Preserving privacy in big data research: the role of federated learning in spine surgery.

PURPOSE: Integrating machine learning models into electronic medical record systems can greatly enhance decision-making, patient outcomes, and value-based care in healthcare systems. Challenges related to data accessibility, privacy, and sharing can impede the development and deployment of effective predictive models in spine surgery. Federated learning (FL) offers a decentralized approach to machine learning that allows local model training while preserving data privacy, making it well-suited for healthcare settings. Our objective was to describe federated learning solutions for enhanced predictive modeling in spine surgery. METHODS: The authors reviewed the literature. RESULTS: FL has promising applications in spine surgery, including telesurgery, AI-based prediction models, and medical image segmentation. Implementing FL requires careful consideration of infrastructure, data quality, and standardization, but it holds the potential to revolutionize orthopedic surgery while ensuring patient privacy and data control. CONCLUSIONS: Federated learning shows great promise in revolutionizing predictive modeling in spine surgery by addressing the challenges of data privacy, accessibility, and sharing. The applications of FL in telesurgery, AI-based predictive models, and medical image segmentation have demonstrated their potential to enhance patient outcomes and value-based care.

Incidence of subsequent surgical decompression following minimally invasive approaches to treat lumbar spinal stenosis: A retrospective review.

BACKGROUND CONTEXT: Surgical decompression is the definitive treatment for managing symptomatic lumbar spinal stenosis; however, select patients are poor surgical candidates. Consequently, minimally invasive procedures have gained popularity, but there exists the potential for failure of therapy necessitating eventual surgical decompression. PURPOSE: To evaluate the incidence and characteristics of patients who require surgical decompression following minimally invasive procedures to treat lumbar spinal stenosis. STUDY DESIGN/SETTING: Retrospective review. PATIENT SAMPLE: Patients who underwent minimally invasive procedures for lumbar spinal stenosis (Percutaneous Image-guided Lumbar Decompression [PILD] or interspinous spacer device [ISD]) and progressed to subsequent surgical decompression within 5 years. OUTCOME MEASURES: The primary outcome was the rate of surgical decompression within 5 years following the minimally invasive approach. Secondary outcomes included demographic and comorbid factors associated with increased odds of requiring subsequent surgery. METHODS: Patient data were collected using the PearlDiver-Mariner database. The rate of subsequent decompression was described as a percentage while univariable and multivariable regression analysis was used for the analysis of predictors. RESULTS: A total of 5278 patients were included, of which 3222 (61.04%) underwent PILD, 1959 (37.12%) underwent ISD placement, and 97 (1.84%) had claims for both procedures. Overall, the incidence of subsequent surgical decompression within 5 years was 6.56% (346 of 5278 patients). Variables associated with a significantly greater odds ratio (OR) [95% confidence interval (CI)] of requiring subsequent surgical decompression included male gender and a prior history of surgical decompression by 1.42 ([1.14, 1.77], p = 0.002) and 2.10 times ([1.39, 3.17], p < 0.001), respectively. In contrast, age 65 years and above, a diagnosis of obesity, and a Charlson Comorbidity Index score of three or greater were associated with a significantly reduced OR [95% CI] by 0.64 ([0.50, 0.81], p < 0.001), 0.62 ([0.48, 0.81], p < 0.001), and 0.71 times ([0.56, 0.91], p = 0.007), respectively. CONCLUSIONS: Minimally invasive procedures may provide an additional option to treat symptomatic lumbar spinal stenosis in patients who are poor surgical candidates or who do not desire open decompression; however, there still exists a subset of patients who will require subsequent surgical decompression. Factors such as gender and prior surgical decompression increase the likelihood of subsequent surgery, while older age, obesity, and a higher Charlson Comorbidity Index score reduce it. These findings aid in selecting suitable surgical candidates for better outcomes in the elderly population with lumbar spinal stenosis.

Identifying Predictors for Early Percutaneous Spinal Cord Stimulator Explant at One and Two Years: A Retrospective Database Analysis.

OBJECTIVES: Placement of percutaneous spinal cord stimulator (SCS) implant has become a therapeutic option for various chronic pain conditions; however, early surgical explant still occurs. Unfortunately, evidence regarding the incidence of early surgical explant, and patient-specific factors and comorbidities associated with such, is limited and mixed. The objective of this retrospective analysis was to elucidate the incidence and predictors of percutaneous SCS explant within the first two years of device placement. MATERIALS AND METHODS: The PearlDiver-Mariner Patient Record Database of all payer claims was used to identify patients who underwent percutaneous lead SCS implant (leads and generator) with subsequent explant within two years of initial device implant. The primary outcome was to determine the incidence of SCS explant within the first two years of device placement. Secondary outcomes included evaluating the effects of several patient-specific comorbidities on explant rates using univariate regression analysis. RESULTS: Across the database, a total of 52,070 patients who underwent percutaneous lead SCS implant were included, of whom 3104 (5.96%) had SCS explant within the first two years. Most explants occurred within the first-year time interval at 72.8% (2260 patients), whereas only 27.2% (844 patients) had SCS explant between years one and two. At the one-year time interval, covariates associated with an increased odds ratio (OR) (95% CI) of SCS explant were 1) depression (1.39 [1.26, 1.52]), 2) chronic preoperative (1.27 [1.16, 1.39]) or postoperative (1.23 [1,13, 1.36]) opioid use, 3) cannabis abuse (1.58 [1.20, 2.02]), 4) tobacco use (1.13 [1.04, 1.23]), and 5) coagulopathy (1.22 [1.07, 1.38]). In contrast, the OR of explant was lower in patients who were older, men, or had diabetes (complicated or uncomplicated). All associated covariates became nonsignificant after the first year of SCS implant (ie, between the first and second years), and only depression and tobacco use remained as associated factors for device explant. CONCLUSIONS: Our retrospective analysis highlights that the rate of percutaneous SCS explant appears to considerably decrease after the first year of device implant. Furthermore, this analysis sheds additional insights into patients who may be at risk of early percutaneous SCS explant, especially within the first year of device placement, and underscores the importance of a continued multidimensional/biopsychologic assessment in patients with chronic pain.

Cognitive dissonance increases spine loading in the neck and low back.

