Faculty Bibliography

BACKGROUND:The impact of preoperative nasal colonization with methicillin resistant staphylococcus aureus (MRSA) on total joint arthroplasty (TJA) outcomes is not well understood. This study aimed to evaluate complications following TJA based on patients' preoperative staphylococcal colonization status. METHODS:We retrospectively analyzed all patients undergoing primary TJA between 2011 and 2022 who completed a preoperative nasal culture swab for staphylococcal colonization. Patients were 1:1:1 propensity matched using baseline characteristics, and stratified into 3 groups based on their colonization status: MRSA positive (MRSA+), methicillin sensitive staphylococcus aureus positive (MSSA+), and MSSA/MRSA negative (MSSA/MRSA-). All MRSA+ and MSSA + underwent decolonization with 5% povidone iodine, with the addition of intravenous vancomycin for MRSA + patients. Surgical outcomes were compared between groups. Of the 33,854 patients evaluated, 711 were included in final matched analysis (237 per group). RESULTS:The MRSA + TJA patients had longer hospital lengths of stay (P = .008), were less likely to discharge home (P = .003), and had higher 30-day (P = .030) and 90-day (P = .033) readmission rates compared to MSSA+ and MSSA/MRSA-patients, though 90-day major and minor complications were comparable across groups. MRSA + patients had higher rates of all-cause (P = .020), aseptic (P = .025) and septic revisions (P = .049) compared to the other cohorts. These findings held true for both total knee and total hip arthroplasty patients when analyzed separately. CONCLUSION/CONCLUSIONS:Despite targeted perioperative decolonization, MRSA + patients undergoing TJA have longer lengths of stay, higher readmission rates, and higher septic and aseptic revision rates. Surgeons should consider patients' preoperative MRSA colonization status when counseling on the risks of TJA.

BACKGROUND:Few studies have assessed how socioeconomic status (SES) influences patient-reported outcomes (PROMs) after total knee arthroplasty (TKA). This study evaluated the impact of patient median ZIP code income levels on PROMs after TKA. METHODS:We retrospectively reviewed patients at our institution undergoing primary, unilateral TKA from 2017 to 2020. Patients who did not have one-year postoperative PROMs were excluded. Patients were stratified based on the quartile of their home ZIP code median income from United States Census Bureau data. There were 1,267 patients included: 98 in quartile 1 (median income ≤ $46,308) (7.7%); 126 in quartile 2 (median income $46,309-$57,848) (10.0%); 194 in quartile 3 (median income $57,849-$74,011) (15.7%); and 849 in quartile 4 (median income ≥ $74,012) (66.4%). We collected baseline demographic data, 2-year outcomes, and PROMs preoperatively, as well as at 12 weeks and one year, postoperatively. RESULTS:The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was significantly higher in quartile 4 preoperatively (P < .001), 12 weeks postoperatively (P < .001), and one year postoperatively (P < .001). There were no significant differences in delta improvements of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement from preoperative to 12 weeks or one year postoperatively. There were no significant differences in lengths of stay, discharge dispositions, readmissions, or revisions. CONCLUSION/CONCLUSIONS:Patients from lower income areas have slightly worse knee function preoperatively and worse outcomes following TKA. However, improvements in PROMs throughout the first year postoperatively are similar across income quartiles, suggesting that patients from lower income quartiles achieve comparable therapeutic benefits from TKA. LEVEL III EVIDENCE/METHODS:Retrospective Cohort Study.

