Publications by authors named "Yuya Kawarai"
Diclofenac etalhyaluronate (DF-HA) sustained diclofenac release with the effects of hyaluronic acid (HA), offering long-term analgesia in osteoarthritis. In this study, the effects of DF-HA on pain improvement and osteoarthritis were evaluated in a rat knee monoiodoacetate-induced osteoarthritis model compared to HA. Eight rats per group had been injected with monoiodoacetate (2.
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- The study aimed to analyze how the alignment of the acetabular component in total hip arthroplasty (THA) can be optimized based on spinal deformities and stiffness to prevent mechanical complications.
- Researchers classified 169 patients waiting for THA into four groups based on their spinal characteristics and monitored cup alignment using fluoroscopy, as well as measuring dislocation rates over two years.
- Findings indicated that patients with normal spinal alignment and stiff spines showed significant differences in radiographic measurements, suggesting that considering spinopelvic parameters during surgery may help reduce the risk of dislocation after THA.
Article Synopsis
- - The study investigated changes in gene expression related to DNA methylation in animal models of hip osteoarthritis (OA), focusing on peripheral blood mononuclear cells and synovial tissues.
- - After treatment with monoiodoacetate, animals showed clear signs of hip OA, including changes in pain sensitivity and increased expression of certain DNA methylation-related genes in the hip's synovial tissue.
- - The findings suggest that induced OA leads to significant alterations in global DNA methylation, potentially influencing disease progression and pain perception.
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- The study evaluates a new imaging technique called MIXTURE, developed by Philips, which produces high-resolution T2 maps for diagnosing cervical radiculopathy.
- It compares T2 relaxation times and their variability using MIXTURE with another method, SHINKEI-Quant (S-Q), in both healthy participants and a patient with cervical disc herniation.
- Results show that MIXTURE provides significantly shorter T2 relaxation times and lower variability in measurements, indicating its potential for more accurate preoperative functional diagnosis of cervical nerve issues.
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- The study investigates the impact of the learning curve on the outcomes of the direct anterior approach (DAA) in total hip arthroplasty (THA), focusing on 5-year results following surgery.
- It involves 402 THA cases, comparing results from the first 50 surgeries by each surgeon during the learning phase against those from more experienced surgeons, with both groups showing a high implant survival rate of 99.2%.
- Findings suggest that while surgical time and blood loss improve with experience, both the short- and mid-term complication rates and clinical scores remain consistent, indicating the learning curve affects procedural efficiency but not overall patient outcomes.
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- This study investigates the time from diagnosis to surgery for osteonecrosis of the femoral head (ONFH) and factors affecting its severity among 2074 cases in Japan from 1997 to 2018.
- The median time to surgery was found to be 9 months, influenced by whether the patient used alcohol or corticosteroids, and the stage of joint destruction at diagnosis.
- The study highlights that a large proportion of patients remain untreated for extended periods, but surgery was performed within 9 months for more than half of the patients, indicating the disease's serious impact.
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- The study aimed to compare patient outcomes using expandable versus static interbody spacers during oblique lateral interbody fusion (OLIF) surgery, utilizing CT and MRI imaging for evaluations.
- A total of 35 patients with degenerative disc disease were analyzed, measuring factors like cage height, lordosis, pain levels, and radiologic changes both preoperatively and 6 months post-op.
- Results indicated that expandable spacers provided better clinical outcomes, including less cage subsidence, improved dural sac area, better correction of vertebral slippage, and reduced leg numbness compared to static spacers.
Background: Femoral neurovascular injury is a serious complication in a direct anterior approach (DAA) total hip arthroplasty. However, dynamic neurovascular bundle location changes during the approach were not examined. Thus, this study aimed to analyze the effects of leg position on the femoral neurovascular bundle location using magnetic resonance imaging (MRI).
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- Osteoarthritis (OA) is a common hip condition with two types: primary and secondary, with increasing cases of primary OA in Japan, leading to more total hip arthroplasties (THAs).
- A study analyzed 1,308 hips to explore how femoral head lateralization relates to bone structure in primary OA, classifying hips into two groups based on lateralization observed on radiographs.
- Key findings indicate that hips with lateralization (group L) showed significant differences in specific radiographic measurements compared to non-lateralized hips (group N), suggesting distinct characteristics linked to the geometry of the acetabulum and proximal femur.
Objective: We aimed to determine the prevalence and risk factors for osteonecrosis of the femoral head (ONFH) in a multicentre cohort of patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV).
Methods: One hundred and eighty-six AAV patients who underwent radiographs and MRI screening of bilateral hip joints at more than 6 months after initial remission induction therapy (RIT) were retrospectively assessed for the presence of ONFH.
Results: Among 186 AAV patients, 33 (18%) were diagnosed with ONFH.
Article Synopsis
- - The study tested the effects of a new pain-relieving drug, Diclofenac etalhyaluronate (DF-HA), on osteoarthritis in a rat model using monoiodoacetate injections to induce the condition.
- - Results showed that DF-HA significantly reduced pain sensitivity and inflammation markers in nerve tissues, but did not change the physical deformity of the joints as assessed through imaging and histology.
- - The conclusion highlights that while DF-HA is effective for alleviating osteoarthritic pain, it does not improve the structural damage in the joints.
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- Monoiodoacetate (MIA) is used in osteoarthritis research to find alternatives to joint replacement, but the optimal dose for hip OA models hasn't been extensively studied.
- The experiment involved administering varying doses of MIA (0.25, 0.5, 1.0, 2.0, 4.0 mg) to rats and monitoring osteoarthritis progression through radiographic and histological evaluations over 12 weeks.
- Results showed that higher MIA doses resulted in more severe OA changes, with significant effects observed as early as one week post-injection, suggesting that dosage is crucial for inducing appropriate OA models.