Cognitive dissonance refers to a state where two psychologically inconsistent thoughts, behaviours, or attitudes are held at the same time. The objective of this study was to explore the potential role of cognitive dissonance in biomechanical loading in the low back and neck. Seventeen participants underwent a laboratory experiment involving a precision lowering task. To establish a cognitive dissonance state (CDS), study participants were provided negative feedback on their performance running counter to a pre-established expectation that their performance was excellent. Dependent measures of interest were spinal loads in the cervical and lumbar spines, calculated via two electromyography-driven models. The CDS was associated with increases to peak spinal loads in the neck (11.1%, p < .05) and low back (2.2%, p < .05). A greater CDS magnitude was also associated with a greater spinal loading increase. Therefore, cognitive dissonance may represent a risk factor for low back/neck pain that has not been previously identified.Practitioner summary: Upon establishing a cognitive dissonance state in a group of participants, spinal loading in the cervical and lumbar spines were increased proportional to the magnitude of the cognitive dissonance reported. Therefore, cognitive dissonance may represent a risk factor for low back and neck pain that has not been previously identified.

Are Foot & Ankle Surgeons Being Adequately Compensated for Ankle Fractures? - An Analysis of Relative Value Units.

The current relative value units (RVU)-based system is built to reflect the varying presentation of ankle fractures (uni-malleolar vs bi-malleolar vs tri-malleolar) by assigning individual RVUs to different fracture complexities. However, no study has evaluated whether the current RVUs reflect an appropriate compensation per unit time following open reduction internal fixation for uni-malleolar versus bi-malleolar versus tri-malleolar ankle fractures. The 2012 to 2017 American College of Surgeons - National Surgical Quality Improvement Program files were queried using current Procedural Terminology (CPT) codes for patients undergoing open reduction internal fixation for uni-malleolar (CPT-27766,CPT-27769,CPT-27792), bi-malleolar (CPT-27814), and tri-malleolar (CPT-27822,CPT-27823) ankle fractures. A total of 7830 (37.2%) uni-malleolar, 7826 (37.2%) bi-malleolar and 5391 (25.6%) tri-malleolar ankle fractures were retrieved. Total RVUs, Mean RVU/minute and Reimbursement rate ($/min) and Mean Reimbursement/case for each fracture type were calculated and compared using Kruskal-Wallis tests. The mean total RVU for each fracture type was as follows: (1) Uni-malleolar: 9.99, (2) Bi-malleolar = 11.71 and 3) Tri-malleolar = 12.87 (p < .001). A statistically significant difference was noted in mean operative time (uni-malleolar = 63.2 vs bi-malleolar = 78.6 vs tri-malleolar = 95.5; p < .001) between the 3 groups. Reimbursement rates ($/min) decreased significantly as fracture complexity increased (uni-malleolar = $7.21/min vs bi-malleolar = $6.75/min vs tri-malleolar = $6.10; p < .001). The average reimbursement/case was $358, $420, and $462 for uni-malleolar, bi-malleolar and tri-malleolar fractures respectively. Foot & ankle surgeons are reimbursed at a higher rate ($/min) for treating a simple uni-malleolar fracture as compared to bi-malleolar and tri-malleolar fractures, despite the higher complexity and longer operative times seen in the latter. The study highlights the need of a change in the RVUs for bi-malleolar and tri-malleolar ankle fractures to ensure that surgeons are adequately reimbursed per unit time for treating a more complex fracture case.

Magnetic Resonance Elastography of Intervertebral Discs: Spin-Echo Echo-Planar Imaging Sequence Validation.

BACKGROUND: Magnetic resonance elastography (MRE) is an imaging technique that can noninvasively assess the shear properties of the intervertebral disc (IVD). Unlike the standard gradient recalled echo (GRE) MRE technique, a spin-echo echo-planar imaging (SE-EPI) sequence has the potential to improve imaging efficiency and patient compliance. PURPOSE: To validate the use of an SE-EPI sequence for MRE of the IVD compared against the standard GRE sequence. STUDY TYPE: Cross-over. SUBJECTS: Twenty-eight healthy volunteers (15 males and 13 females, age range: 19-55). FIELD STRENGTH/SEQUENCE: 3 T; GRE, SE-EPI with breath holds (SE-EPI-BH) and SE-EPI with free breathing (SE-EPI-FB) MRE sequences. ASSESSMENT: MRE-derived shear stiffnesses were calculated via principal frequency analysis. SE-EPI derived shear stiffness and octahedral shear strain signal-to-noise ratios (OSS-SNR) were compared against those derived using the GRE sequence. The reproducibility and repeatability of SE-EPI stiffness measurements were determined. Shear stiffness was evaluated in the nucleus pulposus (NP) and annulus fibrosus (AF) regions of the disc. Scan times between sequences were compared. STATISTICAL TESTS: Linear mixed models, Bland-Altman plots, and Lin's concordance correlation coefficients (CCCs) were used with P < 0.05 considered statistically significant. RESULTS: Good correlation was observed between shear stiffnesses derived from the SE-EPI sequences with those derived from the GRE sequence with CCC values greater than 0.73 and 0.78 for the NP and AF regions, respectively. OSS-SNR was not significantly different between GRE and SE-EPI sequences (P > 0.05). SE-EPI sequences generated highly reproducible and repeatable stiffness measurements with CCC values greater than 0.97 in the NP and AF regions and reduced scan time by at least 51% compared to GRE. SE-EPI-BH and SE-EPI-FB stiffness measurements were similar with CCC values greater than 0.98 for both regions. DATA CONCLUSION: SE-EPI-based MRE-derived stiffnesses were highly reproducible and repeatable and correlated with current standard GRE MRE-derived stiffness estimates while reducing scan times. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.

The Trend of Urinary N Terminal Probrain Natriuretic Peptide in Extremely Low Birth Weight Infants during the Neonatal Period.

