Faculty Bibliography

BACKGROUND:As worldwide utilization of total knee arthroplasty (TKA) broadens, demographic trends can help make projections to inform access to care. This study aimed to assess the temporal trends in the socioeconomic and medical demographics of patients undergoing TKA. METHODS:A retrospective review of 15,848 patients who underwent primary, elective TKA at an urban, New York City-based academic medical center between January 2013 and September 2022 was performed. Trends in patients' age, body mass index (BMI), socioeconomic status (SES) (based on median income by patients' ZIP code), race, and Charlson comorbidity index were evaluated using the Mann-Kendall test. RESULTS:In the last decade, mean patient age (65 to 68 years, P < .001) and Charlson comorbidity index (1.4 to 2.3, P < .001) increased significantly. The proportion of patients who had a BMI ≥ 30 and < 40 increased (43.8 to 51.2%, P = .002), while the proportion of patients who had a BMI ≥ 40 (13.7 to 12.1%, P = .015) and BMI < 30 (42.5 to 36.8%, P = .020) decreased. The distribution of patients' race and SES did not change from 2013 to 2022; Black (18.1 to 16.8%, P = .211) and low SES (12.9 to 11.3%, P = .283) patients consistently represented a minority of TKA patients. CONCLUSIONS:Over the last decade, the average age and comorbidity burden of TKA patients at our institution have increased. This portends the need for higher levels of preoperative optimization and postoperative management for TKA patients. A decreased prevalence of BMI ≥40 could reflect optimization efforts. However, the consistently low prevalence of Black and low-SES patients suggests that recent payment models did not improve access to care for these populations. LEVEL OF EVIDENCE/METHODS:IV.

BACKGROUND:Utilization of total knee arthroplasty (TKA) continues to rise among patients who have a high comorbidity burden (HCB). With changes in reimbursement models over the past decade, it is essential to assess the financial impact of HCB TKA on healthcare systems. This study aimed to examine trends in revenue and costs associated with TKA in HCB patients over time. METHODS:Of 14,978 TKA performed at a large, urban academic medical center between 2013 and 2021, we retrospectively analyzed HCB patients (Charlson comorbidity index ≥ 5 and American Society of Anesthesiology scores of 3 or 4). A total of 1,156 HCB TKA patients who had complete financial data were identified. Patient demographics, perioperative data, revenue, costs, and contribution margin were collected for each patient. Changes in these financial values over time, as a percentage of 2013 values, were analyzed. Linear regression was performed with a trend analysis to determine significance. RESULTS:From 2013 to 2021, the percentage of HCB TKAs per year increased from 4.2% in 2013 to 16.5% in 2021 (P < .001). The revenue of TKA in HCB patients remained steady (P = .093), while direct costs increased significantly (32.0%; P = .015), resulting in a decline of contribution margin to a low of 82.3% of 2013 margins. There was no significant change in rates of 90-day complications or home discharge following HCB TKA during the study period. CONCLUSIONS:The results of this study indicate a major rise in cost for TKA among HCB patients, without a corresponding rise in revenue. As more patients who have HCB become candidates for TKA, the negative financial impact on institutions should be considered, as payments to institutions do not adequately reflect patient complexity. A re-evaluation of institutional payments for medically complex TKA patients is warranted to maintain patient access among at-need populations.

BACKGROUND:Current data evaluating the clinical value and cost-effectiveness of advanced diagnostic tests for periprosthetic joint infection (PJI) diagnosis, including alpha-defensin and synovial C-reactive protein (CRP), is conflicting. This study aimed to evaluate the adequacy of preoperative and intraoperative PJI workups without utilizing these tests. METHODS:This retrospective analysis identified all patients who underwent revision total knee or hip arthroplasty (rTKA and rTHA, respectively) for suspected PJI between 2018 and 2020 and had a minimum follow-up of two years. Perioperative data and lab results were collected, and cases were dichotomized based on whether they met the 2018 Musculoskeletal Infection Society (MSIS) criteria for PJI. In total, 204 rTKA and 158 rTHA cases suspected of PJI were reviewed. RESULTS:Nearly 100% of the cases were categorized as "infected" for meeting the 2018 MSIS criteria without utilization of alpha-defensin or synovial CRP (rTKA: n = 193, 94.6%; rTHA: n = 156, 98.7%). Most cases were classified as PJI preoperatively by meeting either the major MSIS or the combinational minor MSIS criteria of traditional lab tests (rTKA: n = 177, 86.8%; rTHA: n = 143, 90.5%). A subset of cases was classified as PJI by meeting combinational preoperative and intraoperative MSIS criteria (rTKA: 16, 7.8%; rTHA: 13, 8.2%). Only 3.6% of all cases were considered "inconclusive" using preoperative and intraoperative data. CONCLUSION/CONCLUSIONS:Given the high rate of cases satisfying PJI criteria during preoperative workup using our available tests, the synovial alpha-defensin and synovial CRP tests may not be necessary in the routine diagnostic workup of PJI. We suggest that the primary PJI workup process should be based on a stepwise algorithmic approach with the most economical testing necessary to determine a diagnosis first. The use of advanced, commercialized, and costly biomarkers should be utilized only when traditional testing is indeterminate.

