Publications by authors named "Masashi Hirakawa"

Introduction: Open wedge distal tuberosity osteotomy (OWDTO) was the surgical treatment in which tibial tuberosity was attached proximal fragment to avoid an increase in patellofemoral joint pressure. The current paper reported a case of post-operative posterior aspect fracture of the tibia as a rare complication after OWDTO.

Case Report: A 52-year-old Asian man had been performing OWDTO for medial knee osteoarthritis.

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Introduction Intraoperative and postoperative bleeding in total knee arthroplasty (TKA) affects postoperative outcomes. Although the hemostatic effect of a flowable gelatin hemostatic matrix (FGHM) is known across several surgical fields, its effectiveness on TKA remains controversial. This study aimed to compare the amount of bleeding across three groups treated with different doses of FGHM in TKA.

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Introduction Optimal repair of the joint line (JL) in total knee arthroplasty (TKA) is critical for knee joint motion reconstruction and ligament balance. Identification of JL may be difficult, particularly in revision or primary cases of severe femoral condylar bone loss. We aimed to define the relationship between the epicondyles and the articular surface (AS) of the femur using computed tomography-based three-dimensional digital templating software.

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Introduction During total knee arthroplasty (TKA), also referred to as total knee replacement (TKR), patients may experience pain in the posterolateral knee. One possible cause is the impingement between the popliteus tendon and the femoral components. The purpose of this study was to analyze the posterolateral overhang of the femoral component using 3D template software.

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Article Synopsis
  • MCL pie-crusting can improve soft tissue balance during knee surgery but needs more research using finite element methods (FEM).
  • Three different FEM models of MCL pie-crusting were created: one as a single elastic body, one as multiple bundled elastic bodies, and one with adhesive components in the gaps.
  • Results showed that the model with aggregates of fibers and adhesive components (model C) was the most effective for analyzing MCL pie-crusting.
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Although gelatin-thrombin matrix sealants have been used successfully in other surgery types, their effect on reducing blood loss during single-level transforaminal lumbar interbody fusion is unclear. We thus examined the efficacy of gelatin-thrombin matrix sealants for reducing blood loss during such surgery. We analyzed 102 patients who underwent single-level transforaminal lumbar interbody fusion for lumbar degenerative disease.

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Although previous studies indicate that changes in cervical alignment after laminoplasty and dynamic factors influence surgical outcomes of cervical ossification of the posterior longitudinal ligament (OPLL), the relationship between the surgical outcomes, the distance between the kyphosis-line (K-line) and OPLL, and dynamic factors have not yet been quantitatively evaluated. The purpose of the present study was to analyze the relationship between ΔK-line distance and surgical outcomes in cases of laminoplasty for OPLL of the cervical spine. We retrospectively reviewed 46 consecutive patients (33 men and 13 women) with cervical OPLL who underwent laminoplasty.

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The present study is retrospective analysis of consecutively collected data. Lateral lumber interbody fusion (LLIF) is widely used in cases of adult spinal deformities. However, the corrective effects of LLIF cage insertion on the vertebral rotation deformity in the axial plane and the individual effects of LLIF and direct vertebral rotation (DVR) on rotational correction are unclear.

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Case: A 21-year-old man presented with knee pain secondary to tibial plateau malunion and an osteochondral defect 1 year after open reduction and initial fixation. Two-stage reconstruction with transplantation of a bulk heat-treated osteochondral allograft and an autologous chondrocyte implantation was performed.

Conclusion: This technique may be a good choice for large defects in the articular cartilage in cases of tibial plateau malunion.

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The aim of the present study was to investigate the effect of teriparatide on device-related vertebral osteopenia after single lumbar spinal interbody fusion and compare osteopenia in fused and nonfused spinal segments using Hounsfield unit (HU) values. The present study was a retrospective cohort study. We reviewed 68 consecutive patients (28 men and 40 women) who underwent single-segment (L4-5) transforaminal lumbar interbody fusion with cage and pedicle screw fixation.

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Background: For the treatment of bone sarcoma in the distal femur, wide-margin resection and knee reconstruction with tumor endoprosthesis are standard therapies. Extra-articular knee resection is required in cases of tumor invasion of the knee joint; however, the incidence of complications, such as aseptic loosening, prosthesis infection, and implant failure, is higher than that following intra-articular knee resection. To the best of our knowledge, there are three reports of patellar dislocations after replacement of a tumor endoprosthesis.

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This mechanical study was conducted with the shellcement interface in order to construct an acetabular metal shell, and to fix a polyethylene liner with bone cement. Six types of models were tested, with all cementations performed under similar conditions. The "lever out" test was conducted 3 times for each group in order to measure the dissociation strength.

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Equimolar mixtures of glymes and organic lithium salts are known to produce solvate ionic liquids, in which the stability of the [Li(glyme)] complex plays an important role in determining the ionic dynamics. Since these mixtures have attractive physicochemical properties for application as electrolytes, it is important to understand the dependence of the stability of the [Li(glyme)] complex on the ion dynamics. A series of microsecond molecular dynamics simulations has been conducted to investigate the dynamic properties of these solvate ionic liquids.

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Background: Postoperative knee flexion angle is one of the most important outcomes of total knee arthroplasty (TKA). Intraoperative ligament balancing may affect the postoperative range of motion of the knee. However, the relationship between intraoperative ligament balancing and postoperative flexion angle was still controversial.

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Purpose: It was hypothesised that implantation of a total knee prosthesis may change the size and shape of the joint gap. To test this hypothesis, a tensor device was used which was specifically designed to reproduce the conditions before and after implantation, including attachment of the polyethylene insert trial. This study aimed to compare the joint gaps before and after implantation of a total knee prosthesis using this new tensor device.

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Background: The standard for rotational alignment of the tibial component in total knee arthroplasty (TKA) remains unclear. Cases often require positioning of the tibial component, prioritizing adequate coverage of resected bone surface rather than alignment with the tibial rotational axis. We investigated tibial component position in TKA, prioritizing maximum coverage of resected bone surface, and evaluated the correlation with the tibial anteroposterior (AP) axis.

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The relationship between the joint gap before and after implantation in 259 knees during the total knee arthroplasty was investigated using a tensor device which can attach the polyethylene insert trial. Patients were divided into following 3 groups according to the joint gap balance before implantation (flexion joint gap--extension joint gap); group 1: >1mm; group 2: -1 to 1mm, and group 3: <-1mm. Joint gap after implantation was loose at 30°, 60°, 90°, and 120° of flexion in group 1 and 2, but loose only at 30° of flexion in group 3 (p<0.

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Background: Soft-tissue balancing of the knee is fundamental to the success of a total knee arthroplasty (TKA). In posterior-stabilized TKA, there is no stabilizer of the anterior-posterior translation in the midflexion range in which the cam-post mechanism does not engage yet. Therefore, instability in the midflexion range is suspected to occur in posterior-stabilized TKA.

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Purpose: The purpose of the study was to evaluate the entire course of ACL grafts on coronal oblique MR images, focusing on differences in graft morphology and graft-to-tunnel healing among single-bundle (SB), double-bundle (DB), and triple-bundle (TB) reconstructions.

Methods: Eighty-three patients underwent anatomical ACL reconstruction using the semitendinosus tendon. SB reconstruction was performed on 20 patients, DB on 29 patients, and TB on 34 patients.

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