Disease and brain region specific immune response profiles in neurodegenerative diseases with pure and mixed protein pathologies.

The disease-specific accumulation of pathological proteins has long been the major focus of research in neurodegenerative diseases (ND), including Alzheimer's disease (AD) and related dementias (RD), but the recent identification of a multitude of genetic risk factors for ND in immune-associated genes highlights the importance of immune processes in disease pathogenesis and progression. Studies in animal models have characterized the local immune response to disease-specific proteins in AD and ADRD, but due to the complexity of disease processes and the co-existence of multiple protein pathologies in human donor brains, the precise role of immune processes in ND is far from understood. To better characterize the interplay between different extracellular and intracellular protein pathologies and the brain's intrinsic immune system in ND, we set out to comprehensively profile the local immune response in postmortem brain samples of individuals with "pure" beta-Amyloid and tau pathology (AD), "pure" α-Synuclein pathology in Lewy body diseases (LBD), as well as cases with Alzheimer's disease neuropathological changes (ADNC) and Lewy body pathology (MIX). Combining immunohistochemical profiling of microglia and digital image analysis, along with deep immunophenotyping using gene expression profiling on the NanoString nCounter® platform and digital spatial profiling on the NanoString GeoMx® platform we identified a robust immune activation signature in AD brain samples. This signature is maintained in persons with mixed pathologies, irrespective of co-existence of AD pathology and Lewy body (LB) pathology, while LBD brain samples with "pure" LB pathology exhibit an attenuated and distinct immune signature. Our studies highlight disease- and brain region-specific immune response profiles to intracellular and extracellular protein pathologies and further underscore the complexity of neuroimmune interactions in ND.

Medicaid Expansion Is Associated With Increases in Medicaid-Funded Total Joint Arthroplasty.

BACKGROUND: Existing literature presents competing views concerning the impact of Medicaid expansion on total joint arthroplasty (TJA) utilizations. While some reports demonstrate that expansion does not increase Medicaid acceptance by surgeons, others show increases in Medicaid-funded TJA via limited analyses. We conducted a nationwide, multi-insurance, econometric study to determine if Medicaid-funded and all-funding-source total hip arthroplasty (THA) or total knee arthroplasty (TKA) utilizations increased following expansion. METHODS: This study examined 999,015 THA and 2,099,975 TKA from 2010 to 2017 using a commercially available national payer database. Difference-in-differences analyses, econometric regression methods used to assess the impact of policy change, were used to examine the impact of Medicaid expansion on TJA utilizations, and event analyses were used to confirm the parallel trends assumption, which helps to ensure that the estimated effect is not a result of existing differences in trends between treatment and nontreatment groups. RESULTS: Event analyses confirmed parallel trends in the pre-expansion period. Difference-in-differences analyses found a persistent increase in Medicaid-funded THA (40.4%, P = .001, confidence interval [CI]: 12.7, 62.1%), but not THA from all funding sources (4.6%, P = .128, CI: -1.3, 10.8%). Medicaid-funded TKA (35.8%, P < .001, CI: 17.4, 68.0%) increased, but not TKA from all funding sources (3.4%, P = .321, CI: -3.1, 10.1%). CONCLUSION: While the number of Medicaid-funded TJAs increased, expansion had no significant effect when examining all funding sources. This suggests that Medicaid expansion primarily affected source of TJA funding, not overall volume. Further research is needed to examine state-specific predictors of response to Medicaid expansion.

The Effect of Surgical Approach on the Outcomes of Same-Day Discharge Outpatient Total Hip Arthroplasty at a Single Ambulatory Surgery Center.