OBJECTIVE: N-terminal probrain natriuretic peptide (NT-proBNP) is a biomarker of interest in many cardiopulmonary diseases in extremely low birth weight (ELBW) Infants. However, there is a gap in knowledge about the trend of ELBW infant's urinary NT-proBNP during the neonatal period. AIM: To determine the trend of urinary NT-proBNP during the first 4 weeks of life of an ELBW infant. STUDY DESIGN: We analyzed prospectively enrolled 87 ELBW infants. Urinary NT-proBNP to creatinine ratios were measured on days 1 to 7, 14, and 28 of life. We plotted each study point's means to determine the trend of urinary NT-proBNP over the entire neonatal period. Data were analyzed using the Friedman analysis of variance for comparative analysis of study points. RESULTS: Urinary NT-proBNP/creatinine ratios were significantly elevated on days 1 to 7 (mean 2,452, ± 1,518) than day 14 (mean 747, ± 176), and day 28 (mean 149, ± 54), p = 0.001. Overall, urinary NT-proBNP levels were highest during days 1 to 3 (mean 3,232, ± 1,255) and lowest on day 28 (mean 149, ± 54). CONCLUSION: Urinary NT-proBNP levels are higher during the first week in ELBW infants with a downward trend during the neonatal period, the lowest values at 4 weeks postnatal age. More studies are required to determine the clinical utility of this trend during and beyond the neonatal period. KEY POINTS: · NT-proBNP is a biomarker for monitoring cardiac disease in premature infants.. · The trend of urinary NT-proBNP is unknown in premature infants.. · A trend of urinary NT-proBNP was determined during the first 4 weeks in premature infants..

The Potential Relationship Between a Cognitive Dissonance State and Musculoskeletal Injury: A Systematic Review.

OBJECTIVE: The objective of this systematic review was to investigate the potential link between cognitive dissonance or its related constructs (emotional dissonance, emotional labor) and musculoskeletal disorders. BACKGROUND: The etiology of musculoskeletal disorders is complex, as pain arises from complex interactions among physical, social, and psychological stressors. It is possible that the psychological factor of cognitive dissonance may contribute to the etiology and/or maintenance of musculoskeletal disorders. METHOD: MEDLINE, APA PsycInfo, and CINAHL Plus databases were searched for studies investigating cognitive dissonance or its related constructs as exposure(s) of interest and outcomes related to physical health (including, but not limited to, musculoskeletal pain). Risk of bias was assessed using the Appraisal tool for Cross-Sectional Studies (AXIS) tool. RESULTS: The literature search yielded 7 studies eligible for inclusion. None of the included studies investigated cognitive dissonance directly but instead investigated dissonance-related constructs of emotional dissonance and emotional labor, in which a mismatch between required and felt emotions might elicit a psychological response consistent with the cognitive dissonance state. Moderate effect sizes between dissonance-related constructs and musculoskeletal disorders were noted (OR 1.25-2.22). CONCLUSION: There is likely a relationship between the two factors studied. However, as the included studies were cross-sectional in nature, a causal relationship between cognitive dissonance-related constructs and musculoskeletal disorders cannot be inferred. Therefore, future study proposing and validating a causal pathway between these variables is warranted. APPLICATION: Cognitive dissonance and its related constructs may serve as risk factors for musculoskeletal disorders that have not been considered previously.

Expression and co-localization of RFRP-3 and kisspeptin during breeding and non-breeding season in the hypothalamus of male rhesus monkey (Macaca mulatta).

Propose: The mechanism that underpins how RFRP-3 and kisspeptin interacts are not fully understood in higher primates. This study therefore set out to assess RFRP-3 and kisspeptin expression and their morphological interactions in the breeding, and in the non-breeding period in monkey hypothalamus. Methods: Eight mature male macaques (Macaca mulatta) in the breeding season (February; n = 4) and non-breeding season (June; n = 4) were used. To reveal the expression and co-localization of RFRP-3 and kisspeptin, double-labeled immunohistochemistry was performed. Testicular volume, sperm count, and plasma testosterone level were also measured to validate the breeding and non-breeding paradigms. Results: Testicular volume, plasma testosterone level, and sperm count showed a significant reduction during non-breeding season. The number of kisspeptin-positive cells was significantly increased during the breeding season (p < 0.05), whereas more RFRP-3-positive cell bodies were seen in the non-breeding season (p < 0.01). Close contacts of RFRP-3 fibers with kisspeptin cells showed no significant difference (p > 0.05) across seasons. However, co-localization of RFRP-3-ir cell bodies onto kisspeptin IR cell bodies showed a statistical increase (p < 0.01) in non-breeding season. Conclusion: In higher primates, RFRP-3 decreases kisspeptin drives from the same cells to GnRH neurons in an autocrine manner causing suppression of the reproductive axis during the non-breeding period.

Has the Affordable Care Act Been Associated with Increased Insurance Coverage and Early-stage Diagnoses of Bone and Soft-tissue Sarcomas in Adults?

