Faculty Bibliography

BACKGROUND:Non-cruciate total knee arthroplasty designs, including ultracongruent, medially congruent, and medial pivot, are gaining increasing attention in total knee arthroplasty surgery. However there is no consensus for the bearing surface design, whether there should be different medial, lateral, anterior and posterior laxities, or whether the medial side should be a medial pivot. This study proposes the criterion of reproducing the laxity of the anatomic knee, defined as the displacements and rotations of the femur on the tibia in the loaded knee when shear and torque are applied. The purpose of this study was to determine the ideal tibial radii to achieve that goal. METHODS:The femoral component was based on the average knee from 100 mild arthritic knee scans. There were eight tibial components that were designed with different sagittal radii: antero-medial, antero-lateral, postero-medial, and postero-lateral. Radii were defined as the percent height reduction from full conformity with the femoral profile. Components were 3D printed. A test rig was constructed where the tibial component was fixed and shear and torque were applied to the femoral component. Displacements and rotations of the femoral component were measured at 0 and 45 degrees of flexion, the latter representing any flexion angle due to the constant femoral sagittal radius. RESULTS:Displacements ranged from 0 to 11mm, and rotations ranged from 1 to 11 degrees. Anterior femoral displacements were higher than posterior due to the shallow distal-anterior femoral profile. The final femoral and tibial components with the most closely matched anatomic laxity values, were designed and tested. CONCLUSIONS:A steeper distal-anterior femoral radius was an advantage. High medial-anterior tibial conformity was important. However, on the lateral side, the posterior sagittal tibial radius had to be shallower than ideal to allow femoral rollback in high flexion. This meant that the posterior laxity displacements on the lateral side were higher than anatomic, and there was no guidance for lateral femoral rollback.

➤ Aging is associated with well-documented neurocognitive and psychomotor changes.➤ These changes can be expected to impact the skill with which orthopaedic surgeons continue to perform surgical procedures.➤ Currently, there is no standardized approach for assessing the changes in surgical skills and clinical judgment that may occur with aging.➤ Oversight by the U.S. Equal Employment Opportunity Commission, the impact of the Age Discrimination in Employment Act, and the current legal climate make it difficult to institute a mandatory assessment program.➤ The regularly scheduled credentialing process that occurs at each institution can be the most effective time to assess for these changes because it utilizes an established process that occurs at regularly scheduled intervals.➤ Each department of orthopaedic surgery and institution should determine an approach that can be utilized when there is concern that a surgeon's surgical skills have shown signs of deterioration.

BACKGROUND:Liver cirrhosis is associated with increased perioperative morbidity. Our study used the Model for End-Stage Liver Disease (MELD) score to assess the impact of cirrhosis severity on postoperative outcomes following total knee arthroplasty (TKA). METHODS:A retrospective review identified 59 patients with liver cirrhosis who underwent primary TKA at a large, urban, academic center from January 2013 to August 2022. Cirrhosis was categorized as mild (MELD<10; n=47) or moderate-severe (MELD≥10; n=12). Modified Clavien-Dindo classification was used to grade complications, where grade 2+ denoted significant intervention. Hospital length of stay (LOS), non-home discharge, and mortality were collected. 1:1 propensity matching was used to control for demographics and selected comorbidities. RESULTS:Moderate-severe cirrhosis was associated with significantly higher rates of intrahospital overall (58.33% vs 16.67%, p=0.036) complications, 30-day overall complications (75% vs 33.33%, p=0.042), and 90-day overall complications (75% vs 33.33%, p=0.042) when compared to matched mild cirrhosis patients. Compared to matched non-cirrhotic controls, mild cirrhosis patients had no significant increase in complication rate or other outcomes (p>0.05). CONCLUSION/CONCLUSIONS:Patients with moderate-severe liver cirrhosis are at risk of short-term complications following primary TKA. Patients with mild cirrhosis have comparable outcomes to matched non-cirrhotic patients. Surgeons can use MELD score prior to scheduling TKA to determine which patients require optimization or higher levels of perioperative care.

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.

INTRODUCTION/BACKGROUND:Preoperative medical optimization is necessary for safe and efficient care of the orthopaedic trauma patient. To improve care quality and value, a preoperative matrix was created to more appropriately utilize subspecialty consultation and avoid unnecessary consults, testing, and operating room delays. Our study compares surgical variables before and after implementation of the matrix to assess its utility. METHODS:A retrospective review of all orthopaedic trauma cases 6 months before and after the use of the matrix (2/2021-8/2021) was conducted an urban, level one trauma centre in collaboration with internal medicine, cardiology, anaesthesia, and orthopaedics. Patients were separated into two cohorts based on use of the matrix during the initial orthopaedic consultation. Logistic regressions were performed to limit significant differences in comorbidities. Independent samples t-tests and Chi-squared tests were used to compare means and proportions, respectively, between the two cohorts. RESULTS:In total, 576 patients were included in this study (281 pre- and 295 post-matrix implementation). Use of the matrix resulted in no significant difference in time to OR, LOS, readmissions, or ER visits; however, it resulted in 18% fewer overall preoperative consults for general trauma, and 25% fewer pre-operative consults for hip fractures. Older patients were more likely to require a consult regardless of matrix use. When controlling for comorbidities, patients with renal disease were at higher risk for increased LOS. CONCLUSION/CONCLUSIONS:Use of an orthopaedic surgical matrix to predict preoperative subspecialty consultation is easy to implement and allows for better care utilization without a corresponding increase in complications and readmissions. Follow-up studies are needed to reassess the relationships between matrix use and a potential decrease in ER to OR time, and validate its use.

