Characterizing the Native Microbiome Using Next-Generation Sequencing of Bilateral 'Aseptic' Knees.

BACKGROUND: Next generation sequencing (NGS) has proven ability to identify organisms beyond those identified through traditional culture-based techniques in cases of suspected prosthetic joint infection. However, there is concern that some microorganisms identified may represent the natural joint microbiome rather than pathogenic agents. This work sought to evaluate the presence of microorganisms identified with NGS in bilateral native, presumed "aseptic" knees with osteoarthritis. METHODS: There were 40 patients undergoing primary unilateral (30) or bilateral (10) total knee arthroplasty enrolled prospectively. During surgery, samples of fluid and tissue were obtained from operative knees, and joint fluid was obtained from nonoperative knees. Samples were sent for NGS analysis and processed according to manufacturer protocols. Patient age, body mass index, comorbidities, prior history of injections, and grade of arthritis were evaluated for association with positive NGS results. RESULTS: There were 3 of 80 samples (3.8%) that demonstrated positive NGS. There were two of these that had multiple microorganisms identified (1 knee with 4 microorganisms; 1 knee with 2 microorganisms). An additional 2 samples had positive NGS results below the manufacturer's threshold for reporting. The most common organism identified was Cutibacterium acnes, present in 2 of the 3 positive samples. No patient baseline characteristics were associated with positive NGS results. CONCLUSIONS: Some native knee joints with osteoarthritis have positive microorganisms identified with NGS. The presence of microorganisms in the native knee has important implications for better understanding the native joint microbiome as well as utilization of NGS in cases of suspected prosthetic joint infection.

Do Patient-Reported Outcomes Reflect Objective Measures of Function? Implications for Total Knee Arthroplasty.

BACKGROUND: Patient-reported outcomes (PROs) are used in research, clinical practice, and by federal reimbursement models to assess outcomes for patients who have knee osteoarthritis (OA) and total knee arthroplasty (TKA). We examined a large cohort of patients to determine if commonly used PROs reflect observed evaluation as measured by standardized functional tests (SFTs). METHODS: We used data from the Osteoarthritis Initiative, a 10-year observational study of knee osteoarthritis patients. Two cohorts were examined: 1) participants who received TKA (n = 281) and 2) participants who have native OA (n = 4,687). The PROs included Western Ontario and McMaster Osteoarthritis Index (WOMAC), Knee Injury and Osteoarthritis Outcome Score (KOOS), 12-Item Short Form Health Survey (SF-12), and Intermittent and Constant Pain Score (ICOAP). The SFTs included 20 m and 400 meter (m) walks and chair stand pace. Repeated measures correlation coefficients were used to determine the relationship between PROs and SFTs. RESULTS: The PROs and SFTs were not strongly correlated in either cohort. The magnitude of the repeated measures correlation (rrm) between KOOS, WOMAC, SF-12, and ICOAP scores and SFT measurements in native knee OA patients ranged as follows: 400 m walk pace (0.08 to 0.20), chair stand pace (0.05 to 0.12), and 20 m pace (0.02 to 0.21), all with P < .05. In the TKA cohort, values ranged as follows: 400 M walk pace (0.00 to 0.29), chair stand time (0.02 to 0.23), and 20 M pace (0.03 to 0.30). Due to the smaller cohort size, the majority, but not all had P values < .05. CONCLUSION: There is not a strong association between PROs and SFTs among patients who have knee OA or among patients who received a TKA. Therefore, PROs should not be used as a simple proxy for observed evaluation of physical function. Rather, PROs and SFTs are complementary and should be used in combination for a more nuanced and complete characterization of outcome.

Universal Screening for Malnutrition Prior to Total Knee Arthroplasty Is Cost-Effective: A Markov Analysis.

BACKGROUND: Patients undergoing total knee arthroplasty (TKA) who have malnutrition possess an increased risk of periprosthetic joint infection (PJI). Although malnutrition screening and intervention may decrease the risk of PJI, it utilizes healthcare resources. To date, no cost-effectiveness analyses have been performed on the screening and treatment of malnutrition prior to TKA. METHODS: A Markov model projecting lifetime costs and quality-adjusted life years (QALYs) was built to determine the cost-effectiveness of malnutrition screening and intervention for TKA patients from a societal perspective. Costs, health state utilities, and state transition probabilities were obtained from previously published literature, hospital costs at our institution, and expert opinions. Two important assumptions included that 30% of patients would be malnourished and that a malnutrition intervention would be 50% effective. The primary outcome of this study was the incremental cost-effectiveness ratio, with a willingness-to-pay threshold of $100,000 per QALY. One-way and two-way sensitivity analyses were performed to evaluate model parameter assumptions. RESULTS: When using the base case values, universal malnutrition screening and intervention was cost-effective compared to no malnutrition screening or intervention, with an incremental cost-effectiveness ratio of $6,454 per QALY. Universal screening and intervention remained cost-effective, provided the cost of screening remained less than $3,373, the cost of nutritional intervention remained less than $12,042, the prevalence of malnutrition among surgical candidates was higher than 2%, and the risk of PJI among patients with malnutrition was greater than 1%. CONCLUSION: Universal preoperative malnutrition screening and intervention among TKA candidates is cost-effective at parameters encountered in clinical practice. Nutritional optimization programs should be considered to facilitate malnutrition screening and intervention and future studies should evaluate their efficacy at lowering PJI risk.

Does Time to Reimplantation After Explant for Prosthetic Joint Infection Influence the Likelihood of Successful Outcomes at 2 Years?

BACKGROUND: Consensus recommendations are lacking regarding appropriate timing of reimplantation following 2-stage resection arthroplasty for prosthetic joint infections (PJIs). We investigated whether the time from resection arthroplasty to reimplantation was associated with treatment outcome at 2 years. METHODS: Retrospective cohort review was conducted for 101 patients undergoing resection arthroplasty with an antibiotic spacer for PJI at a single tertiary academic referral institution. Time from explantation and spacer placement to reimplantation was categorized into 3 groups: <12, 12-18, and >18 weeks. Baseline patient and treatment course characteristics across these groups were obtained. Multivariate binary logistic regression was used to characterize association between treatment failure and time to reimplantation, controlling for American Society of Anesthesiologists (ASA) score and prior revision surgery. RESULTS: Time to reimplantation (TTR) >18 weeks demonstrated statistically significant increased odds of treatment failure, after controlling for ASA score and prior revision surgery (odds ratio 7.00, confidence interval 2.14-25.42, P = .002). After excluding patients requiring second spacer or Girdlestone prior to replant, this increased odds of failure remained (odds ratio 4.12, confidence interval 1.18-15.37, P = .029). TTR groups were similar with respect to demographics, except for ASA (2.96 for time to reimplantation >18 weeks vs 2.55 for time to reimplantation <12 weeks; P = .011). Patients with TTR >18 weeks were more likely to have an unplanned readmission during the spacer period (48%, 19%, and 6% for time to reimplantation >18, 12-18, and 0-12 weeks, respectively; P < .002). CONCLUSION: Although decision regarding TTR is largely patient specific, surgeons should be aware that TTR >18 weeks may be associated with higher rates of treatment failure at 2 years.

Is the Proportion of Patients with "Successful" Outcomes After Two-stage Revision for Prosthetic Joint Infection Different When Applying the Musculoskeletal Infection Society Outcome Reporting Tool Compared with the Delphi-based Consensus Criteria?

BACKGROUND: There are a variety of criteria for defining successful treatment after two-stage exchange arthroplasty for prosthetic joint infection (PJI). To accurately assess current practices and improve techniques, it is important to first establish reliable, clinically relevant, reproducible criteria for defining persistent infection and "successful" outcomes. QUESTION/PURPOSE: Is the proportion of patients considered to have successful management of PJI after two-stage resection arthroplasty smaller using 2019 Musculoskeletal Infection Society Outcome Reporting Tool (MSIS ORT) criteria than when using a Delphi-based criterion? METHODS: Patients were retrospectively identified by Current Procedural Technology codes for resection arthroplasty with placement of an antibiotic spacer for infected THA or TKA between April 1, 2011 and January 1, 2018 at a tertiary academic institution. The initial review identified 180 procedures during this time period. Nine patients had documented transition of care outside the system, 16 did not meet the MSIS criteria for chronic PJI, and 34 patients were excluded for lack of documented 2-year follow-up. The mean follow-up duration of the final cohort of 121 procedures in 120 patients was approximately 3.7 ± 1.7 years. Forty percent (49 of 121) of the procedures were performed on the hip and 60% (72 of 121) were performed on the knee. The mean time from primary THA or TKA to explantation was 4.6 years. The mean age of the patients at the time of explantation was 66 years. The mean time from spacer placement to replantation was 119 days. The final 121 patient records were reviewed by a single reviewer and outcomes were subsequently assigned to "successful" and "unsuccessful" outcomes based on the MSIS ORT and Delphi-based consensus criterion, two previously published and validated multidimensional definition schemes. Chi-squared and t-test analyses were performed to identify differences between "successful" and "unsuccessful" outcomes with respect to patient baseline characteristics using each outcome-reporting criterion. RESULTS: Overall, the MSIS ORT classified a smaller proportion of patients as having a "successful" treatment outcome after two-stage exchange arthroplasty for PJI than the Delphi-based consensus method did (MSIS: 55% [63 of 114], Delphi: 70% [71 of 102]; relative risk 0.79 [0.65-0.98]; p = 0.03). However, there were no differences when stratified by hips (MSIS: 55% [26 of 47], Delphi: 74% [29 of 39]; relative risk 0.74 [0.54-1.02]; p = 0.07) and knees (MSIS: 55% [37 of 67], Delphi: 67% [42 of 63]; relative risk 0.83 [0.63-1.09]; p = 0.19). Notably, the disease of 16% of the patients (19 of 121) was not classifiable per the Delphi method because these patients never underwent reimplantation. CONCLUSION: The present study demonstrated that the MSIS criteria detect fewer instances of "successful" infection management after two-stage resection arthroplasty for PJI than the Delphi method in this cohort. Based on these findings, researchers and surgeons should aim for standardized reporting after intervention for PJI to allow for a better comparison of outcomes across different studies and ultimately allow for improved techniques and approaches to the treatment of PJI. LEVEL OF EVIDENCE: Level III, diagnostic study.