BACKGROUND: Primary total hip arthroplasty (THA) is increasingly being performed in the outpatient setting. However, there is little known regarding the differences in same-day discharge (SDD) rates and complications of operative approach in same-day total hip arthroplasty in the ambulatory surgery center (ASC) setting. METHODS: A retrospective chart review was performed between July 2019 and October 2021 for all patients who underwent primary THA in a single freestanding ASC. Successful SDDs, surgical approaches, lengths of surgery, estimated blood losses (EBL), complications, and readmission events were recorded for each patient. Complications were compared using Pearson Chi-Squares, while EBL and surgery lengths were compared with 1-way analysis of variances (ANOVA) (alpha = 0.5). There were 17 total complications in 326 total hip arthroplasties (5.2%), including direct admissions to the emergency department, 30-day and 90-day readmissions, wound complications, instability, infection, and revision surgery. Among all complications, there were 5 direct admissions, making the successful SDD rate 98.5%. RESULTS: Complications and direct admissions were not associated with approach. The 30-day readmission rates were associated with approach, with no readmissions in the direct anterior approach (DAA) or the antero-lateral approach (AL) cohorts and 3 (4.3%) in the posterior approach (PA) cohort. CONCLUSIONS: In the ASC setting, patients undergoing THA regardless of approach showed no difference in successful SDDs or complications aside from 30-day readmissions. Same-day THA can be safely performed in the DAA, AL, and PA to the hip.

Underweight Patients are at Increased Risk for Complications following Total Hip Arthroplasty.

BACKGROUND: Given the prevalence of obesity in the United States, much of the adult reconstruction literature focuses on the effects of obesity and morbid obesity. However, there is little published data on the effect of being underweight on postoperative outcomes. This study aimed to examine the risk of low body mass index (BMI) on complications after total hip arthroplasty (THA). METHODS: A large national database was queried between 2010 and 2020 to identify patients who had THAs. Using International Classification of Disease codes, patients were grouped into the following BMI categories: morbid obesity (BMI>40), obesity (BMI 30 to 40), normal BMI (BMI 20 to 30), and underweight (BMI<20). There were 58,151 patients identified, including 2,484 (4.27%) underweight patients, 34,710 (59.69%) obese patients, and 20,957 (36.04%) morbidly obese patients. Control groups were created for each study group, matching for age, sex, and a comorbidity index. Complications that occurred within 1 year postoperatively were isolated. Subanalyses were performed to compare complications between underweight and obese patients. Statistical analyses were performed using Pearson Chi-squares. RESULTS: Compared to their matched control group, underweight patients showed increased odds of THA revision (Odds Ratio (OR) = 1.32, P = .04), sepsis (OR = 1.51, P = .01), and periprosthetic fractures (OR = 1.63, P = .01). When directly comparing underweight and obese patients (BMI 30 and above), underweight patients had higher odds of aseptic loosening (OR = 1.62, P = .03), sepsis (OR = 1.34, P = .03), dislocation (OR = 1.84, P < .001), and periprosthetic fracture (OR = 1.46, P = .01). CONCLUSION: Morbidly obese patients experience the highest odds of complications, although underweight patients also had elevated odds for several complications. Underweight patients are an under-recognized and understudied high risk arthroplasty cohort and further research is needed.

Risk of Dislocation and Revision Following Primary Total Hip Arthroplasty in Patients With Prior Lumbar Fusion With Spinopelvic Fixation.

BACKGROUND: The effect of spinopelvic fixation in addition to lumbar spinal fusion (LSF) on dislocation/instability and revision in patients undergoing primary total hip arthroplasty (THA) has not been reported previously. METHODS: The PearlDiver Research Program was used to identify patients aged 30 and above undergoing primary THA who received (1) THA only, (2) THA with prior single-level LSF, (3) THA with prior 2-5 level LSF, or (4) THA with prior LSF with spinopelvic fixation. The incidence of THA revision and dislocation/instability was compared through logistic regression and Chi-squared analysis. All regressions were controlled for age, gender, and Elixhauser Comorbidity Index (ECI). RESULTS: Between 2010 and 2018, 465,558 patients without history of LSF undergoing THA were examined and compared to 180 THA patients with prior spinopelvic fixation, 5,299 with prior single-level LSF, and 1,465 with prior 2-5 level LSF. At 2 years, 7.8% of THA patients with prior spinopelvic fixation, 4.7% of THA patients with prior 2-5 level LSF, 4.2% of THA patients with prior single-level LSF, and 2.2% of THA patients undergoing only THA had a dislocation event or instability (P < .0001). After controlling for length of fusion, pelvic fixation itself was associated with higher independent risk of revision (at 2 years: 2-5 level LSF + spinopelvic fixation: aHR = 3.15, 95% CI 1.77-5.61, P < .0001 vs 2-5 level LSF with no spinopelvic fixation: aOR = 1.39, 95% CI 1.10-1.76, P < .0001). CONCLUSION: At 2 years, spinopelvic fixation in THA patients were associated with a greater than 3.5-fold increase in hip dislocation risk compared to those without LSF, and an over 2-fold increase in THA revision risk compared to those with LSF without spinopelvic fixation. LEVEL OF EVIDENCE: III.

