patients in the post-operative day-one physical therapy cohort and 58 in the post-operative day zero physical therapy group. Hospital length of stay was significantly decreased in the post-operative day zero physical therapy group. (p < 0.01) There was no difference in discharge disposition between the two groups.

Readmission Rates for One Versus Two-Midnight Length of Stay for Primary Total Knee Arthroplasty: Analysis of the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) Database

BACKGROUND

The length of stay (LOS) in the hospital for total knee arthroplasty (TKA) has been declining over recent decades. The purpose of this study was to determine if patients with an LOS for TKA that includes only 1 midnight have an increased odds of 90-day readmission compared with those with a 2-midnight LOS. We also sought to identify any predictors of 90-day hospital readmission among those readmitted during our period of analysis.

METHODS

A retrospective review of the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) database was performed to identify patients with a 1-midnight or 2-midnight LOS for TKA during a 5-year period. The primary end point of this study was inpatient readmission within the 90-day postoperative period. A multiple logistic regression model and propensity score matching were used to compare the odds of 90-day readmission between 1-midnight and 2-midnight LOS. The secondary end points of this study were 90-day complications.

RESULTS

There were 96,250 TKA procedures identified in the database, and 46,709 met our inclusion criteria for LOS. No difference in 90-day-readmission odds between patients with a 1-midnight LOS and those with a 2-midnight LOS for primary TKA was identified. Male sex, single marital status, age of ≥80 years, type-I diabetes, previous smoking, narcotic use prior to surgery, and a higher American Society of Anesthesiologists (ASA) scores increased the odds of 90-day readmission. Patients in the age group of ≥50 to <65 years, those with a higher preoperative hemoglobin level, and those with a positive social history of alcohol use were found to have decreased odds of readmission.

CONCLUSIONS

We found no association between the LOS for primary TKA (1 midnight compared with 2 midnights) and the 90-day readmission risk.

LEVEL OF EVIDENCE

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

Reasons and Risk Factors for Delayed Discharge After Total Knee Arthroplasty Using an Opioid-Sparing Discharge Protocol

BACKGROUND

In this study, we aimed to assess the length of hospital stay after total knee arthroplasty in a European healthcare setting. We also aimed to investigate risk factors and reasons for delayed discharge when using an opioid-sparing fast-track protocol.

METHODS

From our institutional database, we retrospectively identified all primary elective unilateral total knee arthroplasties performed during January to December 2015. Both patient-related and surgery-related variables were collected from our databases. Risk factors were analyzed using multivariable logistic regression analysis.

RESULTS

The median length of stay (LOS) was 3 days. Independent risk factors for delayed discharge were higher age, higher American Society of Anesthesiologists score, general anesthesia, surgery performed toward the end of the week, longer duration of surgery, longer stay in the post-anesthesia care unit, and shorter preoperative walking distance. The main reasons for delayed discharge were delayed functional recovery and pain.

CONCLUSION

This study identified several independent risk factors for an LOS longer than 3 days. These risk factors add to the current knowledge on which patients have an increased risk of prolonged LOS, and which patients should be targeted when striving to further reduce the LOS.

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.

Factors associated with hospital stay length, discharge destination, and 30-day readmission rate after primary hip or knee arthroplasty: Retrospective Cohort Study

BACKGROUND

In France and in the US, predictions for 2030 include an increased number of total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures together with an overall trend towards shorter hospital stays. Predictors of hospital length of stay (LOS) include the day of surgery, discharge destination, and patient comorbidities. Available data are conflicting, however, and to our knowledge predictors of LOS after THA or TKA have not been evaluated in France. Improved knowledge of these predictors would be expected to increase patient care efficiency. The objectives of this study were: (1) to determine whether the above-listed factors predict LOS after THA or TKA, (2) to identify predictors of discharge to a rehabilitation unit and of readmission within 30 days after surgery.

HYPOTHESIS

Both patient-related factors unamenable to modification and modifiable organisational factors are associated with LOS after THA or TKA.

MATERIAL AND METHODS

This large single-centre retrospective cohort study included all adults who underwent primary THA or TKA at our university hospital between 1 January 2015 and 31 December 2016. Non-inclusion criteria were revision arthroplasty, THA with femoral or acetabular reconstruction, TKA using a constrained hinged implant, and fracture as the reason for arthroplasty. Preoperative parameters, type of arthroplasty, and postoperative care were recorded.

RESULTS

We included 938 patients with THA and 725 patients with TKA. By multivariate analysis, the likelihood of being discharged by day 5 decreased with older age (HR, 0.986; 95%CI: 0.98-0.99) and was lower by 13% in females (HR, 0,871; 95%CI: 0.77-0.986), by 39% in patients with diabetes (HR, 0.606; 95%CI: 0.5-0.73), by 68% in patients discharged to rehabilitation units (HR, 0.322; 95%CI: 0.267-0.389), and by 27% in patients who had arthroplasty on a Friday (HR, 0.733; 95%CI: 0.631-0.852). Factors predicting discharge to rehabilitation unit were older age, female gender, chronic obstructive pulmonary disease, anxiety-depressive disorder, and a history of stroke. Risk factors for 30-day readmission were male gender, obesity, and discharge to rehabilitation unit.

DISCUSSION

In this study, predictors of LOS were identified using a survival model that considered age as a continuous variable, separate comorbidities, and the discharge destination. Our findings are consistent with earlier reports and confirm the strong associations linking LOS to diabetes, day of surgery, and discharge destination in France. We also identified predictors of discharge to rehabilitation and of readmission within 30 days.

LEVEL OF EVIDENCE

IV, retrospective observational cohort study.

