What Drives the Material Costs of Total Knee Arthroplasty in the Operating Room?

INTRODUCTION: Approximately one-third of US healthcare spending is related to surgical care. Optimizing operating room (OR) spending is crucial, specifically for high-volume procedures like total knee arthroplasty (TKA). Therefore, the primary objective was to identify leading material drivers of cost for TKA procedures within the OR. MATERIALS AND METHODS: Patients who underwent a primary, elective TKA from 2018 to 2019 were included (n=8,672). Intraoperative cost details for each TKA patient were captured from the Vizient Clinical Database Resource Manager (CDB/RM) data. Each cost type was categorized into (1) implant, (2) disposables, (3) wound care, and (4) miscellaneous. RESULTS: 7,124 patients undergoing primary TKA were included. Implant-related costs accounted for 87.3% of cost, disposable materials covered 10.7%, and wound care products took 2%. The leading subcategories of implant costs were primary prosthetics (85.1%), revision prosthetics (9.9%), cement (2.8%), and implant instruments (1.7%). Within disposables, surgical products accounted for 81.3% of the cost, patient care products for 8.9%, medical apparel for 7.9%, and electrolytes for 1.8%. For an average individual TKA procedure, 86.4% (±4.4) of total cost went towards the implant, 10.7% (±3.4) towards disposable materials, and 1.6% (±1.4) to wound care products. Within the implant category, 92.5% (± 12.8) of costs were associated with primary implants, 13.3% (± 6.9) with instruments, and 2.5% (± 2.8) with cement. CONCLUSIONS: The primary operative material expense category was costs associated with the TKA prosthesis and its fixation followed by disposable materials. A large amount of variation exists in the percent of the total cost for a given TKA procedure that can be attributed to each category.

Simultaneous bilateral total knee arthroplasty has higher in-hospital complications than both staged surgeries: a nationwide propensity score matched analysis of 38,764 cases.

PURPOSE: To investigate (1) healthcare utilization, (2) in-hospital metrics and (3) total in-hospital costs associated with simultaneous versus staged BTKA while evaluating staged BTKA as a single process consisting of two combined episodes. METHODS: The national readmissions database was reviewed for simultaneous and staged (two primary unilateral TKAs12 months apart) BTKA patients (2016-2017). A total of 19,382 simultaneous BTKAs were identified, and propensity score matched (1:1) to staged BTKA patients (19,382 patients; 38,764 surgeries) based on demographics, comorbidities, and socioeconomic determinants. Outcomes included healthcare utilization [length of stay (LOS) and discharge disposition], in-hospital periprosthetic fractures, non-mechanical complications, and costs. Staged BTKA was evaluated as one process consisting of two episodes. For each staged patient, continuous outcomes were evaluated via the sum of both episodes. Categorical outcomes were added, and percents were expressed relative to total number of surgeries (n = 38,764). RESULTS: Simultaneous BTKA had longer LOS (5.0 days ± 4.7 vs. 4.5 days ± 3.5; p < 0.001), higher non-home discharge [36.9% (n = 7150/19,382) vs. 13.6% (n = 5451/38,764)], in-hospital periprosthetic fractures [0.13% (26/19,382) vs. 0.08% (31/38,764); p = 0.049], any non-mechanical complication [33.76% (6543/19,382) vs.15.93% (6177/38,764); p < 0.0001], hematoma/seroma formation [0.11% (22/19,382) vs. 0.05% (20/38,764); p = 0.0088], wound disruption [0.08% (16/19,382) vs. 0.04% (16/38,764); p = 0.0454], and any infection [1.13% (219/19,382) vs. 0.50% (194/38,764); p < 0.0001]. Average in-hospital costs for the two staged BTKA episodes combined were $5006 higher than those of simultaneous BTKA ($28,196 ± $18,488 vs. $33,202 ± $15,240; p < 0.001). CONCLUSION: Simultaneous BTKA had higher healthcare utilization and in-hospital complications than both episodes of staged BTKA combined, with a minimal in-hospital cost savings. Future studies are warranted to further explore patient selection who would benefit from BTKA.