Body Mass Index and Risk of Complications After Posterior Lumbar Spine Fusion: A Matched Cohort Analysis Investigating Underweight and Obese Patients.

OBJECTIVE: Previous studies have demonstrated that obesity is associated with increased complications after lumbar fusion. However, there are little published data on the effect of being underweight on lumbar fusion outcomes. The purpose of this study was to elucidate the effect of being underweight versus obese on outcomes after lumbar spinal fusion. METHODS: Lumbar spinal fusion patients were identified through the PearlDiver Mariner database between 2010 and 2020. Study groups were created using International Classification of Diseases codes to identify preoperative body mass index (BMI) category as morbid obesity (BMI > 40), obesity (BMI 30 to 40), normal BMI (BMI 20 to 30), and underweight (BMI < 20) cohorts. Complications that occurred within 1 year postoperatively in this study and matched control groups were then isolated. Statistical analyses were conducted using the Pearson chi square method. RESULTS: A total of 62,616 patients were identified in this analysis. This included 1,258 underweight patients (4.0%), 17,996 obese patients (57.5%), and 12,054 morbidly obese patients (38.5%). The number of patients to experience any postoperative complication was 766 (60.9%), 9,440 (52.4%), and 6,982 (57.9%) for the underweight, obese, and morbidly obese cohorts, respectively. Underweight patients showed an increased likelihood of complications related to instrumentation (odds ratio [OR] 1.85, P = 0.0237), revision fusion (OR 1.34, P = 0.04061), pulmonary complications (OR 1.43, P < 0.001), and sepsis (OR 1.91, P < 0.001). Obese patients with BMI 30 to 40 showed increased odds of the following complications: hemorrhages and hematomas (OR 1.20, P = 0.02634), surgical site complications (OR 1.27, P < 0.001), thromboembolism (OR 1.78, P < 0.001), and urinary complications (OR 1.08, P < 0.001). Morbidly obese patients with BMI > 40 showed increased odds of all complications analyzed in this study. CONCLUSION: This investigation indicates that both underweight and obese patients are at elevated risk of complications after lumbar fusion. Similar to obese patients, underweight patients may benefit from preoperative optimization by nutrition counseling to avoid potential complications. LEVEL OF EVIDENCE: III.

Prostate Cancer History and Total Hip Arthroplasty: A Matched Cohort Analysis Investigating Venous Thromboembolism and Anticoagulation.

Background: Prostate cancer (PCa) is a common cancer among men in the United States. While malignancy is a known cause of venous thromboembolism (VTE), little is known about the effect of PCa history on postoperative complications after elective total hip arthroplasty (THA). This study aimed to evaluate the risk of hematologic complications in patients with a history of PCa taking common postoperative anticoagulants. Methods: THA patients were identified through the PearlDiver Mariner database. Patients with a history of PCa were placed in one of the following cohorts based on postoperative anticoagulant prescription: aspirin, warfarin, low-molecular-weight heparin, direct Xa inhibitor, or any anticoagulant. PCa cohorts were matched 1:3 to patients without a history of PCa with the same anticoagulant prescription based on age, gender, and Charlson Comorbidity Index. Postoperative complications were evaluated using multivariable logistic regression. Results: A total of 74,744 patients that underwent THA were included. PCa patients taking any anticoagulant were found to have increased risk of postoperative deep vein thrombosis (DVT) (odds ratio: 1.25, lower 99% confidence interval: 1.09, upper 99% confidence interval: 1.43, P value <.001). PCa patients taking warfarin, low-molecular-weight heparin, and direct Xa inhibitors additionally showed increased risk of postoperative DVT. Patients taking aspirin did not have an increased risk of postoperative DVT. Conclusions: Our results suggest postoperative aspirin prophylaxis may not increase VTE complication risk when compared to other anticoagulants. Surgeons should be aware that PCa history may be an independent risk factor for VTE, and these patients may benefit from medical optimization.

