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Morphological changes in the cervical spine were evaluated using radiography in 140 patients with cervical myelopathy who underwent expansive laminoplasty by sagittal splitting of the spinous process. We assessed the influence of these observed changes on the postoperative clinical results. The mean follow-up period was 33 +/- 19 months. Intervertebral body union occurred in 18%, and interlaminal union in 80% of the patients. The factors influencing the bony union in these were not identified. Bony union did not significantly influence the clinical results. There were changes in cervical alignment in 29 (21%) patients after the operation. Correlation between the spinal curvature and the clinical results was the strongest for the sigmoid-type curvature. The number of patients in whom preoperative ROM was maintained was only 8 (7%). The range of cervical spine motion decreased by approximately 50%, and there was no correlation with the clinical results. The surgical method described in the current study for compression myelopathy was associated with postoperative morphological changes and decreased ROM in the cervical spine, but nonetheless provided good postoperative results unless extreme morphological abnormalities occurred. This surgical technique was safe and gave satisfactory results in patients with preoperative morphological abnormalities in the cervical spine.

A spinal epidural hematoma may result from one of many causes, including coagulopathy, trauma, a vascular lesion, iatrogenesis, and spontaneous occurrence2,4,6,7,11,12. Groen and van Alphen7 reviewed the cases of 333 patients who had a spontaneous spinal epidural hematoma; they had excluded patients in whom the hematoma had occurred after a traumatic episode involving spinal dislocation or fracture, after epidural anethesia, after diagnostic lumbar puncture, after an operation, or in association with a tumor in the spinal canal. Of the 333 patients, forty (12 per cent) had a lumbar epidural hematoma. Overall, fifty-five (17 per cent) of the patients were younger than twenty years old, and only four (7 per cent) of these young patients had a spontaneous lumbar epidural hematoma. Boyd and Pear reported that a hematoma caudad to the level of the conus medullaris was more likely to be chronic because the spinal roots appear to tolerate pressure better than the spinal cord does. In a review of the literature, we found four cases of lumbar epidural hematoma in patients who were younger than twenty years old3,7,17,21, and we compared these cases with that of our patient. A chronic spinal epidural hematoma is rare in young patients; it occurred in only two of the patients, including ours. We report the case of a young patient who had a chronic lumbar epidural hematoma and spondylolysis at the third lumbar vertebra. The patient, a seventeen-year-old high-school student, had radicular pain in the left lower extremity when he was first seen by us in 1991. He was a rugby player (center prop position number three), and, in early December 1991, he had pain on the left side of the low back …

We prospectively investigated and compared the results from wire fixation and those from pedicle screw fixation for an unstable lumbar spine. Between April 1992 and July 1996, we surgically managed 44 cases of unstable lumbar spine using either wire fixation or pedicle screw fixation. Wire fixation was employed for 22 patients (11 male and 11 female, with a mean age at surgery of 51.1 years), and pedicle screw fixation was employed for 22 patients (8 male and 14 female, with a mean age at surgery of 57.1 years). The results showed no difference in % slip, slip-angle, frequency of bone union, or in frequency of instrument failure between those that had received wire fixation and those that had received pedicle screw fixation. In those with lumbar spondylolisthesis, the operative results were excellent or good in only 7 (53.8%) of 12 cases treated with wire fixation and in 13 (81.6%) of the 16 treated with pedicle screw fixation. In those with lumbar disc herniation or lumbar canal stenosis, there was no significant difference in the results between those that had been treated with wire fixation and those that had been treated with pedicle screw fixation.We concluded from these short term results that wire fixation was sufficient for an unstable spine with lumbar disc herniation or lumbar canal stenosis, while pedicle screw fixation was better than wire fixation for an unstable spine with lumbar spondylolisthesis.

