A review was performed of 86 cases of infantile idiopathic scoliosis treated between 1962 and 1979. The single primary curves were classified as resolving, stable, progressive with a low rib--vertebra angle difference (RVAD) and progressive with a high RVAD. Two single primary curves subsequently developed a second curve and 17 were double when first diagnosed. Prognosis was difficult to establish before the age of five years. Only 18 per cent of curves showing progression beyond 50 degrees reached that point before the age of four. Conversely, if a scoliosis of 50 degrees or more was present before the age of four it always progressed. A more favourable outcome was indicated by male sex, a left-sided curve, a low initial curve measurement, an RVAD of less than 20 degrees in the initial radiograph, and the onset of scoliosis in the first year of life.

The association between spondylolisthesis and scoliosis was studied in 84 patients who presented during a 30-year period with symptomatic spondylolisthesis. The incidence of scoliosis was 42 per cent, the majority of cases being lumbar or thoracolumbar curves of less than 15 degrees. The incidence was highest in the group of patients with spondylolisthesis at L4--5 where all except one had scoliosis. Scoliosis was present in 47 per cent of patients with dysplastic spondylolisthesis at the lumbosacral junction; in this group, the incidence of scoliosis was greater where the displacement exceeded 25 per cent. The lowest incidence (25 per cent) was found in the group with isthmic spondylolisthesis at the lumbosacral junction. There appeared to be no relationship between excessive lumbar lordosis or tightness of the hamstrings and scoliosis.

This retrospective study assesses the complications affecting the cervical spine after halo-pelvic traction in 83 patients who were followed up for a minimum of five years. Forty-four patients (53 per cent) had significant cervical complications such as radiological degenerative changes, avascular necrosis of the dens, loss of movement, pain or spontaneous fusion. The most important predisposing factors were a long period in the halo-pelvic apparatus, tuberculous kyphosis, stiffness of the spinal deformity and an age of 15 years or more at the time of application.

Thirteen patients, aged 7 to 45 years, have been treated for atypical forms of spinal tuberculosis at the Neurological Centres at Benghazi and Lahore. All presented with signs and symptoms of compression of the spinal cord or cauda equina, ranging from paraesthesiae and increasing weakness to paraplegia and loss of sphincter control. None of them showed visible or palpable spinal deformity nor the typical radiographic appearance of destruction of the intervertebral disc and the two adjoining vertebral bodies. These atypical cases fell into two well-defined groups: those with involvement of the neural arch only, with associated intraspinal cold abscesses, and those with involvement of a single vertebral body, resulting in its collapse and a radiographic appearance similar to that in secondary carcinoma of the vertebral body. The correct treatment in these two groups was diametrically opposed. Tuberculous disease of the neural arch was best traced by laminectomy; concertina collapse of a single vertebral body required cost-transversectomy and resection of the transverse process, the pedicle, and the portion of the vertebral body that was encroaching on the spinal canal.

The occurrence of "windswept deformity" in the legs of otherwise healthy African children in the second or third year of life is illustrated by three typical case histories. The usual causes of epiphysial abnormality were absent in these and other similar patients seen recently in central Nigeria. It is suggested that an unrecognised hereditary dysplasia of bone, possibly of local geographical distribution and associated with a phase of epiphysial instability due to rapid growth, might underlie the sudden onset of this striking deformity.

The survivorship of total hip replacements in patients operated on at the Royal National Orthopaedic Hospital has been analysed using standard actuarial methods. Between 1963 and 1972 173 metal-on-metal prostheses of various developmental designs were inserted. Between 1969 and 1972 248 prostheses of one design using a metal femoral component and plastic cup were used. The patients were surveyed retrospectively and for each the actual follow-up period was determined as well as the eventual outcome. The criterion of "survival" was that the prosthesis was still in situ and all such prostheses were regarded as "survivors", regardless of whether the patients experienced pain or loss of function. The survivorship was then determined by constructing life tables. The results indicate that for metal-on-metal prostheses the overall probability of survival was only 53 per cent after 11 years and the average annual probability of removal, irrespective of cause, was 5.5 per cent. The results were better for metal-on-plastic prostheses with figures of 88 per cent after eight years and 1.5 per cent respectively. For both prostheses the predominant reason for failure was loosening and the annual rate of removal for loosening increased as the follow-up time increased, suggesting that loosening was a wearing out process. The advantages of the survivorship method of analysis as compared with conventional methods are discussed.

