Faculty Bibliography

BACKGROUND:Patellar maltracking is a potential surgical complication following total knee arthroplasty (TKA) and can result in anterior knee pain, recurrent patellar dislocation, and damage to the medial patellar soft tissue stabilizers. Data remain unclear as to whether the patellar button should be revised during a revision TKA (rTKA) if changing the component implant system. Our study examines whether retaining the original patellar button during an rTKA using a different implant system affects patellar tracking. METHODS:A retrospective cohort study of rTKA patients between August 2011 and June 2019 was performed at an urban, tertiary referral center. Patients were divided into 2 cohorts depending on whether their retained patella from their primary TKA was of the same (SIM) or different implant manufacturer (DIM) as the revision system used. Radiographic measurements were performed on preoperative and postoperative knee radiographs and differences were compared between the 2 groups. Baseline demographic data were also collected. RESULTS:Of the 293 consecutive, aseptic rTKA cases identified, 122 underwent revision in the SIM cohort and 171 in the DIM cohort. There were no demographic differences between the groups. No statistical significance was calculated for differences in preoperative and postoperative patellar tilt or Insall-Salvati ratio between the groups. The DIM group was found to have more lateral patellar translation (-0.01 ± 6.09 vs 2.68 ± 7.61 mm, P = .001). However, when calculating differences in the magnitude of the translation (thereby removing differences due to laterality), no difference was observed (0.06 ± 3.69 vs 0.52 ± 4.95 mm, P = .394). CONCLUSION/CONCLUSIONS:No clinically significant differences in patellar tracking were observed when the original patellar component was retained and a different revision implant system was used. Given the inherent risks of bone loss and fracture with patellar component revision, surgeons performing rTKA may retain the primary patella if it is well fixed and can still expect appropriate patellar tracking regardless of the revision implant system used. LEVEL OF EVIDENCE/METHODS:III, Retrospective cohort study.

Background/UNASSIGNED:Sutures and staples are the mainstay wound closure techniques in total joint arthroplasty. Newer techniques such as zipper devices and novel skin adhesives have emerged because of their potential to decrease operative time and possibly minimize complications. The aim of this study is to compare these newer techniques against conventional sutures with respect to wound complications, closure time, and costs. Methods/UNASSIGNED:A single-center randomized control trial was conducted on 160 patients (52 zipper, 55 suture, 53 mesh) who underwent primary total hip or knee arthroplasty between February 2017 and May 2018. Patients were divided into 3 closure groups: zipper device, monofilament suture plus adhesive, and monofilament plus polyester mesh with adhesive. The primary endpoint was closure time (superficial skin layer). Secondarily we collected perioperative complication rates, including infection, persistent (14-day) wound drainage, 90-day readmission, and emergency room visit rates as well as compared material costs. Results/UNASSIGNED:There were no differences in baseline characteristics between groups for age, body mass index, and American Society of Anesthesiologists classification. There was a trend toward decreased time to closure for the suture group. There were no significant differences between groups for our secondary endpoint, complications. Conclusions/UNASSIGNED:Our study shows that the suture group trended toward shorter closure time but suggests that each of the closure methods after total joint arthroplasty has equivalent complication rates. With small differences in closure time and no significant differences in complications, the decision to use one wound closure device or technique over another should be driven by institutional costs and provider familiarity.