The Emergence of Collaboration in the Education of Fellows and Residents during COVID-19.

BACKGROUND: COVID-19 has created a void in surgical education. Given social distancing and postponed surgeries, unique educational opportunities have arisen. Attendings from 10 adult reconstruction fellowships led a multi-institution web-based weekly collaborative, the Arthroplasty Consortium (AC), developed to educate trainees through complex arthroplasty case-based discussions. METHODS: We performed an anonymous survey of AC participants and American Association of Hip and Knee Surgeons (AAHKS) adult reconstruction fellows. Participants were polled with regards to educational tools used before and after COVID-19 and their value. Specifically, participation in the AC, AAHKS FOCAL (Fellows Orthopedic Continued AAHKS Learning) lectures, institutional lectures, industry lectures, textbooks, online videos, journal articles, and webinars was assessed. RESULTS: Fifty-seven participants responded with 49 (86%) at the fellow level. There was an increase in the use of web-based learning, including the AC (Not applicable pre, 61% post), AAHKS FOCAL lectures (Not applicable pre, 82% post), industry lectures (53% pre, 86% post), and AAHKS/AAOS webinars (35% pre, 56% post). Usage declined with institutional lectures (89% pre, 80% post), textbooks (68% pre, 49% post), and journal articles (97% pre, 90% post), with minimal change in the use of online surgical videos (84% pre, 82% post). The majority of fellows not involved in the AC would like to see the addition of a multi-institutional case conference added to fellowship education. Of AC participants, the 2 most valuable educational tools were the AC and FOCAL lectures. CONCLUSION: Trainee education has changed post-COVID-19 with a greater focus on web-based learning. Multi-institutional collaborative lectures and case-based discussions have significant perceived value among trainees and should be considered important educational tools post-COVID 19.

Perioperative Antibiotic Prophylaxis: Single and 24-Hour Antibiotic Dosages are Equally Effective at Preventing Periprosthetic Joint Infection in Total Joint Arthroplasty.

BACKGROUND: Perioperative antibiotic prophylaxis is used to prevent surgical site infection and periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). Secondary to a national shortage of cefazolin, patients at our institution began receiving a single preoperative prophylactic antibiotic dose for primary TJA and no 24-hour postoperative antibiotic prophylaxis. The purpose of the study was to compare the efficacy of single-dose antibiotic use versus 24-hour dosing of prophylactic antibiotics in the prevention of acute PJI and short-term complications after primary TJA. METHODS: A retrospective review of 3317 patients undergoing primary TJA performed from January 2015 to December 2019 identified 554 patients who received a single dose of preoperative antibiotic prophylaxis during the antibiotic shortage and 2763 patients who received post-TJA 24-hour antibiotic prophylaxis before the shortage. Patient records were evaluated for acute PJI, superficial infection, 90-day reoperation, and 90-day complications. RESULTS: There were no significant differences in patient characteristics between single-dose and 24-hour antibiotic groups. Similarly, there were no significant differences in rates of acute PJI (0.7% vs 0.2%; P = .301), superficial infection (2.4% vs 1.4%; P = .221), 90-day reoperation (2.1% vs 1.1%; P = .155), and 90-day complications (9.9% vs 7.9%; P = .169) between single and 24-hour antibiotic dose. Post hoc power analysis demonstrated adequate sample size, beta = 93%. CONCLUSION: Single-dose prophylactic antibiotics did not lead to an increased risk of acute PJI or short-term complications after TJA. Our study suggests that administration of a single antibiotic dose may be safely considered in patients undergoing routine primary TJA.

Metric Selection, Metric Targets, and Risk Adjustment Should be Considered in the Design of Gainsharing Models for Bundled Payment Programs in Total Joint Arthroplasty.