Introduction: Cemented femoral component design including its mechanical behavior in total hip arthroplasty (THA) has influenced the occurrence of postoperative periprosthetic femoral fracture (PPFF). The main aim of this study was to investigate the influence of the calcar collar and surface finish in the cemented femoral component on the risk of PPFF.
Materials And Methods: This retrospective review was undertaken of 1082 primary THAs in 912 patients using cemented femoral components followed for a minimum of five years (mean, 9.
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- Proximal femur fractures can be categorized as cervical or trochanteric, but how fall direction affects fracture type was examined through mechanical testing and finite element analysis (FEA).
- The study analyzed 26 femurs from cadavers under various simulated fall conditions to look for relationships between fracture types and factors like age and fall direction.
- Results indicated that fall direction significantly influenced fracture type, with posterolateral falls leading to more trochanteric fractures compared to lateral falls, while stress distribution in the femur varied with fall direction as well.
Objectives: The pain of hip osteoarthritis (OA) is generally recognized as nociceptive in origin because of the local pathology. However, some patients with OA experience a neuropathic pain component as an essential part of some nociplastic pain subtype. Here, we sought to examine the mechanism of chronic pain of symptomatic hip OA by the association of its distribution, complex pain mechanism screening, and the prevalence of lumbar spinal stenosis.
View Article and Find Full Text PDFWe investigated the analgesic effects of tramadol and the arthritic changes following tramadol administration in the rat hip osteoarthritis (OA) model using mono-iodoacetate (MIA). The right hip joints of male Sprague-Dawley rats (n = 5 rats/group) in the Sham group were injected with 25 μl of sterile saline and 1% of fluorogold (FG) retrograde neurotracer. In the MIA + Vehicle and MIA + Tramadol groups, FG and 25 μl of sterile saline with 0.
View Article and Find Full Text PDFBackground: In primary and revision total hip arthroplasty, to prevent perioperative complications, the prediction of the optimal implant size is essential. Using three-dimensional computed tomography-based postoperative evaluation software, we explored the accuracy and the precision of measurement of the size, alignment, and position of the prosthetic components after total hip arthroplasty.
Methods: Using postoperative evaluation software, the postoperative computed tomography data from 20 hips in 20 patients were evaluated.
Background Context: Chronic low back pain (LBP) is a multifactorial disorder with complex underlying mechanisms, including associations with intervertebral disc (IVD) degeneration in some individuals. It has been demonstrated that epigenetic processes are involved in the pathology of IVD degeneration. Epigenetics refers to several mechanisms, including DNA methylation, that have the ability to change gene expression without inducing any change in the underlying DNA sequence.
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- The study aimed to identify risk factors for developing radiolucent lines (RLLs) around the acetabular component in patients who underwent total hip arthroplasty (THA) using an interface bioactive bone cement technique, focusing on the first year post-surgery and longer-term impacts at five and ten years.
- A review of 980 primary cemented THAs revealed that 27.2% of patients exhibited RLLs one year after surgery, with specific factors like atrophic osteoarthritis and smaller head diameters significantly increasing the risk, while structural bone grafts and proper hip center location reduced it.
- Long-term analysis showed a high survival rate of acetabular components over ten years, with no
Introduction: A well-fixed cement-bone interface is a crucial factor for acetabular and femoral components in cemented total hip arthroplasty (THA). The aim of the present study was to evaluate the middle-term clinical and radiological results of fixing the acetabular component with an interface bioactive bone cement (IBBC) technique in primary cemented THA.
Materials And Methods: We undertook a retrospective review was undertaken of 193 primary cemented THAs in 174 patients using acetabular components cemented with an IBBC technique and followed for a minimum of 5 years (mean 8.
Introduction: Ceramic-on-ceramic (COC) total hip arthroplasty (THA) was developed to reduce wear debris, and consequently the occurrence of osteolysis and aseptic loosening. The purpose of the present study was to determine the incidence and natural history of noise including squeaking after COC THA, and to clarify whether clinical outcomes and any demographic and implant-related factors are associated with noise from these ceramic bearings.
Methods: This was a retrospective observational study of 137 primary COC THAs between 2004 and 2009 at our institute.
Proximal femoral fractures are common in elderly osteoporosis patients; however, its prevalence is clinically rare in hip fracture patients with hip osteoarthritis (OA). This study aimed to evaluate bone strength of the proximal femur with or without hip OA and proximal femoral fracture risk using computed tomography (CT)-based finite element analysis (FEA). A retrospective analysis was done on CT data of 20 patients who underwent total hip arthroplasty for unilateral hip OA.
View Article and Find Full Text PDFIntroduction: Little is known about the association between well-fixed polished tapered cemented stems (PTCS) implanted by the line-to-line technique and changes of stem migration, or the change of functional anteversion of the femur after total hip arthroplasty (THA).
Materials And Methods: This retrospective study included 422 two-stage bilateral primary THAs performed using PTCS implanted by the line-to-line technique. CT scans were made on both the target side (first postoperative CT) and on the contralateral side (second postoperative CT) 1 week postoperatively.
We investigated the efficacy of duloxetine on hyperalgesia, histopathological and radiographic findings, pain-related sensory innervation of dorsal-root ganglia (DRG), and spinal changes in a rat model of induced hip osteoarthritis (OA). The right hip joints of male Sprague-Dawley rats (n = 6 rats/group) in the Sham group were injected with 25 μl of sterile saline and 25 μl of sterile saline with 2 mg of monosodium iodoacetate (MIA) were injected to the MIA + Vehicle and MIA + Duloxetine groups. We injected duloxetine 20 mg/kg intraperitoneally in the MIA + Duloxetine group 28 days after injection, whereas rats in the MIA + Vehicle group were injected with 0.
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