Racial Disparities in Outcomes After THA and TKA Are Substantially Mediated by Socioeconomic Disadvantage Both in Black and White Patients.

BACKGROUND: Demographic factors have been implicated in THA and TKA outcome disparities. Specifically, patients' racial backgrounds have been reported to influence outcomes after surgery, including length of stay, discharge disposition, and inpatient readmissions. However, in the United States, health-impacting socioeconomic disadvantage is sometimes associated with racial differences in ways that can result in important confounding, thereby raising the question of whether race-associated post-THA/TKA adverse outcomes are an independent function of race or a byproduct of confounding from socioeconomic deprivation, which is potentially addressable. To explore this, we used the Area Deprivation Index (ADI) as a proxy for socioeconomic disadvantage, since it is a socioeconomic parameter that estimates the likely deprivation associated with a patient's home address. QUESTIONS/PURPOSES: The goal of this study was to investigate (1) whether race (in this study, Black versus White) was independently associated with adverse outcomes, including prolonged length of stay (LOS > 3 days), nonhome discharge, 90-day readmission, and emergency department (ED) visits while controlling for age, gender, BMI, smoking, Charlson comorbidity index (CCI), and insurance; and (2) whether socioeconomic disadvantage, measured by ADI, substantially mediated any association between race and any of the aforementioned measured outcomes. METHODS: Between November 2018 and December 2019, 2638 underwent elective primary THA and 4915 patients underwent elective primary TKA for osteoarthritis at one of seven hospitals within a single academic center. Overall, 12% (742 of 5948) of patients were Black and 88% (5206 of 5948) were White. We included patients with complete demographic data, ADI data, and who were of Black or White race; with these criteria, 11% (293 of 2638) were excluded in the THA group, and 27% (1312 of 4915) of patients were excluded in the TKA group. In this retrospective, comparative study, patient follow-up was obtained using a longitudinally maintained database, leaving 89% (2345 of 2638) and 73% (3603 of 4915) for analysis in the THA and TKA groups, respectively. For both THA and TKA, Black patients had higher ADI scores, slightly higher BMIs, and were more likely to be current smokers at baseline. Furthermore, within the TKA cohort there was a higher proportion of Black women compared with White women. Multivariable regression analysis was utilized to assess associations between race and LOS of 3 or more days, nonhome discharge disposition, 90-day inpatient readmission, and 90-day ED admission, while adjusting for age, gender, BMI, smoking, CCI, and insurance. This was followed by a mediation analysis that explored whether the association between race (the independent variable) and measured outcomes (the dependent variables) could be partially or completely attributable to confounding from the ADI (the mediator, in this model). The mediation effect was measured as a percentage of the total effect of race on the outcomes of interest that was mediated by ADI. RESULTS: In the THA group, after adjusting for age, gender, BMI, smoking, CCI, and insurance, White patients had lower odds of experiencing an LOS of 3 days or more (OR 0.43 [95% confidence interval (CI) 0.31 to 0.59]; p < 0.001) and nonhome discharge (OR 0.39 [95% CI 0.27 to 0.56]; p < 0.001). In mediation analysis, ADI partially explained (or mediated) 37% of the association between race and LOS of 3 days or more (-0.043 [95% CI -0.063 to -0.026]; p < 0.001) and 40% of the association between race and nonhome discharge (0.041 [95% CI 0.024 to 0.059]; p < 0.001). However, a smaller direct association between race and both outcomes was observed (LOS 3 days or more: -0.075 [95% CI -0.13 to -0.024]; p = 0.004; nonhome discharge: 0.060 [95% CI 0.016 to 0.11]; p = 0.004). No association was observed between race and 90-day readmission or ED admission in the THA group. In the TKA group, after adjusting for age, gender, BMI, smoking, CCI, and insurance, White patients had lower odds of experiencing an LOS of 3 days or more (OR 0.41 [95% CI 0.32 to 0.54]; p < 0.001), nonhome discharge (OR 0.44 [95% CI 0.33 to 0.60]; p < 0.001), 90-day readmission (OR 0.54 [95% CI 0.39 to 0.77]; p < 0.001), and 90-day ED admission (OR 0.60 [95% CI 0.45 to 0.79]; p < 0.001). In mediation analysis, ADI mediated 19% of the association between race and LOS of 3 days or more (-0.021 [95% CI -0.035 to -0.007]; p = 0.004) and 38% of the association between race and nonhome discharge (0.029 [95% CI -0.016 to 0.040]; p < 0.001), but there was also a direct association between race and these outcomes (LOS 3 days or more: -0.088 [95% CI -0.13 to -0.049]; p < 0.001; nonhome discharge: 0.046 [95% CI 0.014 to 0.078]; p = 0.006). ADI did not mediate the associations observed between race and 90-day readmission and ED admission in the TKA group. CONCLUSION: Our findings suggest that socioeconomic disadvantage may be implicated in a substantial proportion of the previously assumed race-driven disparity in healthcare utilization parameters after primary total joint arthroplasty. Orthopaedic surgeons should attempt to identify potentially modifiable socioeconomic disadvantage indicators. This serves as a call to action for the orthopaedic community to consider specific interventions to support patients from vulnerable areas or whose incomes are lower, such as supporting applications for nonemergent medical transportation or referring patients to local care coordination agencies. Future studies should seek to identify which specific resources or approaches improve outcomes after TJA in patients with socioeconomic disadvantage. LEVEL OF EVIDENCE: Level III, therapeutic study.