BACKGROUND: Under bundled payment models, gainsharing presents an important mechanism to ensure engagement and reward innovation. We hypothesized that metric selection, metric targets, and risk adjustment would impact surgeons' performance in gainsharing models. METHODS: Patients undergoing total joint arthroplasty at an urban health system from 2017 to September 2018 were included. Gainsharing metrics included the following: length of stay, % discharge-to-home, 90-day readmission rate, % of patients with episode spend under target price, and % of patients with patient-reported outcomes (PROs) collected. Four scenarios were created to evaluate how metric selection/adjustment impacted surgeons' performance designation: scenario 1 used "aspirational targets" (>60th percentile), scenario 2 used "acceptable targets" (>50th percentile), scenario 3 risk-adjusted surgeon performance prior to comparing aspirational targets, and scenario 4 included a PRO collection metric. Number of metrics achieved determined performance tier, with higher tiers getting a greater share of the gainsharing pool. RESULTS: In total, 2776 patients treated by 12 surgeons met inclusion criteria (mean length of stay 3.0 days, readmission rate 4.0%, discharge-to-home 74%, episode spend under target price 85%, PRO collection 56%). Lowering of metric targets (scenario 1 vs. 2) resulted in a 75% increase in the number of high performers and 98% of the gainsharing pool being eligible for distribution. Risk adjustment (scenario 3) caused 50% of providers to move to higher performance tiers and potential payments to increase by 28%. Adding the PRO metric did not change performance. CONCLUSION: Quality metric/target selection and risk adjustment profoundly impact surgeons' performance in gainsharing contracts. This impacts how successful these contracts can be in driving innovation and dis-incentivizing the "cherry picking" of patients. LEVEL OF EVIDENCE: Level III.

Does the Impact of Joint Arthroplasty Extend Beyond the Patient? The Effect of Total Joint Arthroplasty on Patient's Significant Others.

BACKGROUND: This prospective cohort study evaluates the impact of total hip arthroplasty and total knee arthroplasty on patient's spouses/significant others (SSOs). METHODS: Patients and SSOs were provided similar outcome metrics (Global Health Patient-Reported Outcomes Measurement Information System, Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement) at preoperative and postoperative visits. Pearson correlation was used to evaluate scores. RESULTS: Our sample included 99 patients (58 total hip arthroplasties and 41 total knee arthroplasties). We found strong correlation between patient and SSO mental status scores. We found moderate correlation for some physical function domains. CONCLUSION: SSOs closely share total joint arthroplasty patient's mental and even some of the physical burden of disease and recovery.

Do Medicare's Patient-Reported Outcome Measures Collection Windows Accurately Reflect Academic Clinical Practice?

BACKGROUND: The Comprehensive Care for Joint Replacement (CJR) mandates collection of patient-reported outcome measures (PROMs) for eligible total hip and total knee arthroplasty (THA and TKA) procedures during specific time periods that may not be attainable within routine academic practice. METHODS: We performed a retrospective analysis of prospectively collected PROM data from a 2017 cohort of primary THA and TKA patients who completed the Patient-Reported Outcomes Measurement Information System-10 global health survey in preoperative or postoperative time periods. The primary outcome was completion rates of Patient-Reported Outcomes Measurement Information System-10 per the CJR collection periods (90-0 days preoperative and 270-365 days postoperative) compared to an extended postoperative collection period of 270-396 days. Bivariate analysis and logistic regression were used to analyze the association between survey completion rates and patient characteristics. RESULTS: Of the 860 primary THAs and TKAs in 2017, 725 (84.3%) had preoperative surveys completed 90-0 days before surgery. Among the 725 patients, 215 (29.7%) completed postoperative surveys within the CJR timeline of 270-365 days. Completion increased by 120 additional surveys (+16.5%) in the additional postoperative time period of 270-396 days (P < .001). No patient or procedural factors significantly correlated with a higher likelihood of postoperative PROM completion (P > .05 for all covariates). CONCLUSION: In an academic clinical practice, completion rates of postoperative PROMs as part of routine clinical practice within the CJR mandated period was low for THA and TKA patients. CJR may consider additional time beyond 365 days to improve PROM completion rates.

What Happens to Unused Opioids After Total Joint Arthroplasty? An Evaluation of Unused Postoperative Opioid Disposal Practices.

BACKGROUND: This study evaluates the fate of unused opioids after total hip arthroplasty (THA) and total knee arthroplasty (TKA) at our facility. METHODS: Medication disposal after primary elective THA and TKA was classified as appropriate (in accordance with United States Food and Drug Administration guidelines) or inappropriate for all patients undergoing these procedures during the second half of the fiscal year 2015. RESULTS: In total, 199 THAs and 144 TKAs met inclusion criteria. Total pills prescribed were 55,635. Approximately 8925 (16%) of pills were unused. About 39.9% of patients disposed of unused opioids appropriately, while 60.1% of patients reported still having (18.5%), not knowing where they were (8.2%), or other (33.4%). There was no significant association with the type of opioid prescribed. CONCLUSION: A large volume of unused opioids were improperly disposed of after total joint arthroplasty.

