Effect of Antibiotic-Impregnated Bone Cement in Primary Total Knee Arthroplasty

BackgroundThe purpose of this study is to evaluate the effect of commercially available antibiotic-impregnated bone cement (AIBC) on (1) prosthetic joint infections (PJIs) and (2) surgical site infections (SSIs) after primary total knee arthroplasty (TKA).MethodsA review of primary TKAs between 2014 and 2017 from an institutional database was conducted. This identified 12,541 cases which were separated into AIBC (n = 4337) and non-AIBC (8,164) cohorts. Medical records were reviewed for PJIs and SSIs (mean 2-year postoperative period). Infection rates between the cohorts were compared with univariate analyses followed by subanalysis of high risk patients (defined as having 2 or more of the following characteristics: >65 years, body mass index >40, or Charlson Comorbidity Index score >3). To control for confounders, multivariate analyses were performed with regression models adjusted for age, gender, body mass index, comorbidities, year, operative times, and lengths of stay.ResultsOn univariate analysis, PJI rates were higher in the AIBC cohort (1.0%) compared to the non-AIBC cohort (0.5%, P < .001). Subanalysis of the high risk patients also showed that PJI rates were higher in the AIBC cohort (1.9% vs 0.6%, P < .01). After adjusting for potential confounders, no significant associations between PJIs and AIBC use were found (odds ratio 1.4, 95% confidence interval 0.9-2.3, P = .133). Similarly, no significant differences in SSI rates were observed between the AIBC (2.9%) and non-AIBC cohorts (2.4%, P = .060) and no significant associations between SSIs and AIBC were found with multivariate analysis (odds ratio 1.0, 95% confidence interval CI 0.8-1.3, P = .948).ConclusionThis study found that there was no clinically or statistically significant decrease in infection rates with AIBC in primary TKAs.     

Low-Dose vs Regular-Dose Aspirin for Venous Thromboembolism Prophylaxis in Primary Total Joint Arthroplasty

BackgroundConsensus on whether low-dose (81 mg) or regular-dose (325 mg) aspirin (ASA) is more effective for venous thromboembolism (VTE) chemoprophylaxis in primary total joint arthroplasties (TJAs) is not reached. The goal of this study is to evaluate the efficacy of low-dose and regular-dose ASA for VTE chemoprophylaxis in primary total hip arthroplasties and total knee arthroplasties.MethodsWe retrospectively identified 3512 primary TJAs (2344 total hip arthroplasties and 1168 total knee arthroplasties) with ASA used as VTE chemoprophylaxis between 2000 and 2019. Patients received ASA twice daily for 4-6 weeks after surgery with 961 (27%) receiving low-dose ASA and 2551 (73%) receiving regular-dose ASA. The primary endpoint was 90-day incidence of symptomatic VTEs. Secondary outcomes were gastrointestinal (GI) bleeding events and mortality. The mean age at index TJA was 66 years, 54% were female, and mean body mass index was 31 kg/m². The mean Charlson Comorbidity Index was 3.5. Mean follow-up was 3 years.ResultsThere was no difference in 90-day incidence of symptomatic VTEs between low-dose and regular-dose ASA (0% vs 0.1%, respectively; P = .79). There were no GI bleeding events in either group. There was no difference in 90-day mortality between low-dose and regular-dose ASA (0.3% vs 0.1%, respectively; P = .24).ConclusionIn 3512 primary TJA patients treated with ASA, we found a cumulative incidence of VTE <1% at 90 days. Although this study is underpowered, it appears that twice daily low-dose ASA was equally effective to twice daily regular-dose ASA for VTE chemoprophylaxis, with no difference in risk of GI bleeds or mortality.Level of EvidenceIII, retrospective cohort study.     

