Osamu Kataoka

Lumbar Disc Herniation in Children and Adolescents: A Review of 70 Operated Cases and Their Minimum 5-year Follow-up Studies

Seventy cases of surgically documented herniated lumbar disc in children and adolescents were analyzed. Twenty-six of the 70 cases were followed at least five years postoperatively. The incidence of juvenile disc herniation in Japanese patients appears to be much higher than in Caucasians. Repeated trauma may be an important etiological factor of herniated lumbar disc in this age group. The history and physical findings in children and adolescents are not fundamentally different from those in the adult, although abnormal neurological findings are not common. Fiveyear follow-up studies suggest that interlaminal laminectomy without fusion is the best procedure when surgical treatment of herniated lumbar disc is necessary in children and adolescents.

Postoperative lumbar spinal instability occurring or progressing secondary to laminectomy.

The manifestations and pathomechanism of postoperative lumbar spinal instability, occurring or progressing secondary to laminectomy, was clarified by means of functional radiographic analysis in a series of 46 patients over 40 years of age. The relation between instability and the clinical symptoms also is discussed. In patients under 60 years of age, instability at the operated level tended to appear in cases of wide laminectomy more often than in cases of partial laminectomy. Occurrence or progress of instability seems to be promoted by resection of the posterior spinal elements rather than the disc. It is further considered that the postoperative aggravation of clinical symptoms may be influenced not only by instability, but also by the other factors.

Pathomechanism, pathogenesis, and results of treatment in cervical spondylotic myelopathy caused by dynamic canal stenosis

In this study, the pathomechanism and pathogenesis of dynamic canal stenosis caused by cervical instability in patients with cervical spondylotic myelopathy and the validity of the concept of instability are clarified by analyzing the results of treatment in 53 cases. In cases of cervical spondylotic myelopathy caused by dynamic canal stenosis, the authors found that the posterior slide of the vertebral body occurs as a result of degeneration in the cervical spine due to aging changes, and that the dynamic sagittal diameter of the spinal canal decreases with an increase of the degree of posterior slide. This is followed by gradual aggravation of the clinical symptoms. Continuous cervical traction was found to be the first choice of treatment. Surgical treatment is indicated in cases in which the traction was ineffective, or even when it was effective, in cases in which the Japanese Orthopaedic Association (JOA) score remained low or when there was a tendency toward rapid aggravation of symptoms. It was demonstrated that the shorter the duration of the myelopathy, the better the results of treatment obtained. A limit of the dynamic sagittal diameter of the spinal canal of 12 mm was considered as valid.

Occipitoatlantal and occipitoaxial hypermobility in Down syndrome.

Study Design In this study, the authors evaluated upper cervical spine in 75 children and adolescents with Down syndrome on the basis of lateral flexion-extension radiographs. Objective To assess occipitoatlantal motion and occipitoaxial motion in children and adolescents with Down syndrome compared with age-matched control subjects. Summary of Background Data Although previous studies have described a high prevalence of occipitoatlantal hypermobility in Down syndrome, there have been no comparisons with age-matched control subjects. Only a few reports have mentioned the physiologic relation between the occiput and axis other than basilar impression. Moreover, there have been no reports examining anteroposterior mobility in abnormal conditions. Methods Seventy-five children and adolescents with Down syndrome and 30 age-matched control subjects were examined. Lateral radiographs of the upper cervical spine in flexion and extension were taken, and anteroposterior translation of the occiput in relation to the atlas and axis was measured. Results Anteroposterior occipitoatlantal hypermobility was found to be present in children and adolescents with Down syndrome even when compared with age-matched control subjects. Occipitoaxial hypermobility was observed only when atlantoaxial instability was present. Conclusion In evaluating the upper cervical spine in Down syndrome, it is necessary to pay attention to the relation between the occiput, atlas, and axis.

Intradural lumbar disc herniation: report of three cases with a review of the literature

Intradural lumbar disc herniation (ILDH) is rare. Three new cases of this condition are reported, adding to the 70 previously documented cases. An incidence of ILDH in between 0.04 and 0.33 percent of lumbar disc protrusions has been reported. More than one third of ILDH were observed at L1-2 to L3-4 levels, while only a tenth of cases occurred at L5-S1. The mechanism of ILDH is not known with certainty. Adhesions between the ventral wall of the dura and posterior longitudinal ligament could act as a preconditioning factor. A diagnosis of ILDH may be made with difficulty, and it is seldom suspected preoperatively. Prompt surgery is necessary because the neurologic prognosis appears to be closely linked with preoperative duration of neurologic symptoms.

Spondylolysis of the axis. Report of four cases.

Spondylolysis or spondylolisthesis of the cervical spine, especially of the upper cervical spine, is very rare. The authors report four cases of spondylolysis of the axis and outline its roentgenographic features for differential diagnosis. The clinical course of the cases and the unvarying roentgenographic findings throughout the course strongly suggest that the lesion is congenital in origin.