Publications by authors named "Hidetoshi Hamada"
Objectives: As many patients with osteoporosis remain undiagnosed, we aimed to develop a simple method to efficiently screen for osteoporosis using a combination of anteroposterior hip X-ray assessment and the Osteoporosis Self-Assessment Tool for Asians (OSTA), which is calculated as (body weight - age) × 0.2.
Methods: One hundred Japanese women (age: 73 ± 11 years, body weight: 54.
Glucocorticoid-induced osteoporosis (GIOP) lacks fully effective treatments. This study investigated the role of Piezo1, a mechanosensitive ion channel component 1, in GIOP. We found reduced Piezo1 expression in cortical bone osteocytes from patients with GIOP and a GIOP mouse model.
View Article and Find Full Text PDFBackground: Periprosthetic femoral fractures (PFFs) are serious complications in hip arthroplasty for femoral neck fractures. The rates of intraoperative (iPFFs) and postoperative PFFs (pPFFs) are higher in cementless stem cases than in cemented cases. This study aimed to investigate the effects of cerclage cabling on PFF prevention in cementless arthroplasty for femoral neck fractures.
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- Diagnosis and treatment of osteoporosis are crucial for successful hip surgery outcomes, and measuring bone mineral density (BMD) via DXA is the established method, but access can be limited.* -
- The study analyzed 1378 female patients undergoing hip surgery, assessing the correlation between BMD and the Osteoporosis Self-assessment Tool for Asians (OSTA) score, finding a strong correlation and establishing a cut-off score that effectively predicts osteoporosis.* -
- Results indicate that the OSTA tool can help screen for osteoporosis in at-risk patients before surgery, enabling targeted investigations and potentially improving patient outcomes.*
Article Synopsis
- This study aimed to automate the classification of hip osteoarthritis (hip OA) severity using deep learning models based on digitally-reconstructed CT images, moving away from subjective manual classifications like Crowe and Kellgren-Lawrence grades.
- The models were trained on a database of 197 hip OA patients, achieving an accuracy of about 65% in exact class accuracy and 95% in one-neighbor class accuracy, while also assessing prediction uncertainty related to classification errors.
- The findings indicate that this automated approach can effectively grade hip OA severity, potentially aiding in large-scale analyses and future disease progression studies, with the developed code expected to be publicly available.
Aims: Femoral component anteversion is an important factor in the success of total hip arthroplasty (THA). This retrospective study aimed to investigate the accuracy of femoral component anteversion with the Mako THA system and software using the Exeter cemented femoral component, compared to the Accolade II cementless femoral component.
Methods: We reviewed the data of 30 hips from 24 patients who underwent THA using the posterior approach with Exeter femoral components, and 30 hips from 24 patients with Accolade II components.
Article Synopsis
- This study focused on the prevalence of lower and whole leg length asymmetries (≥ 5 mm) in patients with unilateral osteoarthritis caused by developmental dysplasia of the hip and primary hip osteoarthritis.
- A total of 116 patients, including 93 with developmental dysplasia of the hip osteoarthritis and 23 with primary hip osteoarthritis, were analyzed using preoperative CT scans to evaluate leg and tibial length.
- The results indicated that asymmetries varied significantly among patient groups, with 43% of those without femoral length asymmetry still showing whole leg length asymmetry, highlighting the importance of measuring both femur and whole leg lengths for accurate assessment.
Background: The ultra-high molecular weight polyethylene (UHMWPE) component of artificial joints is one of the most important factors affecting the clinical outcomes of joint arthroplasty. Although the possibility of in vivo UHMWPE degradation caused by absorbed lipids has been reported, a quantitative evaluation of this phenomenon has not yet been performed.
Objective: This study aimed to establish the lipid index (LI) as a quantitative indicator of the amount of absorbed lipids and the first step to quantify their effects on UHMWPE.
Research is lacking on the effect of intraoperative pelvic tracker displacement relative to the pelvis on cup orientation accuracy in computed tomography (CT)-based navigation (CTN) or multivariable analysis to detect factors associated with CTN accuracy. Here, we asked: (1) how pelvic tracker displacement influences the CTN accuracy of cup orientation in total hip arthroplasty (THA)? and (2) what factors are associated with CTN accuracy on multivariable analysis? Regarding cup orientation in 446 THA procedures using CTN, we evaluated clinical error defined as the difference between postoperative measurement and preoperative planning and measurement error defined as the difference between postoperative and intraoperative measurements. Multivariable regression analyses detected the associated factors.
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- The study investigates the relationship between internal rotation (IR) angles and implant impingement during activities after total hip arthroplasty to ensure patient safety during daily tasks.
- It highlights that traditional simulation studies, typically conducted at lower IR angles, might not accurately reflect the impingement that occurs during activities requiring greater IR.
- Findings suggest that the optimal stem anteversion should be adjusted based on the patient's lifestyle needs, implant design, and femoral head size to maximize the impingement-free safe zone.
Introduction: Forearm dual-energy X-ray absorptiometry (DXA) is often performed in clinics where central DXA is unavailable. Accurate bone mineral density (BMD) measurement is crucial for clinical assessment. Forearm rotation can affect BMD measurements, but this effect remains uncertain.
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- * 41 hospitalized patients with COVID-19 were interviewed about hip pain, and MRI scans were conducted to check for ONFH.
- * Results showed that 1 out of 26 scanned patients had asymptomatic ONFH detected one month after their COVID-19 treatment, highlighting the need for doctors to monitor for this condition.