Total Joint Arthroplasty Outcomes in Patients With a Previously Failed Toxicology Screen: A Propensity Score–Matched Analysis

BackgroundThe purpose of this study is to review the outcomes of a consecutive series of arthroplasty patients who had previously failed a urine toxicology test. Specifically, we assessed (1) mortality at last follow-up; (2) 90-day readmission and reoperation; (3) rate of complications; and (4) hospital length of stay (LOS) and rates of nonhome discharge.MethodsA single-institution, electronic medical record database was queried for primary arthroplasty patients from 2006 to 2017 who had previously failed a day-of-arthroplasty urine toxicology screen. Patients were matched in a 2:1 ratio with toxicology-negative controls.ResultsThe mortality rate among toxicology-positive THA patients was 1 of 20 (5%) compared to 0 of 40 among controls (P = .333); the rate of readmission was 3 of 20 (15%) vs 0 of 40 (P = .033); the rate of reoperation was 1 of 20 vs 0 of 40 (P = .333); the rate of surgical complications was 6 of 20 (30%) vs 1 of 40 (2.5%) (P = .004); the rate of medical complication was 4 of 20 (20%) vs 1 of 40 (2.5%) (P = .038); the average LOS was 4 days (range, 1-8 days) vs 2 days (range, 1-10) (P = .002); and the rate of nonhome discharge was 5 of 20 (25%) vs 2 of 40 (5%) patients in the control group (P = .013). The mortality rate among toxicology-positive TKA patients was 1 of 19 (5.3%) compared to 0 of 38 among controls (P = .333); the rate of readmission was 5 of 19 (26.3%) vs 2 of 39 (5.3%) (P = .033); the rate of reoperation was 3 of 19 (15.8%) vs zero (P = .033); the rate of surgical complications was 4 of 21 (21.1%) vs 1 of 38 (2.6%) (P = .038); the rate of medical complications was 5 of 19 (26.3%) vs 2 of 38 (5.3%) (P = .035); the average LOS was 4 days (range, 2-6 days) vs 2 days (range, 1-8 days) (P = .001), the rate of nonhome discharge was 7 of 19 (36.8%) compared to 2 of 38 (5.3%) in the control group (P = .004).ConclusionThese results suggest that toxicology-positive patients require a careful discussion of goals of care before undertaking total hip arthroplasty or total knee arthroplasty.     

Effects of a Total Knee Arthroplasty Care Pathway on Cost,Quality, and Patient Experience: Toward Measuring the Triple Aim

BackgroundCare pathways are increasingly important as the shift toward value-based care continues; however, there is an inconsistent literature regarding their efficacy. The authors hypothesized that a total knee arthroplasty (TKA) care pathway, at a multihospital health system, would decrease cost, length of stay (LOS), discharges to inpatient facilities, postoperative complications at 90 days, and improve patient experience.MethodsA historical control study with multivariable regression was used to determine the association of an evidence-based care pathway with episode of care cost, LOS, discharge disposition, 90-day postoperative complications, and Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores.ResultsIn total, 6760 primary TKA surgeries were analyzed. Multivariable regression demonstrated that the full protocol period was associated with a decrease in episode of care costs (?8.501%, 95% confidence interval [CI] ?9.639 to ?7.350), a decrease in LOS (?26.966%, 95% CI ?28.516 to ?25.382), and an increase in discharges to home (odds ratio [OR] 3.838, 95% CI 3.318-4.446). The full protocol was not associated with a change in 90-day complications (OR 1.067, 95% CI 0.905-1.258) or patient willingness to recommend (OR 1.06, 95% CI 0.72-1.55). Adjusted episode of care cost savings, normalized to average national Medicare reimbursement, were $2360 per patient.ConclusionTKA care pathways are an effective tool for standardizing care and reducing costs across a large health system. Further investigations are needed to develop interventions to consistently reduce complications. National scale implementation of care pathways in TKA could lead to estimated cost reductions of approximately $1.6 billion annually.     

Diagnostic Accuracy of the Alpha-Defensin Test for Periprosthetic Joint Infection in Patients With Inflammatory Diseases