A SANE Approach to Outcome Collection? Comparing the Performance of Single- Versus Multiple-Question Patient-Reported Outcome Measures After Total Hip Arthroplasty.

BACKGROUND: Several patient-reported outcome measures (PROMs) exist to measure outcomes after total hip arthroplasty (THA) but can be limited by patient-perceived burden and completion rates. We analyzed whether the modified single assessment numerical evaluation (M-SANE), a one-question PROM, would perform similarly to multiple-question PROMs among patients undergoing primary THA. METHODS: Patients undergoing THA completed the Patient-Reported Outcomes Measurement Information System-10 (PROMIS-10), the Hip Disability and Osteoarthritis Outcomes Score Junior (HOOS-Jr), and M-SANE questionnaires both preoperatively and postoperatively. The M-SANE assessment asked patients to assess their hip on a scale from 0 to 10, with 10 being the best possible score. Validity of M-SANE compared with other PROMs was determined by Spearman's correlation and floor and ceiling effects. Responsiveness was analyzed using standardized response mean (SRM). RESULTS: One hundred and thirty six patients with at least 1-year follow-up were reviewed. The average M-SANE score improved from 3.3 preoperatively to 7.1 at one year postoperatively. There was moderate to strong correlation at one-year follow-up between the M-SANE and HOOS-Jr (ρ = 0.75, P < .001) and PROMIS-10 physical component summary (ρ = 0.63, P < .001). Floor and ceiling effects of the M-SANE (floor 2.0%, ceiling 21.3%) were comparable to the HOOS-Jr (floor 0.0%, ceiling 20.8%). The responsiveness of the M-SANE after THA (SRM = 1.06, 95% CI: 0.79-1.33) was comparable to HOOS-Jr (SRM = 1.33, 95% CI: 1.08-1.59) and superior to PROMIS-10 physical component summary (SRM = 0.65, 95% CI: 0.55-0.74). CONCLUSION: The M-SANE has performed similarly across multiple psychometric properties compared with more burdensome PROMs in assessing longitudinal patient-reported outcomes after THA.

Long-Term Implant Survivorship and Modes of Failure in Simultaneous Concurrent Bilateral Total Knee Arthroplasty.

BACKGROUND: There is limited evidence describing long-term implant survivorship and modes of failure in simultaneous concurrent bilateral total knee arthroplasty (TKA). METHODS: We performed a retrospective review of 266 consecutive patients (532 knees) who underwent simultaneous concurrent bilateral TKA. We reviewed medical records for preoperative characteristics, perioperative complications, and revision surgeries. The primary outcome was TKA survivorship. Secondary outcomes included indication and type of revision surgery. We used the Kaplan-Meier method to estimate survivorship and characterize risk of revision up to 20 years post-TKA. RESULTS: Our cohort had median follow-up of 9.8 years (interquartile range, 3.9-15.9). Forty-four patients (17%) underwent revision. Revision was more common among younger and male patients. The cumulative incidence of first-time revision per knee (n = 532) was 1.27 per 100 component-years. Implant survival was 99% (confidence interval, 97%-99%) at 5 years, 92% (89%-95%) at 10 years, 83% (77%-87%) at 15 years, and 62% (50%-73%) at 20 years. Five and 10-year survivorship compared favorably to estimates of TKA survivorship in the literature. The cumulative incidence of revision surgery per patient was 1.91 per 100 component-years. Implant survival at 5-, 10-, 15-, and 20-year time points was 96% (CI, 92%-98%), 84% (77%-89%), 71% (62%-79%), and 59% (46%-70%), respectively. Aseptic loosening (40%), polyethylene wear (34%), and infection (11%) were the most common indications for revision. CONCLUSION: Simultaneous concurrent bilateral TKA is associated with a higher risk of reoperation for the patient when both knees are evaluated but similar implant survivorship to the literature when each knee was evaluated in isolation.

Third-Generation Sequencing in the Clinical Laboratory: Exploring the Advantages and Challenges of Nanopore Sequencing.

Metagenomic sequencing for infectious disease diagnostics is an important tool that holds promise for use in the clinical laboratory. Challenges for implementation so far include high cost, the length of time to results, and the need for technical and bioinformatics expertise. However, the recent technological innovation of nanopore sequencing from Oxford Nanopore Technologies (ONT) has the potential to address these challenges. ONT sequencing is an attractive platform for clinical laboratories to adopt due to its low cost, rapid turnaround time, and user-friendly bioinformatics pipelines. However, this method still faces the problem of base-calling accuracy compared to other platforms. This review highlights the general challenges of pathogen detection in clinical specimens by metagenomic sequencing, the advantages and disadvantages of the ONT platform, and how research to date supports the potential future use of nanopore sequencing in infectious disease diagnostics.

Next-Generation Sequencing vs Culture-Based Methods for Diagnosing Periprosthetic Joint Infection After Total Knee Arthroplasty: A Cost-Effectiveness Analysis.

