Dysphagia After Anterior Cervical Spine Surgery: Pathophysiology, Diagnosis, and Management.

Anterior cervical spine surgery (ACSS) is a surgical intervention widely used for a myriad of indications including degenerative, oncologic, inflammatory, traumatic, and congenital spinal conditions. A primary concern for surgeons performing ACSS is the postoperative development of oropharyngeal dysphagia. Current literature reports a wide incidence of this complication ranging from 1 to 79%. Dysphagia after ACSS is multifactorial, with common risk factors being prolonged duration of operation, revision surgeries, multilevel surgeries, and use of recombinant human bone morphogenetic protein-2. Many technical strategies have been developed to reduce the risk of postoperative dysphagia, including the development of low-profile implants and retropharyngeal local steroid application. In this article, we review the most recent literature regarding the epidemiology and pathophysiology, diagnostic criteria, risk factors, and management of dysphagia after ACSS.

Predictive factors of symptomatic lumbar pseudoarthrosis following multilevel primary lumbar fusion.

Background: Lumbar spinal fusion surgery is a well-established treatment for various spinal disorders. However, one of its complications, pseudoarthrosis, poses a significant concern. This study aims to explore the incidence, time and predictive factors contributing to pseudoarthrosis in patients who have undergone lumbar fusion surgery over a 10-year period. Methods: Data for this research was sourced from the PearlDiver database where insurance claims of patients who underwent multilevel lumbar spinal fusion between 01/01/2010 and 10/31/2022 were examined for claims of pseudoarthrosis within the 10 years of their index procedure. A variety of demographic, comorbid, and surgical factors were assessed, including age, gender, Elixhauser Comorbidity Index (ECI), surgical approach, substance use disorders and history of spinal disorders. Statistical analyses, including chi-squared tests, multivariate analysis, and cox survival analysis were employed to determine significant associations. Results: Among the 76,337 patients included in this retrospective study, 2.70% were diagnosed with symptomatic lumbar pseudoarthrosis at an average of 7.38 years in a 10-year follow-up. Multivariate and Cox hazard analyses revealed that significant predictors of symptomatic pseudoarthrosis development following multilevel primary lumbar fusion include vitamin D deficiency, osteoarthritis, opioid and NSAID use, tobacco use, and a prior history of congenital spine disorders. Conclusions: In summary, this study revealed a 2.70% incidence of symptomatic lumbar pseudoarthrosis within 10 years of the index procedure. It highlighted several potential predictive factors, including comorbidities, surgical approaches, and substance use disorders, associated with the development of symptomatic pseudoarthrosis. Future research should focus on refining our understanding of these factors to improve patient outcomes and optimize healthcare resource allocation.

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.

Interspecialty Variation in Perioperative Health Care Resource Usage for Carpal Tunnel Release.

BACKGROUND: We investigated whether any interspecialty variation exists, regarding perioperative health care resource usage, in carpal tunnel releases (CTRs). METHODS: The 2010 to 2021 PearlDiver Mariner Database, an all-payer claims database, was queried to identify patients undergoing primary CTRs. Physician specialty IDs were used to identify the specialty of the surgeon-orthopedic versus plastic versus general surgery versus neurosurgery. Multivariate logistic regression analysis was used to identify whether there was any interspecialty variation between the use of health care resources. RESULTS: A total of 908 671 patients undergoing CTRs were included, of which 556 339 (61.2%) were by orthopedic surgeons, 297 047 (32.7%) by plastic surgeons, 44 118 (4.9%) by neurosurgeons, and 11 257 (1.2%) by general surgeons. In comparison with orthopedic surgeons, patients treated by plastic surgeons were less likely to have received opioids, nonsteroidal anti-inflammatory drugs, oral steroids, and preoperative antibiotic prophylaxis but were more likely to have received steroid injections and electrodiagnostic studies (EDSs) preoperatively. Patients treated by neurosurgeons were more likely to have received preoperative opioids, gabapentin, oral steroids, preoperative antibiotic prophylaxis, EDSs, and formal preoperative physical/occupational therapy and less likely to have received steroid injections. Patients treated by general surgeons were less likely to receive oral steroids, steroid injections, EDSs, preoperative formal physical therapy, and preoperative antibiotic prophylaxis, but were more likely to be prescribed gabapentin. CONCLUSIONS: There exists significant variation in perioperative health care resource usage for CTRs between specialties. Understanding reasons behind such variation would be paramount in minimizing differences in how care is practiced for elective hand procedures.

