Sinsuke Hukuda

Operations for cervical spondylotic myelopathy. A comparison of the results of anterior and posterior procedures

Over the past 19 years we have operated on 269 patients with myelopathy associated with cervical spondylosis. We report our results in 191 cases which we have followed up for 1 to 12 years (average 31 months). The clinical state before and after operation was recorded using the criteria of the Japanese Orthopaedic Association. Posterior operations gave better results than anterior for the more advanced myelopathies such as transverse lesions, the Brown-Séquard syndrome and the motor syndromes, but the brachialgia and cord syndrome and the central cord syndrome were satisfactorily treated by anterior operations. Of the three anterior and three posterior techniques used, no single one showed an overall superiority. A short duration of symptoms before operation was associated with better results, but these were not influenced by the age of the patients.

Immunohistochemical study of matrix metalloproteinase-3 and tissue inhibitor of metalloproteinase-1 human intervertebral discs.

Study Design. Immunohistologic staining of human intervertebral discs collected at the time of surgery (100 intervertebral discs from 80 patients) and 10 discs collected from 7 cadavers within 12 hours of death was performed using antimatrix metalloproteinase‐3 monoclonal antibody and antitissue inhibitor of metalloproteinase‐1 monoclonal antibody. Objectives. To examine the relationship between matrix destruction and staining for matrix metalloproteinase‐3 and tissue inhibitor of metalloproteinase‐1 in intervertebral disc degeneration. Summary of Background Data. Matrix metalloproteinase‐3, which decomposes aggregating proteoglycans, has attracted research attention as a substance contributing to matrix destruction in the articular cartilage and intervertebral disc. However, except for a few in vitro studies, the relationship between matrix destruction of the intervertebral disc and matrix metalloproteinase‐3 has been little studied. Methods. Immunohistologic staining was performed to examine the relationship between matrix metalloproteinase‐3 and tissue inhibitor of metalloproteinase‐1 in the intervertebral disc, and the relationship of these two agents to magnetic resonance imaging, radiographic, and surgical findings. Results. Those cases testing positive for matrix metalloproteinase‐3 and negative for tissue inhibitor of metalloproteinase‐1 accounted for most of the surgical specimens. The matrix metalloproteinase‐3‐positive cell ratio was significantly correlated with the magnetic resonance imaging grade of intervertebral disc degeneration, and the matrix metalloproteinase‐3‐positive cell ratio observed in prolapsed lumbar intervertebral discs was significantly higher than that in nonprolapsed discs. In cervical intervertebral discs, the matrix metalloproteinase‐3‐positive cell ratio and staining of cartilaginous endplate were correlated with the size of osteophyte formation. Conclusions. These findings suggested that intervertebral disc degeneration is caused by disturbance in the equilibrium of matrix metalloproteinase‐3 and tissue inhibitor of metalloproteinase‐1, and that matrix metalloproteinase‐3 contributes to degeneration of the cartilaginous endplate.

Anterior cervical plate used in degenerative disease can maintain cervical lordosis.

The aim of this study was to show whether anterior cervical plate stabilization is able to maintain cervical lordosis or not when used for cervical degenerative disease. Thirty cases that underwent anterior fusion at multiple levels without cervical plating before 1986 were compared with 44 cases treated with cervical plating since 1986. Changes in the alignment of the total cervical spine and of the fused segment were studied in both groups. Collapse of the grafted bone, which was observed in 9 of 30 cases in the nonplate group, was not observed in the plate group. Alignment of the cervical spine was corrected and well maintained in the plated group, compared with the nonplate group. Anterior cervical plate stabilization could maintain the normal alignment of the cervical spine damaged by degenerative processes, whereas anterior cervical fusion without plating could not.

MRI findings in intramuscular lipomas

Abstract Objective. To investigate the spectrum of magnetic resonance (MR) findings of intramuscular lipoma. Design and patients. A retrospective review of 17 consecutive cases of intramuscular lipoma examined with MR imaging was undertaken. Features assessed included the size and margin of the mass; the homogeneity of the contents, including the presence or absence of intermingled muscle fibers; whether the mass was uninodular or multinodular; and the presence of linear structures between and within the tumor nodules. Three well-differentiated liposarcomas and one dedifferentiated liposarcoma associated with lipoma-like components were also studied to allow a comparison of the benign and malignant lesions. Results. The diameter of the intramuscular lipomas varied from less than 3 cm to more than 10 cm. Ten of the intramuscular lipomas were homogeneous but the remaining seven were inhomogeneous with intermingled muscle fibers within the mass. The intramuscular lipomas were well defined in 12 cases, and infiltrative in five. In one case the margin of the lesion showed prominent infiltration of the surrounding muscle tissue. Of the 17 cases of intramuscular lipoma, 15 were composed of a single nodule, whereas three of four cases of liposarcoma were composed of multinodular masses. Conclusion. The MR findings of intramuscular lipoma varied from a small, single and homogeneous mass identical to ordinary (superficial) lipoma, to a large, inhomogeneous lesion with an infiltrative margin. The presence of infiltrative margins and intermingled muscle fibers in intramuscular lipoma indicates a benign lesion rather than malignancy. In addition, uninodularity of the mass is helpful in differentiating intramuscular lipoma from well-differentiated liposarcoma.

