Morphogenesis of vertebral deformities in involutional osteoporosis. Age-related, three-dimensional trabecular structure.

STUDY DESIGN: The relation between the semiquantitative data of alteration in three-dimensional trabecular structure and deformities of the vertebral body was analyzed to clarify the morphogenesis of vertebral deformities in involutional osteoporosis. OBJECTIVES: To evaluate semiquantitatively the age-related alterations of the three-dimensional structure of trabeculae of the vertebral body and to clarify their relation to vertebral deformities in involutional osteoporosis. SUMMARY OF BACKGROUND DATA: Recent studies have shown that bone fractures and deformities in osteoporosis do not depend only on a reduced amount of bone tissue. There is no previous study on the relation between bone deformity and the alterations of the three-dimensional structure of trabeculae. METHODS: The second lumbar vertebrae were removed at autopsy from 25 patients who had no disease predisposing them to secondary osteoporosis and no severe vertebral deformities. The sections of the vertebral body were immersed in sodium hypochlorite solution to corrode the bone marrow. Atrophy of trabeculae and increased spacing between trabeculae were evaluated semiquantitatively under stereoscopic microscopy. The authors examined the relation between the semiquantitative data found in the autopsy vertebrae and the patterns and frequencies of each deformity of the second lumbar vertebrae in 99 patients with involutional osteoporosis. RESULTS: The most frequent vertebral deformity was wedge-shaped vertebrae with compression of the anterosuperior portion, and the alterations of the trabecular structure of the anterosuperior portion were severe and closely related to aging. Severe trabecular alterations with no relation to aging did not necessarily cause vertebral deformity. CONCLUSIONS: Trabecular abnormality, which is significantly correlated with aging, may be the necessary and sufficient condition for vertebral deformities in involutional osteoporosis.

Appropriate osteotomy site and number in limb lengthening.

The effects of the placement of osteotomy site on osteogenesis during monofocal and bifocal lengthening were investigated in 47 immature rabbits allocated to 4 groups according to osteotomy site: (1) monofocal in the proximal diaphysis; (2) monofocal in the distal diaphysis; (3) bifocal in the proximal and distal diaphysis; and (4) bifocal in the proximal diaphysis. The right tibia was distracted at an overall rate of 1.0 mm per day for 15 days. These groups were compared by assessment of soft radiograph findings and torsional strength 2 and 6 weeks after the end of distraction. Microangiography was done in 5 rabbits in the bifocal proximal and distal group. The proximal distracted site showed favorable bone regeneration compared with the distal site, and torsional strength was significantly greater in the proximal than in the distal osteotomy group. Less bone formation and lower torsional strength were observed in the bifocal proximal diaphysis group, with short intermediate segment, than that in the other bifocal group, with long intermediate segment. The nutrient artery in the latter group was preserved in the intermediate segment and reanastomosed to the metaphyseal arteries. These results suggest that the proximal diaphysis is more suitable for the osteotomy site than is the distal diaphysis. In a 2-level osteotomy, the inflow site of the nutrient artery should be included within the intermediate segment.

Survival rates of patients with metastatic spinal cancer after scintigraphic detection of abnormal radioactive accumulation.

STUDY DESIGN: This retrospective study analyzes the timing of spinal metastases and the survivability of patients with cancer after the detection of spinal metastases. OBJECTIVE: To evaluate the timing of spinal metastases in primary lesions and the survivability of patients with metastatic spinal tumors. SUMMARY OF BACKGROUND DATA: Few studies have analyzed the influence of primary lesions on survival rates of patients with metastatic spinal tumors. METHODS: This is a review of bone scintigraphy that was performed serially in patients with pulmonary cancer, breast cancer, prostatic cancer, cervical cancer, renal cancer, and gastric cancer from 1980 to 1991. To exclude false positive cases, the spinal areas showing abnormal accumulation on bone scintigrams were further examined by other methods of diagnostic imaging. The timing of scintigraphic detection of spinal metastases and the survivability were studied in 425 patients with spinal metastases. The survivability after spinal accumulation was determined by the Kaplan-Meier survival curve. RESULTS: The mean period, from the diagnosis of the primary lesion to the detection of abnormal accumulation in the spine, was shortest in pulmonary cancer (3.6 +/- 6.1 months), and it was longest in breast cancer (29.4 +/- 33.5 months). The 1-year survival rate was high in breast cancer (78%) and prostatic cancer (83%), and it was low in pulmonary cancer (22%) and gastric cancer (0%), respectively. The 6-month survival rate of gastric cancer was 15%. CONCLUSIONS: When managing metastatic spinal tumors, it is essential to select therapeutic methods based on adequate consideration of the features of primary lesions and the expected prognosis.