Nutritional Assessment and Interventions in Elective Hip and Knee Arthroplasty: a Detailed Review and Guide to Management.

PURPOSE OF REVIEW: 8.5 to 50% of total joint arthroplasty (TJA) patients are reported to have preoperative malnutrition. The narrative review identifies the relationship between preoperative malnutrition for TJA patients and postoperative outcomes as well as the use of perioperative nutritional intervention to improve postoperative complications. RECENT FINDINGS: Biochemical/laboratory, anthropometric, and clinical measures have been widely used to identify preoperative nutritional deficiency. Specifically, serum albumin is the most prevalent used marker in TJA because it has been proven to be correlated with protein-energy malnutrition due to the surgical stress response. However, there remains a sustained incidence of preoperative malnutrition in total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients due to a lack of agreement among the available nutritional screening tools and utilization of isolated laboratory, anthropometric, and clinical variables. Previous investigations have also suggested preoperative malnutrition to be a prognostic indicator of complications in general, cardiac, vascular, and orthopaedic surgery specialties. Serum albumin, prealbumin, transferrin, and total lymphocyte count (TLC) can be used to identify at-risk patients. It is important to employ these markers in the preoperative setting because malnourished TKA and THA patients have shown to have worse postoperative outcomes including prolonged length, increased reoperation rates, increased infection rates, and increased mortality rates. Although benefits from high-protein and high-anti-inflammatory diets have been exhibited, additional research is needed to confirm the use of perioperative nutritional intervention as an appropriate treatment for preoperative TJA patients.

Procedures With Longer Intraoperative Times Undervalue Surgeon Work in Total Joint Arthroplasty: A Large, Nationwide Database Study.

