Study design Review. Objective To formally introduce "degenerative cervical myelopathy" (DCM) as the overarching term to describe the various degenerative conditions of the cervical spine that cause myelopathy. Herein, the epidemiology, pathogenesis, and genetics of conditions falling under this hypernym are carefully described. Summary of background data Nontraumatic, degenerative forms of cervical myelopathy represent the commonest cause of spinal cord impairment in adults and include cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum, and degenerative disc disease. Unfortunately, there is neither a specific term nor a specific diagnostic International Classification of Diseases, Tenth Revision code to describe this collection of clinical entities. This has resulted in the inconsistent use of diagnostic terms when referring to patients with myelopathy due to degenerative disease of the cervical spine. Methods Narrative review. Results The incidence and prevalence of myelopathy due to degeneration of the spine are estimated at a minimum of 41 and 605 per million in North America, respectively. Incidence of cervical spondylotic myelopathy-related hospitalizations has been estimated at 4.04/100,000 person-years, and surgical rates seem to be rising. Pathophysiologically, myelopathy results from static compression, spinal malalignment leading to altered cord tension and vascular supply, and dynamic injury mechanisms. Occupational hazards, including transportation of goods by weight bearing on top of the head, and other risk factors may accelerate DCM development. Potential genetic factors include those related to MMP-2 and collagen IX for degenerative disc disease, and collagen VI and XI for ossification of the posterior longitudinal ligament. In addition, congenital anomalies including spinal stenosis, Down syndrome, and Klippel-Feil syndrome may predispose to the development of DCM. Conclusion Although DCMs can present as separate diagnostic entities, they are highly interrelated, frequently manifest concomitantly, present similarly from a clinical standpoint, and seem to be in part a response to compensate and improve stability due to progressive age and wear of the cervical spine. The use of the term "degenerative cervical myelopathy" is advocated. Level of evidence 5.

Degenerative Cervical Myelopathy: Epidemiology, Genetics, and Pathogenesis.

https://www.kau.edu.sa/Files/117/Researches/67223_38723.pdf

Mesenchymal stem cells in regenerative medicine: Focus on articular cartilage and intervertebral disc regeneration

Cervical spondylotic myelopathy (CSM) is a common disorder involving chronic progressive compression of the cervical spinal cord due to degenerative disc disease, spondylosis, or other degenerative pathology. CSM is the most common form of spinal cord impairment and causes functional decline leading to reduced independence and quality of life. Despite a sound understanding of the disease process, clinical presentation and management, a universal definition of CSM and a standardized index of severity are not currently used universally. Work is required to develop a definition and establish clinical predictors of progression to improve management of CSM. Despite advances in decompressive and reconstructive surgery, patients are often left with residual disability. Gaps in knowledge of the pathobiology of CSM have limited therapeutic advances to complement surgery. Although the histopathologic and pathophysiologic similarities between CSM and traumatic spinal cord injury have long been acknowledged, the unique pathomechanisms of CSM remain unexplored. Increased efforts to elucidate CSM pathobiology could lead to the discovery of novel therapeutic targets for human CSM and other spinal cord diseases. Here, the natural history of CSM, epidemiology, clinical presentation, and current methods of clinical management are reported, along with the current state of basic scientific research in the field.

Cervical Spondylotic Myelopathy The Clinical Phenomenon and the Current Pathobiology of an Increasingly Prevalent and Devastating Disorder

外反母趾の Biomechanical analysis-靴のヒール高との関連

Despite the rapid growth of three-dimensional (3D) printing applications in medicine, the accuracy and reproducibility of 3D printed medical models have not been thoroughly investigated. Although current technologies enable 3D models to be created with accuracy within the limits of clinical imaging spatial resolutions, this is not always achieved in practice. Inaccuracies are due to errors that occur during the imaging, segmentation, postprocessing, and 3D printing steps. Radiologists' understanding of the factors that influence 3D printed model accuracy and the metrics used to measure this accuracy is key in directing appropriate practices and establishing reference standards and validation procedures. The authors review the various factors in each step of the 3D model printing process that contribute to model inaccuracy, including the intrinsic limitations of each printing technology. In addition, common sources of model inaccuracy are illustrated. Metrics involving comparisons of model dimensions and morphology that have been developed to quantify differences between 3D models also are described and illustrated. These metrics can be used to define the accuracy of a model, as compared with the reference standard, and to measure the variability of models created by different observers or using different workflows. The accuracies reported for specific indications of 3D printing are summarized, and potential guidelines for quality assurance and workflow assessment are discussed. Online supplemental material is available for this article. ©RSNA, 2017.

Measuring and Establishing the Accuracy and Reproducibility of 3D Printed Medical Models

Study Design.Analysis of National Inpatient Sample (NIS), 2004 to 2015.Objective.Describe recent trends in US rates of lumbar fusion procedures and associated costs, by surgical indication.Summary of Background Data.Spinal fusion is appropriate for spinal deformity and instability, but evidence of e

Trends in Lumbar Fusion Procedure Rates and Associated Hospital Costs for Degenerative Spinal Diseases in the United States, 2004 to 2015

Study design The Oswestry Disability Index v20 (ODI), SF36 Physical Function Domain (SF-36 PFD), and PROMIS Physical Function CAT v12 (PF CAT) questionnaires were prospectively collected from 1607 patients complaining of back or leg pain, visiting a university-based spine clinic All questionnaires were collected electronically, using a tablet computer Objective The aim of this study was to compare the psychometric properties of the PROMIS PF CAT with the ODI and SF36 Physical Function Domain in the same patient population Summary of background data Evidence-based decision-making is improved by using high-quality patient-reported outcomes measures Prior studies have revealed the shortcomings of the ODI and SF36, commonly used in spine patients The PROMIS Network has developed measures with excellent psychometric properties The Physical Function domain, delivered by Computerized Adaptive Testing (PF CAT), performs well in the spine patient population, though to-date direct comparisons with common measures have not been performed Methods Standard Rasch analysis was performed to directly compare the psychometrics of the PF CAT, ODI, and SF36 PFD Spearman correlations were computed to examine the correlations of the three instruments Time required for administration was also recorded Results One thousand six hundred seven patients were administered all assessments The time required to answer all items in the PF CAT, ODI, and SF-36 PFD was 44, 169, and 99 seconds The ceiling and floor effects were excellent for the PF CAT (081%, 386%), while the ceiling effects were marginal and floor effects quite poor for the ODI (691% and 4424%) and SF-36 PFD (597% and 2365%) All instruments significantly correlated with each other Conclusion The PROMIS PF CAT outperforms the ODI and SF-36 PFD in the spine patient population and is highly correlated It has better coverage, while taking less time to administer with fewer questions to answer Level of evidence 2

PROMIS PF CAT Outperforms the ODI and SF-36 Physical Function Domain in Spine Patients.

This article was updated on June 10, 2015, because of previous errors. The title had previously read “Association Between Patient-Reported Measures of Psychological Distress and Patient Satisfaction Scores After Spine Surgery.” It has been changed to “Association Between Patient-Reported Measures of Psychological Distress and Patient Satisfaction Scores in a Spine Surgery Patient Population ” to reflect the fact that not all patients had undergone surgery when they completed their questionnaires. The last sentence in the Background paragraph of the Abstract had previously read “The goal of this study was to determine whether psychological distress influences outpatient satisfaction scores following spine surgery.” It now reads “The goal of this study was to determine whether psychological distress influences outpatient satisfaction scores in a spine surgery patient population. ” The last sentence before the Materials and Methods section, which previously read “Our aim in conducting this study was to determine whether psychological distress, as measured with the Distress and Risk Assessment Method (DRAM) questionnaire, influences outpatient satisfaction scores following spine surgery,” now reads: “Our aim in conducting this study was to determine whether psychological distress, as measured with the Distress and Risk Assessment Method (DRAM) questionnaire, influences outpatient satisfaction scores in a spine surgery patient population. ” Finally, the second sentence in the Materials and Methods section, “Every patient who completed both a patient satisfaction survey and a DRAM questionnaire for the same encounter at any point during the study period was included in this study,” has been changed to “Every patient who completed both a patient satisfaction survey and a DRAM questionnaire for the same encounter, before or after the surgery , at any point during the study period was included in this study.”

An erratum has been published: J Bone Joint Surg Am. 2015 Jul 15;97(14):e54.

Background: Patient satisfaction has become an important component of the delivery of health care in the United States. Previous studies have shown that patient satisfaction is influenced by patient-specific characteristics. The goal of this study was to determine whether psychological distress influences outpatient satisfaction scores in a spine surgery patient population.

Methods: We retrospectively reviewed the records from all outpatient clinical encounters at a single academic spine surgery center between February 2011 and January 2013. Any patient who completed both a patient satisfaction survey and a Distress and Risk Assessment Method (DRAM) questionnaire for the same clinical encounter was included in the study. Statistical analysis was performed to determine whether patient satisfaction scores were influenced by psychological distress.

Results: During the study period, 103 patients who met the inclusion criteria were identified. On the basis of their responses to the DRAM questionnaire, fifty-six were classified as normal (no evidence of distress), twenty-two as at risk, thirteen as distressed depressive, and twelve as distressed somatic. The mean overall patient satisfaction scores (and standard deviation) were 90.2 ± 10.9 in the normal group, 94.7 ± 8.2 in the at-risk group, 87.5 ± 16.2 in the distressed-depressive group, and 75.7 ± 22.4 in the distressed-somatic group (p = 0.003). The mean score for the patients’ satisfaction with their provider was 94.2 ± 12.0 in the normal group, 94.2 ± 9.5 in the at-risk group, 90.6 ± 24.0 in the distressed-depressive group, and 74.9 ± 26.2 in the distressed-somatic group (p = 0.011).