Exploring the incidence and risk factors of reoperation for symptomatic adjacent segment disease following cervical decompression and fusion.

Background: Patients with long-term follow-up after cervical decompression and fusion have often been noted to have development of adjacent segment degeneration with a smaller subset of these patients progressing to adjacent segment disease (ASD), which results in the development of new symptomatic radiculopathy or myelopathy referable to a site either directly above or below a prior fused segment. The cause of ASD is multifactorial often involving natural age-related progression of spondylosis, accelerated progression following cervical decompression and fusion, operative technique, and patient-related factors. The effect of age at the time of index cervical decompression and fusion on the need for reoperation for ASD is not fully understood. This study aims to establish underlying risk factors for the development of symptomatic cervical ASD following cervical decompression and fusion requiring reoperation in patients of various age groups. Methods: A retrospective database review of patients aged 20 or greater with insurance claims of primary cervical decompression and fusion over the course of 11 years and 10 months (January 01, 2010-October 31, 2022) was conducted using an insurance claims database. The primary outcome was to evaluate the incidence of cervical ASD requiring reoperation amongst patients stratified by age at the time of their primary procedure. Secondary outcomes included an evaluation of various risk factors for ASD following cervical decompression and fusion including surgeon-controlled factors such as the number of levels fused and approach taken, patient cervical pathology including cervical disc disorder and cervical spondylosis, and underlying patient medical comorbidities including osteoporosis and vitamin D deficiency, and substance use. Results: A total of 60,292 patient records were analyzed, where the overall reoperation incidence for symptomatic ASD was 6.57%, peaking at 8.12% among those aged 30 to 39 and decreasing with age. Regression analysis revealed ages lower than 50 years as more predictive for the development of symptomatic ASD requiring reoperation. Multivariate regression analysis identified predictive factors for reoperation, including age, Elixhauser Comorbidity Index (ECI), multiple-level surgery, cervical spondylosis, cervical disc disorder, osteoporosis, and vitamin D deficiency. Notably, these factors had a variable impact across various age groups, as revealed by subgroup analysis. Conclusions: The incidence of reoperation secondary to symptomatic ASD is 6.57%, highest in those aged 30 to 39. The surgical approach had no significant impact on the need for reoperation, but multiple-level fusions posed a consistent risk in the development of symptomatic ASD requiring reoperation. Patient factors like degenerative disc disease, spondylosis, osteoporosis, and vitamin D deficiency were associated, urging further age-specific risk assessment and nonoperative intervention exploration.

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.

Osteobiologics and Value-Based Care: Challenges and Opportunities.

BACKGROUND: Autologous bone grafts, sourced from the iliac crest, are the gold standard for bone substitution in spine surgery. However, harvesting autografts increases the risk of postoperative complications. Bone allografts are another popular source of graft material, but their use is rapidly surpassing their availability. There has been considerable interest in manufactured bone graft substitutes, commonly referred to as osteobiologics, which mimic the properties of autologous bone and may be osteoconductive, osteoinductive, osteogenic, or a combination. OBJECTIVE: Osteobiologics have been developed to mimic the properties of autologous bone, but their high cost and variable effectiveness raise questions about their value. This article explores the challenges and opportunities associated with the use of osteobiologics used to aid in bone healing in spinal fusion surgery within a value-based care framework. Spinal fusion treatments such as bone morphogenetic proteins, platelet-rich plasma, autologous conditioned serum, demineralized bone matrix, biomaterial scaffolds, stem cells, and cellular bone matrices are compared. SUMMARY: Bone morphogenetic proteins are highly effective but often associated with serious risks; platelet-rich plasma shows promising results but lacks standardization in research protocols. Autologous conditioned serum is inconclusive and cost-effective, while demineralized bone matrix has variable effectiveness and limited data to use in anterior spinal fusions. Biomaterial scaffolds have limited application in the anterior spine but demonstrate high efficacy when it comes to spinal fusion. Stem cells demonstrate improved postsurgical outcomes but have low yield from bone marrow and potential risks associated with genetic engineering and cell therapy. Cellular bone matrices show promising results and have high fusion rates, yet there is currently no US Food and Drug Adminstration requirement for preclinical or clinical data before commercial usage. Although osteobiologics have considerable potential, their high price and uncertain efficiency raise questions concerning their usefulness in spinal fusion surgery. To ensure better patient outcomes, extensive research is needed to explore their utilization within a value-based care framework.

