Development and Achievement of Cervical Laminoplasty and Related Studies on Cervical Myelopathy.

Cervical laminoplasty (CL) is one of the surgical methods via the posterior approach for treating patients with multilevel affected cervical myelopathy (CM). The main purpose of CL is to decompress the cervical spinal cord by widening the narrowed spinal canal, combined with preserving the posterior anatomical structures to the degree possible and preserving the widened space stably. During the development and improvement of spine surgeries including CL, various studies on CM have progressed and useful achievements have been obtained: (1) posterior cervical spine fixation systems that can be used in combination with CL simultaneously have been developed; (2) various materials to stably maintain the enlarged spinal canal have been developed; (3) the main influential factors on the surgical results are the inner factors of the patients, such as the patient's age and the disease duration; (4) various surgical methods to preserve the function of the posterior cervical muscles have been tried to avoid postoperative kyphotic changes of the cervical spine; (5) postoperative complications, such as C5 palsy and axial pain, have been examined, and the countermeasures have been tried; (6) K-line on lateral X-ray films has been applied to evaluate the indication of CL in patients with CM due to ossification of the posterior longitudinal ligament (OPLL) preoperatively; and (7) the method and idea of CL have been adapted to surgeries at the thoracic and lumbar spine.

Postoperative C5 Palsy: Conjectured Causes and Effective Countermeasures.

Postoperative C5 palsy (C5 palsy) is defined as or aggravating muscle weakness mainly at the C5 region with slight or no sensory disturbance after cervical spine surgery. The features of C5 palsy are as follows: 1) one-half of patients are accompanied by sensory disturbance or intolerable pain at the C5 region; 2) 92% of patients have hemilateral palsy; 3) almost all palsy occurs within a week after surgery; 4) the incidence is almost the same between the anterior and posterior approaches to the cervical spine; 5) the prognosis is relatively good even in patients with severe muscle weakness. Even now, the precise causes of C5 palsy have not yet been revealed.

Surgical Treatment for Ossification of the Posterior Longitudinal Ligament (OPLL) at the Thoracic Spine: Usefulness of the Posterior Approach.

Various methods via anterior or posterior approach with or without spinal stabilization have been performed in accordance with the level and configuration of ossification of the posterior longitudinal ligament (OPLL) as the decompression surgery for thoracic myelopathy due to OPLL. Among them, anterior decompression at the middle thoracic level (T4/T5-T7/T8) is especially difficult to perform because of the special anatomical structures, where the spinal alignment is kyphotic and the thoracic cage containing circulatory-respiratory organs exist nearby. Of the anterior decompression procedures at this level, the posterior approach has various advantages compared to the anterior one.

Recent Surgical Methods of Double-door Laminoplasty of the Cervical Spine (Kurokawa's Method).

Introduction: Double-door laminoplasty (DDL) of the cervical spine (Kurokawa's method) was developed as one of posterior decompression surgical methods in the late 1970s and after then has been modified by adding various procedures such as the posterior muscle handling and the use of artificial spacers. There are three principles of DDL: First, to decompress the cervical spinal cord by central splitting of the spinous processes and laminae, preserving those lengths as much as possible and widening the spinal canal space symmetrically. Second, to maintain the widened spinal canal space steadily by fixing spacers made of hydroxyapatite the contour is almost the same as the widened space.

Ossification of the ligamentum flavum.

Ossification of the ligamentum flavum (OLF or OYL: ossification of the yellow ligament) usually occurs at the lower thoracic level and causes various types of neurological symptoms in accordance with the compression level of the spinal cord, the nerve roots, the conus medullaris, and the cauda equina. Although the greatest compression level to the nerve tissues is thought to be the most pathognomonic one, it is difficult to diagnose it in some cases. The effectiveness of conservative treatment such as applying a corset is small.

SEM analysis of microstructure of adhesive interface between resin cement and dentin treated with self-etching primer.

The purpose of this study was to examine the microstructure of the adhesive interface between resin cement and dentin treated with a self-etching primer by SEM in order to clarify the adhesive efficiencies of four self-etch type resin cement systems, Bistite II (BII), Linkmax (LM), Panavia F2.0 (PF), and ResiCem (RC) to dentin. The fluidity and inorganic filler content of these cements were also determined to examine their influences on the adhesion.

Two types of laminoplasty for cervical spondylotic myelopathy at multiple levels.

Based on the results from pathological analysis and computer simulations by means of finite element analysis that were reported before, the pathological changes of cervical spondylotic myelopathy (CSM) seem to begin at the posterolateral parts of the spinal cord, because the mechanical stress is mainly concentrated in these parts. With progression of the compression, the pathological changes become distributed to a wider area of the spinal cord. In patients with spinal canal stenosis, these changes spread to multiple levels of the cervical spine.

Comparison of enlargement of the spinal canal after cervical laminoplasty: open-door type and double-door type.

The purpose of this study was to compare the degree of enlargement of the spinal canal between two methods of cervical laminoplasty (open-door laminoplasty and double-door laminoplasty) and to determine their appropriate surgical indications based on the results. Tension-band laminoplasty (TBL, one method of open-door type) was performed in 33 patients and double-door laminoplasty (DDL) in 20 patients. The operation level ranged from C2 to C7 in all patients.