Surgeon and Facility Volume are Associated With Postoperative Complications After Total Knee Arthroplasty.

Background: Surgeon and hospital volumes may affect outcomes of various orthopedic procedures. The purpose of this study is to characterize the volume dependence of both facilities and surgeons on morbidity and mortality after total knee arthroplasty. Methods: Adults who underwent total knee arthroplasty for osteoarthritis from 2011 to 2015 were identified using International Classification of Diseases-9 Clinical Modification diagnostic and procedural codes in the New York Statewide Planning and Research Cooperative System database. Readmission, in-hospital mortality, and other adverse events were compared across surgeon and facility volumes using multivariable Cox proportional hazards regression, while controlling for patient demographic and clinical factors. Surgeon and facility volumes were compared between the lowest and highest 20%. Results: Of 113,784 identified patients, 71,827 were treated at a high- or low-volume facility or by low- or high-volume surgeon. Low-volume facilities had higher 1-month, 3-month, and 12-month rates of readmission, urinary tract infection, cardiorespiratory arrest, surgical site infection, and wound complications; higher 3- and 12-month rates of pneumonia, cellulitis, and in-facility mortality; and higher 12-month rates of acute renal failure and revision. Low-volume surgeons had higher 1-, 3-, and 12-month rates of readmission, urinary tract infection, acute renal failure, pneumonia, surgical site infection, deep vein thrombosis, pulmonary embolism, cellulitis, and wound complications; higher 3- and 12-month rates of cardiorespiratory arrest; and higher 12-month rate of in-facility mortality. Conclusions: These results suggest volume shifting toward higher volume facilities and/or surgeons could improve patient outcomes and have potential cost savings. Furthermore, these results can inform healthcare policy, for example, designating institutions as centers of excellence.

Socioeconomic Disparities in the Utilization of Total Knee Arthroplasty.

BACKGROUND: Despite strong evidence supporting the efficacy of total knee arthroplasty (TKA), studies have shown significant socioeconomic disparities regarding who ultimately undergoes TKA. The purpose of the current study is to evaluate socioeconomic factors affecting whether a patient undergoes TKA after a diagnosis of osteoarthritis. METHODS: From 2011 to 2018, claims for adult patients diagnosed with knee osteoarthritis in the New York Statewide Planning and Research Cooperative System (SPARCS) database were analyzed. International Classification of Diseases (ICD), 9/10 CM codes were used to identify the initial diagnosis for each patient. ICD 9/10 PCS codes were used to identify subsequent TKA. Logistic regression analysis was performed to determine the effect of patient factors on the likelihood of having TKA. RESULTS: Of 313,794 osteoarthritis diagnoses, 33.3% proceeded to undergo TKA. Increased age (OR 1.007, P < .0001) and workers' compensation relative to commercial insurance (OR 1.865, P < .0001) had increased odds of TKA. Compared to White race, Asian (OR 0.705, P < .0001), Black (OR 0.497, P < .0001), and "other" race (OR 0.563, P < .0001) had lower odds of TKA. Hispanic ethnicity (OR 0.597, P < .0001) had lower odds of surgery. Compared to commercial insurance, Medicare (OR 0.876, P < .0001), Medicaid (OR 0.452, P < .0001), self-pay (OR 0.523, P < .0001), and "other" insurance (OR 0.819, P < .0001) had lower odds of TKA. Increased social deprivation (OR 0.987, P < .0001) had lower odds of TKA. CONCLUSION: TKA is associated with disparities among race, ethnicity, primary insurance, and social deprivation. Additional research is necessary to identify the cause of these disparities to improve equity in orthopedic care.

Bisphosphonates in Total Joint Arthroplasty: A Review of Their Use and Complications.