BACKGROUND: Treatment of bone and soft-tissue sarcomas can be costly, and therefore, it is not surprising that insurance status of patients is a prognostic factor in determining overall survival. Furthermore, uninsured individuals with suspected bone and/or soft-tissue masses routinely encounter difficulty in obtaining access to basic healthcare (such as office visits, radiology scans), and therefore are more likely to be diagnosed with later stages at presentation. The Patient Protection and Affordable Care Act (ACA) mandate of 2010 aimed to increase access to care for uninsured individuals by launching initiatives, such as expanding Medicaid eligibility, subsidizing private insurance, and developing statewide mandates requiring individuals to have a prescribed minimum level of health insurance. Although prior reports have demonstrated that the ACA increased both coverage and the proportion of early-stage diagnoses among patients with common cancers (including breast, colon, prostate, and lung), it is unknown whether similar improvements have occurred for patients with bone and soft-tissue sarcomas. Understanding changes in insurance coverages and stage at diagnosis of patients with bone and soft-tissue sarcomas would be paramount in establishing policies that will ensure orthopaedic cancer care is made equitable and accessible to all. QUESTIONS/PURPOSES: (1) Has the introduction of the ACA been associated with changes in insurance coverage for adult patients with newly diagnosed bone and soft-tissue sarcomas? (2) Did the introduction of health reforms under the ACA lead to an increased proportion of sarcoma diagnoses occurring at earlier disease stages? METHODS: The 2007 to 2015 Surveillance, Epidemiology and End Results database was queried using International Classification of Diseases for Oncology codes for primary malignant bone tumors of the upper and lower extremity (C40.0 to C40.3), unspecified or other overlapping bone, articular cartilage, and joint and/or ribs, sternum, or clavicle (C40.8 to C40.9, C41.3, and C41.8 to C41.9), vertebral column (C41.2), pelvis (C41.4, C41.8, and C41.9), and soft-tissue sarcomas of the upper or lower extremity and/or pelvis (C49.1, C49.2, and C49.5). A total of 15,287 patients with newly diagnosed cancers were included, of which 3647 (24%) were malignant bone tumors and 11,640 (76%) were soft-tissue sarcomas. The study sample was divided into three cohorts according to specified time periods: pre-ACA from 2007 to 2010 (6537 patients), pre-Medicaid expansion from 2011 to 2013 (5076 patients), and post-Medicaid expansion from 2014 to 2015 (3674 patients). The Pearson chi square tests were used to assess for changes in the proportion of Medicaid and uninsured patients across the specified time periods: pre-ACA, pre-expansion and post-expansion. A differences-in-differences analysis was also performed to assess changes in insurance coverage for Medicaid and uninsured patients among states that chose to expand Medicaid coverage in 2014 under the ACA's provision versus those who opted out of Medicaid expansion. Since the database switched to using the American Joint Commission on Cancer (AJCC) 7th edition staging system in 2010, linear regression using data only from 2010 to 2015 was performed that assessed changes in cancer stage at diagnosis from 2010 to 2015 alone. After stratifying by cancer type (bone or soft-tissue sarcoma), Pearson chi square tests were used to assess for changes in the proportion of patients who were diagnosed with early, late, and unknown stage at presentation before Medicaid expansion (2011-2013) and after Medicaid expansion (2014-2015) among states that chose to expand versus those who did not. RESULTS: After stratifying by time cohorts: pre-ACA (2007 to 2010), pre-expansion (2011 to 2013) and post-expansion (2014 to 2015), we observed that the most dramatic changes occurred after Medicaid eligibility was expanded (2014 onwards), with Medicaid proportions increasing from 12% (pre-expansion, 2011 to 2013) to 14% (post-expansion, 2014 to 2015) (p < 0.001) and uninsured proportions decreasing from 5% (pre-expansion, 2011 to 2013) to 3% (post-expansion, 2014 to 2015) (p < 0.001). A differences-in-differences analysis that assessed the effect of Medicaid expansion showed that expanded states had an increase in the proportion of Medicaid patients compared with non-expanded states, (3.6% [95% confidence interval 0.4 to 6.8]; p = 0.03) from 2014 onwards. For the entire study sample, the proportion of early-stage diagnoses (I/II) increased from 56% (939 of 1667) in 2010 to 62% (1137 of 1840) in 2015 (p = 0.003). Similarly, the proportion of unknown stage diagnoses decreased from 11% (188 of 1667) in 2010 to 7% (128 of 1840) in 2015 (p = 0.002). There was no change in proportion of late-stage diagnoses (III/IV) from 32% (540 of 1667) in 2010 to 31% (575 of 1840) in 2015 (p = 0.13). CONCLUSION: Access to cancer care for patients with primary bone or soft-tissue sarcomas improved after the ACA was introduced, as evidenced by a decrease in the proportion of uninsured patients and corresponding increase in Medicaid coverage. Improvements in coverage were most significant among states that adopted the Medicaid expansion of 2014. Furthermore, we observed an increasing proportion of early-stage diagnoses after the ACA was implemented. The findings support the preservation of the ACA to ensure cancer care is equitable and accessible to all vulnerable patient populations. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Is the Value of Undergoing Surgery for Spinal Metastases at Dedicated Cancer Centers?

BACKGROUND: The Alliance of Dedicated Cancer Centers is an organization of 11 leading cancer institutions and affiliated hospitals that are exempt from the Medicare prospective system hospital reimbursement policies. Because of their focus on cancer care and participation in innovative cancer treatment methods and protocols, these hospitals are reimbursed based on their actual billings. The perceived lack of incentive to meet a predetermined target price and reduce costs has spurred criticism of the value of cancer care at these institutions. The rationale of our study was to better understand whether dedicated cancer centers (DCCs) deliver high-value care for patients undergoing surgical treatment of spinal metastases. QUESTION/PURPOSE: Is there a difference in 90-day complications and reimbursements between patients undergoing surgical treatment (decompression or fusion) for spinal metastases at DCCs and those treated at nonDCC hospitals? METHODS: The 2005 to 2014 100% Medicare Standard Analytical Files database was queried using ICD-9 procedure and diagnosis codes to identify patients undergoing decompression (03.0, 03.09, and 03.4) and/or fusion (81.0X) for spinal metastases (198.5). The database does not allow us to exclude the possibility that some patients were treated with fusion for stabilization of the spine without decompression, although this is likely an uncommon event. Patients undergoing vertebroplasty or kyphoplasty for metastatic disease were excluded. The Medicare hospital provider identification numbers were used to identify the 11 DCCs. The study cohort was categorized into two groups: DCCs and nonDCCs. Although spinal metastases are known to occur among nonMedicare and younger patients, the payment policies of these DCCs are only applicable to Medicare beneficiaries. Therefore, to keep the study objective relevant to current policy and value-based discussions, we performed the analysis using the Medicare dataset. After applying the inclusion and exclusion criteria, we included 17,776 patients in the study, 6% (1138 of 17,776) of whom underwent surgery at one of the 11 DCCs. Compared with the nonDCC group, DCC group hospitals operated on a younger patient population and on more patients with primary renal cancers. In addition, DCCs were more likely to be high-volume facilities with National Cancer Institute designations and have a voluntary or government ownership model. Patients undergoing surgery for spinal metastases at DCCs were more likely to have spinal decompression with fusion than those at nonDCCs (40% versus 22%; p < 0.001) and had a greater length and extent of fusion (at least four levels of fusion; 34% versus 29%; p = 0.001). Patients at DCCs were also more likely than those at nonDCCs to receive postoperative adjunct treatments such as radiation (16% versus 13.5%; p = 0.008) and chemotherapy (17% versus 9%; p < 0.001), although this difference is small and we do not know if this meets a minimum clinically important difference. To account for differences in patients presenting at both types of facilities, multivariate logistic regression mixed-model analyses were used to compare rates of 90-day complications and 90-day mortality between DCC and nonDCC hospitals. Controls were implemented for baseline clinical characteristics, procedural factors, and hospital-level factors (such as random effects). Generalized linear regression mixed-modeling was used to evaluate differences in total 90-day reimbursements between DCCs and nonDCCs. RESULTS: After adjusting for differences in baseline demographics, procedural factors, and hospital-level factors, patients undergoing surgery at DCCs had lower odds of experiencing sepsis (6.5% versus 10%; odds ratio 0.54 [95% confidence interval 0.40 to 0.74]; p < 0.001), urinary tract infections (19% versus 28%; OR 0.61 [95% CI 0.50 to 0.74]; p < 0.001), renal complications (9% versus 13%; OR 0.55 [95% CI 0.42 to 0.72]; p < 0.001), emergency department visits (27% versus 31%; OR 0.78 [95% CI 0.64 to 0.93]; p = 0.01), and mortality (39% versus 49%; OR 0.75 [95% CI 0.62 to 0.89]; p = 0.001) within 90 days of the procedure compared with patients treated at nonDCCs. Undergoing surgery at a DCC (90-day reimbursement of USD 54,588 ± USD 42,914) compared with nonDCCs (90-day reimbursement of USD 49,454 ± USD 38,174) was also associated with reduced 90-day risk-adjusted reimbursements (USD -14,802 [standard error 1362] ; p < 0.001). CONCLUSION: Based on our findings, it appears that DCCs offer high-value care, as evidenced by lower complication rates and reduced reimbursements after surgery for spinal metastases. A better understanding of the processes of care adopted at these institutions is needed so that additional cancer centers may also be able to deliver similar care for patients with metastatic spine disease. LEVEL OF EVIDENCE: Level III, therapeutic study.

