Does Increasing Patient Complexity Have an Effect on Medical Outcomes and Lengths-of-Stay after Total Knee Arthroplasty?

A greater number of medically complex patients with multiple comorbidities are now more readily considered for total knee arthroplasty (TKA). Therefore, the purpose of this study was to determine whether comorbidity burden, measured with the Elixhauser Comorbidity Index (ECI), correlated with 90-day medical complications and longer in-hospital lengths-of-stay (LOS) in TKA patients. The PearlDiver supercomputer was queried for all primary TKA patients in the Medicare Standard Analytic Files from 2005 to 2014 using International Classification of Disease, 9th edition codes. Patients were included based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort was matched based on age and gender to the control cohort, resulting in a total of 715,398 patients included for analysis (ECI 1, n = 144,072; ECI 2, n = 144,072; ECI 3, n = 144,072; ECI 4, n = 144,072; ECI 5, n = 139,110). Logistic regression analyses were performed to compare 90-day medical complications and Welch's t-tests were performed to compare LOS between the cohorts. Patients with higher ECI scores were more likely to develop medical complications and have longer LOS compared with matched patients in the control cohort. Compared with matched ECI 1 patients, patients with ECI scores of 2 (odds ratio [OR]: 1.19, 95% confidence interval [CI]: 1.14-1.24), 3 (OR: 1.27, 95% CI: 1.21-1.32), 4 (OR: 1.32, 95% CI: 1.27-1.38), and 5 (OR: 1.33, 95% CI: 1.27-1.39) were significantly more likely to develop 90-day medical complications. Additionally, the mean LOS of patients in the ECI 2 (2.59 ± 1.49 vs. 2.73 ± 1.52 days), ECI 3 (2.59 ± 1.49 vs. 2.88 ± 1.51 days; p < 0.001), ECI 4 (2.59 ± 1.49 vs. 3.01 ± 1.56 days; p < 0.001), and ECI 5 (2.61 ± 1.49 vs. 3.14 ± 1.61 days; p < 0.001) groups were significantly longer than the mean LOS in the control ECI 1 group. In an increasingly complex patient population, associations between comorbidities and outcomes after TKA procedures can guide providers on how to modify their pre- and postoperative care. These results demonstrate that higher ECI scores are associated with a greater likelihood of 90-day medical complications and longer in-hospital LOS.

Cost Analysis of Medicare Patients with Varying Complexities Who Underwent Total Knee Arthroplasty.

The effort to reduce overall healthcare costs may affect more complex patients, as their pre- and postoperative care can be substantially involved. Therefore, the purpose of this study was to use a large nationwide insurance database to compare (1) costs, (2) reimbursements, and (3) net losses of 90-day episodes of care (EOC) for total knee arthroplasty (TKA) patients according to Elixhauser's Comorbidity Index (ECI) scores. All TKAs performed between 2005 and 2014 in the Medicare Standard Analytic Files were extracted from the database and stratified based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort and control cohort were matched based on age and sex, resulting in a total of 715,398 patients included for analysis. Total EOC costs, reimbursements, and total net losses (defined as total EOC costs minus total EOC reimbursements) were compared between the cohorts. Overall, total EOC costs increased with ECI. For example, compared with the matched ECI 1 cohorts, the total EOC costs for ECI 5 patients ($56,589.19 vs. $51,747.54) were significantly greater (p < 0.01). Although reimbursements increased with increasing ECI, so did net losses. The net losses for ECI 5 patients were greater than that for ECI 1 patients ($42,309.39 vs. $40,007.82). The bundled payments for care improvement (BPCI) and comprehensive care for joint replacement (CJR) are alternative payment models that might de-incentivize treatment of more complex patients. Our study found that despite increasing reimbursements, overall costs, and therefore net losses, were greater for more complex patients with higher ECI scores.

The Effects of Opioid Use on Thromboembolic Complications, Readmission Rates, and 90-Day Episode of Care Costs After Total Hip Arthroplasty.

BACKGROUND: The purpose of this study was to investigate whether opioid use disorder (OUD) patients are at greater odds than non-opioid use disorder (NUD) patients in developing (1) thromboembolic complications; (2) readmission rates; and (3) costs of care. METHODS: All patients with a 90-day history of OUD before total hip arthroplasty (THA) were identified from a national database. Patients were matched 1:5 to controls by age, gender, Elixhauser Comorbidity Index scores, and high-risk medical comorbidities, yielding 38,821 patients with (n = 6398) and without (n = 31,883) OUD. Multivariate logistic regression analyses were performed to compare the risks of developing venous thromboembolism (deep vein thrombosis and/or pulmonary embolism) 90 days after the index procedure, 90-day readmission rates, and total global 90-day episode of care costs. RESULTS: Patients with a history of OUD were found to be at greater risk for 90-day venous thromboembolisms (2.38 vs. 1.07%; OR: 2.25, 95% CI: 1.86-2.73, P < .0001) compared with matched NUD patients. Specifically, OUD patients were at greater risk for both deep vein thromboses (2.13 vs. 0.87%; OR: 2.46, 95% CI: 2.00-3.03, P < .001) and pulmonary embolism (0.61 vs. 0.27%; OR: 2.24, 95% CI: 1.53-3.27, P < .0001). In addition, patients with OUD were at an increased risk for 90-day readmission (28.68 vs. 22.62%; OR: 1.37, 95% CI: 1.29-1.46, P < .0001) compared with controls. Primary THA patients with OUD incurred a 14.72% higher cost of care ($20,610.65 vs. $17,964.58) compared with NUD patients. CONCLUSION: These findings demonstrate that primary THA patients with a history of OUD are at greater risks for thromboembolic complications, readmissions, and higher costs of care in the 90-day postoperative period.