BACKGROUND:Intra-articular hyaluronic acid (IAHA) has been commonly used in the management of knee osteoarthritis (OA). This study sought to assess patient-reported outcomes (PRO) following different formulations of hyaluronic acid injections for patients who have knee OA. METHODS:A retrospective analysis was performed on patients who have knee OA and received IAHA knee injections from October 2018 to May 2022 in sports medicine (SM) and adult reconstructive (AR) clinics. Patients completed PRO measures including the Patient-Reported Outcome Measurement Information System (PROMIS) Mobility, Pain Interference, and Pain Intensity at baseline, 6-week, 6-month, and 12-month follow-up. Univariate and multivariate analyses were used to evaluate changes in PRO measures between baseline and follow-up periods and to evaluate differences between the SM and AR divisions. A total of 995 patients received IAHA for knee OA and completed PRO assessments. RESULTS:There was no difference in the PROMIS measures based on molecular weight at 6 weeks, 6 months, and 12 months. Except for 6-month Mobility scores between the SM and AR patients (-0.52 ± 5.46 versus 2.03 ± 6.95; P = .02), all other PROMIS scores were similar. Mobility scores at 6 months were significantly different based on Kellgren and Lawrence grade (P = .005), but all other PROMIS scores were similar. CONCLUSION/CONCLUSIONS:Average change in PROMIS scores were significantly different only for 6-month Mobility scores based on divisions and Kellgren and Lawrence grade but did not achieve minimally clinical important difference at most timepoints. Further studies are needed to investigate whether improvement is observed in specific patient populations.

BACKGROUND:Revision total hip arthroplasty (rTHA) is a costly procedure, and its prevalence has been steadily increasing over time. This study aimed to examine trends in hospital cost, revenue, and contribution margin (CM) in patients undergoing rTHA. METHODS:We retrospectively reviewed all patients who underwent rTHA from June 2011 to May 2021 at our institution. Patients were stratified into groups based on insurance coverage: Medicare, government-managed Medicaid, or commercial insurance. Patient demographics, revenue (any payment the hospital received), direct cost (any cost associated with the surgery and hospitalization), total cost (the sum of direct and indirect costs), and CM (the difference between revenue and direct cost) were collected. Changes over time as a percentage of 2011 numbers were analyzed. Linear regression analyses were used to determine the overall trend's significance. Of the 1,613 patients identified, 661 were covered by Medicare, 449 by government-managed Medicaid, and 503 by commercial insurance plans. RESULTS:Medicare patients exhibited a significant upward trend in revenue (P < .001), total cost (P = .004), direct cost (P < .001), and an overall downward trend in CM (P = .037), with CM for these patients falling to 72.1% of 2011 values by 2021. CONCLUSION/CONCLUSIONS:In the Medicare population, reimbursement for rTHA has not matched increases in cost, leading to considerable reductions in CM. These trends affect the ability of hospitals to cover indirect costs, threatening access to care for patients who require this necessary procedure. Reimbursement models for rTHA should be reconsidered to ensure the financial feasibility of these procedures for all patient populations.

INTRODUCTION/BACKGROUND:Operating room air quality can be affected by several factors including temperature, humidity, and airborne particle burden. Our study examines the role of operating room (OR) size on air quality and airborne particle (ABP) count in primary total knee arthroplasty (TKA). MATERIALS AND METHODS/METHODS:We analyzed all primary, elective TKAs performed within two ORs measuring 278 sq ft. (small) and 501 sq ft. (large) at a single academic institution in the United States from April 2019 to June 2020. Intraoperative measurements of temperature, humidity, and ABP count were recorded. p values were calculated using t test for continuous variables and chi-square for categorical values. RESULTS:91 primary TKA cases were included in the study, with 21 (23.1%) in the small OR and 70 (76.9%) in the large OR. Between-groups comparisons revealed significant differences in relative humidity (small OR 38.5% ± 7.24% vs. large OR 44.4% ± 8.01%, p = 0.002). Significant percent decreases in ABP rates for particles measuring 2.5 μm (- 43.9%, p = 0.007) and 5.0 μm (- 69.0%, p = 0.0024) were found in the large OR. Total time spent in the OR was not significantly different between the two groups (small OR 153.09 ± 22.3 vs. large OR 173 ± 44.6, p = 0.05). CONCLUSIONS:Although total time spent in the room did not differ between the large and small OR, there were significant differences in humidity and ABP rates for particles measuring 2.5 μm and 5.0 μm, suggesting the filtration system encounters less particle burden in larger rooms. Larger studies are required to determine the impact this may have on OR sterility and infection rates.