Preoperative Weight Loss for Morbidly Obese Patients Undergoing Total Knee Arthroplasty: Determining the Necessary Amount

BACKGROUND

Many surgeons require or request weight loss among morbidly obese patients (those with a body mass index [BMI] of ≥40 kg/m) before undergoing total knee arthroplasty. We sought to determine how much weight reduction was necessary to improve operative time, length of stay, discharge to a facility, and physical function improvement.

METHODS

Using a retrospective review of cohort data that were prospectively collected from 2011 to 2016 at 1 tertiary institution, we identified 203 patients who were morbidly obese at least 90 days before the surgical procedure and had their BMI measured again at the immediate preoperative visit. All heights and weights were clinically measured. We used logistic and linear regression models that adjusted for preoperative age, sex, year of the surgical procedure, bilateral status, physical function (Patient-Reported Outcomes Measurement Information System [PROMIS]-10 physical component score [PCS]), mental function (PROMIS-10 mental component score [MCS]), and the Charlson Comorbidity Index.

RESULTS

Of the 203 patients in the study, 41% lost at least 5 pounds (2.27 kg) before the surgical procedure, 29% lost at least 10 pounds (4.54 kg), and 14% lost at least 20 pounds (9.07 kg). Among morbidly obese patients, losing 20 pounds before a total knee arthroplasty was associated with lower adjusted odds of discharge to a facility (odds ratio [OR], 0.28 [95% confidence interval (CI), 0.09 to 0.94]; p = 0.039), lower odds of extended length of stay of at least 4 days (OR, 0.24 [95% CI, 0.07 to 0.88]; p = 0.031), and an absolute shorter length of stay (mean difference, -0.87 day [95% CI, -1.39 to -0.36 days]; p = 0.001). There were no differences in operative time or PCS improvement. Losing 5 or 10 pounds was not associated with differences in any outcome.

CONCLUSIONS

Losing at least 20 pounds before total knee arthroplasty was associated with shorter length of stay and lower odds of facility discharge for morbidly obese patients, even while most patients remained morbidly or severely obese. Although there were no differences in operative time or physical function improvement, this has considerable implications for patient burden and cost reduction. Patients and providers may want to focus on larger preoperative weight loss targets.

LEVEL OF EVIDENCE

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

The evolution of patellofemoral prosthetic design in total knee arthroplasty: how far have we come?

Total knee arthroplasty (TKA) has evolved into a successful, cost-effective treatment for end-stage knee arthrosis.The patellofemoral articulation in TKA has largely been ignored during its development despite being an important determinant of outcome.New technologies still need further development to incorporate the patella in TKA surgical planning and operative technique.Alternative approaches to alignment in TKA will have a secondary impact on patellofemoral mechanics and possibly future implant designs.Technologies that assist with precise implant positioning may alter our understanding and overall practice of TKA. Cite this article: EFORT Open Rev 2019;4:503-512. DOI: 10.1302/2058-5241.4.180094.

Physical Therapy on Postoperative Day Zero Following Total Knee Arthroplasty: A Randomized, Controlled Trial of 394 Patients

BACKGROUND

Surgeons have increasingly emphasized early mobilization as a way to facilitate discharge following total knee arthroplasty (TKA). The purpose of this study was to determine whether starting formal physical therapy (PT) the afternoon of postoperative day (POD) 0, instead of starting PT the morning of POD 1, could shorten hospital length of stay (LOS).

METHODS

Patients undergoing elective TKA with a planned minimum 1-night hospital stay were randomized to start formal PT the afternoon following surgery or the morning of POD 1. LOS in hours was the primary outcome. An a priori sample size calculation suggested that 394 patients were required to show a 4-hour difference between groups.

RESULTS

Out of 394 patients enrolled and randomized, 378 (95.9%) completed the study. The observed difference in hospital LOS was not large enough to be of clinical significance (intention-to-treat analysis: median of 32.0 hours for POD 0 PT vs 31.0 hours for POD 1 PT, P = .65; as-treated analysis: median of 31.0 hours for POD 0 PT vs 32.0 hours for POD 1 PT, P = .12). Similarly, the observed differences in satisfaction with inpatient PT (10.0 vs 10.0, P = .77), patient-reported readiness for discharge at time of discharge (10.0 vs 10.0, P = .97), and POD 0 pain (3.3 vs 4.0, P = .79) were not large enough to be of clinical significance.

CONCLUSION

While PT on the day of surgery has been suggested as one method to facilitate discharge following TKA, this randomized trial did not demonstrate clinically meaningful differences in hospital LOS or patient satisfaction when PT is initiated on the day of surgery vs on the morning after surgery.

The efficacy of liposomal bupivacaine compared with traditional peri-articular injection for pain control following total knee arthroplasty: an updated meta-analysis of randomized controlled trials

Background

The efficacy of postoperative pain management is an important factor that influences the final outcome of total knee arthroplasty (TKA). Whether liposomal bupivacaine offers better efficacy compared with traditional peri-articular injection after TKA remains inconclusive. We conduct this study to compare the true efficacy of liposomal bupivacaine (LB) with traditional peri-articular injection (TPAI) following TKA.

Materials and methods

Randomized controlled trials (RCTs) from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) and Web of Science were searched. Thirteen RCTs involving 1373 patients were finally included in our meta-analysis (LB = 691, TPAI = 682). The continuous and dichotomous outcome were collected in a standard form, and the data were analysed by using Review Manager 5.3 software. Finally, the results were presented in the forest plots.

Result

The pooled data demonstrated that the postoperative visual analogue score (VAS) in the LB group was not significantly different compared with that in the TPAI group at every time period after TKA. The liposomal bupivacaine group had significantly lower consumption of morphine equivalents 24 to 72 h postoperatively and reduced incidence of nausea and vomiting after TKA compared with the TPAI group. Finally, the length of hospital stay in the two groups was not significantly different.