The number of revision total knee arthroplasties (TKAs) performed annually continues to rise. This article is a summary of a symposium on revision TKAs presented at the 2023 American Association of Hip and Knee Surgeons (AAHKS) annual meeting. It will provide an overview of the surgical tips and tricks for exposure and component removal, use of metaphyseal fixation and stems to manage bone loss and optimize fixation, constraint in TKA, as well as how to manage extensor mechanism disruptions with a synthetic mesh reconstruction.

BACKGROUND:As volume of total hip arthroplasty (THA) continues to increase, the utilization and availability of in-traoperative advanced technologies to arthroplasty surgeons continues to rise as well. Our primary goal was to determine whether the use of a mini navigation technology extended operative times and secondarily if it affected postoperative outcomes following elective THA. METHODS:A single-institution total joint arthroplasty da-tabase was utilized to identify adult patients who underwent elective THA from 2017 to 2019. Baseline demographic data along with surgical operative time, length of stay (LOS) and discharge disposition were collected. The Activity Measure for Post-Acute Care (AM-PAC) was used to determine physi-cal therapy progress. RESULTS:A total of 1,162 THAs were performed of which 69.1% (803) used navigation while 30.9% (359) did not. Baseline demographics including age, sex, body mass index (BMI), insurance, and smoking status were not statistically different between groups. The operative time was shorter in the navigation group compared to THA without navigation (115.1 vs. 118.9 min, p < 0.0001). Mean LOS was signifi-cantly shorter in the navigation THA group as compared to THA without navigation (2.1 vs. 2.6 days, p < 0.0001). Postoperative AM-PAC scores were higher in the navigation group on postoperative day 1 as compared to patients with-out navigation (18.87 vs. 17.52, p < 0.0001). Additionally, a greater percentage of patients were discharged directly home after THA with navigation as compared to THA without navigation (89.54% vs. 83.57%, p < 0.0001). CONCLUSION/CONCLUSIONS:Our study demonstrates that hip navigation technology in the setting of THA is associated with reduced operative times and higher AM-PAC mobilization scores. Hip mini navigation technology shortens operative times while improving early patient outcome scores in association with shorter LOS and greater home-based discharge.

BACKGROUND:Lumbar spinal fusion (LSF) is a risk factor for dislocation following total hip arthroplasty (THA). The effect of the surgical approach on this association has not been investigated. This study examined the association between the surgical approach and dislocation following THA in patients who had prior LSF. METHODS:We retrospectively reviewed 16,223 primary elective THAs at our institution from June 2011 to September 2022. Patients who had LSF prior to THA were identified using International Classification of Diseases (ICD) codes. Patients were stratified by LSF history, surgical approach, and intraoperative robot or navigation use to compare dislocation rates. There were 8,962 (55.2%) posterior, 5,971 (36.8%) anterior, and 1,290 (8.0%) laterally based THAs. Prior LSF was identified in 323 patients (2.0%). Binary logistic regressions were used to assess the association of patient factors with dislocation risk. RESULTS:There were 177 dislocations identified in total (1.1%). In nonadjusted analyses, the dislocation rate was significantly higher following the posterior approach among all patients (P = .003). Prior LSF was associated with a significantly higher dislocation rate in all patients (P < .001) and within the posterior (P < .001), but not the anterior approach (P = .514) subgroups. Multivariate regressions demonstrated anterior (OR [odds ratio] = 0.64, 95% CI [confidence interval] 0.45 to 0.91, P = .013), and laterally based (OR = 0.42, 95% CI 0.18 to 0.96, P = .039) approaches were associated with decreased dislocation risk, whereas prior LSF (OR = 4.28, 95% CI 2.38 to 7.69, P < .001) was associated with increased dislocation risk. Intraoperative technology utilization was not significantly associated with dislocation in the multivariate regressions (OR = 0.72, 95% CI 0.49 to 1.06, P = .095). CONCLUSIONS:The current study confirmed that LSF is a significant risk factor for dislocation following THA; however, anterior and laterally based approaches may mitigate dislocation risk in this population. In multivariate analyses, including surgical approach, LSF, and several perioperative variables, intraoperative technology utilization was not found to be significantly associated with dislocation risk.