This paper presents a prospective trial carried out using the Monk "soft top" endoprosthesis in 33 patients. Two years after operation 70 per cent of the remaining patients had pain. A biomechanical and histopathological analysis of the endoprosthesis and the surrounding tissue, obtained from a further two patients at the time of revision, is presented. It is concluded that the prosthesis has inherent design faults which result in excessive wear of the polyethylene component. The wear debris produced stimulates a prolific fibrous tissue reaction which is associated with progressive clinical deterioration.

In a consecutive series of 87 operations for knee replacement prospective observations were made of the pattern of articular destruction in the form of a triangle of erosion or osteophyte formation, which is seen on the medial femoral condyle, sometimes with an associated strip on the lateral femoral condyle. These areas represent the surfaces which are normally in contact with the anterior horns of the menisci when the knee is fully extended. The lesions in question were found only in association with a flexion contracture in 84 out of the 87 cases.

The intermetatarsophalangeal bursa was investigated by dissection, radiography and injection. In the web spaces between the second and third and the third and fourth digits the bursa lies superior to the transverse metatarsal ligament but projects distally to it, closely applied to the neurovascular bundle. Tissue from the web spaces of patients with classical Morton's metatarsalgia often shows lymphocytic infiltration, with additional fibrinoid necrosis of the bursal wall. It is suggested that inflammatory changes in this bursa could account for the pathological and histological findings in this condition. The bursa in the most lateral web space does not extend beyond the ligament and is not in contact with the neurovascular bundle, which may explain the rarity of symptoms in this space.

Seventy-two Mitchell distal metatarsal osteotomies for hallux valgus performed over a period of 10 years have been reviewed. Sixty-six (92 per cent) were graded as excellent or good. Retrospective radiographic analysis of 29 of these cases showed that the operation had reduced the intermetatarsal angles to within normal anatomical limits. No patient experienced a worsening of symptoms as a result of the operation.

A high stress fracture of the fibula which occurred in 48 out of a class of 120 recruits doing a difficult jumping exercise is described. No more were seen when the exercise was stopped. The importance of this report is that it confirms the theory that different muscular activities cause different stress fractures.

Ligamentous instability of the ankle joint can be confirmed by radiographs taken in two planes. The place of the anteroposterior varus stress view is established, but the lateral view which shows anterior subluxation of the talus is frequently omitted. The anatomical significance of the two stress views has been determined by dividing different components of the lateral ligament of 20 cadaveric ankles and noting the subluxation that resulted from these procedures. A clinical assessment was then made of 54 ankles (46 patients) with radiological evidence of instability when subjected to varus and anterior stress. Anterior subluxation was found to be considerably more common than varus tilt, and it is therefore suggested that the lateral stress view should be an essential part of the investigation of the unstable ankle.

Two hundred and forty-eight high-grade central osteosarcomata were treated by amputation or disarticulation; in 5.2 per cent the tumour recurred at the amputation site. The following causes may be responsible for local recurrence: the level of the amputation is too close to the tumour; there is an unrecognised intramedullary extension of the tumour; during a previous block resection tumour cells may have been seeded in the soft tissues; the primary tumour was too extensive even for radical surgery; "skip" metastases may have been present; iatrogenic tumour implantation may have occurred while a biopsy was being performed during the course of an amputation. Treatment of the primary osteosarcoma should take all these possibilities into account. In our experience adjuvant chemotherapy has not significantly changed the frequency of local recurrences which should be treated by radical operation or, if this is not possible, by irradiation; chemotherapy may be used as an adjuvant. The prognosis of local recurrences is bad.

