Spontaneous strain due to ferroquadrupolar ordering in UCu2_2Sn

The ternary uranium compound UCu$_2$Sn with a hexagonal ZrPt$_2$Al-type structure shows a phase transition at 16 K. We reported previously that huge lattice-softening is accompanied by the phase transition, which originates from ferroquadrupolar ordering of the ground state non-Kramers doublet $\Gamma_5$. A macroscopic strain, which is expected to emerge spontaneously, was not detected by powder X-ray diffraction in the temperature range between 4.2 and 300 K. To search the spontaneous strain, we have carried out thermal expansion measurements on a single-crystalline sample along the $a$, $b$ and $c$ axes using a capacitance technique with the resolution of $10^{-8}$. In the present experiment, we found the spontaneous $e_{xx} - e_{yy}$ strain which couples to the ground state doublet $\Gamma_5$. The effect of uniaxial pressure along the $a$, $b$ and $c$ axes on the transition temperature is also discussed.Comment: 4 pages, 5 figures, submitted to Phys. Rev.

Repair of segmental bone defects in rabbit tibia promoted by a complex of β-tricalcium phosphate and hepatocyte growth factor

Background: Segmental bone defect repair remains a clinical and scientific challenge with increasing interest focused on bone tissue engineering. Clinical studies are ongoing to address application of hepatocyte growth factor (HGF) for treatment of some diseases; however, the use of HGF in bone tissue engineering has not been addressed. This study was performed to evaluate the effect of HGF in a complex of β-tricalcium phosphate (β-TCP) and collagen in repairing segmental bone defects. Methods: Segmental bone defects 5 mm long were created in the middle of the tibial shafts of rabbits. The defect was stabilized with external fixators and implanted with a complex of β-TCP granules and collagen, with or without 100 μg recombinant human HGF. Biweekly, bone regeneration and β-TCP resorption were assessed radiographically and histologically. At 4 and 8 weeks, bone regeneration was evaluated by use of micro-computed tomography and mechanical tests. Results: Compared with the bone tissue treated with β-TCP and collagen, mineralization, angiogenesis, new bone formation, and absorption of β-TCP were promoted 4 weeks postoperatively by treatment with HGF in the β-TCP and collagen group. These changes were associated with promoting biomechanical regeneration. By 8 weeks, the formation of bone marrow in newly generated bone and absorption of the β-TCP granules were completed in a shorter period by combining HGF with β-TCP and collagen, compared with tissues without HGF. Conclusions: The combined application of HGF in a β-TCP and collagen matrix promoted histological bone healing and augmented mechanical strength of the healing bone, particularly in the early stages. The combined use of HGF and β-TCP for treatment of bone defects made a substantial difference. © 2012 The Japanese Orthopaedic Association.金沢大学博士学位論文 五嶋謙一, Theisis of GOSHIMA, Kenich

Precise risk factors for Osgood–Schlatter disease

Introduction: A number of studies have examined the risk factors for Osgood–Schlatter disease (OSD). Studies on risk factors have not necessarily accurately demonstrated the risk factors of this disease because they were not prospective cohort studies or the populations in the studies were not categorized by the skeletal maturation of the tibial tuberosity. We can identify the precise risk factors for OSD by performing a prospective cohort study of a group of asymptomatic patients in particular times of adolescent using ultrasonography. In the present study, we aimed to investigate the precise risk factors for OSD. Methods: For all examinations, we used a 3-stage classification for tibial tuberosity development observed on ultrasonography: sonolucent (stage S), individual (stage I), and connective stages (stage C). Among 150 players with 300 knees, we included 37 male players with 70 knees at asymptomatic stage I on the first examination. We re-examined the included knees 1 year after the first examination and compared 10 knees with OSD (OSD group) and 60 knees without OSD (control group). Height, body weight, body mass index, tightness of the quadriceps femoris and hamstring muscles, muscle strength during knee extension, and flexion were assessed during the first medical examination. Results: The incidence of OSD was 14.3 % in this 1-year cohort study. A significant difference was found in body weight, quadriceps muscle tightness, and muscle tightness and strength during knee extension between the 2 groups. The precise risk factors for OSD were increased, namely the quadriceps femoris muscle tightness and strength during knee extension and flexibility of the hamstring muscles, using logistic regression analysis. Conclusions: This information may be useful for teaching quadriceps stretching in preadolescent male football players with stage I. © 2015 Springer-Verlag Berlin Heidelber