Conclusion

Liposomal bupivacaine did not yield different results on the visual analogue scale compared with traditional peri-articular injection after total knee arthroplasty. However, liposomal bupivacaine was preferred in terms of lower consumption of morphine equivalents 24–72 h postoperatively and lower incidence of nausea and vomiting after total knee arthroplasty.

Effect of Anesthetic Technique on the Occurrence of Acute Kidney Injury after Total Knee Arthroplasty

Recent studies have reported the advantages of spinal anesthesia over general anesthesia in orthopedic patients. However, little is known about the relationship between acute kidney injury (AKI) after total knee arthroplasty (TKA) and anesthetic technique. This study aimed to identify the influence of anesthetic technique on AKI in TKA patients. We also evaluated whether the choice of anesthetic technique affected other clinical outcomes. We retrospectively reviewed medical records of patients who underwent TKA between January 2008 and August 2016. Perioperative data were obtained and analyzed. To reduce the influence of potential confounding factors, propensity score (PS) analysis was performed. A total of 2809 patients and 2987 cases of TKA were included in this study. A crude analysis of the total set demonstrated a significantly lower risk of AKI in the spinal anesthesia group. After PS matching, the spinal anesthesia group showed a tendency for reduced AKI, without statistical significance. Furthermore, the spinal anesthesia group showed a lower risk of pulmonary and vascular complications, and shortened hospital stay after PS matching. In TKA patients, spinal anesthesia had a tendency to reduce AKI. Moreover, spinal anesthesia not only reduced vascular and pulmonary complications, but also shortened hospital stay.

Medium-Term Outcomes of Digital Versus Conventional Home-Based Rehabilitation After Total Knee Arthroplasty: Prospective, Parallel-Group Feasibility Study

Background

Physical rehabilitation is recommended after total knee arthroplasty (TKA). With the expected increase in TKA over the next few decades, it is important to find new ways of delivering cost-effective interventions. Technological interventions have been developed with this intent, but only preliminary evidence exists regarding their validity, with short follow-up times.

Objective

This study aimed to present the follow-up results of a feasibility study comparing two different home-based programs after TKA: conventional face-to-face sessions and a digital intervention performed through the use of an artificial intelligence-powered biofeedback system under remote clinical monitoring.

Methods

The digital intervention uses a motion tracker allowing 3D movement quantification, a mobile app and a Web portal. This study presents the results of the previous single-center, prospective, parallel-group, feasibility study including an 8-week active treatment stage and further assessments at 3 and 6 months post-TKA. Primary outcome was the Timed Up and Go score, and secondary outcomes were the Knee Osteoarthritis Outcome Scale (KOOS) score and knee range of motion.

Results

A total of 59 patients completed the study (30 in the digital intervention group and 29 in the conventional rehabilitation group) and follow-up assessments. During the active treatment stage, patients in the digital intervention group demonstrated high engagement and satisfaction levels, with an 82% retention rate. Both groups attained clinically relevant improvements from baseline to 6 months post-TKA. At the end of the 8-week program, clinical outcomes were superior in the digital intervention group. At the 3- and 6-month assessments, the outcomes remained superior for the Timed Up and Go score (P<.001) and all KOOS subscale scores (at 3 months, P<.001 overall; at 6 months, KOOS Symptoms: P=.006, Pain: P=.002, Activities of Daily Living: P=.001, Sports: P=.003, and Quality of Life: P=.001). There was progressive convergence between both groups in terms of the knee range of motion, which remained higher for standing flexion in the digital intervention group than the conventional group at 6 months (P=.01). For the primary outcome, at 6 months, the median difference between groups was 4.87 seconds (95% CI 1.85-7.47), in favor of the digital intervention group.

Conclusions

The present study demonstrates that this novel digital intervention for independent home-based rehabilitation after TKA is feasible, engaging, and capable of maximizing clinical outcomes in comparison to conventional rehabilitation in the short and medium term; in addition, this intervention is far less demanding in terms of human resources.

Trial Registration

ClinicalTrials.gov NCT03047252; https://clinicaltrials.gov/ct2/show/NCT03047252

What is the evidence to support early supervised exercise therapy after primary total knee replacement? A systematic review and meta-analysis

Background

Total knee replacement (TKR) patients participate in early supervised exercise therapy programs, despite a lack of evidence for such programs or the optimal type, duration or frequency to provide the best clinical outcomes. As hospital stay rates decrease worldwide, the first days after joint replacement surgery are of increasing clinical importance. The purpose of this study was to investigate any reported effects of published early exercise therapy following TKR surgery.

Methods

Databases PubMed, CINAHL, Embase, Cochrane, and Pedro were searched up to August 2018 for trials which investigated an early supervised exercise therapy, commencing within 48 h of surgery. Risk of bias was evaluated using a Modified Downs and Black Checklist and meta-analysis of results was conducted using Review Manager (RevMan). Standardised Mean Differences (SMD) or Mean Differences (MD) and 95% confidence intervals were calculated and combined in meta-analyses.

Results

Four studies (323 patients) that used four different interventions were identified, including Modified Quadriceps Setting, Flexion Splinting, Passive Flexion Ranging and a Drop and Dangle Flexion regime. Patients receiving the Drop and Dangle flexion protocol had superior flexion in the first 2 days after TKR and at discharge, the Flexion Splint patients were discharged earlier and had greater flexion at 6-weeks postoperatively, and the Modified Quadriceps Setting group showed greater hamstring and gluteal muscle strength. Results of the methodological quality assessment showed included studies were of moderate quality. The meta-analysis included 3 of the 4 trials and found no significant differences between groups in maximum knee flexion (MD = 1.34; 95% CI, − 5.55–8.24) or knee society scores (MD = − 1.17; 95% CI, − 4.32–1.98) assessed at 6 weeks post-operatively.