Applications of Augmented Reality in Orthopaedic Spine Surgery.

The application of augmented reality (AR) in surgical settings has primarily been as a navigation tool in the operating room because of its ease of use and minimal effect on surgical procedures. The surgeon can directly face the surgical field while viewing 3D anatomy virtually, thus reducing the need to look at an external display, such as a navigation system. Applications of AR are being explored in spine surgery. The basic principles of AR include data preparation, registration, tracking, and visualization. Current literature provides sufficient preclinical and clinical data evidence for the use of AR technology in spine surgery. AR systems are efficient assistive devices, providing greater accuracy for insertion points, more comfort for surgeons, and reduced operating time. AR technology also has beneficial applications in surgical training, education, and telementorship for spine surgery. However, costs associated with specially designed imaging equipment and physicians' comfort in using this technology continue to remain barriers to its adoption. As this technology evolves to a more widespread use, future applications will be directed by the cost-effectiveness of AR-assisted surgeries.

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.

Declining Trend in Anti-osteoporotic Treatment, Despite a Rise in DEXA Screening Following "Sentinel" Distal Radius Fractures.

PURPOSE: To understand national trends and costs associated with the utilization of anti-osteoporotic medication and DEXA screening within the year following a sentinel/primary distal radius fracture. METHODS: The 2008-2015Q1 Humana Administrative Claims database was queried to identify patients aged ≥50 years, with a "sentinel" occurrence of a primary closed distal radius fracture. Linear regression models were used to report and assess for significant trends in utilization of anti-osteoporotic medication and DEXA screenings within the year following the fracture. Multivariate logistic regression analyses were used to assess for factors associated with receiving or not receiving anti-osteoporotic medication. RESULTS: A total of 14 526 sentinel distal radius fractures were included in the study. Only 7.2% (n = 1046) of patients received anti-osteoporosis medication in the year following the distal radius fracture. Treatment with medication for osteoporosis declined from 8.2% in 2008 to 5.9% in 2015, whereas the rate of DEXA screening increased from 14.8% in 2008 to 23.6% in 2015. The most common prescribed treatment was alendronate sodium (n = 835; 79.8%-$49/patient). Factors associated with increased odds of receiving anti-osteoporotic medication were age 70 to 79 years (odds ratio [OR], 1.45; P = .014), age 80 to 89 years (OR, 1.66; P = .001), Asian (OR, 2.95; P = .002) or Hispanic (OR, 1.77; P = .006) ethnicity, belonging to South (OR, 1.19; P = .029) or West (OR, 1.37; P = .010), and having an Elixhauser Comorbidity Index score of 3 (OR, 2.14; P = .024) or > 3 (OR, 2.05; P = .022). CONCLUSIONS: Despite a rising utilization of DEXA screening following "sentinel" distal radius fractures, the proportion of individuals who receive anti-osteoporotic treatment is decreasing over time.

Firework Injuries to the Hand in the United States: An Epidemiological and Cost Analysis.

