Trendelenburg's test of function of the hip joint was first reported before radiology was available. At least four methods of performing it have since been described in the literature. We examined 50 normal subjects and 103 people with disorders affecting either the spine or the hip, in order to determine the different responses that occurred when they were asked to stand on one leg. This has enabled us to define a standard method of performing the Trendelenburg test, and to interpret the test as a method of assessing hip abductor function. The major pitfalls that result in misinterpretation, or false-positive responses, are pain, lack of cooperation from the patient, and impingement between the rib cage and the iliac crest. False-negative responses result from the patient using muscles above and below the pelvis, and from leaning beyond the hip on the standing side

A new technique for the transthoracic removal of a prolapsed intervertebral disc in the mid or lower thoracic spine is described. Investigations before operation include thoracic myelography, selective spinal angiography and CT scanning. Image intensification is used at operation to check the level of the prolapse. A tunnel in the coronal plane (vertebrotomy) is made through the posterolateral part of the disc and the adjacent vertebral bodies, to reach the spinal canal at the site of the prolapse. This gives good exposure and enables gentle removal of the disc prolapse and any associated osteophytes, under direct vision without need for retraction or pressure on the dura or spinal cord. Spinal stability is not compromised, and the blood supply of the cord is not disturbed. Five consecutive patients are reported, including one in whom the disc prolapse was calcified and had herniated into the spinal cord. All were treated successfully

A clinical, cadaveric, biomechanical and radiological investigation of the pathogenesis of idiopathic scoliosis indicates that biplanar asymmetry is the essential lesion. Many normal children have coronal plane asymmetry (an inconsequential lateral curvature of the spine), and certainly all have vertebral body asymmetry in the transverse plane, but when median plane asymmetry (flattening or more usually reversal of the normal thoracic kyphosis at the apex of the scoliosis) is superimposed during growth, a progressive idiopathic scoliosis occurs. Idiopathic kyphoscoliosis cannot and does not exist, from the mildest cases in the community to the most severe cases in pathology museums. Median plane asymmetry is crucial for progression and the lateral profile of the spine must be carefully scrutinised. Increased anterior vertebral height at the apex of the curve with posterior end-plate irregularity characterises the median plane asymmetry and suggests that idiopathic scoliosis is the reverse of Scheuermann's disease

An electrophysiological system for monitoring the spinal cord during operations for scoliosis is described. During the development of the technique the recording of cortical somatosensory evoked potentials from the scalp and spinal somatosensory evoked potentials from the laminae or spines was superseded by the positioning of recording electrodes in the epidural space cephalad to the area to be fused. All recordings were made in response to stimulation of the posterior tibial nerve at the knee. Results in 138 patients are presented and the findings in three patients who exhibited neurological deficits after operation are described. It is concluded that spinal somatosensory evoked potentials are sensitive to minor spinal cord impairment, possible due to ischaemia, and that these changes may be reversed when the cause is quickly remedied. The monitoring system interferes minimally with anaesthetic and surgical procedures and is now performed as a routine

Entire human cadaveric cervical spines with the basiocciput were subjected to load in a compression apparatus to simulate the clinical situation of forward dislocation. The movements were recorded by lateral cineradiography. Vertical load was measured by a potentiometric transmitter synchronised with each frame of the cineradiograph. The lower part of the spine was flexed and fixed, and the upper extended and free to move forward. Vertical compression then produced bilateral dislocation of the facets without fracture. If lateral tilt or axial rotation occurred as well, a unilateral dislocation was produced. The maximum vertical load was only 145 kilograms, and coincided with the rupture of the posterior ligament and capsule and the stripping of the anterior longitudinal ligament, but this occurred before dislocation. The low vertical load indicates a peculiar vulnerabiity of the cervical spine in this position and correlates well with the minor trauma often seen in association with forward dislocation

1. A forty-nine-year-old man had a chondrosarcoma arising from the body of the seventh thoracic vertebra. The tumour protruded into the mediastinum and also into the spinal canal where it displaced the spinal cord. 2. At operation all the seventh thoracic vertebra and parts of the sixth and eighth were removed together with the tumour. The thoracic spine was reconstructed by inserting two iliac bone-blocks between the cut bodies of the sixth and eighth vertebrae and by wiring two strong "A. O." plates to the transverse processes of the third to the sixth and the eighth to the tenth vertebrae. 3. The patient was nursed in a plaster-of-Paris bed for three and a half months. 4. One year and three months after operation, the patient was walking and well, with no signs of recurrence or metastasis. Radiographs showed that a block-vertebra had been created from the iliac grafts and the two cut vertebrae