Clinical outcomes of cervical spinal cord injuries without radiographic evidence of trauma

We investigated 33 cervical spinal cord injury patients (25 males and eight females) without bony injury. Patients whose neurologic recovery had reached a plateau and who had evidence on imaging of persistent spinal cord compression were considered candidates for surgical decompression. When imaging did not show spinal cord compression or patients were maintaining a good neurologic recovery from the early days after injury, we pursued conservative treatment. Age at injury varied from 20 to 76 years (mean, 55.6). Average follow-up was 31 months. Twelve patients were treated conservatively (Group 1). Groups 2 and 3 had surgery. Group 2 (14 cases) had multi-level compression of spinal cord due to pre-existing cervical spine conditions such as ossification of posterior longitudinal ligament, cervical canal stenosis, and cervical spondylosis. Group 3 (7 cases) patients existed single-level compression of spinal cord by cervical disc herniations or spondylosis. We evaluated clinical results according to the Frankel classification, the American Spinal Injury Association (ASIA) scales and Japanese Orthopaedic Association (JOA) scores. Overall improvement of JOA and ASIA scores after treatment was 56.3±35.5% and 67.1±38.0%, respectively. Patients in Group 1 showed very good recovery after conservative treatment, with improvement of JOA and ASIA scores being 70.4±40.2% and 77.4±34.2%, respectively. The average interval between injury and operation was 4.3±4.4 months. The improvement of the surgically treated patients (Groups 2 and 3) in JOA and ASIA score was 48.2±30.7% and 61.2±39.6% respectively. We obtained good neurological recovery after operation, with significantly more improvement in Group 3 than in Group 2. No significant neurologic recovery had occurred preoperatively in these groups. In such patients operative intervention is essential for neurologic recovery.

Dually innervating nociceptive networks in the rat lumbar posterior longitudinal ligaments.

Study Design. The present study investigated the distribution of sensory and autonomic nerves to the posterior longitudinal ligament of the rat lumbar vertebra. Objective. The results were analyzed to provide a new insight into the pathogenesis of low back pain. Summary of Background Data. Previous studies that have descriptively reported on posterior longitudinal ligament innervation have attributed important roles to the sinuvertebral nerve as an output of nociceptive sensation. Meanwhile, development of immunohistochemistry has made it possible to identify numerous neurotransmitters, and thus various suggested pathophysiologic roles of the nerve fibers in the posterior longitudinal ligament. However, such microscopic identification of the nerve fibers has not been able to reveal comprehensive distributions of the various fibers, which are presumed to be derived from the sinuvertebral nerve. Methods. Rat posterior longitudinal ligaments of whole thickness was immunohistochemically stained for calcitonin gene-related peptide and tyrosine hydroxylase, which have been considered markers of nociceptive and noradrenergic fibers, respectively. Light-microscopic and electron-microscopic observation was reinforced with another experimental study in which resection of the dorsal root ganglia induced characteristic denervation patterns to the rat posterior longitudinal ligament. Results. The present study revealed that the lumbar PLL was dually innervated by two distinctive systems of nociceptive fibers. One of the systems was polysegmentally innervated and closely associated with autonomic innervation, whereas the other was unisegmentally innervated and not associated with autonomic fibers. Conclusion. Pathogenesis of low back pain can be better understood if the presence of the two distinctive nerve systems innervating the posterior longitudinal ligament is taken into account.