Although prior literature has evaluated firework injuries broadly, there are no focused investigations examining trends, etiology, and costs associated with firework injuries to the hand. The 2006 to 2014 National Emergency Department Sample (NEDS) was used. International Classification of Diseases, Ninth Revision (ICD-9) codes identified patients presenting to the emergency department with a firework-related injury of the hand that resulted in a burn, open wound, fracture, blood vessel injury, or traumatic amputation. A linear regression model was used to identify significant changes over time, with a significance threshold of P<.05. A total of 19,473 patients with a firework-related injury to the hand were included, with no significant change in the incidence from 2006 to 2014 (7.5 per 1,000,000 population). The greatest number of injuries occurred in July (57.1%), January (7.4%), and December (3.7%). Age groups affected were young adults (18-35 years; 43.6%), older adults (36-55 years; 19.2%), adolescents (12-17 years; 18.6%), and children (0-11 years; 16.1%). Nearly 74% of the injuries resulted in burns, 24.5% resulted in open wounds, 8.0% resulted in fracture, 7.6% resulted in traumatic amputation, and 1.4% resulted in blood vessel injury. Of 14,320 burn injuries, 15.2% had first-degree burns, 69.9% had second-degree burns, and 5.1% had third-degree burns involving the skin. The median emergency department charge was $914 and the median hospitalization charge (for inpatient admittance) was $30,743. Incidence of firework-related injuries to the hand has not changed over time. There is a need for better dissemination of safety information to mitigate the occurrences of these avoidable accidents. [Orthopedics. 2023;46(3):180-184.].

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.

Is Outpatient Anterior Lumbar Fusion (ALIF) Safe? An Analysis of 30-day Outcomes.

STUDY DESIGN: Review of publicly available database. OBJECTIVE: To compare 30-day outcomes of single-level ALIF procedures performed in outpatient and inpatient settings. SUMMARY OF BACKGROUND DATA: Despite a growing interest in performing standalone anterior lumbar interbody fusions (ALIFs) as an outpatient procedure, no study has evaluated the safety or efficacy of this procedure outside an inpatient setting. METHODS: The 2012-2017 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) was queried using CPT code 22558 to identify patients undergoing a single-level ALIF. Patients receiving concurrent posterior lumbar surgery/fusion/instrumentation, pelvic fixation, or surgery due to tumor, trauma and/or deformity were excluded to capture an isolated cohort of patients receiving single-level standalone ALIFs. A total of 3728 single-level standalone ALIFs were included in the study. Multivariate regression analyses were used to compare 30-day adverse events and readmissions while controlling for baseline clinical characteristics. RESULTS: Out of a total of 3728 ALIFs, 149 (4.0%) were performed as outpatient procedure. Following adjustment, outpatient ALIFs versus inpatient ALIFs had lower odds of experiencing any 30-day adverse event (2.0% vs. 9.2%, OR 0.24 [95% CI 0.08-0.76]; P =0.015). No significant differences were noted with regard to severe adverse events 9p=0.261), minor adverse events 9p=0.995), and readmission rates ( P =0.95). CONCLUSION: On the basis of the results of the study, it appears that ALIFs may be carried out safely in an outpatient setting in an appropriately selected patient population.

Posterior Cervical Fusion for Fracture Is Not the Same as Fusion for Degenerative Cervical Spine Disease: Implications for a Bundled Payment Model.

STUDY DESIGN/SETTING: Retrospective. OBJECTIVE: To understand differences in 30-day outcomes between patients undergoing posterior cervical fusion (PCF) for fracture versus degenerative cervical spine disease. SUMMARY OF BACKGROUND DATA: Current bundled payment models for cervical fusions, such as the Bundled Payments for Care Improvement revolve around the use of diagnosis-related groups to categorize patients for reimbursement purposes. Though a PCF performed for a fracture may have a different postoperative course of care as compared with a fusion being done for degenerative cervical spine pathology, the current DRG system does not differentiate payments based on the indication/cause of surgery. METHODS: The 2012-2017 American College of Surgeons-National Surgical Quality Improvement Program was queried using Current Procedural Terminology code 22600 to identify patients receiving elective PCFs. Multivariate analyses were used to compare rates of 30-day severe adverse events, minor adverse events, readmissions, length of stay, and nonhome discharges between the 2 groups. RESULTS: A total 2546 (91.4%) PCFs were performed for degenerative cervical spine pathology and 240 (8.6%) for fracture. After adjustment for differences in baseline clinical characteristics, patients undergoing a PCF for a fracture versus degenerative pathology had higher odds of severe adverse events [18.8% vs. 10.6%, odds ratio (OR): 1.65 (95% CI, 1.10-2.46); P =0.015], prolonged length of stay >3 days [54.2% vs. 40.5%, OR: 1.93 (95% CI, 1.44-2.59); P <0.001], and nonhome discharges [34.2% vs. 27.6%, OR: 1.54 (95% CI, 1.10-2.17); P =0.012]. CONCLUSIONS: Patients undergoing PCFs for fracture have significant higher rates of postoperative adverse events and greater resource utilization as compared with individuals undergoing elective PCF for degenerative spine pathology. The study calls into question the need of risk adjustment of bundled prices based on indication/cause of the surgery to prevent the creation of a financial disincentive when taking care/performing surgery in spinal trauma patients.