BACKGROUND: Periprosthetic joint infection (PJI) after total knee arthroplasty is challenging to diagnose. Compared with culture-based techniques, next-generation sequencing (NGS) is more sensitive for identifying organisms but is also less specific and more expensive. To date, there has been no study comparing the cost-effectiveness of these two methods to diagnose PJI after total knee arthroplasty. METHODS: A Markov, state-transition model projecting lifetime costs and quality-adjusted life years (QALYs) was constructed to determine the cost-effectiveness from a societal perspective. The primary outcome was incremental cost-effectiveness ratio, with a willingness-to-pay threshold of $100,000/QALY. Sensitivity analyses were performed to evaluate parameter assumptions. RESULTS: At our base case values, culture was not determined to be cost-effective compared to NGS, with an incremental cost-effectiveness ratio of $422,784 per QALY. One-way sensitivity analyses found NGS to be the cost-effective choice above a pretest probability of 45.5% for PJI. In addition, NGS was cost-effective if its sensitivity was greater than 70.0% and its specificity greater than 94.1%. Two-way sensitivity analyses revealed that the pretest probability and test performance parameters (sensitivity and specificity) were the largest factors for identifying whether a particular strategy was cost-effective. CONCLUSION: The results of our model suggest that the cost-effectiveness of NGS to diagnose PJI depends primarily on the pretest probability of PJI and the performance characteristics of the NGS technology. Our results are consistent with the idea that NGS should be reserved for clinical contexts with a high pretest probability of PJI. Further study is required to determine the indications and subgroups for which NGS offers clinical benefit.

A One-Question Patient-Reported Outcome Measure Is Comparable to Multiple-Question Measures in Total Knee Arthroplasty Patients.

BACKGROUND: Patient-reported outcome measures (PROMs) are important for tracking outcomes following total knee arthroplasty (TKA) but can be limited by time constraints and patient compliance. We sought to evaluate the utility of the one-question, modified single assessment numerical evaluation (M-SANE) score in TKA patients compared to legacy PROMs. METHODS: Patients undergoing TKA completed the Patient-Reported Outcomes Measurement Information System-10 (PROMIS-10), the Knee Disability and Osteoarthritis Outcomes Score Junior (KOOS Jr), and M-SANE (modified-SANE) assessments both preoperatively and postoperatively. The M-SANE score asked patients to rate their native or prosthetic knee on a scale from 0 to 10, with 10 being the best function. M-SANE validity was determined by the Spearman's correlation between the collected PROMs and the Bland-Altman plots. PROM responsiveness was assessed using the standardized response mean. RESULTS: In total, 217 patients completed PROMs preoperatively and at 1 year postoperatively. Floor and ceiling effects of the M-SANE were higher than other PROMs but still relatively low (4%-11%). There was a moderate to strong correlation at nearly all time points between the M-SANE and KOOS Jr (ρ = 0.44-0.78, P < .001). There was a weak correlation between the M-SANE and PROMIS physical component summary at the preoperative evaluation (ρ = 0.28) but a strong correlation at 1-year follow up (0.65, P < .001). The long-term responsiveness of the M-SANE to TKA (standardized response mean [SRM] = 0.98, 95% confidence interval [CI] 0.80-1.17) was comparable to both the KOOS Jr (SRM = 1.19, 95% CI 1.00-1.38) and PROMIS physical component summary (SRM = 0.82, 95% CI 0.74-0.91). Bland-Altman plots demonstrated that the M-SANE and KOOS Jr capture combined knee pain and functionality differently. CONCLUSION: The M-SANE score was comparable to validated multiple-question PROMs in TKA patients. The demonstrated validity of the M-SANE, as well as its comparable responsiveness to more lengthy PROMs, highlights its use as a one-question PROM for assessment of patient undergoing TKA.

Defining and Optimizing Value in Total Joint Arthroplasty From the Patient, Payer, and Provider Perspectives.

BACKGROUND: The purpose of this study is to define value in bundled total joint arthroplasty (TJA) from the differing perspectives of the patient, payer/employer, and hospital/provider. METHODS: Demographic, psychosocial, clinical, financial, and patient-reported outcomes (PROs) data from 2017 to 2018 elective TJA cases at a multihospital academic health system were queried. Value was defined as improvement in PROs (preoperatively to 1 year postoperatively) for patients, improvement in PROs per $1000 of bundle cost for payers, and the normalized sum of improvement in PROs and hospital bundle margin for providers. Bivariate analysis was used to compare high value vs low value (>50th percentile vs <50th percentile). Multivariate analysis was performed to identify predictors. RESULTS: A total of 280 patients had PRO data, of which 71 had Medicare claims data. Diabetes (odds ratio [OR], 0.45; P = .02) predicted low value for patients; female gender (OR, 0.25), hypertension (OR, 0.17), pulmonary disease (OR, 0.12), and skilled nursing facility discharge (OR, 0.17) for payers (P ≤ .03 for all); and pulmonary disease (OR, 0.16) and skilled nursing facility discharge (OR, 0.19) for providers (P ≤ .04 for all). CONCLUSION: This is the first article to define value in TJA under a bundle payment model from multiple perspectives, providing a foundation for future studies analyzing value-based TJA.