1. The clinical experience of fourteen cases of traumatic spondylolisthesis of the axis is described. 2. Evidence is presented which suggests that vertical compression and extension forces are frequently involved. 3. Treatment is based on recognition of the deforming force and its extent. 4. Primary treatment of unstable lesions by the coronally placed bone dowel of Barbour allows early stabilisation and long-term security. 5. The increased antero-posterior diameter of the axis explains the low incidence of spinal cord damage. 6. Skull traction is considered illogical in that it runs parallel in effect to the most deadly form of judicial hanging. 7. Secondary stability following injury may allow continuing force to fracture the spine at other levels. 8. The paradox of an extension injury between the second and third cervical vertebrae and a "flexion" injury at a lower level is discussed

Spondylolisthesis without a defect in the neural arch, the "pseudo-spondylolisthesis" of Junghanns, usually affects the fourth lumbar vertebra. The essential lesion is an increase in the angle between tile inferior facets and the pedicles which allows subluxation at the inferior joints. The forward displacement averages less than one centimetre. It commonly produces a clinical picture of backache and sciatica, but may present with. a "drop foot," and in unusual instances compression of the cauda euluina may occur. Patients seen in the early stages without signs of nerve root compression are best treated by localised spinal fusion. Late fusion may afford no relief because of secondary changes in the spine, but these patients obtain some benefit from a corset. Laminectomy is indicated for severe symptoms in patients who show signs of nerve root compression; it should be followed by spinal fusion

In a prospective trial we performed MRI of the spine and hind brain in 31 patients with scoliosis of onset between the ages of four and 12 years. In eight patients (26%) there was a significant neuroanatomical abnormality; there were six cases of Chiari-1 malformation associated with a syrinx, one isolated Chiari-1 malformation and one astrocytoma of the cervical spine. Four of these patients had left-sided curves. There were no clinical features which could reliably identify those patients with abnormalities on MRI. In particular, the unilateral absence of abdominal reflexes was found to be non-specific (1 of 8 of patients with neuroanatomical abnormalities (12.5%) v 2 of 23 with normal scans (8.7%)). In view of the established risks of surgical correction of scoliosis in the presence of undecompressed syringomyelia and the possible improvement that may follow decompression of the foramen magnum, we feel that MRI of all patients with scoliosis of juvenile onset should be obligatory

Aims

The aim of this study was to evaluate the accuracy of implant placement when using robotic assistance during total hip arthroplasty (THA).

We studied MR images of the spine in a consecutive series of 100 patients with acute compression of the spinal cord due to metastases. All patients had documented neurological deficit and histologically proven carcinoma. MRI was used to localise bony metastatic involvement and soft-tissue impingement of the cord. A systematic method of documenting metastatic involvement is described. A total of 43 patients had compression at multiple levels; 160 vertebral levels were studied. In 120 vertebrae (75%), anterior, lateral and posterior bony elements were involved. Soft-tissue impingement of the spinal cord often involved more than one quadrant of its circumference. In 69 vertebrae (43%) there was concomitant anterior and posterior compression. Isolated involvement of a vertebral body was observed in only six vertebrae (3.8%). We have shown that in most cases of acute compression of the spinal cord due to metastases there is coexisting involvement of both anterior and posterior structures

Discitis is uncommon in children and presents in different ways at different ages. It is most difficult to diagnose in the uncommunicative toddler of one to three years of age. We present 11 consecutive cases. The non-specific clinical features included refusal to walk (63%), back pain (27%), inability to flex the lower back (50%) and a loss of lumbar lordosis (40%). Laboratory tests were unhelpful and cultures of blood and disc tissue were negative. MRI reduces the diagnostic delay and may help to avoid the requirement for a biopsy. In 75% of cases it demonstrated a paravertebral inflammatory mass, which helped to determine the duration of the oral therapy given after initial intravenous antibiotics. At a mean follow-up of 21 months (10 to 40), all the spines were mobile and the patients free from pain. Radiological fusion occurred in 20% and was predictable after two years. At follow-up, MRI showed variable appearances: changes in the vertebral body usually resolved at 24 months and recovery of the disc was seen after 34 months

Twelve adult patients with confirmed tuberculosis of the atlanto-axial spine are presented and a classification proposed. Stage I has minimal ligamentous or bone destruction and no displacement of C1 on C2; the suggested treatment is transoral biopsy and decompression followed by an orthosis. Stage II has ligamentous disruption and minimal bone destruction but anterior displacement of C1 on C2; treatment involves transoral biopsy and decompression, reduction by halo traction, then a posterior C1-2 fusion. Stage III has marked ligamentous and bone destruction with displacement of C1 forward on C2; the suggested treatment is transoral biopsy and decompression, reduction by halo traction, then fusion from the occiput to C2 or C3. One patient died before treatment started; all the others have gone on to solid union with resolution of any neurological deficit. There has been no evidence of reactivation of disease over an average follow-up of 36 months