Relationship between the skeletal maturation of the distal attachment of the patellar tendon and physical features in preadolescent male football players

Purpose: The aim of this study was to compare ultrasonography stages of the tibial tuberosity development and physical features. Methods: This study examined 200 knees in 100 male football players aged 10-15 years. Tibial tuberosity development on ultrasonography was divided into 3 stages: Sonolucent stage (stage S), Individual stage (stage I), and Connective stage (stage C). Age, height, quadriceps and hamstring muscle tightness, and muscle strength in knee extension and flexion were determined. These findings were compared with the respective stages of development. Results: The tibial tuberosity was stage S in 27 knees, stage I in 69 knees, and stage C in 104 knees, with right and left sides at the same stage in 95 %. Average age and height significantly increased with advancing tibial tuberosity development. Quadriceps tightness increased with tibial tuberosity development. Hamstring tightness decreased with development. The strength of both knee extension and flexion increased with advancing development, with a greater change seen in knee extension, hamstring/quadriceps ratio: stage C, 0.74; stage A, 0.64; stage E, 0.53. Conclusions: Osgood-Schlatter pathogenesis reportedly involves increased quadriceps tightness with rapidly increasing femoral length during tibial tuberosity development. In this study, it was confirmed that quadriceps tightness increased, yet hamstring tightness decreased, suggesting that quadriceps tightness is not due to femoral length alone. Other factors, including muscle strength, may be involved. The study shows that thigh muscle tightness and thigh muscle performance change with the skeletal maturation of the distal attachment of the patellar tendon. These results add new information to the pathogenesis of Osgood-Schlatter disease. Level of evidence: Cross-sectional study, Level III. © 2012 Springer-Verlag Berlin Heidelberg

Postoperative Urinary Retention in Japanese Elderly Males with a Femoral Neck or Trochanteric Fracture

We assessed risk factors for postoperative urinary retention (UR) in elderly males with femoral bone fractures: 169 Japanese males (mean age 81.95 ± 1.19 years) who had undergone hip surgery at a municipal hospital (Toyama, Japan). A multiple logistic regression analysis was used to test possible risk factors for UR: age, body mass index, serum albumin, cognitive impairment, activities of daily living (ADL), and history of diabetes mellitus (DM). UR occurred in 24 (14.2%) of the 169 patients. A multivariate logistic regression analysis with age adjustment showed that ADL (odds ratio [OR] 3.88; 95% confidence interval [CI]: 1.2-12.5, p=0.023) was significantly associated with the development of UR, and a history of DM showed marginal significance for UR occurrence (OR 0.36, 95%CI: 0.11-10, p=0.064). These results suggests that ADL is a risk factor for UR development in elderly males who have undergone surgery for femoral neck or trochanter fractures

Familial predisposition to anterior cruciate ligament injury

Although several risk factors for anterior cruciate ligament (ACL) injury have been evaluated in the literature, there are few reports on familial predisposition. This study investigated the familial predisposition to ACL injury. The study included 350 patients who underwent ACL reconstruction between January 2005 and September 2008. All patients were surveyed by telephone or a written questionnaire about family history (FH) of ACL injury, sports played by family members, and mechanisms of injury. We also compared age, sex, height, weight, body mass index, Tegner activity score, general joint laxity, and tibial slope between an FH group (with FH) and a control group (without FH). In addition, we compared the incidence of ACL graft rupture and contralateral ACL rupture 2 years after primary surgery. Complete information was obtained from 316 patients, 38 (12.0%) of whom had FH of ACL injury. Two families had three members with ACL injuries. Of the 40 family members with ACL injuries, 38 (95%) had noncontact injuries and 34 (85%) shared a similar mechanism of injury with the related patient. No significant differences were identified between the two groups, except that tibial slope was significantly greater in the FH group than in the control group. Although the incidence of repeat ACL injury was greater in the FH group (23.7%) than in the control group (16.4%), there was no significant difference. Our results indicated a high probability of familial predisposition to many of the identified risk factors for ACL injury. In addition, patients with FH of ACL injury might be at high risk for initial and repeat ACL injuries. Therefore, prevention programs should be implemented for patients with FH of ACL injury in order to decrease the risk of these injuries