BackgroundThe alpha-defensin test has been reported to have high accuracy to diagnose periprosthetic joint infection (PJI). There are remaining concerns about the utility of the test in patients with inflammatory diseases. The purpose of this study is to determine sensitivity and specificity of laboratory-based alpha-defensin in diagnosing PJI in patients with systemic inflammatory disease in revision total hip/knee arthroplasty.MethodsA retrospective review was conducted of 1374 cases who underwent revision total hip/knee arthroplasty at a single healthcare system from 2014 to 2017. Cases with inflammatory diseases who received a 1-stage revision arthroplasty, the first stage of 2-stage revision arthroplasty, or irrigation and debridement with available preoperative alpha-defensin results were included. Patients who received a second-stage procedure, spacer exchange, who had insufficient Musculoskeletal Infection Society criteria, or with early postoperative PJI were excluded from this study. Cases were classified as infected or not according to Musculoskeletal Infection Society criteria. A total of 41 cases met the inclusion criteria. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of alpha-defensin to diagnose PJI were calculated.ResultsThe alpha-defensin test demonstrated a sensitivity of 93%, a specificity of 100%, a positive predictive value of 100%, a negative predictive value of 96%, and an accuracy of 97% for diagnosing PJI. There was 1 patient with polymyositis who had a false-negative result.ConclusionAlpha-defensin had high accuracy for diagnosing PJI even in inflammatory diseases. The alpha-defensin test provides useful information with high accuracy in diagnosing PJI in patients with inflammatory diseases.     

Incidence,Causes, and Timing of 30-Day Readmission Following Total Knee Arthroplasty

BackgroundIt is important to study the incidence and causes of readmissions in order to understand why they occur and how to reduce them. This study looks at a national sample of patients following total knee arthroplasty (TKA) to identify incidences, trends, causes, and timing of 30-day readmissions.MethodsPatients undergoing primary TKA from 2012 to 2016 in the American College of Surgeons National Surgical Quality Improvement Program database were identified (n = 197,192). Patients with fractures (n = 177), nonelective surgery (n = 2234), bilateral TKA (n = 5483), and cases with unknown readmission status (n = 1047) were excluded, leaving a total of 188,251 cases. Linear regression analysis was used to determine trends over time.ResultsThe incidence of overall 30-day readmission following primary TKA from 2012 to 2016 was 3.19% (6014/188,251), with significant decreases in readmission rates during this time (β = ?0.001, P < .001). The top 5 causes of readmission included superficial surgical site infection (SSI; 9.7%), non-SSI infection (9.5%), cardiovascular complications (CV; 9.3%), gastrointestinal complications (8.8%), and venous thromboembolisms (8.8%). The most common cause of readmission during postoperative week 1 was CV complications (12.2%), week 2 was superficial SSI (11.6%), week 3 was deep SSI (11.4%), and week 4 was deep SSI (12.4%).ConclusionOverall, 30-day readmissions following TKA were found to significantly decline from 2012 to 2016. The most common causes of overall readmission included superficial SSI, non-SSI infection, CV complications, gastrointestinal complications, and venous thromboembolisms. However, the most common causes of readmission changed from week to week postoperatively. This data may help institutions develop policies to prevent unplanned readmissions following TKA.     

Low-Dose Aspirin Is Safe and Effective for Venous Thromboembolism Prevention in Patients Undergoing Revision Total Hip Arthroplasty: A Retrospective Cohort Study

BackgroundCurrently, there is no established universal standard of care for prophylaxis against venous thromboembolism (VTE) in orthopedic patients undergoing revision total hip arthroplasty (rTHA). The aim of this study is to determine whether a protocol of 81-mg aspirin (ASA) bis in die (BID) is safe and/or effective in preventing VTE in patients undergoing rTHAs vs 325-mg ASA BID.MethodsIn 2017, a large academic medical center adopted a new protocol for VTE prophylaxis in arthroplasty patients at standard risk. Initially, patients received 325-mg ASA BID but switched to 81-mg ASA BID. A retrospective review (2011-2019) was performed to identify 1361 consecutive rTHA patients and their associated 90-day postoperative complications such as VTE, including pulmonary embolism (PE) and/or deep vein thrombosis (DVT), as the primary outcome; and gastrointestinal and wound bleeding, acute periprosthetic joint infection, and mortality as the secondary outcome.ResultsFrom 2011 to 2017, 973 rTHAs were performed and 13 total VTE cases were diagnosed (1.34%). From 2017 to 2019, 388 rTHAs were performed with 3 total VTE cases identified (0.77%). Chi-squared analyses and logistic regression models showed no differences in rates or odds in postoperative PE (P = .09), DVT (P = .79), PE and DVT (P = .85), and total VTE (P = .38) using either dose. There were also no differences between bleeding complications (P = .14), infection rate (P = .46), and mortality (P = .53).ConclusionUsing a protocol of 81-mg of ASA BID is noninferior to 325-mg ASA BID and may be safe and effective in maintaining low rates of VTE in patients undergoing rTHA.     