Background: Considerable interest has been expressed in the use of bisphosphonates to treat periprosthetic osteoporosis with the clinical goals of reducing periprosthetic fractures and prolonging implant survival. Methods: A systematic review was performed with the goal of identifying both basic science and clinical studies related to the risks and benefits of bisphosphonate use in total joint arthroplasty. Results: Studies have shown that bisphosphonates may increase early bony ingrowth, decrease the postoperative loss of bone mineral density, and increase the longevity of implants by reducing the need for revisions secondary to aseptic loosening. Continuing bisphosphonates for 1 year postoperatively seems to provide the greatest benefit, with only marginal benefit being shown by continuing therapy for up to 2 years. Current data present some concerns for an increased risk of periprosthetic fractures especially in younger patients, and prolonged therapy is not recommended due to the potential risk of atypical femur fractures. Patients should be counseled regarding the risk of side effects of bisphosphonates, including the risk of osteonecrosis of the jaw, which is a rare but serious side effect. They should also be counseled on the risk of atypical femur fractures and gastrointestinal intolerance. Conclusions: Orthopedic surgeons could consider bisphosphonates for up to 1 year postoperatively regardless of the patient's prior bone mineral density, after discussion regarding the risks and benefits with the patient.

Malnutrition, Body Mass Index, and Associated Risk of Complications After Posterior Lumbar Spine Fusion: A 3:1 Matched Cohort Analysis.

OBJECTIVE: The effect of malnutrition on outcomes after posterior lumbar fusion (PLF) remains understudied. This study analyzes the effect of malnutrition across a comprehensive range of body mass index (BMI) on complications after PLF. METHODS: The Pearldiver Mariner database was queried between 2010 and 2020 using International Classification of Diseases (Ninth and Tenth Revisions) codes for malnutrition and Current Procedural Terminology codes for PLF. Patients were identified with preoperative BMI diagnosis codes and partitioned into one of the following BMI cohorts: underweight (BMI <20), normal (BMI 19-30), obese (BMI 30-40), and morbidly obese (BMI >40). An additional all-BMI cohort was created using patients with any BMI code. All cohorts were matched 1:3 to control patients within the same BMI group without malnutrition based on age, gender, and Charlson comorbidity index. Complication rates were calculated using the Pearson χ2 method with statistical significance set to P < 0.05. RESULTS: The number of patients in each cohort were 1106 (all-BMI), 227 (underweight), 808 (normal), 667 (obese), and 449 (morbidly obese). Statistical analysis showed that the all-BMI cohort had greater odds of complications related to instrumentation (odds ratio [OR]: 2.28; P < 0.001), need for revision fusion (OR: 2.04; P < 0.001), pulmonary complications (OR: 1.45; P < 0.001), sepsis (OR: 2.89; P < 0.001), surgical site complications (OR: 1.87; P < 0.001), and urinary complications (OR: 1.41; P < 0.001). No difference was noted between the BMI-specific cohorts for complication risk. CONCLUSION: Our analysis indicates that malnutrition may independently increase PLF complication risk. Surgeons may consider preoperative optimization for malnutrition patients to reduce complication risk.

Uncemented Collared Femoral Stems in Total Hip Arthroplasty.

The procedure of total hip arthroplasty (THA) is rapidly evolving. Patients undergoing THA are younger and more active, and they demand an earlier return to their daily activities. All of these factors increase both the early forces on uncemented femoral stems and the risk for complications. Consequently, surgeons must choose implants that provide immediate primary stability. This has led to renewed interest in the use of uncemented collared stems, which have benefits including increased primary stability, decreased risk of subsidence and periprosthetic fracture, and improved load transfer to the proximal femur. [Orthopedics. 2022;45(3):e122-e126.].

Surgeon and Facility Volumes Are Associated With Social Disparities and Post-Operative Complications After Total Hip Arthroplasty.

BACKGROUND: The purpose of this study is to further characterize the volume dependence of facilities and surgeons on morbidity and mortality after total hip arthroplasty (THA). METHODS: Adults who underwent THA from 2009 to 2014 were identified using International Classification of Diseases, Ninth Revision, Clinical Modification and Procedural codes in the New York Statewide Planning and Research Cooperative System database. Complication rates were compared across surgeon and facility volumes using multivariable Cox proportional hazards regression controlling for factors such as the Social Deprivation Index. Surgeon and facility volumes were compared between the low and high volume using cutoffs established by prior research. RESULTS: In total, 99,832 patients were included. Low volume facilities had higher rates of readmission, urinary tract infection (UTI), acute renal failure, pneumonia, surgical site infection (SSI), cellulitis, wound complications, deep vein thrombosis (DVT), in-hospital mortality, and revision. Low volume surgeons had higher rates of readmission, UTI, acute renal failure, pneumonia, SSI, acute respiratory failure, pulmonary embolism, cellulitis, wound complications, in-hospital mortality, cardiorespiratory arrest, DVT, and revision. African Americans, Hispanics, and those with federal insurance had increased rates of readmission. Those with ≥1 Charlson comorbidities or from areas of higher social deprivation had increased incidence of treatment by low volume surgeons and facilities. CONCLUSION: Both low volume facilities and surgeons performing primary THA have higher rates of readmission, UTI, acute renal failure, pneumonia, SSI, cellulitis, wound complications, DVT, in-hospital mortality, and revision. Demographic disparities exist between who is treated at low vs high volume surgeons and facilities placing those groups at higher risks for complications.