Conclusion

The paucity and heterogeneity of existing studies that examine early supervised exercise therapy following TKR surgery makes it challenging for clinicians to deliver high-quality evidence-based exercise programs in the early postoperative period. Although superior knee flexion range was found across differing regimes, the meta-analysis showed no significant difference in this outcome between groups at 6 weeks. The results of this review show high quality randomized clinical trials are urgently needed to evaluate the impact of early exercise following TKR surgery.

Trial Registration

This review was registered with PROSPERO (CRD42017081016).

Electronic supplementary material

The online version of this article (10.1186/s12891-019-2415-5) contains supplementary material, which is available to authorized users.

Predictors of Increased Hospital Stay in Adolescent Idiopathic Scoliosis Patients Undergoing Posterior Spinal Fusion: Analysis of National Database

STUDY DESIGN

Analysis of population-based national hospital discharge data collected for the Nationwide Inpatient Sample (NIS).

OBJECTIVE

To examine the predictors of increased hospital stay in adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion.

SUMMARY OF BACKGROUND DATA

As policy makers and hospitals are increasingly looking to cut costs, length of stay (LOS) after surgery has come into focus as an area for improvement. Despite this, there is limited research about the factors contributing to increased LOS for AIS patients undergoing posterior spinal fusion.

METHODS

The Nationwide Inpatient Sample was used to identify pediatric patients with idiopathic scoliosis who underwent posterior spinal fusion from 2004 to 2009, using the International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) codes. Patient demographics, surgical variables, hospital characteristics, and in-hospital outcomes were retrieved. LOS was divided into two groups (longer- and shorter-stay groups) by its average. Longer stay was defined as ≥6 days. Multivariable logistic regression analysis was performed to identify the predictors of increased LOS in AIS patients undergoing posterior spinal fusion.

RESULTS

Significant predictors of increased LOS in posterior spinal fusion for AIS patients included increased Elixhauser Comorbidity Score, number of fused levels ≥9 vertebrae, teaching hospital status, in-hospital complications, and nonroutine disposition. Wound-related complications were the strongest predictor and patients with wound-related complications were 3.14-fold more likely to have an increased LOS compared to those without wound-related complications.

CONCLUSIONS

This study identified significant predictors of increased hospital stay in posterior spinal fusion for pediatric patients with idiopathic scoliosis and patients at higher risk of longer hospitalization can be recognized. Eventually these data are expected to help optimize LOS and cost containment.

Modifiable Risk Factors in Primary Joint Arthroplasty Increase 90-Day Cost of Care

BACKGROUND

Risk factors in demographics and health status have been identified that increase the risk of complications after joint arthroplasty, necessitating additional care and incurring additional charges. The purpose of this study was to identify the number of patients in a hospital network database who had one or more predefined modifiable risk factors and determine their impact on average length of stay, need for additional care during the 90-day postoperative period, and the 90-day charges for care.

METHODS

An electronic hospital record query of 6968 lower extremity joint arthroplasty procedures under Diagnosis-Related Group 469/470 performed in 2014-2015 was reviewed, and total 90-day charges were calculated. The case mean was compared to charges for patients with modifiable risk factors: anemia (Hgb < 10 g/dL), malnutrition (albumin < 3.4 g/dL), obesity (body mass index > 45 kg/m²), uncontrolled diabetes (random glucose >180 mg/dL or A1C > 8), narcotic use (prescription filled), and tobacco use (documented within 30 days before surgery). Length of stay, emergency room visits, and hospital readmission were compared.

RESULTS

Mean 90-day charges for Diagnosis-Related Group 469/470 were $36,647. Risk factors were associated with a significant increase in 90-day charges: anemia (+$ 15,869/126 patients), malnutrition (+$9270/592), obesity (+$2048/445), diabetes (+$5074/291), narcotic use (+$1801/1943), and tobacco use (+$2034/1882). Intensive care unit admission rate, emergency department visits, and hospital readmission were significantly increased for patients with each risk factor. Length of stay was higher in patients with anemia, malnutrition, diabetes, and tobacco use. When separated by elective vs fracture admission, 90-day charges were significantly higher for each risk factor.

CONCLUSIONS

Medical strategies to optimize patients before joint arthroplasty are warranted to improve postoperative outcomes.

Predictors and Cost of Readmission in Total Knee Arthroplasty

BACKGROUND

The Comprehensive Care for Joint Replacement bundle was created to decrease total knee arthroplasty (TKA) cost. To help accomplish this, there is a focus on reducing TKA readmissions. However, there is a lack of national representative sample of all-payer hospital admissions to direct strategy, identify risk factors for readmission, and understand actual readmission cost.

METHODS

We used the Nationwide Readmission Database to examine national readmission rates, predictors of readmission, and associated readmission costs for elective TKA procedures. We fit a multivariable logistic regression model to examine factors associated with readmission. Then, we determined mean readmission costs and calculated the readmission cost when distributed across the entire TKA population.

RESULTS

We identified 224,465 patients having TKA across all states participating in the Nationwide Readmission Database. The mean unadjusted 30-day TKA readmission rate was 4%. The greatest predictors of readmission were congestive heart failure (odds ratio [OR] 2.51, 95% confidence interval [CI] 2.62-2.80), renal disease (OR 2.19, 95% CI 2.03-2.37), and length of stay greater than 4 days (OR 2.4, 95% CI 2.25-2.61). The overall median cost for each readmission was $6753 ± 175. Extrapolating the readmission cost for the entire TKA population resulted in the readmission cost being 2% of the overall 30-day procedure cost.

CONCLUSIONS

A major focus of the Comprehensive Care for Joint Replacement bundle is improving cost and quality by limiting readmission rates. TKA readmissions are low and comprise a small percentage of total TKA cost, suggesting that they may not be the optimal measure of quality care or a significant driver of overall cost.

Comparing outcomes between barbed and conventional sutures in patients undergoing knee or hip arthroplasty

AIM

To compare outcomes between barbed sutures and conventional sutures among patients undergoing knee or hip arthroplasty.