Predicting Inpatient Payments Prior to Lower Extremity Arthroplasty Using Deep Learning: Which Model Architecture Is Best?

BackgroundRecent advances in machine learning have given rise to deep learning, which uses hierarchical layers to build models, offering the ability to advance value-based healthcare by better predicting patient outcomes and costs of a given treatment. The purpose of this study is to compare the performance of 2 common deep learning models, traditional multilayer perceptron (MLP), and the newer dense neural network (DenseNet), in predicting outcomes for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) as a foundation for future musculoskeletal studies seeking to utilize machine learning.MethodsUsing 295,605 patients undergoing primary THA and TKA from a New York State inpatient administrative database from 2009 to 2016, 2 neural network designs (MLP vs DenseNet) with different model regularization techniques (dropout, batch normalization, and DeCovLoss) were applied to compare model performance on predicting inpatient procedural cost using the area under the receiver operating characteristic curve (AUC). Models were implemented to identify high-cost surgical cases.ResultsDenseNet performed similarly to or better than MLP across the different regularization techniques in predicting procedural costs of THA and TKA. Applying regularization to DenseNet resulted in a significantly higher AUC as compared to DenseNet alone (0.813 vs 0.792, P = .011). When regularization methods were applied to MLP, the AUC was significantly lower than without regularization (0.621 vs 0.791, P = 1.1 × 10^?15). When the optimal MLP and DenseNet models were compared in a head-to-head fashion, they performed similarly at cost prediction (P > .999).ConclusionThis study establishes that in predicting costs of lower extremity arthroplasty, DenseNet models improve in performance with regularization, whereas simple neural network models perform significantly worse without regularization. In light of the resource-intensive nature of creating and testing deep learning models for orthopedic surgery, particularly for value-centric procedures such as arthroplasty, this study establishes a set of key technical features that resulted in better prediction of inpatient surgical costs. We demonstrated that regularization is critically important for neural networks in arthroplasty cost prediction and that future studies should utilize these deep learning techniques to predict arthroplasty costs.Level of EvidenceIII.     

A Simple Protocol to Stratify Pulmonary Risk Reduces Complications After Total Joint Arthroplasty

BackgroundPulmonary complications after total joint arthroplasty are a burden to patients and the healthcare system. The aim of this study is to demonstrate the effectiveness of a pulmonary screening questionnaire and intervention protocol developed at our institution to prevent pulmonary complications.MethodsBetween 2010 and 2015, 7658 consecutive total joint arthroplasty patients at our institution were reviewed. Based on our pre-operative pulmonary risk assessment tool, 1625 patients were flagged as high pulmonary risk. Patients were determined to be high risk if they were a current or former heavy smoker with an abnormal spirometry, had a positive obstructive sleep apnea screening, required continuous positive airway pressure/bi-level positive airway pressure use, had a history of significant pulmonary disease, had an oxygen saturation <90%, or had body mass index >40. A standardized monitoring protocol and interventions including smoking cessation, treatment and optimization of primary pulmonary conditions, peri-operative inhaler use, spinal anesthesia, aspiration precautions, elevated head of bed >20° resting and >45° while eating, maintaining oxygen saturation ≥92%, early use of incentive spirometer, avoidance of narcotics and early respiratory therapy consult were initiated for all high risk patients.ResultsOnly 7 of 7658 (0.091%) patients suffered pulmonary complications after initiating our intervention protocol. These included 3 aspiration pneumonias, 1 asthma exacerbation, 1 chronic obstructive pulmonary disease exacerbation, 1 continuous positive airway pressure intolerance in a patient with obstructive sleep apnea, and 1 requirement of bi-level positive airway pressure. The pulmonary risk questionnaire accurately identified all patients who had pulmonary complications. The overall pulmonary complication rate at our institution decreased from 5.7% to 0.09% after implementing our screening questionnaire and intervention protocol (P < .0001).ConclusionOur results demonstrate a more than 63-fold reduction in pulmonary complications at our institution. Our screening questionnaire and intervention protocol is an effective way of identifying and preventing pulmonary complications.     