AIMS/OBJECTIVE:Liposomal bupivacaine (LB) as part of a periarticular injection protocol continues to be a highly debated topic in total knee arthroplasty (TKA). We evaluated the effect of discontinuing the use of LB in a periarticular protocol on immediate postoperative pain scores, opioid consumption, and objective functional outcomes. METHODS:On 1 July 2019, we discontinued the use of intraoperative LB as part of a periarticular injection protocol. A consecutive group of patients who received LB as part of the protocol (Protocol 1) and a subsequent group who did not (Protocol 2) were compared. All patients received the same opioid-sparing protocol. Verbal rating scale (VRS) pain scores were collected from our electronic data warehouse and averaged per patient per 12-hour interval. Events relating to the opiate administration were derived as morphine milligram equivalences (MMEs) per patient per 24-hour interval. The Activity Measure for Post-Acute Care (AM-PAC) tool was used to assess the immediate postoperative function. RESULTS:A total of 888 patients received Protocol 1 and while 789 received Protocol 2. The mean age of the patients was significantly higher in those who did not receive LB (66.80 vs 65.57 years, p = 0.006). The sex, BMI, American Society of Anesthesiologists physical status score, race, smoking status, marital status, operating time, length of stay, and discharge disposition were similar in the two groups. Compared with the LB group, discontinuing LB showed no significant difference in postoperative VRS pain scores up to 72 hours (p > 0.05), opioid administration up to 96 hours (p > 0.05), or AM-PAC scores within the first 24 hours (p > 0.05). CONCLUSION/CONCLUSIONS: 2021;103-B(6 Supple A):102-107.

BACKGROUND:To measure functional outcome, patient reported outcome measures (PROMs) are most often used but biomechanical tests can provide valuable supplementary data. The objective of this study was to investigate instrumented insoles for measuring ground-to-foot forces during basic activities. METHODS:Three groups were evaluated: normal controls, preoperative, and postoperative total knees. The Knee Society Scoring System (KSS) Short Form was used, and with foot pressure sensor insoles, a timed-up-and-go (TUG) test and a sit-to-stand (STS) test was used. RESULTS:Comparing preoperative to postoperative and control groups, there were significant differences in most parameters. There were no significant differences between controls and postoperative knees. Of the 33 correlation coefficients between three PROM parameters and six biomechanical parameters for the three groups, only five coefficients were greater than 0.5. CONCLUSIONS:The biomechanical data was substantially independent of the PROM data and provided additional functional evaluation. The most useful parameters were the left-right force ratios during sit-to stand (STS) and the timed-up-and-go (TUG) time.

BACKGROUND:Tranexamic acid (TXA) is increasingly used to minimize blood loss during total joint arthroplasty (TJA). Although TXA has been shown to be highly effective in reducing operative blood loss, many surgeons believe that it places patients with coronary artery disease (CAD) or a history of coronary stents at an increased risk for myocardial infarction. The purpose of this study was to determine if TXA is safe to use in patients with a history of CAD or coronary stents. METHODS:We performed a retrospective analysis at a single, tertiary academic medical center identifying consecutive total hip and knee arthroplasty cases over an 8-year period. From this cohort who received TXA intraoperatively, we identified patients with a history of CAD or coronary stents and determined the total myocardial infarction and venous thromboembolism (VTE) rates within a 90-day postoperative period. Chi-square analyses were used to identify differences in VTE rates between cohorts. A post hoc power analysis was also performed to determine whether our results were powered to detect a difference in VTE rates. RESULTS:In the 26,808 identified at-risk patients, there were no postoperative myocardial infarctions. No significant differences were observed for VTE rates compared with the control cohort using either topical or intravenous TXA, with regard to CAD (0.29% compared with 0.76%; p = 0.09) or coronary stents (0% compared with 0.76%; p = 0.14). Moreover, there was no significant difference observed in VTE rates when administration was subcategorized into intravenous and topical methods with regard to CAD (0.13% compared with 0.72%; p = 0.12) or coronary stents (0% compared with 0%; p = 1.0). CONCLUSIONS:In our series, topical and intravenous TXA were equally safe when used in patients with a history of CAD and coronary stents in comparison with the control cohort. With equal efficacy and risk of adverse events, we recommend intravenous TXA, which may enable easier institutional implementation. LEVEL OF EVIDENCE/METHODS:Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