MATERIALS & METHODS

Retrospective study of patients (aged ≥18 years) undergoing elective knee/hip arthroplasty for osteoarthritis between 1 January 2013 and 1 September 2015. Patients were classified as: any Stratafix™ Knotless Tissue Control Devices (barbed suture group) used for closure vs. conventional sutures only (conventional suture group).

RESULTS

Compared with the conventional suture group, the barbed suture group had statistically significant: shorter length of stay, knee = 0.2 d; hip = 0.3 d and operating room time, knee = 7 min; hip = 22 min and lower rate of discharge to skilled nursing facility/nonhome setting (knee = 3.0%; hip = 6.8%).

CONCLUSION

Use of barbed sutures was associated with shorter length of stay, operating room time and less resource intensive discharge status as compared with conventional sutures alone.

Effectiveness of continuous versus single injection femoral nerve block for total knee arthroplasty: A double blinded, randomized trial

BACKGROUND

Effective analgesia following total knee arthroplasty (TKA) is important for maximizing patient satisfaction, early participation in physical therapy and reducing the hospital stay. This trial compared continuous catheter femoral nerve block (cFNB) to single injection femoral nerve block (sFNB) in terms of analgesia, opioid consumption, and participation in physical therapy and associated side effects.

METHODS

This randomized, double blinded trial was conducted in a non-university hospital setting, without major changes to anesthesia or surgical clinical pathways. A total of 85 patients scheduled for primary TKA were randomized to receive either cFNB (n=44) or sFNB (n=41). All patients had FNB with 0.5% ropivacaine bolus followed by subarachnoid block for surgery. Postoperatively, 0.2% ropivacaine infusion was commenced in cFNB group and a sham catheter was taped to the skin in sFNB group. All patients received a structured multimodal analgesia regimen throughout hospital stay. The primary outcomes were peak resting visual analogue scale (VAS) scores and morphine consumption at 48h postoperatively.

RESULTS

VAS scores (Mean difference 0.25, 95% Confidence Interval (CI) -0.56 to 1.06; [P=0.196]) and morphine consumption (Mean difference 0.95mg, 95% CI -9.99 to 11.89; [P=0.863]) were not significantly different among patients who received cFNB versus sFNB at 48h. There was no difference in hospital stay (P=0.517) or long-term functional recovery between the two groups (P=0.385).

CONCLUSIONS

sFNB block provides equal pain relief compared with cFNB, after TKA with no significant difference in opioid consumption, hospital stay, physical therapy outcomes or associated side effects.

Robotic-arm assisted total knee arthroplasty is associated with improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based total knee arthroplasty: a prospective cohort study

Aims

The objective of this study was to compare early postoperative functional outcomes and time to hospital discharge between conventional jig-based total knee arthroplasty (TKA) and robotic-arm assisted TKA.

Patients and Methods

This prospective cohort study included 40 consecutive patients undergoing conventional jig-based TKA followed by 40 consecutive patients receiving robotic-arm assisted TKA. All surgical procedures were performed by a single surgeon using the medial parapatellar approach with identical implant designs and standardized postoperative inpatient rehabilitation. Inpatient functional outcomes and time to hospital discharge were collected in all study patients.

Results

There were no systematic differences in baseline characteristics between the conventional jig-based TKA and robotic-arm assisted TKA treatment groups with respect to age (p = 0.32), gender (p = 0.50), body mass index (p = 0.17), American Society of Anesthesiologists score (p = 0.88), and preoperative haemoglobin level (p = 0.82). Robotic-arm assisted TKA was associated with reduced postoperative pain (p < 0.001), decreased analgesia requirements (p < 0.001), decreased reduction in postoperative haemoglobin levels (p < 0.001), shorter time to straight leg raise (p < 0.001), decreased number of physiotherapy sessions (p < 0.001) and improved maximum knee flexion at discharge (p < 0.001) compared with conventional jig-based TKA. Median time to hospital discharge in robotic-arm assisted TKA was 77 hours (interquartile range (IQR) 74 to 81) compared with 105 hours (IQR 98 to 126) in conventional jig-based TKA (p < 0.001).

Conclusion

Robotic-arm assisted TKA was associated with decreased pain, improved early functional recovery and reduced time to hospital discharge compared with conventional jig-based TKA.

Cite this article: Bone Joint J 2018;100-B:930–7.

Using Illness Rating Systems to Predict Discharge Location Following Total Knee Arthroplasty

Purpose

Total knee arthroplasty (TKA) is increasing in frequency and cost. Optimization of discharge location may reduce total expenditure while maximizing patient outcomes. Although preoperative illness rating systems—including the American Society for Anesthesiologists Physical Classification System (ASA), severity of illness scoring system (SOI), and Mallampati rating scale (MP)—are associated with patient morbidity and mortality, their predictive value for discharge location, length of stay (LOS), and total costs remains unclear.

Materials and Methods

We conducted a retrospective analysis of 677 TKA patients (550 primary and 127 revision) treated at a single institution. The influence of ASA, SOI, and MP scores on discharge locations, LOS, and total costs was assessed using multivariable regression analyses.

Results

None of the systems were significant predictors of discharge location following TKA. SOI scores of major or higher (β=2.08 days, p<0.001) and minor (β=−0.25 days, p=0.009) significantly predicted LOS relative to moderate scores. Total costs were also significantly predicted by SOI scores of major or higher (β=$6,155, p=0.022) and minor (β=−$1,163, p=0.007).

Conclusions

SOI scores may be harnessed as a predictive tool for LOS and total costs following TKA, but other mechanisms are necessary to predict discharge location.