BACKGROUND:Though previous studies have demonstrated improved cost benefits associated with simultaneous versus staged bilateral total hip arthroplasty (simBTHA and staBTHA), further investigation is needed regarding the revenues and contribution margins (CMs) of these procedures. In this study, we compared revenue, CM, and surgical outcomes between simBTHA and staBTHA. METHODS:All patients who underwent simBTHA (both procedures completed the same day) and staBTHA (procedures completed on different days within one year) between 2011 and 2021 at a single high-volume orthopedic specialty hospital were identified. Of the 1,517 identified patients (n = 139 simBTHA, n = 1,378 staBTHA), 232 were included in a 1:1 propensity match based on baseline demographics (116 per cohort). Revenue, costs, CM, and surgical outcomes were compared between cohorts. RESULTS:Compared to staBTHA, simBTHA procedures had significantly lower total costs (P < .001), direct costs (P < .001), and patient revenue. There was no significant difference in CM between groups (P = .361). Additionally, there were no significant differences in length of stay (P = .173), operative time (P = .438), 90-day readmissions (P = .701), 90-day revisions (P = .313), or all-cause revisions (P = .701) between cohorts. CONCLUSIONS:Though simBTHA procedures have lower revenues than staBTHA, they also have lower costs, resulting in similar CM between procedures. As both procedures have similar postoperative complication rates, further research is required to evaluate specifically which patients may benefit from simBTHA versus staBTHA regarding clinical and patient-reported outcomes. LEVEL OF EVIDENCE/METHODS:III.

INTRODUCTION/BACKGROUND:The direct anterior approach (DAA) and posterior approach (PA) for total hip arthroplasty (THA) have advantages and disadvantages, but their physiologic burden to the surgeon has not been quantified. This study was conducted to determine whether differences exist in surgeon physiological stress and strain during DAA in comparison to PA. METHODS:We evaluated a prospective cohort of 144 consecutive cases (67 DAA and 77 PA). There were five, high-volume, fellowship-trained arthroplasty surgeons who wore a smart-vest that recorded cardiorespiratory data while performing primary THA DAA or PA. Heart rate (beats/minute), stress index (correlates with sympathetic activations), respiratory rate (respirations/minute), minute ventilation (liters/min), and energy expenditure (calories) were recorded, along with patient body mass index and operative time. Continuous data was compared using T-tests or Mann Whitney U tests, and categorical data was compared with Chi-square or Fischer's exact tests. RESULTS:There were no differences in patient characteristics. Compared to PA, performing THA via DAA had a significantly higher surgeon stress index (17.4 versus 12.4; P < 0.001), heart rate (101 versus 98.3; P = 0.007), minute ventilation (21.7 versus 18.7; P < 0.001), and energy expenditure per hour (349 versus 295; P < 0.001). However, DAA had a significantly shorter operative time (71.4 versus 82.1; P = 0.001). CONCLUSION/CONCLUSIONS:Surgeons experience significantly higher physiological stress and strain when performing DAA compared to PA for primary THA. This study provides objective data on energy expenditure that can be factored into choice of approach, case order, and scheduling preferences, and provides insight into the work done by the surgeon.

INTRODUCTION/BACKGROUND:Debridement, antibiotics, and implant retention (DAIR) are the mainstays surgical treatment for acute periprosthetic joint infection (PJI). However, re-operation following DAIR is common, and the risk factors for DAIR failure remain unclear. This study aimed to assess the perioperative characteristics of patients who failed initial DAIR treatment. METHODS:A retrospective review was conducted on 83 patients who underwent DAIR for acute PJI within three months following index surgery from 2011 to 2022, with a minimum one-year follow-up. Surgical outcomes were categorized using the Musculoskeletal Infection Society (MSIS) outcome reporting tool (Tiers 1 to 4). Patient demographics, laboratory data, and perioperative outcomes were compared between patients who had failed (Tiers 3 and 4) (n = 32) and successful (Tiers 1 and 2) (n = 51) DAIR treatment. Logistic regression was also performed. RESULTS:After logistic regression, Charlson Comorbidity Index (CCI) (odds ratio (OR): 1.57; P = 0.003), preoperative C-reactive protein (CRP) (OR: 1.06; P = 0.014), synovial white blood cell (WBC) (OR: 1.14; P = 0.008), and polymorphonuclear cell (PMN%) counts (OR: 1.05; P = 0.015) were independently associated with failed DAIR. Compared with total hip arthroplasty (THA), total knee arthroplasty (TKA) patients (OR: 6.08; P = 0.001) were at increased risk of DAIR failure. The type of organism and time from primary surgery were not correlated with DAIR failure. CONCLUSION/CONCLUSIONS:Patients who had failed initial DAIR tended to have significantly higher CCI, CRP, synovial WBC, and PMN%. The TKA DAIRs were more likely to fail than the THA DAIRs. These characteristics should be considered when planning acute PJI management, as certain patients may be at higher risk for DAIR failure and may benefit from other surgical treatments.