We reviewed 161 patients, from four centres in Switzerland, who had undergone posterior fusion of the upper cervical spine with transarticular screw fixation of the atlanto-axial joints. They were followed up for a mean 24.6 months. The vertebral artery and the medulla escaped injury and only 5.9% of the complications were directly related to the screws. The rate of pseudarthrosis was 0.6%

The results of surgery in 59 patients with Scheuermann's kyphosis are reported at an average follow-up of 56 months. These show that in skeletally immature patients, in whom the iliac apophysis has not yet fused to the body of the ilium, posterior fusion alone is adequate and is followed by little loss of correction. For skeletally mature patients combined anterior and posterior surgery is recommended. In all cases a period of pre-operative treatment is important. It is stressed that the indications for surgery are limited

1. A relatively simple method of occipito-cervical fusion using autogenous bone chips without internal fixation is described. 2. In patients with atlanto-axial subluxation posterior fusion from the occiput to the axis rather than from the atlas to the axis is more reliable and is preferred. Inclusion of the occiput adds no more than a few degrees to the restriction of movement that follows C. 1-2 fusion. 3. The indications for occipito-cervical fusion are discussed, particularly in relation to C. 1-2 instability in rheumatoid arthritis

We reviewed 20 adult patients with spondylolysis and isthmic spondylolisthesis an average of 10.5 years after treatment by anterior spinal fusion. Nineteen patients had excellent or satisfactory results. Ten of the patients were symptom-free at one year, and 15 were asymptomatic at final follow-up. Anterior spinal fusion can produce results comparable to those of posterior fusion with or without decompression. The results tend to improve with time in contrast to the known worsening of late results after posterior decompression without fusion

The effect of early fusion on growth of the spine has been studied in rabbits. Free periosteal grafts from the tibia were transplanted either posteriorly between the spinous and articular processes or postero-laterally between the articular and transverse processes. Sound bony fusion was achieved in both the thoracic and the lumbar spine. Spinal fusion caused local narrowing and wedging of the intervertebral spaces, followed by retardation of growth and wedging of the vertebrae. A progressive structural scoliosis developed after unilateral postero-lateral fusion and a lordosis developed after posterior fusion

We describe two patients with an atypical congenital kyphosis in which a hypoplastic lumbar vertebral body lay in the spinal canal because of short pedicles. There were no defects in the posterior elements, or any apparent instability of the facet joints. Both patients were treated successfully by anterior fusion to the levels immediately above and below the affected vertebra, and posterior fusion which extended one level more both proximally and distally. This gave progressive correction of the kyphotic deformity by allowing some continued anterior growth at the levels which had been fused posteriorly

1. Nineteen patients with classical rheumatoid arthritis complicated by severe subluxation of the cervical spine are reported. 2. Thirteen patients had atlanto-axial subluxation. This was the only level ofinvolvement in ten. 3. The next most frequent level to be involved was C.4-5. This occurred in five patients. 4. Eleven patients required surgery for symptoms or signs of spinal cord compression or vertebral artery insufficiency. 5. Operations included six posterior fusions, three anterior fusions and two laminectomies. 6. The differential diagnosis, the radiological findings, the indications for surgery and the results of treatment are discussed

In 17 patients (eleven males, six females) with Morquio-Brailsford syndrome (mucopolysaccharidosis IV) we have used onlay femoral and tibial autografts placed posteriorly and secured to the laminae of C1 and C2 to obtain satisfactory occipito-C1/C2 posterior fusion. They were immobilised postoperatively in a halo-plaster body jacket for four months. The age at operation varied between three and 28 years. Those with myelopathic symptoms of recent onset made some recovery, but severely myelopathic patients showed little or no recovery. We advise prophylactic occipitocervical fusion in these patients since the cartilaginous dens is not strong enough to ensure atlanto-axial mechanical stability