What Is the Quality of Surgical Care for Patients with Hip Fractures at Critical Access Hospitals?

BACKGROUND: Critical access hospitals (CAHs) play an important role in providing access to care for many patients in rural communities. Prior studies have shown that these facilities are able to provide timely and quality care for patients who undergo various elective and emergency general surgical procedures. However, little is known about the quality and reimbursement of surgical care for patients undergoing surgery for hip fractures at CAHs compared with non-CAH facilities. QUESTIONS/PURPOSES: Are there any differences in 90-day complications, readmissions, mortality, and Medicare payments between patients undergoing surgery for hip fractures at CAHs and those undergoing surgery at non-CAHs? METHODS: The 2005 to 2014 Medicare 100% Standard Analytical Files were queried using ICD-9 procedure codes to identify Medicare-eligible beneficiaries undergoing open reduction and internal fixation (79.15, 79.35, and 78.55), hemiarthroplasty (81.52), and THA (81.51) for isolated closed hip fractures. This database was selected because the claims capture inpatient diagnoses, procedures, charged amounts and paid claims, as well as hospital-level information of the care, of Medicare patients across the nation. Patients with concurrent fixation of an upper extremity, lower extremity, and/or polytrauma were excluded from the study to ensure an isolated cohort of hip fractures was captured. The study cohort was divided into two groups based on where the surgery took place: CAHs and non-CAHs. A 1:1 propensity score match, adjusting for baseline demographics (age, gender, Census Bureau-designated region, and Elixhauser comorbidity index), clinical characteristics (fixation type and time to surgery), and hospital characteristics (whether the hospital was located in a rural ZIP code, the average annual procedure volume of the operating facility, hospital bed size, hospital ownership and teaching status), was used to control for the presence of baseline differences in patients presenting at CAHs and those presenting at non-CAHs. A total of 1,467,482 patients with hip fractures were included, 29,058 of whom underwent surgery in a CAH. After propensity score matching, each cohort (CAH and non-CAH) contained 29,058 patients. Multivariate logistic regression analyses were used to assess for differences in 90-day complications, readmissions, and mortality between the two matched cohorts. As funding policies of CAHs are regulated by Medicare, an evaluation of costs-of-care (by using Medicare payments as a proxy) was conducted. Generalized linear regression modeling was used to assess the 90-day Medicare payments among patients undergoing surgery in a CAH, while controlling for differences in baseline demographics and clinical characteristics. RESULTS: Patients undergoing surgery for hip fractures were less likely to experience many serious complications at a critical access hospital (CAH) than at a non-CAH. In particular, after controlling for patient demographics, hospital-level factors and procedural characteristics, patients treated at a CAH were less likely to experience: myocardial infarction (3% (916 of 29,058) versus 4% (1126 of 29,058); OR 0.80 [95% CI 0.74 to 0.88]; p < 0.001), sepsis (3% (765 of 29,058) versus 4% (1084 of 29,058); OR 0.69 [95% CI 0.63 to 0.78]; p < 0.001), acute renal failure (6% (1605 of 29,058) versus 8% (2353 of 29,058); OR 0.65 [95% CI 0.61 to 0.69]; p < 0.001), and Clostridium difficile infections (1% (367 of 29,058) versus 2% (473 of 29,058); OR 0.77 [95% CI 0.67 to 0.88]; p < 0.001) than undergoing surgery in a non-CAH. CAHs also had lower rates of all-cause 90-day readmissions (18% (5133 of 29,058) versus 20% (5931 of 29,058); OR 0.83 [95% CI 0.79 to 0.86]; p < 0.001) and 90-day mortality (4% (1273 of 29,058) versus 5% (1437 of 29,058); OR 0.88 [95% CI 0.82 to 0.95]; p = 0.001) than non-CAHs. Further, CAHs also had risk-adjusted lower 90-day Medicare payments than non-CAHs (USD 800, standard error 89; p < 0.001). CONCLUSION: Patients who received hip fracture surgical care at CAHs had a lower risk of major medical and surgical complications than those who had surgery at non-CAHs, even though Medicare reimbursements were lower as well. Although there may be some degree of patient selection at CAHs, these facilities appear to provide high-value care to rural communities. These findings provide evidence for policymakers evaluating the impact of the CAH program and allocating funding resources, as well as for community members seeking emergent care at local CAH facilities. LEVEL OF EVIDENCE: Level III, therapeutic study.

Undergoing an Arthroscopic Procedure Prior to Shoulder Arthroplasty is Associated With Greater Risk of Prosthetic Joint Infection.

