Tmem161a regulates bone formation and bone strength through the P38 MAPK pathway.

Bone remodeling is an extraordinarily complex process involving a variety of factors, such as genetic, metabolic, and environmental components. Although genetic factors play a particularly important role, many have not been identified. In this study, we investigated the role of transmembrane 161a (Tmem161a) in bone structure and function using wild-type (WT) and Tmem161a-depleted (Tmem161aGT/GT) mice. Mice femurs were examined by histological, morphological, and bone strength analyses. Osteoblast differentiation and mineral deposition were examined in Tmem161a-overexpressed, -knockdown and -knockout MC3T3-e1 cells. In WT mice, Tmem161a was expressed in osteoblasts of femurs; however, it was depleted in Tmem161aGT/GT mice. Cortical bone mineral density, thickness, and bone strength were significantly increased in Tmem161aGT/GT mice femurs. In MC3T3-e1 cells, decreased expression of alkaline phosphatase (ALP) and Osterix were found in Tmem161a overexpression, and these findings were reversed in Tmem161a-knockdown or -knockout cells. Microarray and western blot analyses revealed upregulation of the P38 MAPK pathway in Tmem161a-knockout cells, which referred as stress-activated protein kinases. ALP and flow cytometry analyses revealed that Tmem161a-knockout cells were resistant to oxidative stress. In summary, Tmem161a is an important regulator of P38 MAPK signaling, and depletion of Tmem161a induces thicker and stronger bones in mice.

Shear stress in the medial meniscus posterior root during daily activities.

BACKGROUND: Medial meniscus posterior root (MMPR) tears have been reported to occur in middle-aged patients with minor trauma. However, the injury mechanism of MMPR tears remains unclear. The purpose of this study was to evaluate the shear stress in the MMPR during daily activities using a finite-element analysis. METHODS: Subject-specific finite-element models of the knee joint of a healthy middle-aged subject were developed from computed tomographic and magnetic resonance images. A three-dimensional motion capture system "VICON" was used to capture four daily activities: walking, jogging, descending stairs, and landing. The knee joint reaction force was estimated using the AnyBody modeling system. Based on these procedures, the shear stress in the MMPR was calculated during each motion. The shear stress in the lateral meniscus posterior root (LMPR) was also measured to compare the stress between the MMPR and LMPR. RESULTS: The shear stress in the MMPR increased as the knee flexion angle increased during each motion. Descending stairs caused more than two-fold greater stress in the MMPR than walking and a similar or greater amount of stress than jogging. The LMPR tended to receive more shear stress than the MMPR throughout each motion. CONCLUSIONS: The present study showed that descending stairs confers almost the same amount of shear stress to the MMPR as jogging. The results of the present study may suggest that descending motion of the knee is an important cause of MMPR tear, and the initiation of descending stairs should be delayed after MMPR repair.

Three-dimensional fine structures in deep fascia revealed by combined use of cryo-fixed histochemistry and low-vacuum scanning microscopy.

Recent physiological studies have shown that the deep fascia has received much attention concerning clinical medicine; however, histological examination of the deep fascia has not been well established. In this study, we aimed to clarify and visualize the structure of the deep fascia by taking advantage of cryofixation techniques and low-vacuum scanning electron microscopy. As a result, the ultrastructural observations revealed three-dimensional stratification of the deep fascia composed of three layers: the first superficial layer consisting of collagen fibers extending in various directions with blood vessels and peripheral nerves; the second intermediate layer formed by single straight and thick collagen fibers with flexibility; and the third deepest layer, consisting of relatively straight and thin collagen fibers. We explored the use of two hooks to hold a piece of deep fascia in place through the course of cryo-fixation. A comparative observation with or without the hook-holding procedure would indicate the morphological adaptation to physiological stretch and contraction of the deep fascia. The present morphological approach paves the way to visualize three-dimensional ultrastructures for future biomedical studies including clinical pathophysiology.

Insertion sites of the muscles attached to the clavicle: a cadaveric study of the clavicle.

BACKGROUND: Clavicle fractures are common injuries, especially in young, active individuals. Operative treatment is recommended for completely displaced clavicle shaft fractures, and plate fixation is stronger than the use of intramedullary nails. Few studies have reported on iatrogenic injuries to the muscle attached to the clavicle during fracture surgery. The aim of this study was to clarify the area of the insertion sites of muscles attached to the clavicle in Japanese cadavers using gross anatomy and three-dimensional (3D) analysis. We also aimed to compare the effects of anterior plate templating and superior plate templating on clavicle shaft fractures using 3D images. METHODS: Thirty-eight clavicles from Japanese cadavers were analyzed. We removed all clavicles to identify the insertion sites and measured the size of the insertion area of each muscle. Three-dimensional templating was performed on both the superior and anterior plates of the clavicle using data obtained from computed tomography. The areas covered by these plates on the muscles attached to the clavicle were compared. Histological examination was performed on four randomly selected specimens. RESULTS: The sternocleidomastoid muscle was attached proximally and superiorly; the trapezius muscle was attached posteriorly and partly superiorly; and the pectoralis major muscle and deltoid muscles were attached anteriorly and partially superiorly. The non-attachment area was located mainly in the posterosuperior part of the clavicle. It was difficult to distinguish the borders of the periosteum and pectoralis major muscles. The anterior plate covered a significantly broader area (mean 6.94 ± 1.36 cm2) of the muscles attached to the clavicle than did the superior plate (mean 4.11 ± 1.52 cm2) (p < 0.0001). On microscopy, these muscles were inserted directly into the periosteum. CONCLUSION: Most of the pectoralis major and deltoid muscles were attached anteriorly. The non-attachment area was located mainly from the superior to posterior part of the clavicle midshaft. Both macroscopically and microscopically, the boundaries between the periosteum and these muscles were difficult to demarcate. The anterior plate covered a significantly broader area of the muscles attached to the clavicle than that by the superior plate.

