Publications by authors named "Yamamuro Y"

Objective: Tyrosinase is a rate-limiting enzyme for the biosynthesis of melanin pigment in peripheral tissues, such as skin and the retina. We recently reported the expression and enzymatic activity of tyrosinase as well as its protective effects against oxidative stress-induced protein damage in the mouse brain. The functional role of tyrosinase in the central nervous system, however, remains largely unknown.

View Article and Find Full Text PDF
Article Synopsis
  • Greater trochanteric fractures can occur during total hip arthroplasty (THA) when using the anterolateral approach, and this study aimed to explore how bone mineral density (BMD) and the shape of the femur affect the risk of these fractures.
  • A total of 209 hips were analyzed after THA, with a focus on identifying fractures and assessing the correlation between bone density and femoral morphology through multivariate analysis.
  • Results indicated that a bone density below 80% of the young adult mean (YAM) combined with a specific femoral shape (Type B) significantly increased the risk of greater trochanteric fractures during surgery.
View Article and Find Full Text PDF

Adipose-derived stem cells (ADSCs) have been studied for many years as a therapeutic option for osteoarthritis (OA); however, their efficacy remains insufficient. Since platelet-rich plasma (PRP) induces chondrogenic differentiation in ADSCs and the formation of a sheet structure by ascorbic acid can increase the number of viable cells, we hypothesized that the injection of chondrogenic cell sheets combined with the effects of PRP and ascorbic acid may hinder the progression of OA. The effects of induction of differentiation by PRP and formation of sheet structure by ascorbic acid on changes in chondrocyte markers (collagen II, aggrecan, Sox9) in ADSCs were evaluated.

View Article and Find Full Text PDF

Periprosthetic joint infection (PJI) is characterized by biofilm infection, which is difficult to alleviate while preserving implant integrity. Furthermore, long-term antibiotic therapy may increase the prevalence of drug-resistant bacterial strains, necessitating a non-antibacterial approach. Adipose-derived stem cells (ADSCs) exert antibacterial effects; however, their efficacy in PJI remains unclear.

View Article and Find Full Text PDF
Article Synopsis
  • This study evaluated OpenPose, a posture estimation algorithm, for measuring hip-knee-ankle (HKA) angle in knee osteoarthritis patients by comparing it to radiographic methods.
  • The results showed that OpenPose has excellent reliability and strong agreement with traditional radiography, indicating it can provide accurate measurements with a minor fixed error.
  • OpenPose offers a non-invasive and simple way to monitor HKA angles, making it a valuable tool for both clinical settings and personal self-assessment at home or in gyms.
View Article and Find Full Text PDF

Introduction: A greater trochanteric fracture is a perioperative complication of primary total hip arthroplasty (THA) via an anterolateral approach. Although surgeons determine risk factors in the preoperative planning phase, no study explored the relationship between the planned femoral implant and greater trochanter. This study attempts to determine the risk factors for perioperative greater trochanteric fractures in primary THA via an anterolateral approach.

View Article and Find Full Text PDF

Obesity is a major public health problem, and its prevalence is progressively increasing worldwide. In addition, accumulating evidence suggests that diverse nutritional and metabolic disturbances including obesity can be transmitted from parents to offspring via transgenerational epigenetic inheritance. The previous reports have shown that paternal obesity has profound impacts on the development and metabolic health of their progeny.

View Article and Find Full Text PDF

Background: A chronic expanding hematoma (CEH) is a rare complication caused by surgery or trauma; it mostly affects the soft tissues, such as those in the trunk or extremities. We present the first case of a large intraosseous CEH presenting with chronic disseminated intravascular coagulation (DIC), 22 years after total hip arthroplasty (THA); the CEH was treated with a single-stage excision and revision THA.

Case Presentation: A 67-year-old man presented to our hospital with left thigh pain and an enlarging mass.

View Article and Find Full Text PDF

Nutmeg, a dried seed kernel of a tall evergreen Myristicaceae tree, is widely used as a spice and herbal medicine and is known to have antidepressant-like effects. This study evaluates the mechanisms underlying this antidepressant-like effect and safety of nutmeg n-hexane extract (NNE) in mice. Tail suspension and open field tests showed that NNE (10 mg/kg, per OS (p.

View Article and Find Full Text PDF

Background: This report seeks to clarify whether the dosage and duration of preoperative concurrent corticosteroid use influence postoperative complications after primary total joint arthroplasty (TJA).

Methods: This retrospective single institutional study enrolled 1128 primary TJA cases, including 905 total hip arthroplasties and 223 total knee arthroplasties at a minimum 6 months of follow-up. Mean follow-up period was 51.

View Article and Find Full Text PDF

Introduction: The frequency of intraoperative periprosthetic occult fracture of the acetabulum (IPOA) in primary total hip arthroplasty (THA) is relatively high. However, the effect of this fracture on clinical outcome and survival of primary THA remains unknown. This study aimed to determine the impact of IPOA on the outcomes of primary THA during a minimum follow-up of 5 years.

View Article and Find Full Text PDF

Understanding the morphology of the superior aspect of the proximal femur is critical for treating femoral fracture. We assessed the correlation among the ideal insertion point of the femoral nail, femur head-neck axis, and native anteversion. One hundred patients with normal femurs were included in this study.

View Article and Find Full Text PDF

Background: The purpose of this study was to evaluate true change in leg length after open-wedge high tibial osteotomy (OWHTO) using three-dimensional (3D) assessments, examine the factors that influence leg lengthening and verify their validity in clinical practice.

