Major Surgical Treatment of Osteoporotic Vertebral Fractures in the Elderly: A Comparison of Anterior Spinal Fusion, Anterior-Posterior Combined Surgery and Posterior Closing Wedge Osteotomy

Study DesignA retrospective study.PurposeTo clarify the differences among the three major surgeries for osteoporotic vertebral fractures based on the clinical and radiological results.Overview of LiteratureMinimally invasive surgery like balloon kyphoplasty has been used to treat osteoporotic vertebral fractures, but major surgery is necessary for severely impaired patients. However, there are controversies on the surgical procedures.MethodsThe clinical and radiographic results of patients who underwent major surgery for osteoporotic vertebral fracture were retrospectively compared, among anterior spinal fusion (group A, 9 patients), single-stage combined anterior-posterior procedure (group AP, 8 patients) and posterior closing wedge osteotomy (group P, 9 patients). Patients who underwent revision surgery were evaluated just before the revision surgery, and the other patients were evaluated at the final follow-up examination, which was defined as the end point of the evaluations for the comparison.ResultsThe operation time was significantly longer in group AP than in the other two groups. The postoperative correction of kyphosis was significantly greater in group P than in group A. Although the differences were not significant, better outcomes were obtained in group P in: back pain relief at the end point; ambulatory ability at the end point; and average loss of correction.ConclusionsThe posterior closing wedge osteotomy demonstrated better surgical results than the anterior spinal fusion procedure and the single-stage combined anterior-posterior procedure

Non-planar Diagrams and Non-commutative Superspace in Dijkgraaf-Vafa theory

We consider the field theory on non-commutative superspace and non-commutative spacetime that arises on D-branes in Type II superstring theory with a constant self-dual graviphoton and NS-NS $B$ field background. $\N=1$ supersymmetric field theories on this non-commutative space (such theories are called $\N=1/2$ supersymmetric theories.) can be reduced to supermatrix models as in hep-th/0303210 \cite{KKM}. We take an appropriate commutative limit in these theories and show that holomorphic quantities in commutative field theories are equivalent to reduced models, including non-planar diagrams to which the graviphoton contributes. This is a new derivation of Dijkgraaf-Vafa theory including non-planar diagrams.Comment: 15 pages, 1 figure, the version to appear in Phys. Lett.

Penrose limits and Green-Schwarz strings

We discuss the Green-Schwarz action for type IIB strings in general plane-wave backgrounds obtained as Penrose limits from any IIB supergravity solutions with vanishing background fermions. Using the normal-coordinate expansion in superspace, we prove that the light-cone action is necessarily quadratic in the fermionic coordinates. This proof is valid for more general pp-wave backgrounds under certain conditions. We also write down the complete quadratic action for general bosonic on-shell backgrounds in a form in which its geometrical meaning is manifest both in the Einstein and string frames. When the dilaton and 1-form field strength are vanishing, and the other field strengths are constant, our string-frame action reduces, up to conventions, to the one which has been written down using the supercovariant derivative.Comment: 18 pages, latex, no figures; (v2) relation to ref.14 clarified; (v3) typos corrected, minor change

Reference values for the locomotive syndrome risk test quantifying mobility of 8681 adults aged 20–89 years: A cross-sectional nationwide study in Japan

Background The locomotive syndrome risk test was developed to quantify the decrease in mobility among adults, which could eventually lead to disability. The purpose of this study was to establish reference values for the locomotive syndrome risk test for adults and investigate the influence of age and sex. Methods We analyzed 8681 independent community dwellers (3607 men, 5074 women). Data pertaining to locomotive syndrome risk test (the two-step test, the stand-up test, and the 25-question geriatric locomotive function scale [GLFS-25]) scores were collected from seven administrative areas of Japan. Results The reference values of the three test scores were generated and all three test scores gradually decreased among young-to-middle-aged individuals and rapidly decreased in individuals aged over 60 years. The stand-up test score began decreasing significantly from the age of 30 years. The trajectories of decrease in the two-step test score with age was slightly different between men and women especially among the middle-aged individuals. The two physical test scores were more sensitive to aging than the self-reported test score. Conclusion The reference values generated in this study could be employed to determine whether an individual has mobility comparable to independent community dwellers of the same age and sex

Surveys of full–coverage restorations made of titanium at Matsumoto Dental University Hospital

Considering the presence of metal allergies and the sharp rise in the prices of precious metals, full–coverage restorations made of titanium have been covered by Japanese insurance since June 1, 2020. The clinical application of these restorations is expected to increase in the future. However, due to its high melting point and high affinity to oxygen at high temperatures, titanium has not been widely used in prosthetic clinical practice. This study aimed to survey the actual use of full–coverage metal restorations at Matsumoto Dental University Hospital. Patients who had full–coverage metal restorations placed on their molars from June 1 to December 28, 2020, were consecutively enrolled, and data on the type of metal, placement site, and time were recorded. Besides, the dentists who used titanium restorations (Ti–Rs) were given a questionnaire. We asked them to rate their impressions of Ti–Rs in comparison with full–coverage restorations made of Ag–Pd–Cu–Au alloy (Pd–R) in six categories, including occlusal adjustment, polishing, and luting operations. In all, 338 molars received full–coverage metal restorations. Ti–R was used in 33 cases and Pd–R in 305 cases; 14 upper and 19 lower, 12 first molars, 18 second molars, and 3 third molars received Ti–Rs, while 137 upper and 168 lower, 174 first molars, 174 second molars, and 3 third molars received Pd–Rs. Seven dentists responded to the questionnaire survey. Many dentists stated that Ti–R was more challenging to use than Pd–R for occlusal adjustment, polishing, and adjustment time. On the other hand, most of them stated that the luting process was similar for both. Besides, Ti–R was favorably evaluated in terms of metal allergy. The number of patients who received Ti–Rs increased during the study period, suggesting that Ti–Rs will be a commonly used metal allergy–friendly prosthetic in the future. We plan to continue the survey and study the prognosis