A Consultation Phone Service for Patients With Total Joint Arthroplasty May Reduce Unnecessary Emergency Department Visits

BACKGROUND

Different measures for reducing costs after total joint arthroplasty (TJA) have gained attention lately. At our institution, a free-of-charge consultation phone service was initiated that targeted patients with TJA. This service aimed at reducing unnecessary emergency department (ED) visits and, thus, potentially improving the cost-effectiveness of TJAs. To our knowledge, a similar consultation service had not been described previously. We aimed at examining the rates and reasons for early postdischarge phone calls and evaluating the efficacy of this consultation service.

METHODS

During a 2-month period, we gathered information on every call received by the consultation phone service from patients with TJAs within 90 days of the index TJA procedure. Patients were followed for 2 weeks after making a call to detect major complications and self-initiated ED visits. Data were collected from electronic medical charts regarding age, gender, type of surgery, date of discharge, and length of hospital stay.

RESULTS

We analyzed 288 phone calls. Calls were mostly related to medication (41%), wound complications (17%), and mobilization issues (15%). Most calls were resolved in the phone consultation. Few patients (13%) required further evaluation in the ED. The consultation service failed to detect the need for an ED visit in 2 cases (0.7%) that required further care.

CONCLUSION

The consultation phone service clearly benefitted patients with TJAs. The service reduced the number of unnecessary ED visits and functioned well in detecting patients who required further care. Most postoperative concerns were related to prescribed medications, wound complications, and mobilization issues.

Predicting hospital length of stay and short-term function after hip or knee arthroplasty: are both performance and comorbidity measures useful?

PURPOSE

Variations in hospital length of stay (LOS) and function are present after hip or knee arthroplasty. Comorbidity and performance measures have been associated with post-operative outcomes. It is however not known if both independently contribute to outcome prediction. The objective of this study was to evaluate the combined predictive ability of comorbidity scores (American Society of Anesthesiologists classification system (ASA), Charlson comorbidity index (CCI), 2008 version of the CCI (CCI08)) and a performance measure (Timed-Up-and-Go (TUG)) on LOS and short-term function in patients undergoing knee or hip arthroplasty.

METHODS

One hundred eight patients undergoing hip or knee arthroplasty were assessed preoperatively with the ASA, CCI, CCI08, and TUG. LOS was determined through administrative data. The Older Americans Resources and Services ADL questionnaire (OARS) was used to assess function two and six weeks after surgery. Logistic regression was used to assess the relationship between pre-operative assessments and LOS and OARS scores.

RESULTS

Both the ASA and TUG significantly contributed to LOS prediction. Odds ratio (OR) was 3.57 (95% confidence interval (CI) 1.26-10.07) for the ASA, and 2.18 (95% CI 1.67-4.15) for a one-standard deviation (SD) increase of 4.45 s of the TUG. Only the TUG was predictive of two weeks function and trending towards significance for six weeks function. One SD TUG increase yielded an OR of 2.14 (95% CI 1.53-3.79) for two week function.

CONCLUSIONS

The TUG and ASA can be used pre-operatively in combination to predict LOS, and TUG can also be used to predict short-term post-operative function.

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.

Trends and determinants of length of stay and hospital reimbursement following knee and hip replacement: evidence from linked primary care and NHS hospital records from 1997 to 2014

OBJECTIVES

To measure changes in length of stay following total knee and hip replacement (TKR and THR) between 1997 and 2014 and estimate the impact on hospital reimbursement, all else being equal. Further, to assess the degree to which observed trends can be explained by improved efficiency or changes in patient profiles.

DESIGN

Cross-sectional study using routinely collected data.

SETTING

National Health Service primary care records from 1995 to 2014 in the Clinical Practice Research Datalink were linked to hospital inpatient data from 1997 to 2014 in Hospital Episode Statistics Admitted Patient Care.

PARTICIPANTS

Study participants had a diagnosis of osteoarthritis or rheumatoid arthritis.

INTERVENTIONS

Primary TKR, primary THR, revision TKR and revision THR.

PRIMARY OUTCOME MEASURES

Length of stay and hospital reimbursement.

RESULTS

10 260 primary TKR, 10 961 primary THR, 505 revision TKR and 633 revision THR were included. Expected length of stay fell from 16.0 days (95% CI 14.9 to 17.2) in 1997 to 5.4 (5.2 to 5.6) in 2014 for primary TKR and from 14.4 (13.7 to 15.0) to 5.6 (5.4 to 5.8) for primary THR, leading to savings of £1537 and £1412, respectively. Length of stay fell from 29.8 (17.5 to 50.5) to 11.0 (8.3 to 14.6) for revision TKR and from 18.3 (11.6 to 28.9) to 12.5 (9.3 to 16.8) for revision THR, but no significant reduction in reimbursement was estimated. The estimated effect of year of surgery remained similar when patient characteristics were included.

CONCLUSIONS

Length of stay for joint replacement fell substantially from 1997 to 2014. These reductions have translated into substantial savings. While patient characteristics affect length of stay and reimbursement, patient profiles have remained broadly stable over time. The observed reductions appear to be mostly explained by improved efficiency.

Total Knee Arthroplasty: Does Day of Surgery Matter?

Introduction

There has been an influx of research studies aimed at identifying all factors that contribute to minimizing cost and maximizing postoperative care after total knee arthroplasty (TKA). Length of stay (LOS) has been defined as a significant factor that contributes to increased burden. We aimed at looking whether day of surgery has any significant effect on the LOS and postoperative complications following total knee arthroplasty (TKA).

Materials and methods

Retrospective cohort study done at the Aga Khan University Hospital, Pakistan, from January 2007 to December 2015. A total of 611 patients who underwent a unilateral or bilateral total knee arthroplasty (TKA) were included in study: 269 (44.0%) patients underwent unilateral TKA and 342 (56.0%) underwent a bilateral TKA.