BACKGROUND:In response to physician and patient concerns, many institutions have adopted protocols aimed at reducing postoperative opioid consumption after total knee arthroplasty (TKA). Thus, this study sought to examine how consumption of opioids has changed following TKA in the past 6 years. METHODS:We conducted a retrospective review of all 10,072 patients who received primary TKA at our institution from January 2016 to April 2021. We collected baseline demographic data including patient age, sex, race, body mass index (BMI), American Society of Anesthesiologist (ASA) classification, as well as dosage and type of opioid medication prescribed on each postoperative day while the patient was hospitalized following TKA. This data was converted to milligram morphine equivalents (MME) per day hospitalized to compare rates of opioid use over time. RESULTS:Our analysis found the greatest daily opioid use was in 2016 (43.2 ± 68.6 MME/day) and the least was in 2021 (15.0 ± 29.2 MME/day). Linear regression analyses found a significant linear downward trend in postoperative opioid consumption over time, with a decrease of 5.55 MME per day per year (Adjusted R-squared: 0.982, P < .001). The highest visual analog scale (VAS) score was 4.45 in 2016 and the lowest was 3.79 in 2021 (P < .001). CONCLUSION/CONCLUSIONS:Opioid reducing protocols have been implemented for patients recovering from primary TKA in an effort to decrease reliance on opioids for postoperative pain control. The results of this study demonstrate that such protocols have been successful in reducing overall opioid use during hospitalization following TKA. LEVEL III EVIDENCE/METHODS:Retrospective Cohort.

INTRODUCTION/BACKGROUND:Selective use of dual mobility (DM) implants in total hip arthroplasty (THA) patients at high dislocation risk has been proposed. However, evidence-based utilization thresholds have not been defined. We explored whether surgeon-specific rates of DM utilization correlate with rates of readmission and reoperation for dislocation. METHODS:We retrospectively reviewed 14,818 primary THA procedures performed at a single institution between 2011 and 2021, including 14,310 FB and 508 DM implant constructs. Outcomes including 90-day readmissions and reoperations were compared between patients who had fixed-bearing (FB) and DM implants. Cases were then stratified into three groups based on the attending surgeon's rate of DM utilization (≤1, 1 to 10, or >10%) and outcomes were compared. RESULTS:There were no differences in 90-day outcomes between FB and DM implant groups. Surgeon frequency of DM utilization ranged from 0 to 43%. There were 48 surgeons (73%) who used DM in ≤ 1% of cases, 11 (17%) in 1 to 10% of cases, and 7 (10%) in >10% of cases. The 90-day rates of readmission (7.3 vs 7.6 vs 7.2%, P=0.7) and reoperation (3.4 vs 3.9 vs 3.8%, P=0.3), as well as readmission for instability (0.5 vs 0.6 vs 0.8%, P=0.2) and reoperation for instability (0.5 vs 0.5 vs 0.8%, P=0.6), did not statistically differ between cohorts. CONCLUSION/CONCLUSIONS:Selective DM utilization did not reduce 90-day readmissions or reoperations following primary THA. Other dislocation-mitigation strategies (i.e., surgical approach, computer navigation, robotic assistance, and large diameter fixed-bearings) may have masked any benefits of selective DM use.

Background:National projections of future joint arthroplasties are useful for understanding the changing burden of surgery and related outcomes on the health system. The aim of this study is to update the literature by producing Medicare projections for primary total joint arthroplasty (TJA) procedures until 2040 and 2060.Methods:The present study used data from the Centers for Medicare & Medicaid Services (CMS) Medicare/Medicaid Part B National Summary and combined procedure counts with use of Current Procedural Terminology (CPT) codes to identify whether the procedure was a primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) procedure. In 2019, the annual volume of primary TKA was 480,958 and that of primary THA was 262,369. These values formed a baseline from which we generated point forecasts for 2020-2060 and 95% forecast intervals (FIs).Results:Between 2000 and 2019, the estimated annual volume of THA increased by 177% and that of TKA increased by 156% on average. Regression analysis projected an annual growth rate of 5.2% for THA and 4.44% for TKA. Based on these yearly projected increases, an estimated increase of 28.84% and 24.28% is expected for each 5-year period after 2020 for THA and TKA, respectively. By 2040, the number of THAs is projected to be 719,364 (95% FI, 624,766 to 828,286) and the number of TKA is projected to be 1,222,988 (95% FI, 988,714 to 1,512,772). By 2060, the number of THAs is projected to be 1,982,099 (95% FI, 1,624,215 to 2,418,839) and the number of TKAs is projected to be 2,917,959 (95% FI, 2,160,951 to 3,940,156). In 2019, Medicare data showed that THA constituted approximately 35% of TJA procedures performed.Conclusions:Based on 2019 total volume counts, our model forecasts an increase in THA procedures of 176% by 2040 and 659% by 2060. The estimated increase for TKA is projected to be 139% by 2040 and 469% by 2060. An accurate projection of future primary TJA procedure demands is important in order to understand future health-care utilization and surgeon demand. This finding is only applicable to a Medicare population and demands further analysis to see if this extends to other population groups.Level of Evidence:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