Effect of total hip arthroplasty on improving locomotive syndrome in hip disease patients: A prospective cohort study focused on total clinical decision limits stage 3.

BACKGROUND: In 2020, the Japanese Orthopaedic Association established a new stage 3 in clinical decision limits (CDL) to evaluate the stage of locomotive syndrome (LS). This study focused on total CDL stage 3 with the aim of investigating indicators related to improvements in total CDL by evaluating the improvement of LS in patients who underwent total hip arthroplasty (THA). METHODS: Of the 125 patients who underwent THA at our hospital, the subjects of the analysis were 105 patients determined to be total CDL stage 3 in an evaluation performed before THA. LS was evaluated using the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale (GLFS-25). Indicators related to improvements in total CDL were also investigated. All evaluation items were measured before THA and three months after THA. RESULTS: Before THA, all subjects (n = 105) were classified as total CDL stage 3. Three months after THA, improvements in total CDL were seen in 49 subjects (46.7%). The results of stepwise multiple logistic regression analysis showed that the before THA stand-up test and GLFS-25 were significantly related to improvements in total CDL. CONCLUSIONS: Three months after THA, improvements in LS were seen in approximately half of the subjects. The stand-up test and GLFS-25 can be used as indicators of improvement in total CDL. DESIGN: Prospective cohort study design.

The impact of helicopter emergency medical services and craniocervical traction on the early reduction of cervical spine dislocation in a rural area of Japan.

BACKGROUND: Several studies have shown an association between achieving decompression of the spinal cord within a few hours and neurological recovery, even in patients with complete paralysis due to cervical spine dislocation. This study aimed to clarify the impact of helicopter emergency medical services (HEMSs) and craniocervical traction on the rapid reduction of lower cervical spine dislocation in rural Japan. METHODS: The success rate of and factors inhibiting closed reduction, the time from injury to reduction and the functional prognosis of lower cervical spine dislocations treated between July 2012 and February 2020 were retrospectively analysed. RESULTS: Fourteen patients were transported by HEMS (group H), seven by ambulance (group A) and two by themselves. Although the average traveled distance and injury severity score were significantly higher in group H (64.5 km, 28.0) than in group A (24.7 km, 18.6), there was no significant difference in the average time to admission or the time to initiation of craniocervical traction after admission between groups H (159.4 min, 52.2 min) and A (163.6 min, 53.2 min). The success rate of closed reduction was 95%, and neurological deterioration was not observed in any cases. The average traction time and weight for reduction were 30.3 min and 16.3 kg, respectively. Body size and fracture-dislocation type did not significantly affect the traction time or weight. The rate of reduction within 4 h after injury was higher in group H (79%) than in group A (33%). Inner fixations were treated an average of 5.7 days after admission. After treatment, three of nine AIS A patients recovered the ability to walk, and all three patients underwent successful closed reduction within 4 h after injury. CONCLUSION: HEMS and highly successful closed reduction contributed to the early reduction of cervical spine dislocation and can potentially improve complete paralysis.

Googling Musculoskeletal-Related Pain and Ranking of Medical Associations' Patient Information Pages: Google Ads Keyword Planner Analysis.

BACKGROUND: Most people currently use the internet to obtain information about many subjects, including health information. Thus, medical associations need to provide accurate medical information websites. Although medical associations have their own patient education pages, it is not clear if these websites actually show up in search results. OBJECTIVE: The aim of this study was to evaluate how well medical associations function as online information providers by searching for information about musculoskeletal-related pain online and determining the ranking of the websites of medical associations. METHODS: We conducted a Google search for frequently searched keywords. Keywords were extracted using Google Ads Keyword Planner associated with "pain" relevant to the musculoskeletal system from June 2016 to December 2019. The top 20 search queries were extracted and searched using the Google search engine in Japan and the United States. RESULTS: The number of suggested queries for "pain" provided by Google Ads Keyword Planner was 930 in the United States and 2400 in Japan. Among the top 20 musculoskeletal-related pain queries chosen, the probability that the medical associations' websites would appear in the top 10 results was 30% in the United States and 45% in Japan. In five queries each, the associations' websites did not appear among the top 100 results. No significant difference was found in the rank of the associations' website search results (P=.28). CONCLUSIONS: To provide accurate medical information to patients, it is essential to undertake effective measures for search engine optimization. For orthopedic associations, it is necessary that their websites should appear among the top search results.