Facet Preserving Technique by En Bloc Flavectomy in Microscopic Posterior Decompression Surgery for Lumbar Spinal Stenosis: Semicircumferential Decompression (SCD).

Posterior decompression surgery which enlarges the spinal canal in cases with lumbar spinal stenosis is the most fundamental technique in spine surgery, but controversy still remains for the exact technique. Because nerve roots run under the ventral side on the superior articular process (SAP), achieving both facet joint preservation and nerve root decompression is problematic. In conventional laminotomies or laminectomies, medial facetectomies are performed to decompress the nerve root, but it is ideal to preserve the facet joints completely for preserving joint stability.

Morphology and clinical importance of epidural membrane and periradicular fibrous tissue in lumbar spinal stenosis.

Purpose: Compared to the ligamentum flavum (LF), morphology of the epidural membrane (EM) and the periradicular fibrous tissue (PRFT) has been largely ignored in studies of lumbar spinal stenosis (LSS). The aim of this prospective study was to elucidate the morphologies and clinical importance of the EM and PRFT in LSS.

Methods: Before starting this study, neural compressive EM (c-EM) and PRFT (c-PRFT) were defined as follows based on our microsurgical experience and a literature review.

Microscopic Posterior Transdural Resection of Cervical Retro-Odontoid Pseudotumors.

Retro-odontoid pseudotumors are noninflammatory masses formed posterior to the odontoid process. Because of their anatomy, the optimal surgical approach for resecting pseudotumors is controversial. Conventionally, 3 approaches are used: the anterior transoral approach, the lateral approach, and the posterior extradural approach; however, each approach has its limitations.

Long-term clinical results of microsurgical transdural discectomy with laminoplasty: follow-up results over 10 years.

Object: In this retrospective analysis the authors describe the long-term clinical results of microsurgical transdural discectomy with laminoplasty (MTDL) in patients with cervical disc herniation (CDH).

Methods: Thirty patients (21 males, 9 females; mean age at surgery 55 years) with CDH had surgical treatments consisting of MTDL between 1990 and 1998. All patients demonstrated signs or symptoms of cervical myelopathy and/or radiculomyelopathy.

Morphological features and clinical significance of epidural membrane in the cervical spine.

Study Design: A prospective clinical study.

Objective: To elucidate the histomorphological features and clinical significance of the epidural membrane (EM) in the cervical spine based on operative and histological findings.

Summary Of Background Data: The anatomical features of the EM have been mostly discussed on the basis of cadaver studies in the whole spine.

Relationship between the histological findings of spondylolytic tissue, instability of the loose lamina, and low back pain.

Study Design: We investigated the histomorphological features of the tissue occupying the spondylolytic defect (spondylolytic tissue), which was similar to ligament, and then graded the complete enthesis structure and the density of the fibrous portion. The relationships between the features, instability of the loose lamina against the affected vertebra, and the severity of low back pain were studied.

Objective: To elucidate the histomorphological features of spondylolytic tissue and the associations between the features, instability of the loose lamina, and low back pain.

Clinical characterizations and radiologic findings of pure foraminal-type cervical disc herniation: CT discography as a useful adjuvant in its precise diagnosis.

Study Design: A retrospective study of 15 cases of pure foraminal type cervical disc herniation (CDH) was performed.

Objectives: The objectives were to describe the clinical characteristics and to assess the radiologic findings.

Summary Of Background Data: Although foraminal lumbar disc herniation has been reported, pure foraminal-type CDH has not been fully elucidated.

The pathology of ligamentum flavum in degenerative lumbar disease.

Study Design: A pathologic study of the ligamentum flavum in degenerative lumbar disease.

Objectives: To elucidate the clinical significance of each pathologic finding of the ligamentum flavum.

Summary Of Background Data: In many reports, researchers observed the ligamentum flavum removed partially during surgery and did not evaluate the whole image of the ligamentum flavum.

Microsurgical transdural discectomy with laminoplasty: New treatment for paracentral and paracentroforaminal cervical disc herniation associated with spinal canal stenosis.

Study Design: A clinical study of the surgical procedure for cervical disc herniation was conducted.

Objectives: To describe microsurgical transdural discectomy with laminoplasty, and to assess the clinical outcome of this surgical technique.

Summary Of Background Data: A posterior approach for cervical disc herniation has been considered risky, and few reports on a transdural approach to this disorder have appeared in the past decade.