Efferent targets of osseous CGRP-immunoreactive nerve fiber before and after bone destruction in adjuvant arthritic rat : An ultramorphological study on their terminal-target relations

We report the ultramorphological characterization of the terminal‐target relation of sensory peptidergic nerve fibers in healthy and diseased osseous tissues. Bone tissue sections were immunoelectronmicroscopically investigated for calcitonin gene‐related peptide (CGRP), a neuropeptide widely distributed in sensory peptidergic fibers. Ultramorphological relation of the osseous CGRP‐immunoreactive (ir) nerve terminals and their target cells was comparatively analyzed using healthy, arthritic, and postarthritic bone specimens from control and adjuvant‐induced arthritic rats. Terminal‐like profiles of the osseous CGRP‐ir axons were evidenced in direct contact with the metaphyseal osteoblasts and osteoclasts of the control animals. Terminal‐like profiles were also noted in the vicinity of the periosteal lining cells. Nonterminal‐like profiles did not make intimate spatial relation to the cells/structures surrounding the nerve. Osseous CGRP‐ir terminals and axons, which are either uncovered or thinly ensheathed by the supportive tissues, were extensively degenerated in adjuvant‐induced infiltration, whereas larger fibers were relatively resistant. Numerous CGRP‐ir axons with distinctive features reinnervated the postarthritic, ossifying periosteum. CGRP‐ir axons appeared to reinnervate the eroded surface of metaphyseal bone and cartilage as early as the recruited osteoblasts resume osteogenesis in the postarthritic metaphysis. The observed terminal‐target relations in the healthy and diseased bone tissues give an ultramorphological basis for the putative trophic, modulatory actions of CGRP innervation of the bone cells.

Sex discrepancy in the canal/body ratio of the cervical spine implicating the prevalence of cervical myelopathy in men

Study Design. A radiographic analysis of the cervical spine in healthy young adults. Objectives. To investigate the size correlations among the vertebral height, the anteroposterior diameter of the vertebral body, and the anteroposterior diameter of the spinal canal and to investigate the sex discrepancy of the canal/body ratio. Summary of Background Data. Narrow spinal canal, large vertebral body, and male gender have been thought to be risk factors for cervical myelopathy. However, the association among those risk factors has been seldom analyzed. Methods. The height and the anteroposterior diameter of the vertebral body as well as the anteroposterior diameter of the spinal canal were measured on the lateral radiographs of healthy young adults (105 men and 114 women) using a distance-measuring tool of computer software. The canal/body ratio was compared between men and women. Results. The height and the anteroposterior diameter of the vertebral body were both larger in males than in females throughout C3–C7, but the anteroposterior diameter of the spinal canal was similar for both sexes. The height of the vertebral body was not correlated with the spinal canal size at any measured segment in both sexes, whereas the anteroposterior diameter of the vertebral body was significantly correlated with the size of the spinal canal in males but not in females. The canal/body ratio was significantly larger in women than in men. Conclusions. A significantly small canal/body ratio in men may implicate the male prevalence of cervical myelopathy.

Association of oestrogen receptor gene polymorphisms with age at onset of rheumatoid arthritis

OBJECTIVE In view of the possible role of oestrogens in the pathogenesis of rheumatoid arthritis (RA), this study investigated the association between oestrogen receptor (OR) gene polymorphisms and RA. METHODS Pvu II and Xba I restriction fragment length polymorphisms of the OR gene were analysed in 70 male and 240 female patients with RA, and in 300 male and 350 female controls. The absence or presence of restriction sites were represented as P, p (Pvu II ) or X, x (Xba I ). The distribution of OR genotypes was compared between the RA and control subjects by sex. RA patients were divided into subgroups according to their OR genotypes, then the age at onset, seropositivity, and rheumatoid nodule positivity were compared between the subgroups. RESULTS The OR genotype frequency of distribution did not have significant differences between the male RA and male controls nor between the female RA and female controls. In women with RA, there was a significant difference of age at onset between the subgroups (uncorrected p=0.047, corrected p=0.94). Female patients with the OR genotype PPxx (homozygote of Px) tended to have developed RA at a younger age, whereas those with PPXX and ppxx (lack of Px haplotype) developed RA at an older age. In men with RA, there was no association between the OR genotype and age at onset. In seropositivity and rheumatoid nodule positivity, there was no significant difference between subgroups for either sex. CONCLUSIONS Some variants of the OR gene are related to the onset of RA in women in certain age periods, suggesting the role of the interaction between the OR gene and serum concentrations of oestrogen at the onset of the disease.

The Effect of Constant Direct Electrical Current on Intrinsic Healing in the Flexor Tendon in Vitro An ultrastructural study of differing attitudes in epitenon cells and tenocytes

Light and electron microscopy were performed in a study of the effects of electrical stimulation upon the reparative processes in flexor tendons cultured in vitro. After one or two weeks of incubation, the unstimulated control tendons were covered with fibroblastic surface cells, thought to have originated from the epitenon. In contrast, the tendons subjected to electrical stimulation had no proliferation of the epitenon cells in the surface layer. The results indicate that electrical currents of low amperage suppress adhesion-causing synovial proliferation in the epitenon and promote active collagen synthesis in the tenocytes. This suggests the potential value of electrical stimulation in the control of adhesion formation after flexor tendon repair.