Unexpected Neoplasms in Lungs Explanted From Lung Transplant Recipients: A Single-Center Experience and Review of Literature

Introduction

Lung transplantation is a common treatment for various indications, but undiagnosed neoplasms are found in 0.5% to 2.4% of explanted lungs. We report the largest single-institution series of patients with unexpected neoplasms in explanted lungs and compare rates of undiagnosed malignancies before and after the 2005 Lung Allocation Score (LAS) update.

A surgical residency preparatory course for senior medical students leads to earlier independence in ACGME competencies

Background

It is unknown whether surgery residency preparatory courses lead to earlier independent practice.

Preoperative Prediction of Value Metrics and a Patient-Specific Payment Model for Primary Total Hip Arthroplasty: Development and Validation of a Deep Learning Model

BackgroundThe primary objective was to develop and test an artificial neural network (ANN) that learns and predicts length of stay (LOS), inpatient charges, and discharge disposition for total hip arthroplasty. The secondary objective was to create a patient-specific payment model (PSPM) accounting for patient complexity.MethodsUsing 15 preoperative variables from 78,335 primary total hip arthroplasty cases for osteoarthritis from the National Inpatient Sample and our institutional database, an ANN was developed to predict LOS, charges, and disposition. Validity metrics included accuracy and area under the curve of the receiver operating characteristic curve. Predictive uncertainty was stratified by All Patient Refined comorbidity cohort to establish the PSPM.ResultsThe dynamic model demonstrated “learning” in the first 30 training rounds with areas under the curve of 82.0%, 83.4%, and 79.4% for LOS, charges, and disposition, respectively. The proposed PSPM established a risk increase of 2.5%, 8.9%, and 17.3% for moderate, major, and severe comorbidities, respectively.ConclusionThe deep learning ANN demonstrated “learning” with good reliability, responsiveness, and validity in its prediction of value-centered outcomes. This model can be applied to implement a PSPM for tiered payments based on the complexity of the case.     

Preemptive Analgesia With Oxycodone Is Associated With More Pain Following Total Joint Arthroplasty

BackgroundPreemptive multimodal analgesia (PMA) is a commonly used technique to control pain following total joint arthroplasty. PMA protocols use multiple analgesics immediately preoperatively to prevent central sensitization and amplification of pain during surgery. While benefits of some individual components of a PMA protocol have been established, there are little data to support inclusion or exclusion of opioids in this context.MethodsThis is a retrospective cohort study of 550 patients undergoing elective, primary total joint arthroplasty at a single institution using a standardized preoperative perioperative protocol. Two hundred seventy-five patients received oxycodone in addition to a standard multimodal preoperative analgesia regimen just before surgery and were compared to a matched cohort of 275 patients who received the standard regimen alone. Outcome measures included inpatient visual analog scale pain scores, inpatient opioid consumption, length of stay, and ambulation distance with physical therapy.ResultsPatients who received opioids in preoperative holding reported significantly greater visual analog scale pain scores on postoperative day 1 (3.7 vs 3.1; P = .01), when compared to those who did not. These patients also walked shorter distances on postoperative day 0 (59.5’ vs 125.7’; P < .001) and consumed greater morphine equivalents per hospital day over the course of their hospital stay (52.2 vs 37.2 mg; P < .001). These differences remained significant when stratified by procedure, total knee arthroplasty or total hip arthroplasty. Differences in pain and function between groups were more pronounced in patients undergoing total hip arthroplasty than those undergoing total knee arthroplasty.ConclusionTotal joint patients who were given preemptive opioids immediately before surgery experienced more pain, consumed more postoperative opioids, and exhibited impaired early function as compared to those who were not given preemptive opioids. Orthopedic surgeons should reconsider routine use of preemptive opioids in this context.     