We investigated the pathological changes and alterations in intradiscal pressure after an experimental intradiscal injection in the mature rabbit. Thirty intervertebral discs in 6 rabbits were used as controls, and normal pressures were measured. Chymopapain, 10% sodium chloride, or betamethasone were injected separately into 5 intervertebral discs of 9 rabbits. Rabbits were sacrificed at 1 week, 4 weeks, and at 12 weeks after the intradiscal drug injection. The intradiscal pressure changed depending on the degree of disc degeneration and if there was any regeneration. The chymopapain-injected intradiscal pressure decreased significantly at 4 weeks compared with the pressure at 1 week and at 12 weeks (p

The purpose of this experimental study was to investigate the effects of spinal external fixation in scoliosis. Two of four ribs on the right side of growing rabbits were partially resected. Between 4 and 6 weeks later, moderate right-convex thoracic scoliosis had developed. Then, in seven rabbits, a mini-Orthofix or fixano fixator was attached by Kischner wires to T9/10 and L1/2. The average Cobb angle was 27.1 degrees before external fixation, and was 13.6 degrees at initial correction just after attaching the fixator. In three of these, the fixators were removed at more than 8 weeks after the operation. Only slight progressive vertebral curvature was seen in these rabbits after removal of the fixator, with a relatively good effect of prophylaxis of progression compared to the controls. We propose that the effects of this spinal external fixation for scoliosis was due to correction of the axial rotation at the apical vertebra rather than to the traction force.

In recent years, many authors have reported that an extruded lumbar intervertebral disc was absorbed through phagocytosis and dehydration. However, absorption of an extruded cervical intervertebral disc has rarely been repoted. We have investigated the follow-up MRI of all 24 patients with cervical disc herniation seen between 1991 and 1995. Of these, 8 patients with radiculopathy and 7 with myelopathy had been treated nonoperatively, and a further 9 patients with severe myelopathy had undergone expansive laminoplasty. In follow-up MRI, a reduction in the size of the extruded disc was seen in 5 of the 15 nonoperative patients and in 8 of the 9 operative patients. The 9 operative patients showed a mean recovery rate of 68.4±15.2% (range from 44 to 90%) according to their JOA score. In the nonoperative group, recovery of symptoms was seen in all 5 patients with reduction, and in only 4 of 10 patients with nonreduction. The initial MRI of the 5 patients with reduction was taken between 2 and 7 weeks (mean 4 weeks) after onset, and between 1 month and 14 years (mean 13 months, not including the one at 14 years) after onset in the 10 patients with nonreduction. The initial MRI of the 9 operative patients was taken between 1 month and 6 years (mean 14 months after onset). The pathomechanism for disc reduction was concluded to have been the same as for lumbar disc herniation in the nonoperative patients. However, the pathomechnism in the operative patients was inconclusive and was likely to be different from that in the nonoperative patients.

The purpose of this study was to investigate experimentally the morphological changes of scoliosis. In 10 rabbits, underX-ray imaging two Kirshner wires were inserted into intervertebral discs at regular intervals, together with two parallel wires on the left side. In 9 of these 10 rabbits, right convex thoracolumbar or lumbar scoliosis was produced. In 3 rabbits, the K-wires were removed between 8 and 12 weeks after insertion and the scoliosis was found to be irreversible.However in the 4 rabbits, from which the wires wire removed at less than 8 weeks after the operation, the scoliosis was found to be reversible. In the other 2 rabbits, although the upper K-wire was loose after the operation, a scoliotic deformity remained. In this experimental scoliosis model, degenerative changes were seen in the facet cartilage on the apical concave side histomorphologically.

Since 1978, chemonucleolysis and percutaneous discectomy have been employed for treating dise herniation, with their efficacy recognized for some types of herniation.Recently, a new method of intradiscal vaporization using laser irradiation has been developed. We report our investigation into the experimental efficacy of this new method, particularly with respect to its effect on intradiscal pressure.We measured the effects both radiographically and histologically on intradiscal ablation in rabbits, and obtained successful ablation of the nucleus pulposus with a decrease in the intradiscal pressure.However, excess laser irradiation also caused ablation in the annulus, with carbonization, but with no adverse effects seen on the disc periphery or canal.

A three-month-old female baby was diagnosed by roentgenograms as having bilateral multifocal ossification of the os calcis. Five ossification centers in the bilateral calcaneus were recognized. However, at one year of age the roentgenograms showed only three ossification centers, with cleft separating on both sides the anterior third from the posterior two-thirds of the bone. At two years of age, the three ossification centers had coalesced into a single composite ossification center and the cleft at the calcaneus disappeared.

Quantitive Computed Tomography (QCT) is one of the most successful method in determining bone mineral content of the spine.Lumbar mineral contents of one hundred patients (thirty-one males and sixty-nine females) were determined by the QCT method.Following results were obtained.1) In the female patients, bone mineral content of the lumbar spine severely decreased to marginal value of abnormality, boundary of their anomeria.2) Bone mineral contents of the cases of trochanteric fractures were less than the cases of femoral neck fracture.3) The results of QCT method were related to the classification system on plain x-ray photographs.