Patients Who Have Cannabis Use Disorder Have Higher Rates of Venous Thromboemboli, Readmission Rates, and Costs Following Primary Total Knee Arthroplasty.

BACKGROUND: Studies have shown that cannabis can interfere with hematological parameters and platelet morphology. The purpose of this study is to investigate whether patients with cannabis use disorder undergoing primary total knee arthroplasty (TKA) have higher rates of (1) venous thromboemboli (VTEs); (2) readmissions; and (3) costs. METHODS: Study group patients undergoing primary TKA were identified from a large, nationwide database. Patients who had a history of VTEs, deep vein thromboses (DVTs), pulmonary emboli (PEs), and coagulopathies before their TKA were excluded. Study group patients were matched to controls in a 1:4 ratio by age, sex, a comorbidity index, and medical comorbidities. The query yielded 18,388 patients (cannabis = 3680; controls = 14,708). Outcomes analyzed included rates of 90-day VTEs, DVTs, and PEs, in addition to 90-day readmissions and costs. A P value less than .01 was considered statistically significant. RESULTS: Patients who have cannabis use disorder were found to have significantly higher incidence and odds (2.79% vs 1.78%; odds ratio [OR], 1.58; P < .0001) of VTEs, DVTs (2.41% vs 1.44%; OR, 1.68; P < .0001), and PEs (0.97% vs 0.62%; P = .01). Readmissions were significantly higher (27.03% vs 23.18%; OR, 1.22; P < .0001) in patients who have cannabis use disorder. Patients with cannabis use disorder have significantly higher day of surgery ($14,024.88 vs $12,127.49; P < .0001) and 90-day costs ($19,155.45 vs $16,315.00; P < .0001). CONCLUSION: This study found that patients who have a cannabis use disorder have higher rates of thromboembolic complications, readmission rates, and costs following primary TKA compared to a matched cohort.

Hospital Volume and Postoperative Infections in Total Knee Arthroplasty.

BACKGROUND: The purpose of this study was to evaluate the associations of hospital volume with revision surgery for infection and superficial incisional infections. METHODS: A review of 12,541 primary total knee arthroplasties (TKAs) at a large integrated health system from 2014 to 2017 was conducted. Sixteen hospitals were classified as low-volume, medium-volume, or high-volume hospitals according to the mean number of TKAs/year (<250, 250-500, and >500, respectively). Thresholds were guided by percentiles and the literature on volume-outcome relationships. Medical records were reviewed for revision surgery for infection and superficial incisional infections during a mean 2-year review period. Multivariate analyses, adjusted for clinical and patient characteristics, were performed to evaluate the association between hospital volume and infection. RESULTS: The overall rate of revision surgery for infection was 0.7% (n = 82), and the overall rate of superficial incisional infection was 2.6% (n = 324). After accounting for potential confounders, hospital volume was not found to have a significant association with revision surgery for infection when comparing high-volume and low-volume hospitals (odds ratio, 1.615; 95% confidence interval, 0.761-3.427; P = .212) as well as when comparing high-volume and medium-volume hospitals (odds ratio, 1.464; 95% confidence interval, 0.853-2.512; P = .166). Moreover, the risk of superficial incisional infection at high-volume hospitals was similar to that at low-volume (P = .107) and medium-volume (P = .491) hospitals. CONCLUSION: Infection outcomes are quality metrics that are frequently used to compare hospitals including those of varying volumes. Using contemporary thresholds, this study found that infection rates after TKA at high-volume hospitals are comparable to low-volume and medium-volume hospitals.

Comparison of a Posterior versus Anterior Approach for Lumbar Interbody Fusion Surgery Based on Relative Value Units.