The origin and significance of spinal cord pulsation.

We studied the origin and mechanism of spinal cord pulsation in ten dogs in order to elucidate its clinical significance. Under general anesthesia, a 6 cm length of the animals' cervical spinal cord was exposed and the cerebrospinal fluid removed. The amplitude of spinal pulsation was then measured by means of ultrasonography in Mode M. The measurements were made after the spinal cord was cut: (1) on the cranial side; (2) on the cranial as well as caudal side, with the nerve roots and radicular arteries intact; (3) on both sides as in (2), which was then supplemented with the severance of the nerve roots and radicular arteries. It was demonstrated that, while the pulsation amplitude stood at an average of 88.0 microns before the surgical treatment, it rose to 455.0 microns in (1) and 274.8 microns in (2), but dropped to nearly zero in (3). The 5.2-fold increase in pulsation following the cordotomy on the cranial side was attributed to two factors: (1) the increased spinal mobility due to the cordotomy; (2) the elevation of blood pressure. The results of the three different degrees of spinal detachment suggested that spinal pulsation derived mainly from the radicular arteries and that its presence indicated low tonicity in the spinal cord and favorable circulation in the radicular arteries.

Factors related to the severity of myelopathy in atlantoaxial instability.

STUDY DESIGN: This study retrospectively reviewed the factors seemingly associated with neurologic symptoms in 46 patients with atlantoaxial instability. OBJECTIVES: This study revealed the most significant factors related to the severity of myelopathy and surgical prognosis of atlantoaxial instability. SUMMARY OF BACKGROUND DATA: Spinal morphometry has been reported to provide a useful means of predicting the prognosis of cervical spondylotic myelopathy after surgery. However, no quantitative and statistical evaluation of this method has been reported in atlantoaxial instability. Furthermore, there is a poor correlation between neurologic deficit and plain radiographic findings of atlantoaxial instability. METHODS: Four times of clinical information were investigated, six parameters were measured on radiographs, and two morphometric parameters of the spinal cord were measured. These parameters were used as predictor variables. Three multiple regression analyses were carried out, using pre- and post-treatment Japanese Orthopaedic Association scores as criteria variables. RESULTS: Pretreatment Japanese Orthopaedic Association scores were found to correlate with the spinal compression ratio, history of trauma, and the C1-C2 ratio. Postoperative Japanese Orthopaedic Association scores correlated with preoperative Japanese Orthopaedic Association scores, the C1-C2 ratio, and the compression ratio. The multiple coefficient of determination was 93.2%. The recovery rate correlated with the C1-C2 ratio and age. CONCLUSIONS: Neurologic symptoms were found to be closely related to the morphology of the spinal cord. Compression ratio and the C1-C2 ratio were found to be useful in understanding neurologic symptoms. The C1-C2 ratio seems to serve as an important predictor of the prognosis of atlantoaxial instability.

Lengthening of the forearm by callus distraction.

Ten patients aged 3 to 13 years (mean, 9 years and 7 months) underwent forearm lengthening by callotasis. The indications for lengthening were shortening and/or deformity of the forearm due to exostosis of the distal ulna in five cases, enchondroma of the distal ulna in one, growth disturbance after fracture of the distal radius in one, radial club hand in one, congenital amputation of the forearm in one and congenital dislocation of the radial head in one. Four had lengthening of the ulna, one of the radius and five of both the radius and the ulna. The average lengthening achieved was 30 mm. Complications encountered were pin track discharge in three cases, callus fracture in five, delayed consolidation of the callus in one and no callus formation in one. Review after 1 to 7 years follow-up (with a mean of 4 years and 9 months) showed satisfactory improvement in appearance and function especially in patients who had tumorous conditions or traumatic epiphyseal arrest.

Epiphyseal separation of the distal end of the humeral epiphysis: a follow-up note.

Twenty-one children with fracture-separations of the distal end of the humeral epiphysis were treated. Fifteen of the 21 children developed cubitus varus deformity after treatment. Thirteen children were treated at our hospital, and seven of these children developed cubitus varus deformity. Eight children were treated elsewhere initially and were referred to our institution after development of cubitus varus deformity. Nine patients underwent osteotomies for correction of cubitus varus deformities. Ages at injury ranged from 1-10 years. Fourteen patients were < 6 years of age. Fractures were classified according to Ogden; one was type IA, 16 were type IIA, and four were type IIC. Follow-up was from 10 months to 17 years. Most of the patients who were initially treated at our institution regained nearly normal function. All nine patients who were treated with closing wedge osteotomies regained nearly normal carrying angles. The carrying angles after treatment of the injury and osteotomy for the deformity did not change except in one patient.