Platelet-rich plasma (PRP) has garnered widespread and increasing attention in recent years. We aimed to characterize the most influential articles in PRP research while clarifying controversies surrounding its use and clinical efficacy and identifying important areas on which to focus future research efforts. The Science Citation Index Expanded subsection of the Web of Science Core Collection was systematically searched to identify the top 50 cited publications on orthopedic PRP research. Publication and study characteristics were extracted, and Spearman's correlations were calculated to assess the relationship between citation data and level of evidence. The top 50 articles were published between the years 2005 and 2016, with 68% published in the year 2010 or later. Of the 33 studies for which level of evidence was assessed, the majority were of level I or II (18, 54.5%). Seventeen articles (34%) were classified as basic science. All clinical studies were prospective, and most (12 studies, 60%) included a high number of metrics related to the PRP preparation protocol and composition. Knee osteoarthritis was the most common topic among clinical studies in the top 50 cited articles (11 studies, 34%). More recent articles were associated with higher citation rates (ρ = 0.46, p < 0.001). The most influential articles on orthopaedic PRP research are recent and consist of high-level of evidence studies mostly. Randomized controlled trials were the most common study type, while basic science articles were relatively less common. The most influential clinical studies reported a high number of metrics related to their PRP preparation protocol and the final PRP composition. These results suggest a rapidly evolving field with the potential to better explain inconsistent clinical results with improved understanding and documentation of basic science concepts such as PRP composition, preparation, and combination techniques.

BACKGROUND:Over the past decade, reimbursement models and target payments have been modified in an effort to decrease costs of revision total knee arthroplasty (rTKA) while maintaining the quality of care. The goal of this study was to investigate trends in revenue and costs associated with rTKA. METHODS:We retrospectively reviewed all patients who underwent rTKA between 2011 and 2021 at our institution. Patients were stratified into groups based on insurance coverage: Medicare, government-managed or Medicaid (GMM), or commercial insurance. Patient demographics were collected, as well as revenue, costs, and contribution margin (CM) of the inpatient episode. Changes over time as a percentage of 2011 numbers were analyzed. Linear regressions were used to determine trend significance. In the 10-year study period, 1,698 patients were identified with complete financial data. RESULTS:Overall total cost has increased significantly (P < .01). While revenues and CM for Medicare and Commercial patients remained steady between 2011 and 2021, CM for GMM patients decreased significantly (P = .01) to a low of 53.2% of the 2011 values. Since 2018, overall CM and revenues decreased significantly (P = .05, P = .01, respectively). CONCLUSION/CONCLUSIONS:While from 2011 to 2018 general revenues and CM were relatively steady, since 2018 they have decreased significantly to their lowest values in over a decade for GMM and commercial patients. This trend is concerning and may potentially lead to decreased access to care. Re-evaluation of reimbursement models for rTKA may be necessary to ensure the financial viability of this procedure and prevent issues with access to care. LEVEL OF EVIDENCE/METHODS:III.

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:Removal of primary total knee arthroplasty (TKA) and primary total hip arthroplasty (THA) from the inpatient-only (IPO) list has financial implications for both patients and institutions. The aim of this study was to evaluate and compare financial parameters between patients designated for inpatient versus outpatient total joint arthroplasty (TJA) surgery. METHODS:We reviewed all patients who underwent TKA or THA after these procedures were removed from the IPO list. Patients were stratified into cohorts based on inpatient or outpatient status, procedure type, and insurance type. This included 5,284 patients, of which 4,279 were designated inpatient while 1,005 were designated outpatient. Patient demographic, perioperative, and financial data including per patient revenues, total and direct costs, and contribution margins (CMs) were collected. Data were compared using t-tests and Chi-square tests. RESULTS:Among Medicare patients receiving THA, CM was 89.1% lower for the inpatient cohort when compared to outpatient (p<0.001), though there was no significant difference between cohorts for TKA (p=0.501). Among patients covered by Medicaid or Government-managed plans, CM was 120.8% higher for inpatients receiving THA (p<0.001) when compared to outpatients and 136.3% higher for inpatients receiving TKA (p<0.001). CONCLUSION/CONCLUSIONS:Our analyses showed that recent costs associated with inpatient stay inconsistently match or outpace additional revenue, causing CM to vary drastically depending on insurance and procedure type. For Medicare patients receiving THA, inpatient surgery is financially disincentivized leaving this vulnerable patient population at risk of losing access to care.

BACKGROUND:Deep surgical site infections (dSSI) following spinal laminectomy and fusion are serious complications associated with poor patient outcomes. The objective of this study is to investigate the monthly and seasonal variability of dSSI rates following common spinal surgeries to investigate the "July effect," which refers to the alleged increase in adverse health outcomes due to new hospital trainees at the beginning of the academic year. METHODS:We performed a retrospective analysis of patients who had a dSSI following laminectomy (without fusion) or spinal fusion (with or without laminectomy) at a single large urban academic medical center between January 2009 and August 2018. The change in dSSI rate over the entire study period was calculated. The monthly and seasonal variability of dSSI were assessed using a Poisson regression model to assess for the presence of the July effect. RESULTS:= 0.04 ). With July as the reference month, there was a significantly higher dSSI rate in April following spinal fusions. CONCLUSION/CONCLUSIONS:The overall decrease in dSSI rate over the study period is consistent with previous reports. The monthly analysis revealed no significant differences in either procedure, calling into question the July effect. CLINICAL RELEVANCE/CONCLUSIONS:This study is relevant to practicing spinal surgeons and can inform surgeons about seasonal data regarding dSSIs. LEVEL OF EVIDENCE: 3/METHODS/: