Biomechanical Study of Cervical Posterior Decompression

Study Design Biomechanical study. Purpose We examined the dynamic characteristics of different operative procedures using three-dimensional finite-element models. Overview of Literature Cervical laminoplasty is often selected for patients requiring multilevel spinal decompression. Many laminoplasty techniques have been developed and are continually being improved. Methods Images were extracted for the two intervertebral joints between C3 and C5 in domestic rabbits. The following models were created: preoperative, laminectomy, Z-plasty, open door laminoplasty, French open door laminoplasty, en-bloc laminoplasty, and double-door laminoplasty. The loads required for sagittal rotation of 2.5°, 5°, and 7.5° were measured in vitro and respectively placed at the bottom of the C5 model. Displacement of the plate in the X, Y, and Z coordinates was measured and the rotational angles of the plate were determined. Results The sagittal rotation angle was greater in the laminectomy model than in the preoperative model, but was almost the same in the preoperative and Z-plasty models. Compared with the preoperative model, sagittal rotation angles were smaller in the French open door, open door, en-bloc, and double-door laminoplasty models. Conclusions Laminectomy and various types of laminoplasty are associated with different mechanical features, such as stability and mobility, allowing for selection of the most appropriate surgical procedure for each case

Normal Values of Diffusion Tensor Magnetic Resonance Imaging Parameters in the Cervical Spinal Cord

Study DesignProspective study.PurposeWe evaluated the usefulness of diffusion tensor imaging (DTI) in diagnosing patients with cervical myelopathy by determining the accuracy of normal DTI parameter values.Overview of LiteratureDTI can visualize white matter tracts in vivo and quantify anisotropy. DTI is known to be more sensitive than conventional magnetic resonance imaging (MRI) in detecting subtle pathological changes of the spinal cord.MethodsA total of 31 normal subjects (13 men and 18 women; age, 23-87 years; mean age, 46.0 years) were included in this study. The patients had no symptoms of myelopathy or radiculopathy. A Philips Achieva 3-Tesla MRI with SE-type Single Shot EPI was used to obtain diffusion tensor images. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were measured as DTI parameters on axial sections of several cervical levels. Subjects were divided into two groups: >40 years (n=16) and ≤40 years (n=15). A paired t-test was used to compare significant differences between the groups. ADC and FA values were most stable on axial sections.ResultsFor all subjects, mean ADC and FA values were 1.06±0.09×10-3 mm2/sec and 0.68±0.05, respectively. ADC was significantly higher in subjects >40 years of age than in those ≤40 years. There was no significant difference in FA values between the two groups. The mean ADC value was significantly higher in normal subjects >40 years of age than in those ≤40 years.ConclusionsIt is important to consider age when evaluating cervical myelopathy by DTI

Comparisons on Efficacy of Elcatonin and Limaprost Alfadex in Patients with Lumbar Spinal Stenosis and Concurrent Osteoporosis: A Preliminary Study Using a Crossover Design

Study DesignMulticenter prospective study with a crossover design.PurposeThe objective of this study is to compare the efficacy of limaprost alfadex (LP) and elcatonin (EL) for lumbar spinal stenosis (LSS) patients with concurrent osteoporosis.Overview of LiteratureIt has been increasingly important to improve quality of life by establishing appropriate conservative treatments for LSS patients with concurrent osteoporosis who will presumably continue to increase due to the percentage of the aging elevations, however there is no prospective study.MethodsA total of 19 patients with LSS and concurrent osteoporosis were enrolled in this study. The patients were divided into two groups and compared using a crossover design. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and short-form (SF)-8 health survey scale were used for clinical evaluations.ResultsThere was a significant improvement of buttock-leg pain and numbness in the EL group. A significant improvement of impaired walking function was noted for the LP group according to the JOABPEQ while the rest of the items in the JOABPEQ showed no significant differences. The SF-8 health survey revealed that somatic pains and physical summary scores in the EL group and physical functioning and physical summary scores in the LP group tended to improve but not to any statistically significant extents.ConclusionsConcomitant uses of EL may be useful in patients who do not respond satisfactorily to the treatments of LP for 6-8 weeks

Hyperbranched 5,6-glucan as reducing sugar ball

The ring-opening polymerization of 5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose (1) as a latent cyclic AB2-type monomer was carried out using potassium tert-butoxide (t-BuOK) or boron trifluoride diethyletherate (BF3・OEt2) as an initiator in order to synthesize a novel hyperbranched glycopolymer. The anionic and cationic polymerizations proceeded via the proton-transfer reaction mechanism to produce the hyperbranched poly(5,6-anhydro-1,2-O-isopropylidene-α-D-glucofuranose) (2). In particular, the cationic polymerization with the slow-monomer-addition strategy is a facile method leading to the hyperbranched glycopolymers with high molecular weights and highly branched structures. The weight-average molecular weight (Mw,SEC-MALLs) values of 2 measured by multi-angle laser light scattering (MALLS) varied in the range from 7,400 to 122,400, which were significantly higher than the weight-average molecular weight (Mw,SEC) values determined by size exclusion chromatography (SEC). The intrinsic viscosities ([η]) of these polymers were very low in the range of 3.3-4.6 mL g^[-1] and the Mark-Houwink-Sakurada exponents α were calculated to be 0.08-0.27. These results of the MALLS, SEC, and viscosity measurements suggested that these polymers exist in a compact spherical conformation in solution because of their highly branched structure. The synthesis of the hyperbranched 5,6-glucan (3) by hydrolysis of polymer 2 was also demonstrated. Polymer 3 is a novel water-soluble hyperbranched glycopolymer arranged with numerous reducing D-glucose units on the peripheries of the polymer, and has a higher reducing ability than D-glucose because of the glycocluster effect or the multivalent effect of the reducing D-glucose units. Therefore, polymer 3 should be called a "reducing sugar ball"

Diagnosis and Characters of Non-Specific Low Back Pain in Japan: The Yamaguchi Low Back Pain Study.

Cross sectional data from the Yamaguchi low back pain study conducted in Yamaguchi prefecture, Japan, was used for this analysis.A total of 320 patients were recruited from walk-in orthopedic clinics in Yamaguchi Prefecture, Japan. Patients visited the clinics primarily for low back pain (LBP) and sought treatment between April and May 2015. A self-questionnaire was completed by patients, while radiographic testing and neurological and physical examination was performed by the orthopedist in each hospital. The cause and characters of LBP was determined following examination of the data, regional anesthesia and block injection.'Specific LBP' was diagnosed in 250 (78%) patients and non-diagnosable, 'non-specific LBP' in 70 (22%) patients. The VAS scores of patients were: LBP, 5.8±0.18; leg pain, 2.9±0.18 and the intensity of leg numbness was 1.9±0.16. Item scores for SF-8 were: general health, 46.6±0.40; physical function, 43.5±0.51; physical limitations, 42.8±0.53; body pain, 42.1±0.52; vitality, 48.4±0.37; social function, 46.9±0.53; emotional problems, 48.9±0.43; mental health, 46.9±0.43.The incidence of non-specific LBP in Japan was lower than previous reports from western countries, presumably because of variation in the diagnosis of LBP between different health care systems. In Japan, 78% of cases were classified as 'specific LBP' by orthopedists. Identification of the definitive cause of LBP should help to improve the quality of LBP treatment