Occipitocervical fusion using a hook and rod system between cervical levels C2 and C3.

We aimed to evaluate the clinical utility and safety of the hook and rod method for occipitocervical fusion. Eleven consecutive patients (3 males, 8 females; 50-78 years old, average 63.8 years; 16-77 months follow-up, average 33.

[Using tension-band laminoplasty as a management for cervical ossification of posterior longitudinal ligament].

Objective: To evaluate the effectiveness of Tension-band Laminoplasty (TBL) as a management for cervical ossification of posterior longitudinal ligament (OPLL).

Methods: Forty-six patients with cervical OPLL and undergone TBL in our department were chosen for the present study, including 33 male and 13 female. The mean age was 59 years (36 - 77 years).

Surgical results and related factors for ossification of posterior longitudinal ligament of the thoracic spine: a multi-institutional retrospective study.

Study Design: Retrospective multi-institutional study

Objective: To describe the surgical outcomes in patients with ossification of the posterior longitudinal ligament in the thoracic spine (T-OPLL) and to clarify factors related to the surgical outcomes.

Summary Of Background Data: Detailed analyses of surgical outcomes of T-OPLL have been difficult because of the rarity of this disease.

Methods: The subjects were 154 patients with T-OPLL who were surgically treated at 34 institutions between 1998 and 2002.

Posterior atlantoaxial subluxation due to os odontoideum combined with cervical spondylotic myelopathy: a case report.

In patients with os odontoideum and posterior atlantoaxial subluxation are extremely rare. No reports have described posterior atlantoaxial subluxation associated with os odontoideum combined with cervical spondylotic canal stenosis, both of which require surgical treatment. We report one case of a 75-year-old female who underwent arthrodesis between the occiput and C3 using a hook-and-rod system and also a double-door laminoplasty from levels C3 to C7.

Traumatic anterior lumbosacral dislocation caused by hyperextension mechanism in preexisting L5 spondylolysis: a case report and a review of literature.

Of many reports referring to injury mechanism in anterior lumbosacral dislocation, there were none concerning hyperextension mechanism. We report a case of a 46-year-old man with preexisting L5 spondylolysis sustaining traumatic complete anterior lumbosacral dislocation. The operative findings, together with the radiologic findings, strongly suggested that the dislocation occurred by hyperextension mechanism.

A large-scale genetic association study of ossification of the posterior longitudinal ligament of the spine.

Research to date has identified several genes that are implicated in the etiology of ossification of the posterior longitudinal ligament of the spine (OPLL); however, their pathogenetic relevance remains obscure. The aim of this study is to identify susceptibility genes for OPLL through a large-scale case-control association study and to re-examine previously reported associations. A total of 109 single nucleotide polymorphisms (SNPs) in 35 candidate genes were genotyped for 711 sporadic OPLL patients and 896 controls.

Effectiveness of multiple-level decompression in laminoplasty and simultaneous C1 laminectomy for patients with cervical myelopathy.

A retrospective study to investigate the relationship between the surgical levels and decompression effects was performed in patients with cervical myelopathy who had undergone Tension-band laminoplasty (TBL) with/without simultaneous C1 laminectomy. One hundred and sixty-eight patients (115 males, 53 females; age: 31-80 years, average 58.9 years; follow-up period: 12-120 months, average 20 months) were divided into three groups according to the range of the surgical levels: seventy-two patients in group A underwent TBL at the C2-C7 levels with C1 laminectomy; 60 patients in group B underwent TBL at the C2-C7 levels; 36 patients in group C underwent TBL at the C3-C7 levels.

Occipitocervicothoracic fixation using a hook and rod system for patients with rheumatoid cervical spine.

Abstract We retrospectively examined the outcomes of occipitocervicothoracic fixation using a hook and rod system for rheumatoid patients with cervical myelopathy in which decompression of the spinal cord and spinal fusion were performed simultaneously at multiple levels. There were 10 female patients with rheumatoid arthritis (ages 51-77 years, average 62.8 years; follow-up period 6 months to 3 years and 9 months, average 2 years and 8 months).

Surgical anatomy of the nerves and muscles in the posterior cervical spine: a guide for avoiding inadvertent nerve injuries during the posterior approach.

Study Design: An anatomic study investigated the cervical dorsal rami and major cervical paravertebral muscles.

Objective: To provide a detailed description of the cervical dorsal rami and important paravertebral muscles as a way of avoiding inadvertent injuries during the posterior approach.

Summary Of Background Data: No detailed anatomic studies of the nerves and the muscles in the posterior neck useful for the posterior approach have been reported previously.

Anatomically correct reduction and fixation of a Tile C-1 type unilateral sacroiliac disruption using a rod and pedicle screw system between the S1 vertebra and the ilium: experimental and clinical case report.

We have developed a new surgical technique for the treatment of Tile C-1 type sacroiliac disruption. We tried this procedure first in a cadaveric specimen and then applied it to a clinical case. We used the Texas Scottish Rite Hospital (TSRH) rod and pedicle screw system to insert one screw into the S1 vertebra without using an image intensifier and the other screw into the bone marrow of the ilium from the posterosuperior iliac spine.