»/UNASSIGNED:The potential benefits of computer-assisted surgical (CAS) navigation and robotic total knee arthroplasty (TKA) systems, such as increased reliability of restoring the mechanical axis, fewer outliers, more rapid hospital discharge, less physical therapy requirements, decreased blood loss, and decreased revision rates, have led to their application not only in primary cases but also in complex cases such as preoperative deformity and revision. »/UNASSIGNED:Early evidence demonstrates that CAS navigation may help to improve alignment in complex cases of femoral and tibial deformity and in cases of femoral bowing. »/UNASSIGNED:Data regarding deformity correction with robotic systems are similar to CAS navigation with regard to alignment, but are more limited. There are also scant data regarding revision cases and cases of previous intramedullary canal instrumentation. »/UNASSIGNED:Concerns remain regarding cost, learning curves, and operative times. There are potential long-term cost savings associated with a decrease in revisions and readmissions that require additional investigation. »/UNASSIGNED:Early evidence for the use of these emerging technologies for deformity correction and revision cases is promising, but their impact on long-term functional outcomes remains to be demonstrated. Additional well-designed comparative studies are warranted.

BACKGROUND:As orthopaedic physician fees continue to come under scrutiny by the U.S. Centers for Medicare & Medicaid Services (CMS), there is a continued need to evaluate trends in reimbursement rates across contemporary time intervals. Although substantially lower work relative value units (RVUs) have been previously demonstrated for septic revision total knee arthroplasty (TKA) compared with aseptic revisions, to our knowledge, there has been no corresponding analysis comparing total physician fees. Therefore, the purpose of our study was to analyze temporal trends in Medicare physician fees for septic and aseptic revision TKAs. METHODS:Current Procedural Terminology (CPT) codes related to septic 1-stage and 2-stage revision TKAs and aseptic revision TKAs were categorized. From 2002 to 2019, the facility rates of physician fees associated with each CPT code were obtained from the CMS Physician Fee Schedule Look-Up Tool. Monetary data from Medicare Administrative Contractors at 85 locations were used to calculate nationally representative means. All total physician fee values were adjusted for inflation and were translated to 2019 U.S. dollars using Consumer Price Index data from the U.S. Bureau of Labor Statistics. Cumulative annual percentage changes and compound annual growth rates (CAGRs) were computed utilizing adjusted physician fee data. RESULTS:After adjusting for inflation, the total mean Medicare reimbursement (and standard deviation) for aseptic revision TKA decreased 24.83% ± 3.65% for 2-component revision and 24.21% ± 3.68% for 1-component revision. The mean septic revision TKA total Medicare reimbursement declined 23.29% ± 3.73% for explantation and 33.47% ± 3.24% for reimplantation. Both the dollar amount (p < 0.0001) and the percentage (p < 0.0001) of the total Medicare reimbursement decline for septic revision TKA were significantly greater than the decline for aseptic revision TKA. CONCLUSIONS:Septic revision TKAs have been devalued at a rate greater than their aseptic counterparts over the past 2 decades. Coupled with our findings, the increased resource utilization of septic revision TKAs may result in financial barriers for physicians and subsequently may reduce access to care for patients with periprosthetic joint infections. CLINICAL RELEVANCE/CONCLUSIONS:The devaluation of revision TKAs may result in reduced patient access to infection management at facilities unable to bear the financial burden of these procedures.

BACKGROUND:In 2015, the healthcare system transitioned from International Classification of Diseases, Ninth Revision (ICD-9) coding to the Tenth Revision (ICD-10). We sought to determine the effect of this change on the reported incidence of complications following total knee arthroplasty (TKA). METHODS:The Humana administrative claims database was queried from 2 years prior to October 1, 2015 (ICD-9 cohort) and for 1 year after this date (ICD-10 cohort) to identify all TKA procedures. Complications occurring within 6 months of surgery were captured using the respective coding systems. Incidence of each complication was compared between cohorts using risk ratios (RR) and 95% confidence intervals. RESULTS:There were 19,009 TKAs in the ICD-10 cohort and 38,172 TKAs in the ICD-9 cohort. The incidence of each complication analyzed was significantly higher in the ICD-9 cohort relative to the ICD-10 cohort. Periprosthetic joint infection occurred in 1.9% vs 1.3% (RR 1.5, 1.3-1.9), loosening in 0.3% vs 0.1% (RR 2.7, 1.8-4.9), periprosthetic fracture in 0.3% vs 0.1% (RR 3.0, 1.6-4.5), and other mechanical complications in 0.7% vs 0.4% (RR 2.0, 1.5-2.5) (P < .05 for all). CONCLUSION/CONCLUSIONS:The transition from ICD-9 to ICD-10 coding has altered the reported incidence of complications following TKA. These results are likely due to the added complexity of ICD-10 which is joint and laterality specific. It is important to understand the differences between coding systems as this data is used for quality initiatives, risk adjustment models, and clinical research. Thoughtful methodology will be necessary when ICD-9 and ICD-10 data are being analyzed simultaneously.