Five patients with classical Ehlers-Danlos syndrome developed severe spinal deformities. Two were shown to have type-VI collagen abnormalities. Three had a double structural scoliosis of the thoracic and lumbar regions, one had a single thoracic scoliosis and one had a thoracic kyphosis. The curves first developed before the age of four years, and were not controlled by bracing. Major corrective surgery with posterior fusion was performed at a mean age of 11 years 8 months. Excessive blood loss could be controlled and although wound haematoma and dehiscence were common, they did not provide major problems. The spinal fusions healed satisfactorily

Fifty patients with adolescent idiopathic scoliosis treated by posterior fusion and Harrington instrumentation augmented by a Cotrel bar or by sublaminal Luque wires were studied in a prospective trial to ascertain the need for postoperative bracing. Twenty-five patients wore a plaster brace postoperatively for six months, while 25 were managed without a brace. The mean loss of correction from the first standing postoperative radiograph to one obtained two years later was 7 degrees in the braced group, and 6.3 degrees in the unbraced group, the difference not being statistically significant. We conclude that postoperative bracing is unnecessary after augmented Harrington instrumentation

Seven patients treated in infancy by a lumbar theco-peritoneal shunt for idiopathic communicating hydrocephalus presented later in childhood after developing a characteristic orthopaedic syndrome. This included a severe, rigid and progressive lumbar hyperlordosis, severe bilateral restriction of straight leg raising and abnormalities of stance and gait. Four of the patients, who had severe hyperlordotic curves of over 90 degrees, required operations to correct their extreme deformity. The recommended method of correction is a three-stage procedure: first, anterior wedge resection osteotomies at several levels in the lumbar spine, then a period of "90-90" femoral traction, and finally a posterior fusion and stabilisation using Harrington instrumentation. The results were good, with few complications

We reviewed 40 extensive destructive vertebral lesions in 35 patients with established ankylosing spondylitis. Of these, 31 had presented with localised pain while three had a neurological deficit. The radiographs suggested ununited fractures through either ankylosed discs (37) or vertebral bodies (3). Corresponding fractures were seen in the posterior column in 34 cases. Sixteen patients with 18 lesions underwent anterior spinal fusion, and pseudarthrosis was consistently proven by histopathology. Two pseudarthroses healed in conservatively treated patients. Thirteen of the operated patients were followed for an average of 7 years 7 months. There were two cases of non-union and one required an additional posterior fusion; in the remainder fusion was sound

Sixty patients with congenital deformities of the spine were operated upon in the past fifteen years using a two-stage procedure. In the fifty patients with scoliosis half of the deformities were due to hemivertebrae and half to unilateral bars. The average correction of the deformity was 47 per cent. Early neurological signs observed in two patients with a diastematomyelia resolved. Of the ten patients with kyphosis nine had neurological signs of impending paraplegia and one was completely paraplegic before operation; all improved markedly. Posterior spinal fusion alone in the rapidly progressing congenital deformity may not prevent further progression, particularly in those cases iwth unilateral bars. Anterior resection of the vertebral body with later posterior fusion with Harrington instrumentation is safe and effective

1. At the present stage of our experience, when 150 patients have been analysed over a period of five years, the conclusion has been reached that anterior interbody fusion in the lower lumbar spine is a procedure which should be added to our surgical armamentarium for use in selected cases. 2. Patients suffering from chronic intervertebral disc degeneration whose main symptoms are recurrent incapacitating backache derive the most benefit from this procedure. 3. When used as a salvage operation in patients who have had previous unsuccessful laminectomy or posterior fusion, good results can be expected. 4. In patients with spondylolisthesis anterior interbody fusion should be confined to cases in which the vertebral bodies have not slipped forward more than one-third

High definition computed cervical myelograms have been made in flexion and extension in 13 patients with Morquio-Brailsford's disease. We observed that: 1) odontoid dysplasia was present in every case, with a hypoplastic dens and a detached distal portion which was not always ossified; 2) atlanto-axial instability was mild, and anterior atlanto-axial subluxation was absent in most cases; 3) severe spinal cord compression, when present, was due to anterior extradural soft-tissue thickening; 4) this compression was not relieved by flexing or extending the neck and was manifested early in life; 5) posterior occipitocervical fusion resulted in disappearance of the soft-tissue thickening and normalisation of subsequent development of the dens. We conclude that the severity of neurological involvement at the craniovertebral junction was determined by soft-tissue changes, not by the type of odontoid dysplasia nor by subluxation. Posterior occipitocervical fusion proved to be an effective treatment