Socioeconomic Disparities in the Utilization of Total Hip Arthroplasty.

BACKGROUND: There is increasing focus on highlighting disparities in both access to and equity of care in orthopedics and understanding the impact disparities have on patient health. The purpose of the present study is to evaluate socioeconomic-related factors affecting whether a patient undergoes total hip arthroplasty (THA) after a diagnosis of osteoarthritis. METHODS: From 2011 to 2018, patients ≥40 years of age diagnosed with hip osteoarthritis were identified in the New York Statewide Planning and Research Cooperative System, a comprehensive all-payer database collecting preadjudicated claims in New York State. International Classification of Diseases, Ninth Revision/Tenth Revision codes were used to identify the initial diagnosis and subsequent THA. Logistic regression analysis was performed to determine the effect of patient factors on the likelihood of undergoing THA. RESULTS: Of 142,681 hip osteoarthritis diagnoses, 48.6% proceeded to THA. Compared to non-Hispanic white patients, Asian (odds ratio [OR] 0.65, P < .0001), Black (OR 0.51, P < .0001), and "Other" race (OR 0.54, P < .0001) had lower odds of THA. Hispanic patients (OR 0.55, P < .0001) had lower odds of surgery. Compared to commercial insurance, Medicare (OR 0.83, P < .0001), Medicaid (OR 0.49, P < .0001), Self-pay (OR 0.78, P < .0001), and workers' compensation (OR 0.71, P < .0001) had lower odds of THA. Having one or more Charlson Comorbidity Index (OR 0.45, P < .0001) was associated with lower odds of THA, as was increased social deprivation (OR 0.99, P < .0001). CONCLUSION: THA is associated with disparities among race, gender, primary insurance, and social deprivation. Additional research is necessary to identify the cause of these disparities to improve equity in patient care.

Supervised Machine Learning for Predicting Length of Stay After Lumbar Arthrodesis: A Comprehensive Artificial Intelligence Approach.

INTRODUCTION: Few studies have evaluated the utility of machine learning techniques to predict and classify outcomes, such as length of stay (LOS), for lumbar fusion patients. Six supervised machine learning algorithms may be able to predict and classify whether a patient will experience a short or long hospital LOS after lumbar fusion surgery with a high degree of accuracy. METHODS: Data were obtained from the National Surgical Quality Improvement Program between 2009 and 2018. Demographic and comorbidity information was collected for patients who underwent anterior, anterolateral, or lateral transverse process technique arthrodesis procedure; anterior lumbar interbody fusion (ALIF); posterior, posterolateral, or lateral transverse process technique arthrodesis procedure; posterior lumbar interbody fusion/transforaminal lumbar interbody fusion (PLIF/TLIF); and posterior fusion procedure posterior spine fusion (PSF). Machine learning algorithmic analyses were done with the scikit-learn package in Python on a high-performance computing cluster. In the total sample, 85% of patients were used for training the models, whereas the remaining patients were used for testing the models. C-statistic area under the curve and prediction accuracy (PA) were calculated for each of the models to determine their accuracy in correctly classifying the test cases. RESULTS: In total, 12,915 ALIF patients, 27,212 PLIF/TLIF patients, and 23,406 PSF patients were included in the algorithmic analyses. The patient factors most strongly associated with LOS were sex, ethnicity, dialysis, and disseminated cancer. The machine learning algorithms yielded area under the curve values of between 0.673 and 0.752 (PA: 69.6% to 80.1%) for ALIF, 0.673 and 0.729 (PA: 66.0% to 81.3%) for PLIF/TLIF, and 0.698 and 0.749 (PA: 69.9% to 80.4%) for PSF. CONCLUSION: Machine learning classification algorithms were able to accurately predict long LOS for ALIF, PLIF/TLIF, and PSF patients. Supervised machine learning algorithms may be useful in clinical and administrative settings. These data may additionally help inform predictive analytic models and assist in setting patient expectations. LEVEL III: Diagnostic study, retrospective cohort study.