Article Synopsis
- A new hip stem made of carbon fiber-reinforced polyetheretherketone (CFR/PEEK) is being developed to help treat periprosthetic joint infections (PJIs) through an antibiotic release mechanism.
- In an experimental study with sheep, researchers tested how well the antibiotic vancomycin eluted from the implants and assessed their effectiveness in treating induced PJIs caused by Staphylococcus aureus.
- Results showed that the implant released about 70% of vancomycin over 21 days, and all successfully infected joints exhibited negative cultures and no signs of infection three weeks after surgery, demonstrating the efficacy of the therapeutic stem.
Aims: This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images.
Methods: The study analyzed 978 pairs of hip CT and dual-energy X-ray absorptiometry (DXA) measurements of the proximal femur (DXA-BMD) collected from three institutions. From the CT images, the femur and a calibration phantom were automatically segmented using previously trained deep-learning models.
Article Synopsis
- Periprosthetic joint infection (PJI) can occur after total hip replacement, leading to severe complications, prompting the development of a new drug-loaded carbon fiber-reinforced polymer (CFRP) prosthesis that allows for one-stage surgery.
- The study aimed to analyze how vancomycin, an antibiotic, diffuses from CFRP implants by modifying the mixing ratio of vancomycin paste and the size of holes in the implants.
- Results showed the best diffusion occurred with a 1:1.4 mixing ratio of vancomycin paste and a 2 mm hole diameter, both in laboratory tests and in a rabbit model, indicating drug release can be optimized by adjusting these parameters.
Article Synopsis
- The study examines how different hip positions—flexion, abduction, and rotation—impact bone mineral density (BMD) measurements during dual-energy x-ray absorptiometry (DXA) imaging.
- It utilized CT images from 120 patients to simulate and calculate BMD changes, finding significant variations particularly with hip flexion (up to 17.7% change) and smaller effects with hip rotation (up to 2.2% change).
- The findings suggest that careful positioning of patients is crucial for accurate DXA imaging, as even minor changes in hip angles can affect BMD readings significantly.
Unlabelled: This study developed a system to quantify the lumbar spine's bone mineral density (BMD) in two and three dimensions for osteoporosis screening using quantitative CT images. Measuring the two-dimensional BMD could reproduce the BMD measurement performed in dual-energy X-ray absorptiometry, and an accurate diagnosis of osteoporosis was possible.
Purpose: To date, the assessment of bone mineral density (BMD) using CT images has been made in three dimensions, leading to errors in detecting osteoporosis based on the two-dimensional assessments of BMD using dual-energy X-ray absorptiometry (DXA-BMD).
Purpose: Artificial intelligence (AI) technologies have enabled precise three-dimensional analysis of individual muscles on computed tomography (CT) or magnetic resonance images via automatic segmentation. This study aimed to perform three-dimensional assessments of pelvic and thigh muscle atrophy and fatty degeneration in patients with unilateral hip osteoarthritis using CT and to evaluate the correlation with health-related quality of life (HRQoL).
Methods: The study included one man and 43 women.
Purpose: The sacroiliac joint (SIJ) has attracted increasing attention as a source of low back and groin pain, but the kinematics of SIJ against standing load and its sex difference remain unclear due to the difficulty of in vivo load study. An upright magnetic resonance imaging (MRI) system can provide in vivo imaging both in the supine and standing positions. The reliability of the mobility of SIJ against the standing load was evaluated and its sex difference was examined in healthy young volunteers using an upright MRI.
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- - The study investigates errors in measuring pelvic incidence (PI) using radiographs in patients with hip osteoarthritis (OA), finding an average discrepancy of 3.6° between radiographic (rPI) and accurate CT measurements (cPI).
- - Factors contributing to measurement errors include coronal and axial pelvic rotation, with the study showing a positive correlation between error and coronal rotation, while axial rotation has a negative correlation.
- - Results indicate the mean rPI was significantly larger than the cPI (57.8° vs. 54.1°) and highlight the importance of considering pelvic rotation during radiographic assessments to improve clinical outcomes.
Objectives: The functional pelvic plane, which adopts the natural pelvic sagittal tilt in the supine position, is a good reference for determining the cup angle in total hip arthroplasty. However, hip flexion contracture may change pelvic tilt postoperatively by the release of contracture. This study investigated the influence of hip flexion contracture on pelvic sagittal tilt in the supine position.
View Article and Find Full Text PDFBackground: Cup orientation in THA in the supine, standing, and sitting positions is affected by pelvic sagittal tilt (PT). Patterns of PT shift between these positions may increase the risk of dislocation and edge loading. The PT has also been reported to change during the aging process; however, there is limited research regarding long-term changes in PT and PT shifts after THA.
View Article and Find Full Text PDFBackground: Osteonecrosis of the femoral head (ONFH) classification systems are based on the size, volume, and location of necrotic lesions. Often-but not always-ONFH results in femoral head collapse. Because acetabular coverage is associated with mechanical stress on the femoral head, it might also be associated with femoral head collapse in patients with ONFH.
View Article and Find Full Text PDFWhile accurate measurement of bone mineral density (BMD) is essential in the diagnosis of osteoporosis and in evaluating the treatment of osteoporosis, it is unclear how region of interest (ROI) settings affect measurement of BMD at the total proximal femur region. In this study, we performed a simulation analysis to clarify the effect on BMD measurement of changing the ROI using hip computed tomography (CT) images of 75 females (mean age, 62.4 years).
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