Resident Participation is Not Associated With Worse Outcomes After TKA.

BACKGROUND: Approximately one-half of all US surgical procedures, and one-third of orthopaedic procedures, are performed at teaching hospitals. However, the effect of resident participation and their level of training on patient care for TKA postoperative physical function, operative time, length of stay, and facility discharge are unclear. QUESTIONS/PURPOSES: (1) Are resident participation, postgraduate year (PGY) training level, and number of residents associated with absolute postoperative Patient-Reported Outcomes Measurement Information System (PROMIS®-10) global physical function score (PCS), and achieving minimum clinically important difference (MCID) PCS improvement, after TKA? (2) Are resident participation, PGY, and number of residents associated with increased TKA operative time? (3) Are resident participation, PGY, and number of residents associated with increased length of stay after TKA? (4) Are resident participation, PGY, and number of residents associated with higher odds of patients being discharged to another inpatient facility, rather than to their home (facility discharge)? METHODS: We performed a retrospective study using a longitudinally maintained institutional registry of TKAs that included 1626 patients at a single tertiary academic institution from April 2011 through July 2016. All patients who underwent primary, elective unilateral TKA were included with no exclusions. All patients were included in the operative time, length of stay, and facility discharge models. The PCS model required postoperative PCS score (n = 1417; 87%; mean, 46.4; SD, 8.5) and the MCID PCS model required pre- and postoperative PCS (n = 1333; 82%; 55% achieved MCID). Resident participation was defined as named residents being present in the operating room and documented in the operative notes, and resident PGY level was determined by the date of TKA and its duration since the resident entered the program and using the standard resident academic calendar (July - June). Multivariable regression was used to assess PCS scores, operative time, length of stay, and facility discharge in patients whose surgery was performed with and without intraoperative resident participation, accounting for PGY training level and number of residents. We defined the MCID PCS score improvement as 5 points on a 100-point scale. Adjusting variables included surgeon, academic year, age, sex, race-ethnicity, Charlson Comorbidity Index, preoperative PCS, and patient-reported mental function, BMI, tobacco use, alcohol use, and postoperative PCS time for the PCS models. We had postoperative PCS for 1417 (87%) surgeries. RESULTS: Compared with attending-only TKAs (5% of procedures), no postgraduate year or number of residents was associated with either postoperative PCS or MCID PCS improvement (PCS: PGY-1 = -0.98, 95% CI, -6.14 to 4.17, p = 0.708; PGY-2 = -0.26, 95% CI, -2.01to 1.49, p = 0.768; PGY-3 = -0.32, 95% CI, -2.16 to 1.51, p = 0.730; PGY-4 = -0.28, 95% CI, -1.99 to 1.43, p = 0.746; PGY-5 = -0.47, 95% CI, -2.13 to 1.18, p = 0.575; two residents = 0.28, 95% CI, -1.05 to 1.62, p = 0.677) (MCID PCS: PGY-1 = odds ratio [OR], 0.30, 95% CI, 0.07-1.30, p = 0.108; PGY-2 = OR, 0.86, 95% CI, 0.46-1.62, p = 0.641; PGY-3 = OR, 0.97, 95% CI, 0.49-1.89, p = 0.921; PGY-4 = OR, 0.73, 95% CI, 0.39-1.36, p = 0.325; PGY-5 = OR, 0.71, 95% CI, 0.39-1.29, p = 0.259; two residents = OR, 1.23, 95% CI, 0.80-1.89, p = 0.337). Longer operative times were associated with all PGY levels except for PGY-5 (attending surgeon only [reference] = 85.60 minutes, SD, 14.5 minutes; PGY-1 = 100. 13 minutes, SD, 21.22 minutes, +8.44 minutes, p = 0.015; PGY-2 = 103.40 minutes, SD, 23.01 minutes, +11.63 minutes, p < 0.001; PGY-3 = 97.82 minutes, SD, 18.24 minutes, +9.68 minutes, p < 0.001; PGY-4 = 96.39 minutes, SD, 18.94 minutes, +4.19 minutes, p = 0.011; PGY-5 = 88.91 minutes, SD, 19.81 minutes, -0.29 minutes, p = 0.853) or the presence of multiple residents (+4.39 minutes, p = 0.024). There were no associations with length of stay (PGY-1 = +0.04 days, 95% CI, -0.63 to 0.71 days, p = 0.912; PGY-2 = -0.08 days, 95% CI, -0.48 to 0.33 days, p = 0.711; PGY-3 = -0.29 days, 95% CI, -0.66 to 0.09 days, p = 0.131; PGY-4 = -0.30 days, 95% CI, -0.69 to 0.08 days, p = 0.120; PGY-5 = -0.28 days, 95% CI, -0.66 to 0.10 days, p = 0.145; two residents = -0.12 days, 95% CI, -0.29 to 0.06 days, p = 0.196) or facility discharge (PGY-1 = OR, 1.03, 95% CI, 0.26-4.08, p = 0.970; PGY-2 = OR, 0.61, 95% CI, 0.31-1.20, p = 0.154; PGY-3 = OR, 0.98, 95% CI, 0.48-2.02, p = 0.964; PGY-4 = OR, 0.83, 95% CI, 0.43-1.57, p = 0.599; PGY-5 = OR, 0.7, 95% CI, 0.41-1.40, p = 0.372; two residents = OR, 0.93, 95% CI, 0.56-1.54, p = 0.766) for any PGY or number of residents. CONCLUSIONS: Our findings should help assure patients, residents, physicians, insurers, and hospital administrators that resident participation, after adjusting for numerous patient and clinical factors, does not have any association with key medical and financial metrics, including postoperative PCS, MCID PCS, length of stay, and facility discharge. Future research in this field should focus on whether residents affect knee-specific patient-reported outcomes such as the Knee Injury and Osteoarthritis Score and additional orthopaedic procedures, and determine how resident medical education can be further enhanced without compromising patient care and safety.Level of Evidence Level III, therapeutic study.