PURPOSE: To utilize a national all-payer claims dataset to understand whether a history of a prior shoulder arthroscopy is associated with adverse outcomes or complications after the index shoulder arthroplasty itself. METHODS: The Symphony Integrated DataVerse, an all-payer claims database, was used to identify patients undergoing primary shoulder arthroplasty (hemiarthroplasty, anatomic total shoulder arthroplasty, or reverse total shoulder arthroplasty) between 2017 to 2018. Current Procedural Terminology codes were used to identify patients who had undergone a shoulder arthroscopic procedure on the ipsilateral side within 2 years before the arthroplasty. Multivariate logistic regression analyses were used to assess whether prior shoulder arthroscopy was associated with higher risks of wound complications, postoperative stiffness, mechanical complications, prosthetic joint infection, revision surgery and readmissions within 90 days of the arthroplasty. RESULTS: In total, 19,429 patients were included, of which 837 (4.3%) had undergone shoulder arthroscopy within 2 years before the arthroplasty. Prior shoulder arthroscopy was associated with a significantly higher risk of prosthetic joint infection (odds ratio [OR] 2.74 [95% confidence interval {CI} 1.51-4.69]; P < .001) within 90 days of the arthroplasty. The greatest risk of prosthetic joint infection was associated with arthroscopies that took place within 3 months before the arthroplasty (OR 5.32 [95% CI 1.42-15.14]; P = .005). CONCLUSIONS: Undergoing an arthroscopic procedure of the ipsilateral shoulder before undergoing an arthroplasty was associated with greater risk of prosthetic joint infection. Furthermore, it appears that patients who received arthroscopy within the 3 months before arthroplasty had the highest risk of prosthetic joint infections. Physicians should not only anticipate possible inferior outcomes in patients who have had prior arthroscopy, but also consider delaying the arthroplasty by at least 3 months after the arthroscopy to mitigate the risks of experiencing this costly adverse event. LEVEL OF EVIDENCE: III.

Malignant fibrous histiocytoma of bone: A survival analysis from the National Cancer Database.

BACKGROUND AND OBJECTIVES: Malignant fibrous histiocytoma (MFH) of bone, now known as undifferentiated pleomorphic sarcoma of bone, is a rare neoplasm that accounts for less than 2% of all primary malignant bone tumors. The objective of the current study was to evaluate prognosis and survival for MFH of bone. METHODS: The 2004 to 2016 National Cancer Database was queried to identify patients with a primary MFH of bone. Kaplan-Meier survival and Cox regression analyses were used to analyze overall survival and risk factors associated with overall mortality. RESULTS: The overall 5-year and 10-year survival rates were 38.3% and 30.5%, respectively. Increasing stage and metastatic disease at presentation were associated with poor overall survival (P < .001). Patients aged 18 to 50 years (hazard ratio [HR], 0.51), 51 to 75 years (HR, 0.61), and those undergoing surgery (HR, 0.39) had improved survival. Having Medicare insurance (HR, 1.48), residing in a low educated area (HR, 2.56), and positive surgical margins (HR, 1.80) were associated with poor survival. CONCLUSIONS: The overall prognosis of MFH of bone is poor with a reported 5-year survival rate of 38.3%. Undergoing surgery and younger age were associated with a better prognosis. Older age, having Medicare insurance, and positive surgical margins were predictors of mortality.

Is Treatment at a High-volume Center Associated with an Improved Survival for Primary Malignant Bone Tumors?

BACKGROUND: Centralization of cancer care to high-volume facilities has been shown to improve the overall survival of patients with soft-tissue sarcomas. Current evidence regarding the impact of increased hospital volume on treatment patterns and survival rates for patients with primary malignant bone tumors remains limited. Understanding the facility volume-outcome relationship for primary malignant bone tumors will further discussion on ways to promote delivery of quality cancer care across the nation. QUESTIONS/PURPOSES: (1) Is there a difference in overall survival for patients with primary malignant bone tumors undergoing treatment at a high-volume facility (at least 20 patients per year) versus those treated at a low-volume facility (less than 20 patients per year)? (2) Do surgical treatment patterns (limb-salvage versus amputation) and margin status (positive versus negative) vary between high-volume and low-volume facilities? METHODS: The 2004 to 2015 National Cancer Database was queried using International Classification of Disease for Oncology topographical codes to identify patients undergoing treatment (surgery, chemotherapy, and/or radiation therapy) for primary malignant bone tumors of the extremities (C40.0-C40.3, C40.8, and C40.9) or pelvis (C41.4). Histologic codes were used to group the tumors into the following categories: osteosarcomas, Ewing's sarcomas, chondrosarcomas, chordomas, and other or unspecified. Patients who did not receive any treatment (surgery, chemotherapy, and/or radiotherapy) at the reporting facility were excluded from the study. Facility volume was calculated based on the average number of patients per year for the entire study period. A preliminary stratified Cox regression model was used to identify evidence-based thresholds or cutoffs for high-volume and low-volume facilities, while adjusting for differences in patient, tumor, and treatment characteristics. We identified high-volume facilities as those treating at least 20 patients per year and low-volume facilities as those treating fewer than 20 patients per year. A Kaplan-Meier survival analysis was used to report overall unadjusted 5-year survival rates at high-volume and low-volume facilities. Multivariate Cox regression analyses were used to assess whether undergoing treatment at a high-volume facility was associated with a lower risk of overall mortality, after controlling for differences in baseline demographics, tumor presentation, and treatment characteristics. For patients undergoing surgery, multivariate regression models were used to evaluate whether patients receiving care in a high-volume facility were more likely to receive resections with limb salvage surgery than to receive amputation and whether facility volume was associated with a patient's likelihood of having a positive or negative surgical margin. RESULTS: A total of 14,039 patients were included, 15% (2115) of whom underwent treatment in a high-volume facility. Patients undergoing treatment at a high-volume facility were more likely to be white, have tumors involving the pelvis, have larger tumor sizes, and have a higher tumor grade at presentation than those undergoing treatment at a low-volume facility. Unadjusted 5-year overall survival rates were greater for high-volume facilities than for low-volume facilities (65% versus 61%; p = 0.003). After controlling for differences in patient demographics, tumor characteristics (including histologic type, grade, stage, size, and location) and treatment factors, we found that patients treated at high-volume facilities had a slightly lower overall mortality risk than those treated at low-volume facilities (hazard ratio 0.85 [95% CI 0.77 to 0.93]; p < 0.001). Patients treated at high-volume facilities were also slightly more likely to undergo resection with limb-salvage surgery to than to undergo amputation (odds ratio 1.34 [95% CI 1.14 to 1.59]; p = 0.001). Patients undergoing surgical treatment at high-volume facilities also had a lower odds of having positive resection margins than those undergoing treatment at low-volume facilities (OR 0.56 [95% CI 0.44 to 0.72]; p < 0.001). CONCLUSIONS: Patients undergoing treatment for primary malignant bone tumors at high-volume facilities experience a slightly better overall survival than those receiving treatment at low-volume facilities. Further research questioning the value of care at high-volume facilities is required before sweeping changes in regionalization can be considered. LEVEL OF EVIDENCE: Level III, therapeutic study.