Total Hip Arthroplasty After Hip Arthroscopy Has Increased Complications and Revision Risk.

BACKGROUND: There has been an increase in hip arthroscopy (HA) over the last decade. After HA, some patients may ultimately require a total hip arthroplasty (THA). However, there is a scarcity of research investigating the outcomes in patients undergoing THA with a history of ipsilateral HA. METHODS: The PearlDiver research program (www.pearldiverinc.com) was queried to capture all patients undergoing THA between 2015 and 2020. Propensity matching was performed to match patients undergoing THA with and without a history of ipsilateral THA. Rates of 30-day medical complications, 1-year surgical complications, and THA revision were compared using multivariate logistic regression. Kaplan-Meier analysis was conducted to estimate survival probabilities of each of the groups with patients undergoing THA . RESULTS: After propensity matching, cohorts of 1940 patients undergoing THA without prior HA and 1940 patients undergoing a THA with prior HA were isolated for analysis. The mean time from HA to THA was 1127 days (standard deviation 858). Patients with a history of ipsilateral HA had an increased risk for dislocation (odds ratio [OR] 1.56, P = .03) and overall decreased implant survival within 4 years of undergoing THA (OR 1.53; P = .05). Furthermore, our data demonstrate the timing of previous HA to be associated with the risk of complications, as illustrated by the increased risk for dislocation (OR 1.75, P = .03), aseptic loosening (OR 2.18, P = .03), and revision surgery at 2 (OR 1.92, P = .02) and 4 years (OR 2.05, P = .01) in patients undergoing THA within 1 year of HA compared twitho patients undergoing THA more than 1 year after HA or with no previous history of HA. CONCLUSION: Patients undergoing THA after HA are at an increased risk for surgical complications, as well as the need for revision surgery.

Predicting Readmission After Anterior, Posterior, and Posterior Interbody Lumbar Spinal Fusion: A Neural Network Machine Learning Approach.

BACKGROUND: Readmission after spine surgery is costly and a relatively common occurrence. Previous research identified several risk factors for readmission; however, the conclusions remain equivocal. Machine learning algorithms offer a unique perspective in analysis of risk factors for readmission and can help predict the likelihood of this occurrence. This study evaluated a neural network (NN), a supervised machine learning technique, to determine whether it could predict readmission after 3 lumbar fusion procedures. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried between 2009 and 2018. Patients who had undergone anterior, lateral, and/or posterior lumbar fusion were included in the study. The Python scikit Learn package was used to run the NN algorithm. A multivariate regression was performed to determine risk factors for readmission. RESULTS: There were 63,533 patients analyzed (12,915 anterior lumbar interbody fusion, 27,212 posterior lumbar interbody fusion, and 23,406 posterior spinal fusion cases). The NN algorithm was able to successfully predict 30-day readmission for 94.6% of anterior lumbar interbody fusion, 94.0% of posterior lumbar interbody fusion, and 92.6% of posterior spinal fusion cases with area under the curve values of 0.64-0.65. Multivariate regression indicated that age >65 years and American Society of Anesthesiologists class >II were linked to increased risk for readmission for all 3 procedures. CONCLUSIONS: The accurate metrics presented indicate the capability for NN algorithms to predict readmission after lumbar arthrodesis. Moreover, the results of this study serve as a catalyst for further research into the utility of machine learning in spine surgery.

Predicting Postoperative Mortality After Metastatic Intraspinal Neoplasm Excision: Development of a Machine-Learning Approach.