BACKGROUND: Work relative value units (wRVUs) measure a surgeon's time and intensity required to perform the pre-service, intra-service, and post-service work of a surgical procedure and are commonly used to compare a physician's work between different procedures. Previous literature across multiple specialties report that longer, often revision, operations are undervalued when compared to primary procedures. Our study aims to analyze the differences in intra-operative time, and its corresponding wRVU/h between the Medicare benchmarks and real-world time-stamped data for total joint arthroplasty procedures. METHODS: Thirteen primary and revision hip and knee arthroplasty procedures were identified, and intra-operative times were collected using the National Surgical Quality Improvement Program databases from 2014 to 2019. The Relative Value Scale Update Committee's (RUC) estimated median intra-operative times for each procedure was compared to the calculated median intra-operative times from National Surgical Quality Improvement Program, as were their corresponding wRVU/h. Procedures were additionally stratified by "long" (>110 minutes) and "short" (≤110 minutes) intra-operative times. RESULTS: The RUC over-estimated intra-operative time by 35.24% on average and this overestimation was more profound in longer operations than shorter operations (47.75% vs 15.22%, P = .011). The RUC intensity per unit time values (wRVU/h) between "long" and "short" procedures were significantly different (P < .001) and showed the undervaluation of intensity for the longer procedures by an average of 3.47 wRVU/h. CONCLUSION: Our study provides further evidence that physician work is undervalued in revision total hip and knee surgeries.

NarxCare Scores Greater Than 300 Are Associated with Adverse Outcomes After Primary THA.

BACKGROUND: The association between preoperative prescription drug use (narcotics, sedatives, and stimulants) and complications and/or greater healthcare utilization (length of stay, discharge disposition, readmission, emergency department visits, and reoperation) after total joint arthroplasty has been established but not well quantified. The NarxCare score (NCS) is a weighted scalar measure of overall prescription opioid, sedative, and stimulant use. Higher scores reflect riskier drug-use patterns, which are calculated based on (1) the number of prescribing providers, (2) the number of dispensing pharmacies, (3) milligram equivalence doses, (4) coprescribed potentiating drugs, and (5) overlapping prescription days. The aforementioned factors have not been incorporated into association measures between preoperative prescription drug use and adverse events after THA. In addition, the utility of the NCS as a scalar measure in predicting post-THA complications has not been explored. QUESTIONS/PURPOSES: (1) Is the NarxCare score (NCS) associated with 90-day readmission, reoperation, emergency department visits, length of stay, and discharge disposition after primary THA; and are there NCS thresholds associated with a higher risk for those adverse outcomes if such an association exists? (2) Is there an association between the type of preoperative active drug prescription and the aforementioned outcomes? METHODS: Of 3040 primary unilateral THAs performed between November 2018 and December 2019, 92% (2787) had complete baseline information and were subsequently included. The cohort with missing baseline information (NCS or demographic/racial determinants; 8%) had similar BMI distribution but slightly younger age and a lower Charlson Comorbidity Index (CCI). Outcomes in this retrospective study of a longitudinally maintained institutional database included 90-day readmissions (all-cause, procedure, and nonprocedure-related), reoperations, 90-day emergency department (ED) visits, prolonged length of stay (> 2 days), and discharge disposition (home or nonhome). The association between the NCS category and THA outcomes was analyzed through multivariable regression analyses and a confirmatory propensity score-matched comparison based on age, gender, race, BMI, smoking status, CCI, insurance status, preoperative diagnosis, and surgical approach, which removed significant differences at baseline. A similar regression model was constructed to evaluate the association between the type of preoperative active drug prescription (opioids, sedatives, and stimulants) and adverse outcomes after THA. RESULTS: After controlling for potentially confounding variables like age, gender, race, BMI, smoking status, CCI, insurance status, preoperative diagnosis, and surgical approach, an NCS of 300 to 399 was associated with a higher odds of 90-day all-cause readmission (odds ratio 2.0 [95% confidence interval 1.1 to 3.3]; p = 0.02), procedure-related readmission (OR 3.3 [95% CI 1.4 to 7.9]; p = 0.006), length of stay > 2 days (OR 2.2 [95% CI 1.5 to 3.2]; p < 0.001), and nonhome discharge (OR 2.0 [95% CI 1.3 to 3.1]; p = 0.002). A score of 400 to 499 demonstrated a similar pattern, in addition to a higher odds of 90-day emergency department visits (OR 2.2 [95% CI 1.2 to 3.9]; p = 0.01). After controlling for potentially confounding variables like age, gender, race, BMI, smoking status, CCI, insurance status, preoperative diagnosis, and surgical approach, we found no clinically important association between an active opioid prescription and 90-day all-cause readmission (OR 1.002 [95% CI 1.001 to 1.004]; p = 0.05), procedure-related readmission (OR 1.003 [95% CI 1.001 to 1.006]; p = 0.02), length of stay > 2 days (OR 1.003 [95% CI 1.002 to 1.005]; p < 0.001), or nonhome discharge (OR 1.002 [95% CI 1.001 to 1.003]; p = 0.019); the large size of the database allowed us to find statistical associations, but the effect sizes are so small that the finding is unlikely to be clinically meaningful. A similarly small association that is unlikely to be clinically important was found between active sedative use and 90-day ED visits (OR 1.002 [95% CI 1.001 to 1.004]; p = 0.02). CONCLUSION: Preoperative prescription drug use, as reflected by higher NCSs, has a dose-response association with adverse outcomes after THA. Surgeons may use the preoperative NCS to initiate and guide a patient-centered discussion regarding possible postoperative risks associated with prescription drug-use patterns (sedatives, opioids, or stimulants). An interdisciplinary approach can then be initiated to mitigate unfavorable patterns of prescription drug use and subsequently lower patient NCSs. However, given its nature and its reflection of drug-use patterns rather than patients' current health status, the NCS does not qualify as a basis for surgical denial or ineligibility. LEVEL OF EVIDENCE: Level III, diagnostic study.