Is Surgical Resection of the Primary Site Associated with an Improved Overall Survival for Patients with Primary Malignant Bone Tumors Who Have Metastatic Disease at Presentation?

BACKGROUND: The management of primary malignant bone tumors in patients with metastatic disease at presentation remains a challenge. Although surgical resection has been a mainstay in the management of nonmetastatic malignant bone tumors, there is a lack of large-scale evidence-based guidance on whether surgery of the primary site/tumor improves overall survival in malignant bone tumors with metastatic disease at presentation. QUESTIONS/PURPOSES: (1) Is surgical resection of the primary tumor associated with improved overall survival in patients with primary malignant bone tumors who have metastatic disease at presentation? (2) What other factors are associated with improved and/or poor overall survival? METHODS: The 2004 to 2016 National Cancer Database (NCDB), a national registry containing data from more than 34 million cancer patients in the United States, was queried using International Classification of Diseases, 3rd Edition, topographical codes to identify patients with primary malignant bone tumors of the extremities (C40.0-C40.3, C40.8, and C40.9) and/or pelvis (C41.4). The NCDB was preferred over other national cancer registries (that is, the Surveillance, Epidemiology, and End Results database) because it includes a specific variable that codes for patients who received additional surgeries at metastatic sites. Patients with malignant bone tumors of the head or skull, trunk, and spinal column were excluded because these patients are not routinely encountered and treated by orthopaedic oncologists. Histologic codes were used to categorize the tumors into the following groups: osteosarcomas, chondrosarcomas, and Ewing sarcomas. Patients whose tumors were classified as Stage 1, 2, or 3 based on American Joint Commission of Cancer guidelines were excluded. Only patients who presented with metastatic disease were included in the final study sample. The study sample was divided into two distinct groups: those who underwent surgical resection of the primary tumor and those who did not receive any operation for the primary tumor. A total of 2288 patients with primary malignant bone tumors (1121 osteosarcomas, 345 chondrosarcomas, and 822 Ewing sarcomas) with metastatic disease at presentation were included, of whom 46% (1053 of 2288) underwent surgical resection of the primary site. Thirty-three percent (348 of 1053) of patients undergoing surgical resection of the primary site also underwent additional resection of metastases. Patients undergoing surgical resection of the primary site typically were younger than 18 years, lived further from a facility, had tumors involving the upper or lower extremity, had a diagnosis of osteosarcoma or chondrosarcoma, and had a greater tumor size and higher tumor grade at presentation. To account for baseline differences within the patient population and to adjust for additional confounding variables, multivariate Cox regression analyses were used to assess whether undergoing surgical resection of the primary tumor was associated with improved overall survival, after controlling for differences in baseline demographics, tumor characteristics (grade, location, histologic type, and tumor size), and treatment patterns (resection of distant or regional metastatic sites, positive or negative surgical margins, and use of radiation therapy or chemotherapy). Additional sensitivity analyses, stratified by histologic type for osteosarcomas, chondrosarcomas, and Ewing sarcomas, were used to assess factors associated with overall survival for each tumor type. RESULTS: After controlling for differences in baseline demographics, tumor characteristics, and treatment patterns, we found that surgical resection of the primary site was associated with reduced overall mortality compared with those who did not have a resection of the primary site (hazard ratio 0.42 [95% confidence interval 0.36 to 0.49]; p < 0.001). Among other factors, in the stratified analysis, radiation therapy was associated with improved overall survival for patients with Ewing sarcoma (HR 0.71 [95% CI 0.57 to 0.88]; p = 0.002) but not for those with osteosarcoma (HR 1.14 [95% CI 0.91 to 1.43]; p = 0.643) or chondrosarcoma (HR 1.0 [95 % CI 0.78 to 1.50]; p = 0.643). Chemotherapy was associated with improved overall survival for those with osteosarcoma (HR 0.50 [95% CI 0.39 to 0.64]; p < 0.001) and those with chondrosarcoma (HR 0.62 [95% CI 0.45 to 0.85]; p = 0.003) but not those with Ewing sarcoma (HR 0.7 [95% CI 0.46 to 1.35]; p = 0.385). CONCLUSIONS: Surgical resection of the primary site was associated with an overall survival advantage in patients with primary malignant bone tumors who presented with metastatic disease. Further research, using more detailed data on metastatic sites (such as, size, location, number, and treatment), chemotherapy regimen and location of radiation (primary or metastatic site) is warranted to better understand which patients will have improved overall survival and/or a benefit in the quality of life from resecting their primary malignant tumor if they present with metastatic disease at diagnosis. LEVEL OF EVIDENCE: Level III, therapeutic study.

Damned if you monitor, damned if you don't: medical malpractice and intraoperative neuromonitoring for spinal surgery.

OBJECTIVE: The aim of this study was to identify trends in medical malpractice litigation related to intraoperative neuromonitoring. METHODS: The Westlaw Edge legal research service was queried for malpractice litigation related to neuromonitoring in spine surgery. Cases were reviewed to determine if the plaintiff's assertion of negligence was due to either failure to use neuromonitoring or negligent monitoring. Comparative statistics and a detailed qualitative analysis of the resulting cases were performed. RESULTS: Twenty-six cases related to neuromonitoring were identified. Spinal fusion was the procedure in question in all cases, and defendants were nearly evenly divided between orthopedic surgeons and neurosurgeons. Defense verdicts were most common (54%), followed by settlements (27%) and plaintiff verdicts (19%). Settlements resulted in a mean $7,575,000 damage award, while plaintiff verdicts resulted in a mean $4,180,213 damage award. The basis for litigation was failure to monitor in 54% of the cases and negligent monitoring in 46%. There were no significant differences in case outcomes between the two allegations of negligence. CONCLUSIONS: The use and interpretation of intraoperative neuromonitoring findings can be the basis for a medical malpractice litigation. Spine surgeons can face malpractice risks by not monitoring when required by the standard of care and by interpreting or reacting to neuromonitoring findings inappropriately.