The long flexor tendons of the second, third and fourth toes of 94 chickens were cut and sutured. After operation the birds were divided into three groups. To reduce peritendinous adhesions, an aqueous solution of beta-aminopropionitrile (BAPN) was added to a solution of enriched native collagen (ECS) and applied to the cut tendons of one group; untreated controls and controls treated with collagen solution alone comprised the other groups. Chickens from each group were killed one, two, three, four and five weeks after operation. The results were evaluated both biomechanically and biochemically. It was found that the collagen solution alone had the same effect as the treatment with BAPN. It is suggested that the exogenous collagen present at the site of injury binds the collagenase inhibitor released by tendon cells, thus providing enough active collagenase to control the formation of fibrous adhesions. The inefficiency of BAPN in these experiments might have been due to either inadequate dosage or wrong timing, or both.

The early diagnosis of caisson disease of bone is hindered by the long delay which must elapse before an abnormality becomes apparent on a radiograph. The possible use of bone scintigraphy for this purpose was investigated. Necrosis of the bone and marrow was produced in rabbits by glass microspheres to simulate persistent gas-bubble emboli and then serial radiographs and scintigrams using 99mTc-diphosphonate were obtained. Regions of necrosis could be detected as "hot-spots" on the scintigrams as early as three weeks after the causative insult, which was many weeks before any abnormality could be detected on the radiographs. Histological examination of excised femora suggested that the scintigraphic abnormality might depend on the new bone formation during a reactive or repair process. It is suggested that scintigraphy may have clinical value in caisson disease.

In an attempt to explain the distribution of lesions of caisson disease of bone in the human femur, the regional distribution of circulating microspheres which had been labelled with scandium-46 was studies in the femur of the rabbit. Microspheres with a diameter of 15 microns were equally distributed between the two ends of the bone and between the upper and lower halves of the shaft. However, microspheres with a diameter of 50 microns congregated in the upper end of the femur and in the lower half of the shaft, the two sites most commonly affected by caisson disease. A large percentage of the microspheres in the shaft, especially the larger spheres, were retained in the marrow. It is suggested that the microcirculation of the marrow may act as a filter and that the nature and distribution of its vessels determine the site of impaction of circulating emboli. This would explain why lesions of the shaft mainly affect the medulla of the bone and not the cortex.

The intensity of scattered radiation in both a forward and a backward direction from a portable fluoroscope during pinning of the neck of the femur was measured by experiments on a cadaver. The intensity decreased rapidly with increasing distance from the flare of the greater trochanter. Hazard to the surgeon's hands from scattered radiation can be greatly reduced by positioning the C-arm of the fluoroscope so that the x-ray beam is directed laterally.

In order to study the effect of pure torsional forces upon the rotational development of the growing tibia, 35 immature rabbits underwent torsional loading of one tibia in vivo with a spring-loaded cylinder while the other tibia was a control. The radiographic results showed rotation occurring only at the epiphysial plate. Histologically this was assocaited with angulation of the hypertrophic cartilage columns occurring as little as 24 hours after loading which with longer periods of loading produced angled primary and secondary trabeculae. Radiographic and histological analyses of the diaphysis using tetracycline labelling and Spalteholtz injection techniques failed to show any evidence of cortical remodelling or reorientation of the cortical vessels of a rotational nature, suggesting that rotational modelling occurs solely at the epiphysial plate.

A new method for the measurement of tibial torsion using computerised transverse tomography is presented. Its accuracy is equal to that of cadaveric skeletal measurement. This method may be used in patients with unilateral post-traumatic torsional deformities, especially when these are combined with genu varum or valgum. The study of torsional aberrations in connection with congenital abnormalities of the foot is of further interest.

The Fairbank Collection in the Radiology Department of the Royal National Orthopaedic Hospital contains details of 15 patients in the section labelled "Metaphysial Dysplasia and Dysostosis". This material has been reviewed, long-term follow-up of the patients carried out and the diagnosis revised, where indicated, according to current concepts. Of the 15 patients, all children, seven had recognisable bone dysplasias. The remaining eight, all listed under the heading "metaphysial fragility", had the characteristic radiographic features of "battered" babies.