Publications by authors named "Yoshihide Yanai"

Article Synopsis
  • - The study aimed to evaluate the effectiveness of the long cortical bone trajectory (CBT) technique in achieving lumbar spinal fusion and to identify factors that affect the time taken for fusion among patients undergoing this surgery for degenerative spondylolisthesis.
  • - A total of 167 patients were analyzed, with results showing a high bone fusion rate of 95.8% by the last follow-up, averaging a fusion time of about 16.6 months post-surgery, but found no significant impact from specific surgical techniques on fusion times.
  • - Key independent factors affecting the time to fusion included patient age, sex (females took longer), and BMI, highlighting the importance of these demographic variables over technical procedural choices.
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Study Design: This study adopted a cross-sectional study design.

Purpose: This study was designed to investigate the effects of bone cross-link bridging on fracture mechanism and surgical outcomes in vertebral fractures using the maximum number of vertebral bodies with bony bridges between adjacent vertebrae without interruption (maxVB).

Overview Of Literature: The complex interplay of bone density and bone bridging in the elderly can complicate vertebral fractures, necessitating a better understanding of fracture mechanics.

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Background: No study has assessed the incidence or predictors of postoperative shoulder imbalance (PSI) in patients with Lenke type 5C adolescent idiopathic scoliosis (AIS) who underwent selective anterior spinal fusion (ASF). This study evaluated the incidence and predictors of shoulder imbalance after selective ASF for Lenke type 5C AIS.

Methods: In total, 62 patients with Lenke type 5C AIS (4 men and 58 women, mean age at surgery of 15.

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Introduction: Vertebral slip reduction has been recommended in arthrodesis for lumbar degenerative spondylolisthesis (LDS) to achieve balanced spinal alignment and bone fusion. However, what determines the degree of slip reduction using cortical bone trajectory technique for lumbar pedicle screw insertion is yet to be determined. Thus, in this study, we aim to investigate the slip reduction capacity using cortical bone trajectory (CBT) technique and to identify factors affecting the slip reduction rate.

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Background: Iatrogenic pseudomeningocele incidence after lumbar surgery is 0.068%-2%, and most lumbar pseudomeningoceles are smaller than 5 cm; however, in rare cases, "giant" pseudomeningoceles greater than 8 cm in size may develop. Normal pressure hydrocephalus (NPH) is another rare condition in which the ventricles expand despite the presence of normal intracranial pressure.

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Background: The bicortical or tricortical fixation technique with purchase into the anterior sacral wall or promontory has been recommended to achieve rigid sacral pedicle screw fixation, which carries the potential risk of neurovascular injuries. The penetrating endplate screw (PES) technique was proposed as an alternative screw trajectory to facilitate both strong fixation and safety. However, there has been no report on the practical significance of using the PES technique.

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Study Design: Retrospective comparative study.

Objective: The aim of this study was to evaluate the changes in global spinal sagittal alignment (GSSA) following selective anterior spinal fusion (ASF) in patients with Lenke type 5 adolescent idiopathic scoliosis (AIS).

Summary Of Background Data: Few studies have assessed the changes in postoperative GSSA, including cervical, thoracic, and lumbosacral sagittal alignment in AIS patients with major thoracolumbar/lumbar (TL/L) curve who underwent selective ASF.

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Objective: Contrary to original cortical bone trajectory (CBT), "long CBT" directed more anteriorly in the vertebral body has recently been recommended because of improved screw fixation and load sharing within the vertebra. However, to the authors' knowledge there has been no report on the clinical significance of the screw length and screw insertion depth used with the long CBT technique. The aim of the present study was to investigate the influence of the screw insertion depth in the vertebra on lumbar spinal fusion using the CBT technique.

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Background: The cortical bone trajectory (CBT) technique has developed as an alternative to the traditional pedicle screw fixation technique due to its minimum invasiveness for screw insertion and rigid fixation for posterior lumbar interbody fusion (PLIF). However, the factors contributing to bone union after CBT-PLIF is a controversial subject. The aim of this study was to investigate factors important to bone union after CBT-PLIF.

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Background: The sufficiency of screw anchoring is a critical factor for achieving successful spinal fusion; however, no reliable method for predicting pedicle screw fixation has been established. Recently, Hounsfield units (HU) obtained from computed tomography (CT) was developed as a new reliable tool to determine the bone quality. The purpose of the present study was to demonstrate the utility of regional HU measurement of the screw trajectory to predict the primary and long-term fixation strength of pedicle screws.

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