OBJECTIVES/OBJECTIVE:Primary purpose was to generate a model to identify key factors relevant to acute care hospital readmission within 90 days from 3 types of post-acute care (PAC) sites: home with home care services (HC), skilled nursing facility (SNF), and inpatient rehabilitation facility (IRF). Specific aims were to (1) examine demographic characteristics of adults discharged to 3 types of PAC sites and (2) compare 90-day acute hospital readmission rate across PAC sites and risk levels. DESIGN/METHODS:Retrospective, secondary analysis design was used to examine hospital readmissions within 90 days for persons discharged from hospital to SNF, IRF, or HC. SETTINGS AND PARTICIPANTS/METHODS:Cohort sample was composed of 2015 assessment data from 3,592,995 Medicare beneficiaries, including 1,536,908 from SNFs, 306,878 from IRFs, and 1,749,209 patients receiving HC services. MEASURES/METHODS:Initial level of analysis created multiple patient profiles based on predictive patient characteristics. Second level of analysis consisted of multiple logistic regressions within each profile to create predictive algorithms for likelihood of readmission within 90 days, based on risk profile and PAC site. RESULTS:Total sample 90-day hospital readmission rate was 27.48%. Patients discharged to IRF had the lowest readmission rate (23.34%); those receiving HC services had the highest rate (31.33%). Creation of model risk subgroups, however, revealed alternative outcomes. Patients seem to do best (i.e., lowest readmission rates) when discharged to SNF with one exception, those in the very high risk group. Among all patients in the low-, intermediate-, and high-risk groups, the lowest readmission rates occurred among SNF patients. CONCLUSIONS AND IMPLICATIONS/CONCLUSIONS:The proposed model has potential use to stratify patients' potential risk for readmission as well as optimal PAC destination. Machine-learning modeling with large data sets is a useful strategy to increase the precision accuracy in predicting outcomes among patients who have nonhome discharges from the hospital.

BACKGROUND:Patients with hepatitis C virus (HCV) have an increased risk of complications after total joint arthroplasty (TJA). There is a limited but growing body of evidence on the benefit of preoperative antiviral treatment to reduce complications after TJA. What has not been well established is the effect of preoperative antiviral treatment among those with advanced disease as indicated by hepatic fibrosis. METHODS:In total, 270 patients at 2 urban medical centers were reviewed for patient demographics, comorbidities, HCV treatment, hepatic fibrosis status, surgical information, and postoperative complications. Patients were divided into 2 groups based on their antiviral treatment status prior to TJA: Treated (n = 129) and Untreated (n = 141). Pearson's chi-squared test, Student's t-test, and multivariate logistic regressions were used to analyze complications between groups. RESULTS:Patients in the Treated group had significantly fewer all-type complications (4.7% vs 14.9%, P = .007), infections (2.3% vs 12.1%, P = .002), and reoperations (0.8% vs 9.9%, P = .001) compared to the Untreated group. After controlling for hepatic fibrosis, we found that Treated patients still had significantly lower odds of experiencing all-type complications (odds ratio [OR] 0.30, 95% confidence interval [CI] 0.10-0.88; P = .028), infection (OR 0.19, 95% CI 0.04-0.87; P = .033), and reoperation (OR 0.11, 95% CI 0.01-0.90; P = .039) following TJA. CONCLUSION/CONCLUSIONS:HCV antiviral treatment reduces postoperative complications after primary TJA, even among those who have progressed to hepatic fibrosis. Surgeons can use this information in shared decision making prior to TJA to counsel patients about the benefits of preoperative antiviral treatment even in the presence of hepatic fibrosis.