INTRODUCTION/BACKGROUND:Reduced bone mineral density (BMD) and disruption of normal bony architecture are the characteristics of osteopenia and osteoporosis and in patients undergoing total hip arthroplasty (THA) may cause failure of trabecular ingrowth. The purpose of this study is to evaluate the impact of reduced BMD on outcomes following primary elective THA. METHODS:A retrospective chart review of 650 elective THAs with a DEXA scan in their electronic health record (EHR) from 2011 to 2020 was conducted at an urban, academic center and a regional, health center. Patients were separated into three cohorts based on their t-score and the World Health Organizations definitions: normal (t-score ≥ - 1), osteopenia (t-score < - 1.0 and > - 2.5), and osteoporosis (t-score ≤ - 2.5). Demographic and outcome data were assessed. Subsidence was assessed for patients with non-cemented THAs. Regression models were used to account for demographic differences. RESULTS:650 elective THAs, of which only 11 were cemented, were included in the study. Patients with osteopenia and osteoporosis were significantly older than those without (p = 0.002 and p < 0.0001, respectively) and had a lower BMI (p < 0.0001 and p < 0.0001, respectively). PFx was significantly greater in patients with osteoporosis when compared to those with normal BMD (6.5% vs. 1.0%; p = 0.04). No such difference was found between osteoporotic and osteopenic patients. The revision rate was significantly higher for osteoporotic patients than osteopenic patients (7.5% vs. 1.5%; p = 0.04). No such difference was found between the other comparison groups. CONCLUSION/CONCLUSIONS:Patients with osteoporosis were older with reduced BMI and had increased PFx after non-cemented elective THA. Understanding this can help surgeons formulate an appropriate preoperative plan for the treatment of patients with osteoporotic bone undergoing elective THA.

This study sought to determine common complications and the rates of readmission and revision in total hip arthroplasty patients younger than 65 years. Using the American Joint Replacement Registry, we conducted a retrospective review of all THAs in patients aged 18 to 65 years from 2012 to 2020. We excluded patients aged older than 65 years, revisions, oncologic etiology, conversion from prior surgery, and nonelective cases. Primary outcomes included cumulative revision rate, 90-day readmission rate, and reason for revision. The Kaplan-Meier method and univariate analysis were used. Five thousand one hundred fifty-three patients were included. The average age was 56.7 years (SD 7.8 years), 51% were female, 85% were White, and 89% had a Charlson Comorbidity Index of 0 (1 = 7%, >2 = 4%). The mean follow-up was 39.57 months. Fifty-three patients (1.0%) underwent revision. Seventy-four patients (1.4%) were readmitted within 90 days. Revision was more common in Black patients (P = 0.023). Survivorship was 99% (95% confidence interval, 98.7 to 99.3) and 99% (95% confidence interval, 98.5 to 99.3) at 5 and 8 years, respectively. Infection (21%), instability (15%), periprosthetic fracture (15%), and aseptic loosening (9%) were the most common indications for revision. Total hip arthroplasty performed in young and presumed active patients had a 99% survivorship at 8 years. A long-term follow-up is needed to evaluate survival trends in this growing population.