Masaki Mizuno

Midline Lumbar Fusion with Cortical Bone Trajectory Screw

A novel cortical bone trajectory (CBT) screw technique provides an alternative fixation technique for lumbar spine. Trajectory of CBT screw creates a caudo-cephalad path in sagittal plane and a medio-lateral path in axial plane, and engages cortical bone in the pedicle. The theoretical advantage is that it provides enhanced screw grip and interface strength. Midline lumbar fusion (MIDLF) is composed of posterior mid-line approach, microsurgical laminectomy, and CBT screw fixation. We adopted the MIDLF technique for lumbar spondylolisthesis. Advantages of this technique include that decompression and fusion are available in the same field, and it minimizes approach-related damages. To determine whether MIDLF with CBT screw is as effective as traditional approach and it is minimum invasive technique, we studied the clinical and radiological outcomes of MIDLF. Our results indicate that MIDLF is effective and minimum invasive technique. Evidence of effectiveness of MIDLF is that patients had good recovery score, and that CBT screw technique was safety in clinical and stable in radiological. MIDLF with CBT screw provides the surgeon with additional options for fixation. This technique is most likely to be useful for treating lumbar spondylolisthesis in combination with midline decompression and insertion of an interbody graft, such as the transforaminal lumbar interbody fusion or posterior lumbar interbody fusion techniques.

The significance of the cervical soft disc herniation in the ossification of the posterior longitudinal ligament.

The significance and role of cervical soft disc hernia in ossification of the posterior longitudinal ligament were investigated based on 54 surgical cases. The types of ossification of the posterior longitudinal ligament were divided into three sub-types: segmental, continuous, and mixed types. In the current series, there were 29 segmental type, 12 continuous type, and 13 mixed type. In the 29 segmental type, 23 patients had accompanying cervical disc hernias (79%). In the 12 continuous type, only 2 patients (17%), and in the 13 mixed type, 5 patients (33%), had accompanying disc hernias. According to the current study, an essential difference exists between the segmental type and the continuous or mixed types. In addition, the current result seems to indicate that, at least in the segmental type, disc herniation is not the promoting or initiating factor of ossification of the posterior longitudinal ligament, but that, in these cases, the fragility of the posterior longitudinal ligament may increase the chance of a disc hernia.

The Pitfalls in Surgical Management of Lumbar Canal Stenosis Associated With Rheumatoid Arthritis

There have been few clinical studies in the area of cervical spine that focused on surgery for treating degenerative lumbar disease in patients with rheumatoid arthritis (RA). High rates of wound complications and instrumentation failure have been reported more for RA than for non-RA patients, although clinical outcomes are similar between the two groups. Lumbar canal stenosis in RA is caused not only by degeneration but also by RA-related spondylitis, which includes facet arthritis and inflammation around the vertebral endplate. The pitfalls in surgical management of lumbar canal stenosis in RA patients are highlighted in this study. The study reviewed 12 patients with RA,who were surgically treated for lumbar canal stenosis. Two out of five patients with pulmonary fibrosis died of worsened pulmonary condition, even though there were no perioperative pulmonary complications. Two patients with pedicle screw fixation showed no instrumentation failure, but two patients with spinous process fixation needed re-operation or vertebral fracture. Surgical treatment for lumbar canal stenosis in RA patients needs to be individually adjusted. Preoperative assessments and treatments of pulmonary fibrosis and osteopenia are essential. Surgery for lumbar canal stenosis with RA should be deferred for patients with advanced pulmonary fibrosis because of its potential life-threatening risk. Fusion surgery is indicated only in patients with kyphosis or severe symptoms caused by intervertebral instability. Pedicle screw fixation with hydroxyapatite granules or sublaminar tape is recommended. Closer follow-up after surgery is necessary because of possible delayed wound infection, instrumentation failure, pathological fracture, and respiratory deterioration.

Onion-skin Hemifacial Dysesthesia Successfully Treated with C2–4 Anterior Cervical Decompression and Fusion: A Case Report

A 49-year-old man with cervical spondylosis at the C2–4 level presented with onion-skin hemifacial dysesthesia in addition to the right extremities. C2–4 anterior cervical decompression and fusion were performed. Onion-skin hemifacial pain disappeared after surgery. Although we cannot conclude the etiology of the pain was either referred pain or direct injury to the spinal trigeminal nucleus, cervical spondylosis at the middle cervical level has a possibility to present facial pain.