We report four children aged two to nine years with traumatic tears of the transverse ligament of the atlas and atlanto-axial subluxation. This is extremely rare in this age group since trauma usually causes a skeletal rather than a ligamentous injury. The injuries resulted from falls or motor vehicle accidents, with considerable delay in diagnosis. Flexion radiographs showed atlas-dens intervals (ADI) of 6, 7, 8 and 13 mm; all four patients were treated by posterior fusion at C1-C2 after the failure of conservative treatment. In one child with quadriparesis and a fixed ADI of 13 mm, transoral anterior resection of the odontoid was performed before the fusion. Diagnosis of this traumatic lesion requires a high level of suspicion. Conservative treatment is likely to fail; surgical stabilisation is indicated

We present a study of 30 fusion operations in 26 rheumatoid arthritics with cervical spine instability. Atlanto-axial instability was present in 15, of whom 12 were fused; three had cord involvement and all made a partial or complete recovery following fusion. Cranial settling necessitated cranio-cervical fusion in four patients; all fused, and one with myelopathy was relieved. Subaxial instability required fusion in seven cases; two postoperative deaths followed the only two anterior interbody fusions. Posterior fusion was successful in the other five, with remission of neurological compromise in the three with myelopathy and one with radiculopathy. We conclude that neurological compromise in an unstable but mobile rheumatoid cervical spine can usually be brought to remission by immobilisation alone, so decompressive procedures are unnecessary in the first instance

1. Anterior transperitoneal lumbar fusion is a successful method of stabilising painful mechanical derangements which have not responded to the usual conservative measures. 2. The operation in this series was done mainly for backache; it should not be contemplated if there is definite evidence of nerve root compression, because sequestrated disc material cannot be removed from the spinal canal from the anterior route. 3. Careful technique has resulted in few complications attributable to the operation. 4. This method is sometimes thought to be inapplicable in cases of spondylolisthesis with a displacement of more than one-third. However, in this series we have seen the block type of graft used with a good measure of clinical and radiological success. 5. There is no doubt that for those patients who have had previous unsuccessful laminectomies or posterior fusions anterior interbody fusion offers an excellent prospect of recovery

We treated 36 patients with unilateral facet dislocations or fracture-dislocations of the cervical spine at the Mayo Clinic between 1975 and 1986. Adequate records were available for 34: ten patients were treated by open reduction and posterior fusion, and 24 by nonoperative management. Of these, 19 had halo traction followed by halo-thoracic immobilisation, four had a simple cervicothoracic orthosis, and one received no active treatment. Anatomical reduction was achieved more frequently in the operative group (60% compared with 25%). Nonoperative treatment was more likely to result in cervical translation on flexion/extension lateral radiographs, and in significant symptoms. Only 36% of the patients treated by halo traction achieved anatomical alignment; in 25% halo traction failed to achieve or maintain any degree of reduction. During halo-thoracic immobilisation, half of the patients lost some degree of reduction and patient satisfaction with the appliance was low. Open reduction and internal fixation of unilateral facet injuries gave better results. 6

The results of a study of the use of autograft versus allograft bone in the surgery of idiopathic adolescent scoliosis are presented. Two groups of patients, matched for age, sex, level and angle of curve, received bone grafts, 20 patients having autogenous bone from the iliac crest and the other 20 having donor bone from a bone bank. Both groups had otherwise identical posterior fusions and Harrington instrumentation. There was no difference between the two groups in a blind, radiographic assessment of bone graft mass at six months, nor in maintenance of the curve correction over the same period. No major operative complications nor failures of instrumentation were encountered. There was, however, a marked reduction in operative time and blood loss in the patients receiving donor bone and also a much lower incidence of late symptoms relating to the operative sites. We conclude that, even in the presence of adequate iliac crest, the use of bank bone is superior for grafting in idiopathic scoliosis surgery