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.

Effects of a Total Knee Arthroplasty Care Pathway on Cost, Quality, and Patient Experience: Toward Measuring the Triple Aim.

BACKGROUND: Care pathways are increasingly important as the shift toward value-based care continues; however, there is an inconsistent literature regarding their efficacy. The authors hypothesized that a total knee arthroplasty (TKA) care pathway, at a multihospital health system, would decrease cost, length of stay (LOS), discharges to inpatient facilities, postoperative complications at 90 days, and improve patient experience. METHODS: A historical control study with multivariable regression was used to determine the association of an evidence-based care pathway with episode of care cost, LOS, discharge disposition, 90-day postoperative complications, and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores. RESULTS: In total, 6760 primary TKA surgeries were analyzed. Multivariable regression demonstrated that the full protocol period was associated with a decrease in episode of care costs (-8.501%, 95% confidence interval [CI] -9.639 to -7.350), a decrease in LOS (-26.966%, 95% CI -28.516 to -25.382), and an increase in discharges to home (odds ratio [OR] 3.838, 95% CI 3.318-4.446). The full protocol was not associated with a change in 90-day complications (OR 1.067, 95% CI 0.905-1.258) or patient willingness to recommend (OR 1.06, 95% CI 0.72-1.55). Adjusted episode of care cost savings, normalized to average national Medicare reimbursement, were $2360 per patient. CONCLUSION: TKA care pathways are an effective tool for standardizing care and reducing costs across a large health system. Further investigations are needed to develop interventions to consistently reduce complications. National scale implementation of care pathways in TKA could lead to estimated cost reductions of approximately $1.6 billion annually.

Emergency Department Visits Within Thirty Days of Discharge After Primary Total Hip Arthroplasty: A Hidden Quality Measure.