Results

Kruskal-Wallis test and post hoc pairwise comparisons showed that unilateral TKAs performed on Tuesday, Saturday, and Sunday resulted in a lower median LOS (P < .05). No significant association was seen in bilateral TKA group. Day of surgery was not associated with postoperative complications.

Conclusions

Unilateral TKAs performed earlier during the week and later on the weekend are associated with a significantly lower LOS. It is highly probable that patch ancillary services during the latter part of the week and a higher workload for the staff are important reasons for this phenomenon.

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.

Do Aggregate Socioeconomic Status Factors Predict Outcomes for Total Knee Arthroplasty in a Rural Population?

BACKGROUND

We sought to determine whether several preoperative socioeconomic status (SES) variables meaningfully improve predictive models for primary total knee arthroplasty (TKA) length of stay (LOS), facility discharge, and clinically significant Veterans RAND-12 physical component score (PCS) improvement.

METHODS

We prospectively collected clinical data on 2198 TKAs at a high-volume rural tertiary academic hospital from April 2011 through March 2016. SES variables included race and/or ethnicity, living alone, education, employment, and household income, along with numerous adjusting variables. We determined individual SES predictors and whether the inclusion of all SES variables contributed to each 10-fold cross-validated area under the model's area under the receiver operating characteristic (AUC). We also used 1000-fold bootstrapping methods to determine whether the SES and non-SES models were statistically different from each other.

RESULTS

At least 1 SES predicted each outcome. Ethnic minority patients and those with incomes <$35,000 predicted longer LOS. Ethnic minority patients, the unemployed, and those living alone predicted facility discharge. Unemployed patients were less likely to achieve PCS improvement. Without the 5 SES variables, the AUC values of the LOS, discharge, and PCS models were 0.74 (95% confidence interval [CI] 0.72-0.77, "acceptable"); 0.86 (CI 0.84-0.87, "excellent"); and 0.80 (CI 0.78-0.82, "excellent"), respectively. Including the 5 SES variables, the 10-fold cross-validated and bootstrapped AUC values were 0.76 (CI 0.74-0.79); 0.87 (CI 0.85-0.88); and 0.81 (0.79-0.83), respectively.

CONCLUSION

We developed validated predictive models for outcomes after TKA. Although inclusion of multiple SES variables provided statistical predictive value in our models, the amount of improvement may not be clinically meaningful.

Economic evaluation of different suture closure methods: barbed versus traditional interrupted sutures

Healthcare systems are receiving increasing pressures from payers, such as the Centers for Medicare and Medicaid (CMS), to reduce the costs associated with procedures, and with the implementation of the Affordable Care Act, high costs are addressed through pay-for-performance programs. Thus, multiple areas of total knee arthroplasty (TKA) surgery are under scrutiny, including surgical times, material costs, and the costs of associated complications and readmissions. Suture type has been determined to be a factor that may influence closure times, as well as direct material costs. Therefore, the purpose of this review was to compare: (I) the cost of using barbed vs. conventional interrupted sutures; (II) the additional cost of differences in complications, if any; (III) to extrapolate cost savings on a hospital and national level; and (IV) to discuss the role of these findings on hospital savings and the effect on bundled payments. It was found that the main factors affecting differences in overall costs between barbed and standard interrupted suture were material cost and closure time. Many studies have demonstrated greater cost savings with the barbed suture due to shorter operative times, despite the higher material costs. The majority of studies also demonstrated similar complication rates between the suture types, and thus these are unlikely to affect the cost difference. However, to the best of our knowledge, there are no TKA studies in the literature evaluating the effect of suture type and associated complications on lengths of stay and readmission rates. Thus, it is unclear how these cost savings will translate to reimbursements rates and the role that they might play in bundled payments. Several studies in other specialties demonstrate decreased infection rates with the use of barbed sutures, which, if found to be true for TKA can be extrapolated to 3 million dollars of savings in revision TKA costs. Further studies on this topic are needed to define these relationships.

National Incidence of Reportable Quality Metrics in the Knee Arthroplasty Population

BACKGROUND

The Centers for Medicare and Medicaid Services (CMS) characterizes adverse quality events in the inpatient setting as patient safety indicators (PSI). The incidence of PSI has not been quantified in the total knee arthroplasty (TKA) population.

METHODS

All patients in the Nationwide Inpatient Sample who underwent primary TKA during an inpatient episode in 2013 were identified using International Classification of Disease, Ninth Revision, Clinical Modification codes. The incidence of PSI was determined using the International Classification of Disease, Ninth Revision diagnosis code algorithms used by CMS. Multivariable logistic regression was used to determine significant associations between patient level covariates (demographics, comorbidities, and hospital characteristics) and the risk of experiencing one or more PSI after TKA.

RESULTS

We identified 132,453 primary TKA patients in the Nationwide Inpatient Sample in 2013. We estimated the national incidence rate of experiencing one or more PSI as 0.98%. After adjusting for patient demographics and hospital characteristics, we found that relative to Medicaid/self-pay patients, neither Medicare nor privately insured patients faced significantly different risk of experiencing one or more PSI after TKA. However, alcohol abuse, deficiency anemia, congestive heart failure, coagulopathy, and electrolyte imbalance were associated with increased risk of experiencing one or more PSI after TKA.

CONCLUSION

The national incidence of PSI among TKA patients was lower than has been reported in other surgical populations. CMS uses the incidence of adverse quality events (measured using PSI) in part to determine hospital reimbursement. As value-based payment becomes more widely adopted in the United States, initiatives designed to eliminate and reduce PSI incidence can benefit vulnerable patient populations, physicians, and hospital systems.

How Do Preoperative Medications Influence Outcomes After Total Joint Arthroplasty?

BACKGROUND

Recent health care policy changes require hospitals and physicians to demonstrate improved quality. In 2012, a prospective database was formed with the Blue Cross and Blue Shield of Michigan to improve quality of care. The purpose of this study was to analyze patient preoperative medication as predictors of outcomes after total joint arthroplasty.