Methods: Study 1: a retrospective case series simulation study, included 46 patients (55 knees) that underwent knee arthroplasty or HTO. OWHTO was simulated from preoperative computed tomography using 3D preoperative planning software.

View Article and Find Full Text PDF

Background: We developed iodine-coated titanium implants to suppress microbial activity and prevent periprosthetic joint infection (PJI); their efficacy was demonstrated in animal and in vitro models. The iodine content in iodine-coated implants naturally decreases in vivo. However, to our knowledge, the effect of reduced iodine content on the implant's antimicrobial activity has not been evaluated to date.

View Article and Find Full Text PDF

Objectives: Although both sarcopenia and hip disease decrease physical function, few studies have investigated the association. We investigated the prevalence of sarcopenia in patients awaiting total hip arthroplasty for osteoarthritis and examined the impact of sarcopenia on pre- and postoperative outcomes.

Methods: This prospective study included 96 females.

View Article and Find Full Text PDF

Tyrosinase is a key enzyme for the biosynthesis of melanin pigments in peripheral tissues such as skin and retina. Although tyrosinase activity is specifically detected in melanocytes, several studies have shown the expression and enzymatic activity of tyrosinase in the central nervous system, especially in the midbrain substantia nigra. In the present study, we investigated the antioxidative effects of tyrosinase on protein damage in the substantia nigra of mice.

View Article and Find Full Text PDF

Background: Subcutaneous adipose tissue represents an abundant source of multipotent adult stem cells named as Adipose-derived stem cells (ADSCs). With a cell sheet approach, ADSCs survive longer, and can be delivered in large quantities. We investigated whether intra-articular ADSC sheets attenuated osteoarthritis (OA) progression in a rabbit anterior cruciate ligament transection (ACLT) model.

View Article and Find Full Text PDF

Implant-related infection is difficult to treat without extended antibiotic courses. However, the long-term use of antibiotics has led to the development of multidrug- and methicillin-resistant Staphylococcus aureus. Thus, alternatives to conventional antibiotic therapy are needed.

View Article and Find Full Text PDF

Background: There is limited understanding of anterior acetabular component overhang, which induces groin pain, in post-periacetabular osteotomy (PAO) hips during conversion to total hip arthroplasty (THA). The aim of the study were to determine the following: (1) the differences in the amount of acetabular component overhang among pre-PAO hips and post-PAO hips in simulating THA; (2) the factors associated with the amount of component overhang in THA following PAO; (3) whether high component placement with elevation of the hip center by 10 mm reduces the amount of component overhang compared to the anatomical component position in THA following PAO.

Methods: Computer-based simulations of acetabular component implantation were performed using preoperative and postoperative CT data from 30 patients undergoing PAO.

View Article and Find Full Text PDF

Background: Locomotive syndrome (LS) is a predictive factor of future motor dysfunction. Our aim was to evaluate the change in the total LS grade and, its the association with the Japanese Orthopaedic Association (JOA) hip score after total hip arthroplasty (THA) among patients with hip osteoarthritis.

Methods: This was a prospective case-control study of 72 patients who underwent primary THA.

View Article and Find Full Text PDF
Article Synopsis
  • - In total knee arthroplasty, the surgical transepicondylar axis (SEA) is essential for stabilizing the patellofemoral joint, but obtaining accurate measurements can be challenging since the lateral epicondyle and medial sulcus often don't appear on the same CT image.
  • - The study compared true SEAs with pseudo SEAs, defined as measurements taken from the same image, in both normal and varus knees using 3D models from CT scans.
  • - Results showed no significant differences between true and pseudo SEA angles overall, but some knees (particularly in the normal group) had measurement differences exceeding 1 degree, suggesting that pseudo SEA can typically be substituted for true SEA.
View Article and Find Full Text PDF

Background: A few previous studies have investigated patient satisfaction after total hip arthroplasty (THA) according to the degree of pelvic deformity. This study compared patient-reported outcomes after primary THA for Crowe types III, IV and I dysplasia.

Methods: This retrospective, single-center, single-surgeon case-control study included patients who underwent primary THA between 2008 and 2016.

View Article and Find Full Text PDF

This study investigated the influence of the rotation of innominate bone on anterior pelvic plane (APP) tilt, the angle formed by the APP, and coronal plane of the body to determine whether the provision of proper information about the sagittal balance of the body by the value of the APP tilt (APPT). In total, 244 patients (171 females, 73 males) who were candidates for total hip or knee arthroplasty, periacetabular osteotomy, or shelf arthroplasty were included. The rotational angle of the innominate bone was quantified using computed tomography images at the level of the anterior superior, and anterior inferior iliac spine, and ischiopubic portion.

View Article and Find Full Text PDF

Purpose: A computed tomography (CT)-based hip navigation system is a useful tool for achieving precise implant alignment angle. However, it has the disadvantage of prolonged procedure duration. A prolonged procedure duration may increase the incidence of postoperative surgical site infection (SSI) or periprosthetic joint infection (PJI) following primary THA.

View Article and Find Full Text PDF

Background: Intraoperatively acquired pressure ulcers are serious postsurgical complications requiring additional treatment, reoperation, and extended hospitalization. No study has investigated the frequency of the ulcers caused by compression with a pelvic positioner, which is used in hip surgeries to stabilize patients in the lateral decubitus position.

Methods: This retrospective study investigated the risk factors and the frequency of the ulcers caused by the use of pelvic positioners in hip surgeries.

View Article and Find Full Text PDF