Declining Trend in Medicare Physician Reimbursements for Hand Surgery From 2002 to 2018.

PURPOSE: To evaluate trends in Medicare physician reimbursements for 20 common hand procedures/surgeries from 2002 to 2018. METHODS: The Physician Fee Schedule Look-up Tool was used to retrieve average reimbursement rates for 20 common hand surgeries/procedures from 2002 to 2018. All reimbursement data were adjusted for inflation to 2018 dollars. RESULTS: After adjusting all data for inflation, the average reimbursement for all included procedures decreased by 20.9% from 2002 to 2018, with a compound annual growth rate of -3.25%. Reimbursement percentage decreases were the greatest prior to 2010 (18.4% decrease), followed by a relative stabilization (0.94% increase) from 2010 to 2014, after which physicians experienced a decrease of 3.9% in reimbursements between 2014 and 2018, following implementation of the Medicare Access and Children's Health Insurance Program Reauthorization Act in 2015. The most significant decreases in reimbursements over time were noted for primary tendon/muscle repair (-49.6%), wrist arthroscopy for triangular fibrocartilage repair/debridement (-44.0%), trigger finger release in facility (-40.1%), excision of extensor tendon sheath (-38.2%), ganglion cyst excision (-36.7%), wrist arthroscopy for diagnostic/synovial biopsy (-35.7%), wrist arthroscopy for drainage/infection/lavage (-35.1%), wrist arthrodesis (-30.6%), endoscopic carpal tunnel release (-27.2%), total wrist arthroplasty (-26.6%), carpometacarpal/basal joint arthroplasty (-25.1%), and open carpal tunnel release (-22.3%). The only procedures with a significant increase in reimbursement over time were trigger finger release in office (+4.2%), open reduction internal fixation distal radius fracture (+2.5%), and cubital tunnel release (+1.5%). CONCLUSIONS: After adjusting for inflation, Medicare physician reimbursements for a major proportion of hand surgical procedures have decreased over time. CLINICAL RELEVANCE: Health-policy makers need to understand the impact of decreasing reimbursements to develop policies of reimbursements that will not only ensure provider satisfaction but also maintain access to care for patients.

Declining trends in Medicare physician reimbursements for shoulder surgery from 2002 to 2018.

BACKGROUND: As the current health care system evolves toward cost-containment and value-based approaches, evaluating trends in physician reimbursements will be critical for assessing and ensuring the financial stability of shoulder surgery as a subspecialty. METHODS: The Medicare Physician Fee Schedule Look-up Tool was used to retrieve average reimbursement rates for 39 shoulder surgical procedures (arthroscopy with or without repair, arthroplasty, acromioclavicular or clavicular open reduction-internal fixation, fixation for proximal humeral fracture and/or shoulder dislocation, open rotator cuff repair or tendon release and/or repair, and open shoulder stabilization) from 2002 to 2018. All reimbursement data were adjusted for inflation to 2018 dollars. RESULTS: After adjusting for inflation to 2018 dollars, average reimbursement for all included procedures decreased by 26.9% from 2002 to 2018. After stratifying the analysis by 3 distinct time groups, we observed that reimbursement decreases were the most significant prior to 2010. However, reimbursement rates still declined by an average of 2.9% from 2010 to 2014 and 7.2% from 2014 to 2018. Arthroscopic rotator cuff repair, capsulorrhaphy, and biceps tenodesis experienced smaller declines in reimbursement than their open-surgery counterparts. CONCLUSION: Medicare physician reimbursements for shoulder surgical procedures have decreased over time. Health care policy makers need to understand the impact of decreasing reimbursements to develop agreeable financial policies that will not only ensure provider satisfaction but also maintain access to care for patients.

Current diagnosis-related group-based bundling for upper-extremity arthroplasty: a case of insufficient risk adjustment and misaligned incentives.

BACKGROUND: The current Centers for Medicare & Medicaid Services diagnosis-related group (DRG) bundled-payment model for upper-extremity arthroplasty does not differentiate between the type of arthroplasty (anatomic total shoulder arthroplasty [ATSA] vs. reverse total shoulder arthroplasty vs. total elbow arthroplasty [TEA] vs. total wrist arthroplasty) or the diagnosis and indication for surgery (fracture vs. degenerative osteoarthritis vs. inflammatory arthritis). METHODS: The 2011-2014 Medicare 5% Standard Analytical Files (SAF5) database was queried to identify patients undergoing upper-extremity arthroplasty under DRG-483 and -484. Multivariate linear regression modeling was used to assess the marginal cost impact of patient-, procedure-, diagnosis-, and state-level factors on 90-day reimbursements. RESULTS: Of 6101 patients undergoing upper-extremity arthroplasty, 3851 (63.1%) fell under DRG-484 and 2250 (36.9%) were classified under DRG-483. The 90-day risk-adjusted cost of an ATSA for degenerative osteoarthritis was $14,704 ± $655. Patient-level factors associated with higher 90-day reimbursements were male sex (+$777), age 75-79 years (+$740), age 80-84 years (+$1140), and age 85 years or older (+$984). Undergoing a TEA (+$2175) was associated with higher reimbursements, whereas undergoing a shoulder hemiarthroplasty (-$1000) was associated with lower reimbursements. Surgery for a fracture (+$2354) had higher 90-day reimbursements. Malnutrition (+$10,673), alcohol use or dependence (+$6273), Parkinson disease (+$4892), cerebrovascular accident or stroke (+$4637), and hyper-coagulopathy (+$4463) had the highest reimbursements. In general, states in the South and Midwest had lower 90-day reimbursements associated with upper-extremity arthroplasty. CONCLUSIONS: Under the DRG-based model piloted by the Centers for Medicare & Medicaid Services, providers and hospitals would be reimbursed the same amount regardless of the type of surgery (ATSA vs. hemiarthroplasty vs. TEA), patient comorbidity burden, and diagnosis and indication for surgery (fracture vs. degenerative pathology), despite each of these factors having different resource utilization and associated reimbursements. Lack of risk adjustment for fracture indications leads to strong financial disincentives within this model.