METHODS

Data were collected on patient's preoperative medications from 2012 to 2015 using a total joint arthroplasty database. Medications were categorized as antiplatelet, antimicrobial, anticoagulant, narcotic, steroid, insulin, or oral diabetes medication. Outcomes included hospital length of stay (LOS), discharge disposition/destination, and 90-day readmission. Univariate and multivariate regression analyses were performed.

RESULTS

A total of 3959 patients were studied. Eighty percent (3163 patients) were discharged home. The remainder (795) went to an extended-care facility (ECF). Patients discharged to an ECF were taking more medications (1.13 vs 0.80 in total knee arthroplasty; 1.18 vs 0.83 in total hip arthroplasty; P <.001). Patients who were readmitted took more medications (1.0 vs 0.85; P <.01). There were more discharges to an ECF in narcotic, steroid, and diabetes medication users. Patients taking anticoagulants, narcotics, insulin, and antiplatelets had greater readmission rates. There was a significant correlation between the number of medications and an increased LOS.

CONCLUSION

Patients taking more medications were more frequently discharged to an ECF and had increased LOS and readmission rates. Narcotics and diabetic medications had the greatest influence. Category and quantity of preoperative medications can be used as predictors of outcomes after arthroplasty surgery.

The Evaluation of Comorbidities Relative to Length of Stay for Total Joint Arthroplasty Patients

BACKGROUND

The ability to identify those at risk for longer inpatient stay helps providers with postoperative planning and patient expectations. Decreasing length of stay (LOS) in the future will be determined by appropriate patient selection, risk stratification, and preoperative patient optimization. The purpose of this study was to identify factors that place patients at risk for extended postoperative LOSs.

METHODS

The study cohort included 2009 primary total knee arthroplasty (TKA) patients and 905 total hip arthroplasty (THA) patients. Patient comorbidities were prospectively identified and the LOS for each patient was tracked after a primary arthroplasty. Statistical analysis was performed to correlate which comorbidities were associated with longer inpatient stays.

RESULTS

In the TKA population, gender, smoking status, venous thromboembolism history, body mass index, and diabetes status were not found to be a significant predictor for the LOS. Age was found to be a factor in univariate regression testing (P < .001). In the THA population, univariate testing showed female gender (P < .001), smoking status (P = .002), and age (P < .001) to be factors, but like the TKA population, venous thromboembolism history or diabetes status was not significant. In THA multivariate analysis, age (P < .001) and female gender (P = .018) continued to be factors, but smoking was determined to be a confounding variable.

CONCLUSION

Age and gender were associated with a longer LOS after THA, whereas only age was a significant factor after TKA. Development of age-adjusted LOS models may help aid patient expectations and risk management.

Which Hospital and Clinical Factors Drive 30- and 90-Day Readmission After TKA?

BACKGROUND

The purpose of this study was to analyze the hospital, clinical, and patient factors associated with inpatient readmission after total knee arthroplasty (TKA) in the Medicare population and to understand the primary reasons for readmission.

METHODS

The Medicare 100% national hospital claims database was used to identify 952,593 older patients (65+) with a primary TKA in 3848 hospitals between 2010 and 2013. A multilevel logistic regression analysis with a clustered data structure was used to investigate the risk of all-cause 30- and 90-day readmission, incorporating hospital, clinical, and patient factors.

RESULTS

At 30 days, readmission ranged from 0% to 22% (median, 4.9%), whereas at 90 days, readmission ranged from 0% to 32% (median, 8.6%). Geographic census region, hospital procedure volume, rural hospital location, and nonprofit ownership were the only significant hospital factors among those we studied. Evaluation of clinical factors showed use of a perioperative transfusion was associated with 13% greater risk; patients discharged to home had 25% lower risk; and surgeon volume and length of stay were also significant. These effect sizes were at least comparable to patient factors, such as age, gender, comorbidities, and socioeconomic status. The top 5 most frequently reported primary reasons for 30- or 90-day readmission in TKA were surgery and medical related: wound infection, deep infection, atrial fibrillation, cellulitis and abscess of leg, or pulmonary embolism.

CONCLUSION

The results of this study support further optimization of anti-infection measures, both intraoperative and postoperative, to reduce the broad variation in hospital readmissions.

Hospital, Patient, and Clinical Factors Influence 30- and 90-Day Readmission After Primary Total Hip Arthroplasty

BACKGROUND

The purpose of this study was to analyze the hospital, clinical, and patient factors associated with inpatient readmission after total hip arthroplasty (THA) in the Medicare population and to understand the primary reasons for readmission.

METHODS

The Medicare 100% national hospital claims database was used to identify 442,333 older patients (65+) with a primary THA in 3730 hospitals between 2010 and 2013. A multilevel logistic regression analysis with a clustered data structure was used to investigate the risk of all-cause 30- and 90-day readmission, incorporating hospital, clinical, and patient factors.

RESULTS

At 30 days, 5.8% (median) of the patients were readmitted, whereas at 90 days, 10.5% (median) were readmitted. Geographic census region, hospital procedure volume, and nonprofit ownership were the only significant hospital factors among those we studied. Overall, clinical factors explained more of the variation in readmission rates than general hospital factors. Use of a perioperative transfusion was associated with 14% greater risk, patients discharged to home had 28% lower risk, and surgeon volume and length of stay were also significant risk factors. The top 5 most frequently reported primary reasons for 30-day readmission in THA were procedure related: dislocation (5.9%), deep infection (5.1%), wound infection (4.8%), periprosthetic fracture (4.4%), or hematoma (3.4%).

CONCLUSION

These findings support further optimization of the delivery of care-both intraoperative and postoperative-to reduce the broad variation in hospital readmissions.