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.

In vivo Mouse Intervertebral Disc Degeneration Models and Their Utility as Translational Models of Clinical Discogenic Back Pain: A Comparative Review.

Low back pain is a leading cause of disability worldwide and studies have demonstrated intervertebral disc (IVD) degeneration as a major risk factor. While many in vitro models have been developed and used to study IVD pathophysiology and therapeutic strategies, the etiology of IVD degeneration is a complex multifactorial process involving crosstalk of nearby tissues and systemic effects. Thus, the use of appropriate in vivo models is necessary to fully understand the associated molecular, structural, and functional changes and how they relate to pain. Mouse models have been widely adopted due to accessibility and ease of genetic manipulation compared to other animal models. Despite their small size, mice lumbar discs demonstrate significant similarities to the human IVD in terms of geometry, structure, and mechanical properties. While several different mouse models of IVD degeneration exist, greater standardization of the methods for inducing degeneration and the development of a consistent set of output measurements could allow mouse models to become a stronger tool for clinical translation. This article reviews current mouse models of IVD degeneration in the context of clinical translation and highlights a critical set of output measurements for studying disease pathology or screening regenerative therapies with an emphasis on pain phenotyping. First, we summarized and categorized these models into genetic, age-related, and mechanically induced. Then, the outcome parameters assessed in these models are compared including, molecular, cellular, functional/structural, and pain assessments for both evoked and spontaneous pain. These comparisons highlight a set of potential key parameters that can be used to validate the model and inform its utility to screen potential therapies for IVD degeneration and their translation to the human condition. As treatment of symptomatic pain is important, this review provides an emphasis on critical pain-like behavior assessments in mice and explores current behavioral assessments relevant to discogenic back pain. Overall, the specific research question was determined to be essential to identify the relevant model with histological staining, imaging, extracellular matrix composition, mechanics, and pain as critical parameters for assessing degeneration and regenerative strategies.

Does a Reported Penicillin Allergy Affect Outcomes Following Elective Posterior Lumbar Fusions?

BACKGROUND: Patients with a reported penicillin allergy (PA) receive alternative antibiotics that may not be as effective as cephalosporins for surgical site infection (SSI) prophylaxis. While patient-reported PA has been correlated to increased complications in other fields, this has not been conclusively shown in spine surgery. We investigate the impact of PA on 90-day complications and inpatient charges/costs after elective posterior lumbar fusion between PA and non-PA cohorts. METHODS: The 2005 to 2014 SAF100 database was queried using International Classification of Diseases, Ninth Edition (ICD-9) procedure codes to identify patients undergoing elective posterior lumbar fusions. The reported PA ICD-9 code was used to divide the study sample into a PA cohort and non-PA cohort. Multivariate logistic regression analyses were used to assess significant differences in 90-day complications between PA and non-PA groups after controlling for confounding factors. Generalized linear regression modeling was used to assess for differences in inpatient charges and costs. RESULTS: A total of 286,042 patients, 7497 (2.6%) of whom reported a PA, who underwent elective posterior lumbar fusions were included. Following adjustment for confounding factors, patients in the PA group had significantly higher odds of experiencing SSIs (3.8% vs 3.1%, OR 1.20 [95% CI 1.07-1.36]; P = 0.002), urinary tract infections (12.3% vs 10.0%, OR 1.16 [95% CI 1.08-1.24]; P < 0.001), sepsis (1.5% vs 1.2%, OR 1.24 [95% CI 1.02-1.50]; P = 0.026), acute kidney injuries (3.8% vs 3.2%, OR 1.19 [95% CI 1.05-1.34]; P = 0.006), readmissions (9.8% vs 8.5%, OR 1.15 [95% CI 1.07-1.25]; P < 0.001), increased inpatient charges (+$4340; P < 0.001), and increased reimbursements (+$1221; P < 0.001). CONCLUSIONS: Patients with a reported PA experienced significantly higher rates of 90-day complications and cost following elective posterior lumbar fusion. The findings of the study highlight the importance of preoperative PA testing to minimize the use of alternative antibiotics and potentially improve patient outcomes. CLINICAL RELEVANCE: Patients should be tested for penicillin allergy to minimize the use of alternative antibiotics among patients with a reported PA.