Fifty-nine total hip replacements were performed for 56 patients since 1985 to 1989. The cases consist of of 9 males and 47 females. The age range was 36 to 94 years old with an average being 66 years old. We classified the cases into 4 groups according to methods of fixation of the acetabular cup and stem (cemented or non-cemented). These 4 groups were compared to each other about JOA score, roentgenographic findings, etc.There was no definite difference between cemented and non-cemented groups clinically.

We reviewed the results of operative treatment in 32 patients with lumbar disc herniation in adolesence. During 1991-1996 we operated on 18 patients (13 men, 5 women, mean age at surgery, 16.4 years) with percutaneous discectomy (PD); 14 patients (10 men, 4 women, mean 15.5 years) with open discectomy. The post operative results, were excellent or good in 11 of 18 patients (61.1%) with PD, and in 13 of 14 patients (92.5%) with open disectomy, respectively. The average period of recovery to playing sports was 1.75 months with PD, 2.90 months with open disectomy. One of the important things in surgical treatment of lumbar disk herniation in adolesence is the period of recovery to full sporthing activities. In this study, it is suggested that PD is the most useful treatment for lumbar disk herniation in adolesence.

A total of 47 patients with cervical myelopathy underwent double door laminoplasty. We examined the radiological changes and their local symptoms for any potential correlationship. The 47 patients involved 31 males and 16 females, with an average age of 61 years. Cervical back muscle area was measured by computed tomography. Local symptoms remained in 7 patients after the operation. These local symptoms did not correlate with ligament deviation nor the CT measurements of back muscle area.

We investigated the changes in pathology and intradiscal pressure after repeat intradiscal drug injection in the mature rabbit, Chymopahain (500pku/ml) or 10% hypertonic saline was injected into five lumbar intervertebral discs of 9 rabbits. The injection volume was 0.02ml/disc, and a repeat injection was performed 4 weeks after the first injection. Rabbits were sacrificed at 1 week, 4 weeks, and 8 weeks after the repeat injection. They were classified into 3 groups; the HH group received hypertonic saline twice, the HC group was first injected with hypertonic saline and with chymopapain at the second injection, and the CC group received chymopapain twice. The intradiscal pressure changed depending on the degree of disc degeneration and on any regeneration. When hypertonic saline was injected first (HH and HC groups), the degeneration in the disc was slight compared to when chymopapain was injected first (CC group), and the intradiscal pressure was further decreased by the second injection of hypertonic saline (HH group). In comparison, when chymopapain was injected first (CC group), marked degeneration and disc narrowing were observed with a marked decrease in pressure compared to when hypertonic saline was injected first (HH and HC groups). Following a second injection of chymopapain (CC group) there was further degeneration but there was no additional decrease in pressure. Disc regeneration was observed in the HH group, but not in the HC or CC groups.

The purpose of this study was to investigate the operative results and the problems for elderiy patients with cervical myelopathy. Sixty seven patients (65 years or older) were compared with another 140 patients (younger than 65 years). Pre-and post-operative JOA scores of the Young-group were significantly higher than in the Old-group. The frequency of achieving restoration in the cord in the Old-group was significantly lower than that in the Young-group, according to postoperative MRI. The most significat factor affecting the clinical results was the disease duration prior to surgery. We conclude that in elderly patients, it is neccessary to perform decompression surgery as soon as possible after onset of progressive myelopathy.

A 35-year-old healthy female patient sustained an ipsilateral intracapsular fracture of the femoral neck and fracture of the femoral shaft in a car accident. This was successfully treated by DHS fixation.Four and a half years after the operation, DHS was removed, and a new subcapital fracture of the femoral neck was found by X-ray one week after surgery. This was treated by bone grafting to the bone cavity by removal of the lag screw, followed by triangular crossed MK. multiple pinning for the subcapital fracture. Favorable clinical results were achieved.

Freeze-dried bone chips were implanted in 20 patients with defects after curettage of bone tumor. Patients were followed for 2 to 36 months. Diagnoses of the tumors were as follows: enchondroma (11 cases), solitary bone cyst (5 cases), aneurymal bone cyst (2 cases), and others. The evaluation of the result was made by new bone formation on roentgenogram and the immune response. All bone lesions were found to be remodelled to some degree within 7 months. And no immune response had occurred with the exception of a case showing fever-up.