OBJECTIVE: Mortality following surgical resection of spinal tumors is a devastating outcome. Naïve Bayes machine learning algorithms may be leveraged in surgical planning to predict mortality. In this investigation, we use a Naïve Bayes classification algorithm to predict mortality following spinal tumor excision within 30 days of surgery. METHODS: Patients who underwent laminectomies between 2006 and 2018 for excisions of intraspinal neoplasms were selected from the National Surgical Quality Initiative Program. Naïve Bayes classifier analysis was conducted in Python. The area under the receiver operating curve (AUC) was calculated to evaluate the classifier's ability to predict mortality within 30 days of surgery. Multivariable logistic regression analysis was performed in R to identify risk factors for 30-day postoperative mortality. RESULTS: In total, 2094 spine tumor surgery patients were included in the study. The 30-day mortality rate was 5.16%. The classifier yielded an AUC of 0.898, which exceeds the predictive capacity of the National Surgical Quality Initiative Program mortality probability calculator's AUC of 0.722 (P < 0.0001). The multivariable regression indicated that smoking history, chronic obstructive pulmonary disease, disseminated cancer, bleeding disorder history, dyspnea, and low albumin levels were strongly associated with 30-day mortality. CONCLUSIONS: The Naïve Bayes classifier may be used to predict 30-day mortality for patients undergoing spine tumor excisions, with an increasing degree of accuracy as the model better performs by learning continuously from the input patient data. Patient outcomes can be improved by identifying high-risk populations early using the algorithm and applying that data to inform preoperative decision making, as well as patient selection and education.

Larger Initial Opioid Prescriptions Following Total Joint Arthroplasty Are Associated with Greater Risk of Prolonged Use.

BACKGROUND: The ongoing U.S. opioid epidemic threatens quality of life and poses substantial economic and safety burdens to opioid abusers and their communities, physicians, and health-care systems. Public health experts have argued that prescription opioids are implicated in this epidemic; however, opioid dosing following surgical procedures remains controversial. The purpose of this study was to evaluate the relationship between initial opioid prescribing following total hip arthroplasty (THA) and total knee arthroplasty (TKA) and the risk and quantity of long-term opioid use. METHODS: Patients undergoing THA or TKA from January 1, 2016, to June 30, 2016, were identified. Preoperative 30-day opioid and benzodiazepine exposures were evaluated using the Rhode Island Prescription Drug Monitoring Program. Cumulative morphine milligram equivalents (MMEs) in the postoperative inpatient stay, initial outpatient opioid prescription, and prescriptions filled from 31 to 90 days (prolonged use) and 91 to 150 days (chronic use) following the surgical procedure were calculated. Regression analyses evaluated the association between the initial postoperative opioid dosing and prolonged or chronic use, controlling for demographic characteristics, procedure, preoperative opioid and benzodiazepine exposures, anesthesia type, and use of a peripheral nerve block. RESULTS: A total of 507 patients (198 who underwent a THA and 309 who underwent a TKA) were identified. Increased inpatient opioid dosing (odds ratio [OR], 1.49 per 1 standard deviation increase in inpatient opioid MMEs; p = 0.001) and increased dosing in the first outpatient prescription (OR, 1.26 per 1 standard deviation increase in initial outpatient prescription MMEs; p = 0.049) were each independently associated with an increased risk of prolonged opioid use. Additionally, increased inpatient dosing postoperatively was strongly associated with a greater risk of chronic use (OR, 1.77 per 1 standard deviation increase in inpatient MMEs; p < 0.001). Among the 30% (151 of 507) of patients requiring prolonged postoperative opioids, each 1-MME increase in the initial outpatient prescription dose was associated with a 0.997-MME increase in quantity filled during the prolonged period (p < 0.001). Among the 14% (73 of 507) of patients requiring chronic opioids, every 1-MME increase in the initial outpatient dose was associated with a 1.678-MME increase in chronic opioid dosing (p = 0.008). CONCLUSIONS: Increased opioid dosing in the early postoperative period following total joint arthroplasty (TJA) is associated with an increased risk of extended opioid use. A dose-dependent relationship between initial outpatient dosing and greater future quantities consumed by those with prolonged usage and those with chronic usage was noted. This study suggests that providers should attempt to minimize inpatient and early outpatient opioid utilization following TJA. Multimodal pain management strategies may be employed to assist in achieving adequate pain control while minimizing opioid utilization. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.