INTRODUCTION: The current value-driven healthcare system encourages physicians to continuously optimize the value of the services they provide. Relative value units (RVUs) serve as the basis of a reimbursement model linking the concept that as the effort and value of services provided to patient's increases, physician reimbursement should increase proportionately. Spine surgery is particularly affected by these factors as there are multiple ways to achieve similar outcomes, some of which require more time, effort, and risk. Specifically, as the trend of spinal interbody fusion has increased over the past decade, the optimal approach to use-posterior versus anterior lumbar interbody fusion (PLIF vs. ALIF)-has been a source of controversy. Due to potential discrepancies in effort, one factor to consider is the correlation between RVUs and the time needed to perform a procedure. Therefore, the purpose of this study was to compare: 1) mean RVUs; 2) mean operative time; and 3) mean RVUs per unit of time between PLIF and ALIF with the utilization of a national surgical database. We also performed an individual surgeon cost benefit analysis for performing PLIF versus ALIF. MATERIALS AND METHODS: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was utilized to identify 6,834 patients who underwent PLIF (CPT code: 22630) and 6,985 patients who underwent ALIF (CPT code: 22558) between 2008 and 2015. The mean operative times (in minutes), mean RVUs, and RVUs per minute were calculated and compared using the Student's t-tests. In addition, the reimbursement amount (in dollars) per minute, case, day, and year for an individual surgeon performing PLIF versus ALIF were also calculated and compared. A p-value of less than 0.05 was used as the threshold for statistical significance. RESULTS: Compared to ALIF cases, PLIF cases had longer mean operative times (203 vs. 212 minutes, p<0.001). However, PLIF cases were assigned lower mean RVUs than ALIF cases (22.08 vs. 23.52, p<0.001). Furthermore, PLIF had a lower mean RVU/minutes than ALIF cases (0.126 vs. 0.154, p<0.001). The reimbursement amounts calculated for PLIF versus ALIF were: $4.52 versus $5.53 per minute, $958.66 versus $1,121.95 per case, and $2,875.98 versus $3,365.86 per day. The annual cost difference was $78,380.92. CONCLUSION: The data from this study indicates a potentially greater annual compensation of nearly $80,000 for performing ALIF as opposed to PLIF due to a higher "hourly rate" for ALIF as is noted by the significantly greater RVU per minute (0.154 vs. 0.126 RVU/minutes). These results can be used by spine surgeons to design more appropriate compensation effective practices while still providing quality care.

Surgical and Medical Costs for Fibromyalgia Patients Undergoing Total Knee Arthroplasty.

The potential added costs of managing fibromyalgia patients after total knee arthroplasty (TKA) have not been assessed. Therefore, the purpose of this study was to perform a cost analysis of fibromyalgia versus nonfibromyalgia patients who underwent TKA. Specifically, we evaluated the following episodes of care: (1) readmission rates, (2) total costs, (3) total reimbursements, and (4) net losses for surgical and medical complications. Patients who underwent TKAs between 2005 and 2014 from the Medicare Standard Analytical Files of the PearlDiver supercomputer were propensity score matched by patients with and without fibromyalgia in a 1:1 ratio based on age, sex, and the Charlson Comorbidity Index, yielding a total of 305,510 patients distributed equally between the cohorts for analysis. Odds ratios (ORs), 95% confidence intervals (CIs), and p-values were calculated. Mean costs, total costs, and total reimbursements were assessed as along with total net losses, which were defined as total costs minus total reimbursements. Fibromyalgia patients had similar 90-day readmission rates compared with nonfibromyalgia patients (OR: 1.03; 95% CI: 1.00-1.06; p = 0.06) but incurred lower readmission costs (US$2,318,384,295 vs. US$2,534,482,404; p < 0.001). Although fibromyalgia patients had higher total reimbursements for medical complications ($27,758,057 vs. US$18,780,610; p < 0.001), the increased management costs (US$106,049,870 vs. US$66,080,469; p < 0.001) led to greater net losses (US$78,291,813 vs. US$47,299,859; p < 0.001). Similarly, although fibromyalgia patients had higher total reimbursements for surgical complications (US$94,192,334 vs. US$73,969,026; p < 0.001), the increased surgical costs (US$382,122,613 vs. US$306,359,910; p < 0.001) led to greater net losses (US$287,930,279 vs. US$232,390,884; p < 0.001). This study highlights some of the potential financial discrepancies of managing patients with fibromyalgia. Our findings suggest medical and surgical complication costs to be greater than reimbursement, resulting in overall net financial losses. These findings need to be considered in the light of health care reform and cost structuring.

A Systematic Review of Suture Technologies in Total Knee Arthroplasty.

Over time, various materials and techniques have been developed for superficial and deep wound closure. However, potential complications, such as infections and dehiscences, can still occur, driving the development of new closure modalities. As wound closure technology continues to advance and change, the need to continuously evaluate the current techniques and materials persists. Therefore, the purpose of this systematic review was to evaluate the current literature on the various closure materials and techniques utilized for total knee arthroplasty. Specifically, we evaluated: 1) closure times; 2) infections and complication rates; as well as 3) costs related to superficial and deep wound closures. Based on the findings from the current literature, barbed suture was associated with significantly shorter closing times in all five studies when compared to interrupted sutures (p<0.05). Additionally, the use of barbed sutures may result in similar postoperative complication rates. Although the cost of an individual barbed suture is potentially higher than the cost of an individual conventional suture, a knotless technique can require a shorter suture length, which might also help decrease costs.