Recurrent posterior dislocation of the head of the radius in post-traumatic cubitus varus.

Four patients who had injured the lower end of the humerus in childhood with resulting cubitus varus developed recurrent posterior dislocation of the head of the radius after further injury to the elbow. Dislocation occurred when the forearm was supinated and spontaneous reduction took place on pronation. At operation the lateral ligament complex was seen to be lax and elongated. After tightening of the ligament and with a supracondylar osteotomy of the humerus to correct the cubitus varus the recurrent dislocation was eliminated.

Tardy ulnar nerve palsy caused by cubitus varus deformity.

Fifteen patients with tardy ulnar nerve palsy caused by cubitus varus deformity were studied. All patients had a history of previous fracture of the humerus during childhood. The mean interval between fracture and onset of symptoms was 15 years. The severity of the palsy was classified as McGowan's grade I in 12 patients, grade II in 2 patients, and grade III in 1 patient. The mean carrying angle was -2 degrees before surgery. X-ray films showed a shallow ulnar nerve groove, a dysplastic humeral trochlea, medial shift of the ulna, and deformity of the medial epicondyle. The ulnar nerve was explored in all but one patient. Operative findings suggested that the main cause of the palsy was compression by a fibrous band running between the two heads of flexor carpi ulnaris. Surgical steps included release of the fibrous band in 14 patients with anterior subcutaneous transposition of the ulnar nerve in 5 of those patients. A corrective osteotomy was done in 11 patients who requested correction of the varus deformity. Traumatic cubitus varus deformity should be recognized as another cause of cubital tunnel syndrome.

Giant neurinoma occupying the holocervical and upper thoracic regions: case report.

We report a case with a giant spinal neurinoma located between the foramen magnum and fifth thoracic levels. The patient did not develop any neurologic symptoms until 16 years after the onset of hydrocephalus. The latter, successfully treated with a ventriculoperitoneal shunt, was associated with a cerebrospinal fluid protein of 400 mg/dL and was in all probability the first sign of the spinal cord tumor.

[A case of spinal glioblastoma with intracranial dissemination].

A 50-year-old male developed gait disturbance and bilateral sensory disturbance in territories below Th 11 level in February, 1990. On February 26, 1990, an intradural tumor was partially removed at Th 11-12 levels, which was histologically diagnosed as glioblastoma multiforme; followed by post-operative radiotherapy (40Gy to the tumor area). CT scan of the brain was unremarkable and he was discharged home as ambulatory in July, 1990. Gait disturbance, occasional headache and vomiting developed in June, 1991. MRI revealed multiple spinal cord tumors at Th 11-12 and L 2-3 levels, as well as multiple intracranial tumors in the cerebellum, cingulate gyrus, and sylvian fissure, all of which were thought to be located in the cerebrospinal fluid (CSF) space. VP shunt was performed for hydrocephalus. MRI taken 2 months after operation demonstrated diffuse subarachnoid dissemination and new spinal cord tumors at C 3-4 and Th 3-10 levels. Although pathology of the intracranial tumors was not confirmed, dissemination from the spinal tumor was strongly suggested by the evidence including the long interval after the spinal cord operation, the location of the multiple tumors in the CSF space, and the simultaneous intraspinal dissemination. Only 31 cases with intracranial dissemination from malignant spinal astrocytoma or glioblastoma have been reported, and, of these, most were located around the brainstem, cerebellum, and other regions bordering the CSF space. In malignant spinal cord tumor, every effort should be made to prevent CSF dissemination at operation or to detect it as early as possible thereafter. MRI was found to be the most effective method for evaluating CSF dissemination.

Endoscopic observation of the syrinx in Chiari malformation--case report.

The cervical syrinx cavity in a 27-year-old male with Chiari 1 malformation was inspected with a flexible small-caliber endoscope during syringo-subarachnoid shunting. A cleft was observed in the midline on the ventral wall of the cavity, from which blood vessels emerged and ran along the wall. Several strands accompanying the blood vessels passed from one wall to another. The endoscope was also used to evaluate whether any obstacles to the passage of a shunt tube were present in the subarachnoid space. Endoscopic observation of the syrinx cavity is helpful in performing the shunt operation.