Rapid Recovery After Total Joint Arthroplasty Using General Anesthesia

BackgroundMultiple papers have purported the superiority of spinal anesthesia used in total joint arthroplasty (TJA). However, there is a paucity of data available for modern general anesthesia (GA) regimens used at high-volume joint replacement centers.MethodsWe retrospectively reviewed a series of 1527 consecutive primary TJAs (644 total hip arthroplasties and 883 total knee arthroplasties) performed over a 3-year span at a single institution that uses a contemporary GA protocol and report on the length of stay, early recovery rates, perioperative complications, and readmissions.ResultsFrom the elective TJAs performed using a modern GA protocol, 96.3% (n = 1471) of patients discharged on postoperative day 1, and 97.2% (n = 1482) of subjects were able to participate with physical therapy on the day of surgery. Only 6 patients (0.4%) required an intensive care unit stay postoperatively. The 90-day readmission rate over this time was 2.4% (n = 36), while the reoperation rate was 1.3% (n = 20).DiscussionNeuraxial anesthesia for TJA is commonly preferred in high-volume institutions utilizing contemporary enhanced recovery pathways. Our data support the notion that the utilization of modern GA techniques that limit narcotics and certain inhalants can be successfully used in short-stay primary total joint arthroplasty.Level of EvidenceIV– Case series.     

Quadriceps Snip in 321 Revision Total Knee Arthroplasties: A Safe Technique in a Matched Cohort Study

BackgroundQuadriceps snips (QSs) are commonly used to gain enhanced exposure during revision total knee arthroplasties (TKAs). The goals of this study were to evaluate the longer-term clinical outcomes and complications in a contemporary cohort of patients treated with QS and to compare them to a matched cohort treated with standard exposure during revision TKAs.MethodsWe retrospectively identified 3107 revision TKAs performed at our institution between 2002 and 2012. QS was performed in 321 of these knees. Each QS revision TKA was 1:1 matched to a control (standard exposure) based on age, gender, body mass index, surgery date, and reason for revision. Clinical outcomes studied included Knee Society Score, range of motion, and extensor lag. Other outcomes assessed were complications (especially extensor mechanism disruption) and survivorship. Mean follow-up was 5 years.ResultsThe mean Knee Society Score improvement was not significantly different between groups (P = .9). At latest follow-up, the mean range of motion was 93° in the QS group and was slightly higher at 100° in the control group (P = .002). Postoperative extensor lag of 10 degrees or more was present in 21 (6.7%) QS knees versus 19 (6.8%) control knees (P = .95). Complication rates were similar in both groups with extensor mechanism disruption occurring in 3 in the QS group (0.7% at 10 years) versus 4 in the control group (0.8% at 10 years; P = .91). Kaplan-Meier survivorships free of revision for aseptic loosening, free of any revision, and free of any reoperation were similar at 10 years (85%, 71%, and 61%, respectively, in the QS group vs 89%, 70% and 60%, respectively, in the control group).ConclusionThis matched cohort study is the largest to report the results of QS and also the largest to report results compared with patients treated with standard exposure. Building on the results of smaller historical series, this study demonstrates QS was a facile technique in complex revision TKAs allowing for safe exposure with few complications.Level of EvidenceIII (case-control study).     

Discharge Home is Associated With Decreased Early Complications Following Primary Total Joint Arthroplasty

BackgroundPrimary total hip (THA) and total knee arthroplasty (TKA) volume has increased over the past decade. Patients discharged home (HD) have demonstrated improved postoperative outcomes compared with non-home discharge (NHD) patients. We reviewed trends in HD over the past decade and compared complication rates between HD and NHD primary total joint arthroplasty (TJA) patients.MethodsRetrospective analysis of the National Surgical Quality Improvement Program was performed on TJA cases and patients were grouped by discharge type. Trends in the prevalence of HD were compared by chi-square test, from 2011 to 2016. Univariate and bivariate statistics were performed. Multivariate logistic and propensity score–matched analyses were used to control for confounding variables.ResultsDuring the 6-year review, HD increased significantly for THA (71.2% to 83.6%) and TKA (65.6% to 80.7%). Overall HD was 75.4% of THA and 71.0% of TKA patients. Propensity matching identified 16,580 THA pairs and 34,952 TKA pairs. Compared with NHD patients, HD patients had shorter operative times, were younger, and had shorter lengths of stay. Controlling for confounders, the HD patients had lower risk of death within 30 days, lower risk of major medical morbidity, decreased risk of reoperation, and decreased risk of readmission compared with NDH patients. Multivariate models demonstrated similar findings.ConclusionHD in both THA and TKA independently predicts decreased early (30-day) postoperative complications after controlling for confounding variables. Given the improved outcomes, we advocate for continued emphasis on HD rather than NHD when clinically appropriate.