Conclusions: These results indicate a significant association between patient satisfaction and psychological distress as measured with the DRAM questionnaire. “Distressed” patients gave significantly lower scores for overall satisfaction and satisfaction with their provider compared with patients categorized as “normal.” These results suggest that psychological factors may influence patients’ perception of the medical care provided to them.

Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

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Association Between Patient-Reported Measures of Psychological Distress and Patient Satisfaction Scores in a Spine Surgery Patient Population

STUDY DESIGN Retrospective review. OBJECTIVE To define the geographic variation in costs of anterior cervical discectomy and fusion (ACDF) and posterolateral fusion (PLF). SUMMARY OF BACKGROUND DATA ACDF and lumbar PLF are common procedures that are used in the treatment of spinal pathologies. To optimize value, both the benefits and costs of an intervention must be quantified. Data on costs are scarce in comparison with data on total charges. This study aims at defining the costs of ACDF and PLF and describing the geographic variation within the United States. METHODS Medicare Provider Utilization and Payment data were used to investigate the costs associated with ACDF, PLF, and total knee arthroplasty (TKA). Average total costs of the procedures were compared by state and geographic region. RESULTS Combined professional and facility costs for a single-level ACDF had a national mean of $13,899. Total costs for a single-level PLF had a mean of $25,858. Total costs for a primary TKA had a national mean of $13,039. The cost increased to an average of $22,138 for TKA with major comorbidities. Analysis of geographic trends showed statistically significant differences in total costs of PLF, TKA, and TKA, with major complications or comorbidities between geographic regions (P < 0.01 for all). CONCLUSION Three of the 4 procedures (PLF, TKA, and TKA with major complications or comorbidities) showed statistically significant variation in cost between geographic regions. The Midwest provided the lowest cost for all procedures. Similar geographic trends in the cost of spinal fusions and TKAs suggest that these trends may not be limited to spine-related procedures. Surgical costs were found to correlate with cost of living but were not associated with the population of the state. These data shed light on the actual cost of common surgical procedures throughout the United States and will allow further progress toward the development of cost-effective, value-driven care. LEVEL OF EVIDENCE 3.

Geographic variations in the cost of spine surgery.

Back pain is the second most common reason for patients to seek medical treatment in the United States1, and the lifetime risk of low back pain is estimated to be 84%2. The socioeconomic impact of low back pain is difficult to overstate as a recent study has shown that the total cost of low back pain in the United States exceeds $100 billion per year3. With low back pain, lumbar disc degeneration is a common finding. Along with disc degeneration, lumbar disc herniation may occur, resulting in back and/or leg pain symptoms. Despite the prevalence of lumbar disc disease, its etiology is not completely understood. Previous studies have suggested a multifactorial etiology including contributions from mechanical stresses to the spine4, age-dependent disc degeneration5, biochemical factors6, and genetics7. Although several studies have suggested a familial predisposition8-10, we are aware of no study that has evaluated the familial clustering of lumbar disc disease on a population-based, multigenerational level.

The Utah Population Database allows the combination of a computerized genealogy of the Utah founding pioneers and their descendents with disease diagnosis data. The Utah genealogy database was linked to the University of Utah Health Sciences Center data warehouse, a resource that contains diagnosis and procedure data on patients treated at the University Hospital. The resultant information is a unique and invaluable resource and has been previously used to evaluate familial clustering in other disease processes11-14.

The purpose of this study was to define the familial clustering observed among individuals with a diagnosis of, or treated for, lumbar disc herniation or disc degeneration in an inpatient hospital or outpatient clinic setting. We tested the hypothesis of a heritable predisposition to lumbar disc disease, using two well-established methods: the estimation of relative risks in relatives and the Genealogical Index of Familiality (GIF).

/pdf/evidence-for-an-inherited-predisposition-to-lumbar-disc-4em7zy49y5.pdf

William Ryan Spiker

Papers

Trends in Lumbar Fusion Procedure Rates and Associated Hospital Costs for Degenerative Spinal Diseases in the United States, 2004 to 2015

PROMIS PF CAT Outperforms the ODI and SF-36 Physical Function Domain in Spine Patients.

Association Between Patient-Reported Measures of Psychological Distress and Patient Satisfaction Scores in a Spine Surgery Patient Population

Geographic variations in the cost of spine surgery.

Evidence for an Inherited Predisposition to Lumbar Disc Disease