BACKGROUND: Thirty-day hospital readmissions following total hip arthroplasty (THA) have received increasing scrutiny by policy makers and hospitals. Emergency department (ED) visits may not necessarily result in an inpatient readmission but can be a measure of performance and can incur costs to the health system. The purpose of this study is to describe the following: (1) the frequency and subsequent disposition; (2) patient characteristics; (3) reasons; and (4) potential risk factors for ED visits that did not result in a readmission within 30 days of discharge after THA. METHODS: All primary THAs performed at a large healthcare system between 2013 and 2015 were identified. Patients who received unplanned hospital services for complications within 30 days following surgery were identified and analyzed. A multiple regression analysis was utilized to identify risk factors predisposing for returning to the ED without readmission. RESULTS: From a total of 6270 primary THAs, 440 patients (7%) had an unplanned return to the hospital within 30 days. Of those, 227 (3.6%) patients presented to the ED and were not readmitted. Higher percentage of African Americans was noted among patients who returned to the ED versus those who did not (20.2% vs 9.8%, P < .01). The most common medical diagnoses were nonspecific medical symptoms (24.8%) followed by minor gastrointestinal problems (10.5%). The most common surgery-related diagnoses were pain and swelling (35%), followed by wound complications (12%) and hip dislocations (7.3%). Nearly 50% of wound complications and 40% of hip dislocations were managed and discharged from the ED without a readmission. Both African Americans (odds ratio 2.28, 95% confidence interval 1.55-3.36) and home discharge (odds ratio 1.90, 95% confidence interval 1.28-2.82) were independent risk factors for return to the ED without readmission. CONCLUSION: ED visits that do not result in hospital readmissions, many of which may be due to serious complications, are more frequent than inpatient readmission. This is extremely relevant to policy makers and quality metrics, especially as comprehensive and bundled payment initiatives become more prevalent.

Practice Management Strategies Among Current Members of the American Association of Hip and Knee Surgeons.

BACKGROUND: At the 2017 annual meeting of the American Association of Hip and Knee Surgeons (AAHKS), a survey was conducted to assess current practice management strategies by AAHKS members. METHODS: During the annual AAHKS meeting, a survey was conducted using an audience response system. The moderator queried AAHKS members with respect to a variety of practice management issues. The survey included both multiple choice and yes or no questions. The answers were collected in a central database and provided to the audience in real time. RESULTS: The survey responses provided valuable information with respect to the practice activity of AAHKS members. A total of 47% of AAHKS members are in private practice, and fee for service remains the major form of compensation for 39% of the membership. Participation in bundled-payment programs was 46%. A minority (22%) had performed a total joint arthroplasty in an outpatient surgery center. CONCLUSION: This survey of AAHKS members' practice patterns provided interesting data. Future surveys should determine potential changes in practice activity related to private practice, fee for service compensation, the use of outpatient surgery centers for total joint arthroplasty, and surgeon participation in bundled-payment programs.

Day of Surgery Affects Length of Stay and Charges in Primary Total Hip and Knee Arthroplasty.

BACKGROUND: Length of hospital stay (LOS) is a large driver of cost after primary total joint arthroplasty (TJA). Strategies to decrease LOS may help reduce the economic burden of TJA. This study's aim was to investigate the effect of day of the week of surgery on mean LOS and total charges following primary total knee arthroplasty (TKA) and total hip arthroplasty (THA). METHODS: An administrative clinical database at a large US health care system was reviewed for all primary THA and TKA admissions performed between 2010 and 2012 (n = 15,237). Of these, 14,800 cases met our inclusion criteria and were analyzed. Furthermore, the cohort was divided into early (Monday/Tuesday) and late week (Thursday/Friday) surgeries, excluding Wednesday surgeries (n = 2835). Univariate and multiple regression analyses examined the effect of each variable on LOS. RESULTS: Mean LOS for THA and TKA on Monday was 3.54 and 3.35 days and increased to 4.12 and 3.66 days on Friday (P < .0001), respectively. Late vs early week admissions had 0.358 (95% confidence interval: 0.29-0.425, P < .001) additional hospital days. Increased age (0.003 days per unit increase in age, P = .02) and severity of illness score (0.781 days per level increase, P < .001) were associated with increased LOS. Late week surgery had a greater effect on LOS for TKA than for THA. TKAs were associated with higher charges for late week surgery vs early week surgery (P < .001). CONCLUSION: Late week TJA cases, older age, and increasing severity of illness score were associated with increased LOS. Furthermore, late week TKA was associated with increased total charges.