Orthoses of ventilative plastics.

Plastics are extensively used as a material for orthoses. However, one remaining problem is the ventilation of the orthosis. This is a real problem in countries such as Japan, where it is hot and humid especially in summer. The authors have invented a new orthosis "POROPLAST", which is made of mesh plastic sheets, combined in a cross-like weave. These orthoses provide good ventilation and are very comfortable to wear. They have been fitted to seventy-four cases with satisfactory results.

[An intradural arachnoid cyst of the craniovertebral junction; a case report].

An intradural arachnoid cyst of the craniovertebral junction possibly of traumatic origin is reported. A 59-year-old man was admitted to our hospital with a 10-month history of progressive gait disturbance. He had a history of head injury with a fracture of the occipital bone. Myelography revealed pooling of the contrast medium in the posterior fossa and on the dorsal sides of C1 and C2. Metrizamide-enhanced computed tomography also showed pooling at the same level. Magnetic resonance imaging indicated a large cystic lesion at the craniovertebral junction. Craniectomy of the posterior fossa and laminectomy of C1, C2 and C3 were performed, and an intradural cyst with thickened dura and arachnoid was found. The cyst wall was opened to communicate with the subarachnoid space. Histological findings of the specimen showed that the arachnoid was thickened. There are over 130 reports of intradural arachnoid cyst of the spine, but those of traumatic origin are rare, and cysts located in the intracranial to spinal region are extremely rare.

The system and procedures of percutaneous intradiscal laser nucleotomy.

Since 1986, percutaneous intradiscal laser nucleotomy (PILN) has been studied in the authors' laser laboratory. The purpose of this report is to develop PILN as an alternative to chemonucleolysis and percutaneous discectomy, which are currently applied, and to establish a safe, easy, accurate and short-time therapy method for lumbar disc herniation. After laser irradiation, intradiscal pressures (IDP) decreased and the nucleus pulposus was gradually replaced with cartilaginous fibrous tissue. The evaluation of heat distribution with thermocouples and thermography was done to determine safe optimum irradiating conditions and to develop a new double-lumen needle and a bare quartz fiber. Neodymium-yttrium-aluminum-garnet (Nd-YAG) laser devices have been improved for easy and safe use, and a new tip type pressure transducer has been made for improved therapeutic results using this new method.

Correctional effect of Cotrel-Dubousset instrumentation for idiopathic scoliosis. An early follow-up study.

We reviewed the results of posterior spinal fusion with Cotrel-Dubousset Instrumentation for idiopathic scoliosis from fifty-six patients (sixty-five curves). The postoperative follow-up on them ranged six months to three years and seven months with an average of one year and nine months. From overall results, scoliotic curves were corrected by 36.5 from 60.3 degrees before operation to 23.8 degrees after operation on average. The rate of correction was 60.5%. On a sagittal plane, thoracic kyphosis improved from 22 to 35 degrees in the Cobb angle of T1-T12, to be more physiologically aligned. In addition, the derotational effect was elucidated by the measurement on pre- and post-operative CAT scan images in the apical vertebra, and on moiré topography. A reduction of the rib hump and the trunk inclination was also noted, but did not necessarily reflect the correctional gain of the scoliotic curvature. From the biomechanical point of view, the correction of rotational deformity by CD instrumentation is derived from a couple of the following movements: one is rotation of the apical vertebra around its axis and the other is revolutional displacement of that vertebra on a transverse plane (R-R movement).

Bone scintigraphy in patients with breast cancer, pulmonary cancer, uterine cervix cancer, and prostatic cancer. Statistical study of spinal accumulation cases.

This is a review of bone scintigraphy performed in patients with breast cancer, pulmonary cancer, uterine cervix cancer, and prostatic cancer from 1980 to 1985. The incidence of accumulation in the spine was 25.0% in breast cancer, 29.5% in lung cancer, 24.3% in cervical cancer, and 47.0% in prostatic cancer. The predominant location of the accumulation was the lumbar vertebra (68.9%), followed by the thoracic vertebra (45.0%), sacral vertebra (37.5%), and cervical vertebra (23.6%). The survivability after spinal accumulation was determined by the Kaplan-Meyer survival curve. The 1-year survival rate of breast cancer, pulmonary cancer, cervical cancer, and prostatic cancer was 88%, 19%, 74%, and 90%, respectively, the record of pulmonary cancer being significantly lower. Hence, in the treatment of patients with metastatic spinal tumors, the therapeutic method should be selected according to the underlying disease.