A survey was conducted to document the results of bracing and spinal fusion for scoliosis associated with osteogenesis imperfecta. Observations were made of 121 patients who underwent treatment by bracing or spinal fusion and who had been treated by 51 orthopaedic surgeons in 14 countries. The average curve before bracing measured 43 degrees. The braces were ineffective in stopping progression even in small curves. We were unable to determine whether braces slowed the rate of progression of curvature. The average age at fusion was 15 years 7 months, the average curve before operation measured 74 degrees, and the average correction was 36 per cent. The high incidence of complications was related to the size of the curve before spinal fusion, the use of Harrington instrumentation, and the presence of associated kyphosis. In the absence of pseudarthrosis or kyphosis, late bending of the fused spine did not seem to occur

Thirty-four patients wtih fibrodysplasia (syn., myositis) ossificans progressiva are described. Marked delay in diagnosis was usual, but all had characteristic skeletal malformations and ectopic ossification. The clinical features included: four types of malformation of the big toe, reduction defects of all digits, deafness, baldness of the scalp, and mental retardation. Progression of disability was erratic in all, but severe restriction of movement of the shoulder and spine was usual by the age of 10 years; the hips were usually involved by the age of 20 years; and most patients were confined to a chair by the age of 30 years. Exacerbating factors included trauma to the muscles, biopsy of the lumps, operations to excise ectopic bone, intramuscular injections, careless venepuncture and dental therapy. Progression of disability did not appear to be influenced by any form of medical treatment and therefore management of the patients must concentrate on the avoidance of exacerbating factors

1. The results of 243 thoracoplasty operations are discussed. It was found that scoliosis developed in over 99 per cent of cases and that the curve was convex towards the side of operation. The angle of curvature correlated closely with the number of ribs removed. 2. If the head, neck and tubercle of the rib and the transverse process of the corresponding vertebra were all removed the degree of scoliosis was increased, whereas if a thoracoplasty was performed with apicolysis and embedding of the scapula the spinal deformity was less. Possible explanations for these phenomena are discussed. 3. No evidence was found to support the theory of causation by imbalance between the paired "pneumatic cylinders" (lungs and thoracic cage) supporting the thoracic spine. 4. The scoliosis was found to progress for many years; some factors influencing this course are discussed. 5. No correlation was found between the age of the patient at the time of thoracoplasty and the degree of subsequent scoliosis, but severe spinal deformity can arise even in older adults

1. Thirty-five children suffering from a mild illness with narrowing of an intervertebral disc have been studied. 2. Backache was the presenting symptom in only a small proportion of children, vague aching in the legs being almost as common at the onset. 3. Stiffness of the affected part of the spine is often present, but there may be no abnormal signs in the back. 4. Radiographs reveal a narrowed disc space with adjacent bony changes. There is usually progressive narrowing of the disc space which may go on to fusion of the affected vertebrae. Less commonly there is reconstitution of the affected disc. 5. The symptoms and signs quickly subside with immobilisation in recumbency and this treatment should be continued until the blood sedimentation rate returns to normal. 6. Adults who have suffered from discitis in childhood are probably more prone to develop backache. 7. The etiology remains uncertain

Everywhere I visited, both in England and in other parts of Europe, I met with wonderful hospitality and friendliness. Generally our common language was English, and I felt thoroughly ashamed of my poor efforts at speaking other languages. During my tour in England, France, Germany, Austria, Italy, Denmark, Norway and Sweden I heard many new ideas propounded, and have seen many new and different methods of treatment. In particular I have been able to compare thoughts on such subjects as tuberculosis of the spine, congenital dislocation of the hip, osteoarthritis of the hip, scoliosis, many aspects of trauma, Perthes' disease, hand surgery, poliomyelitis, paraplegia, the treatment of cerebral palsy, rehabilitation of patients suffering from all kinds of orthopaedic disabilities, and surgical appliances. I am very grateful indeed to the British Orthopaedic Association for making this six-months' tour possible

We classified fixed pelvic obliquity in patients after poliomyelitis into two major types according to the level of the pelvis relative to the short leg. Each type was then divided into four subtypes according to the direction and severity of the scoliosis. In 46 patients with type-I deformity the pelvis was lower and in nine with type II it was higher on the short-leg side. Subtype-A deformity was a straight spine with a compensatory angulation at the lower lumbar level, mainly at L4-L5, subtype B was a mild scoliosis with the convexity to the short-leg side, subtype C was a mild scoliosis with the convexity opposite the short-leg side, and subtype D was a moderate to severe paralytic scoliosis with the convexity to the short-leg side in type I and to the opposite side in type II. A combination of surgical procedures improved the obliquity in most patients. These included lumbodorsal fasciotomy, abductor fasciotomy and stabilisation of the hip by triple innominate osteotomy with or without transiliac lengthening. In patients with type ID or type IID appropriate spinal fusion was usually necessary