Pharmacologic Hemostatic Agents in Total Joint Arthroplasty-A Cost-Effectiveness Analysis.

BACKGROUND: Total knee and hip arthroplasties can be associated with substantial blood loss, affecting morbidity and even mortality. Two pharmacological antifibrinolytics, ε-aminocaproic acid (EACA) and tranexamic acid (TXA) have been used to minimize perioperative blood loss, but both have associated morbidity. Given the added cost of these medications and the risks associated with then, a cost-effectiveness analysis was undertaken to ascertain the best strategy. METHODS: A cost-effectiveness model was constructed using the payoffs of cost (in United States dollars) and effectiveness (quality-adjusted life expectancy, in days). The medical literature was used to ascertain various complications, their probabilities, utility values, and direct medical costs associated with various health states. A time horizon of 10 years and a willingness to pay threshold of $100,000 was used. RESULTS: The total cost and effectiveness (quality-adjusted life expectancy, in days) was $459.77, $951.22, and $1174.87 and 3411.19, 3248.02, and 3342.69 for TXA, no pharmacologic hemostatic agent, and EACA, respectively. Because TXA is less expensive and more effective than the competing alternatives, it was the favored strategy. One-way sensitivity analyses for probability of transfusion and myocardial infarction for all 3 strategies revealed that TXA remains the dominant strategy across all clinically plausible values. CONCLUSION: TXA, when compared with no pharmacologic hemostatic agent and with EACA, is the most cost-effective strategy to minimize intraoperative blood loss in hip and knee total joint arthroplasties. These findings are robust to sensitivity analyses using clinically plausible probabilities.

The Cost-Effectiveness of Total Hip Arthroplasty in Patients 80 Years of Age and Older.

BACKGROUND: This study investigates the cost-effectiveness of total hip arthroplasty (THA) in patients 80 years old. METHODS: A Markov, state-transition model projecting lifetime costs and quality-adjusted life years (QALYs) was constructed to determine cost-effectiveness from a societal perspective. Costs (in 2016 US dollars), health state utilities, and state transition probabilities were obtained from published literature. Primary outcome was incremental cost-effectiveness ratio, with a willingness-to-pay threshold of $100,000/QALY. Sensitivity analyses were performed to evaluate parameter assumptions. RESULTS: At our base-case values, THA was cost-effective compared to non-operative treatment with a total lifetime accrued cost of $186,444 vs $182,732, and a higher lifetime accrued utility (5.60 vs 5.09). Cost per QALY for THA was $33,318 vs $35,914 for non-operative management, and the incremental cost-effectiveness ratio was $7307 per QALY. Sensitivity analysis demonstrated THA to be cost-effective with a utility of successful primary THA above 0.67, a peri-operative mortality risk below 0.14, and a risk of primary THA failure below 0.14. Analysis further demonstrated that THA is a cost-effective option below a base-rate mortality threshold of 0.19, corresponding to the average base-rate mortality of a 93-year-old individual. Markov cohort analysis indicated that for patients undergoing THA at age 80 there was an approximate 28% reduction in total lifetime long-term assisted living expenditure compared to non-operatively managed patients with end-stage hip osteoarthritis. CONCLUSION: The results of our model demonstrate that THA is a cost-effective option compared to non-operative management in patients ≥80 years old. This analysis may inform policy regarding THA in elderly patients.