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.

Primary hip arthroscopy and conversion to total hip arthroplasty: trends and survival analysis in the Medicare population.

INTRODUCTION: With limited evidence on national incidences of hip arthroscopy in the elderly population, the current study aims to investigate trends of primary hip arthroscopies being performed in the elderly population, using the US Medicare database, and determine risk factors for conversion to total hip arthroplasty (THA). METHODS: Medicare Standard Analytic Files were queried using CPT codes to retrieve records of primary hip arthroscopies done for degenerative pathology during 2005-2014. Overall and age-stratified trends in the incidence of hip arthroscopy over time were analysed. Kaplan Meier survival curves were used to assess the overall 2-year conversion rate to a THA. Cox regression analysis was implemented to study risk factors for conversion. RESULTS: 8100 primary hip arthroscopies for degenerative pathology were performed during 2005-2014. There was a 280% increase in overall incidence of arthroscopy. The most commonly performed arthroscopic procedure was for chondroplasty and/or resection of labrum, with 4712 (58.1%) procedures. Around 18.5% patients underwent arthroplasty within 2 years after primary arthroscopy. Following Cox regression an existing diagnosis of osteoarthritis, ages 65-69, ages 70-74, and arthroscopies done in the West were associated with higher risk of conversion to THA within 2 years. Undergoing a repeat arthroscopy was not significantly associated with a higher risk of conversion. CONCLUSIONS: Despite inconclusive clinical evidence, hip arthroscopies are being increasingly used in patients older than 65 in the Medicare population. We conclude that patients in the age bracket of 65-74 years and with a pre-existing diagnosis of osteoarthritis, arthroscopy should be approached with caution.

Discharge to inpatient care facilities following hip fracture surgery: incidence, risk factors, and 30-day post-discharge outcomes.

BACKGROUND: Discharge to an inpatient care facility (skilled-care or rehabilitation) has been shown to be associated with adverse outcomes following elective total joint arthroplasties. Current evidence with regard to hip fracture surgeries remains limited. METHODS: The 2015-2016 ACS-NSQIP database was used to query for patients undergoing total hip arthroplasty, hemiarthroplasty and open reduction internal fixation for hip fractures. A total of 15,655 patients undergoing hip fracture surgery were retrieved from the database. Inpatient facility discharge included discharges to skilled-care facilities and inpatient rehabilitation units. Multi-variate regression analysis was used to assess for differences in 30-day post-discharge outcomes between home-discharge versus inpatient care facility discharge, while adjusting for baseline differences between the 2 study populations. RESULTS: A total of 12,568 (80.3%) patients were discharged to an inpatient care facility. Discharge to an inpatient care facility was associated with higher odds of any complication (OR 2.03 [95% CI, 1.61-2.55]; p < 0.001), wound complications (OR 1.79 [95% CI, 1.10-2.91]; p = 0.019), cardiac complications (OR 4.49 [95% CI, 1.40-14.40]; p = 0.012), respiratory complication (OR 2.29 [95% CI, 1.39-3.77]; p = 0.001), stroke (OR 7.67 [95% CI, 1.05-56.29]; p = 0.045, urinary tract infections (OR 2.30 [95% CI, 1.52-3.48]; p < 0.001), unplanned re-operations (OR 1.37 [95% CI, 1.03-1.82]; p = 0.029) and readmissions (OR 1.38 [95% CI, 1.16-1.63]; p < 0.001) following discharge. CONCLUSION: Discharge to inpatient care facilities versus home following hip fracture surgery is associated with higher odds of post-discharge complications, re-operations and readmissions. These results stress the importance of careful patient selection prior to discharge to inpatient care facilities to minimise the risk of complications.