We investigated the reproducibility of the various radiological methods of assessment of hip dysplasia by making 474 assessments of hips and quantifying the inter-observer and intra-observer variation. There was a wide range of variability between the readings made by different observers and by one observer on two occasions. A measurement of acetabular index has to be given a range of +/- 6 degrees in order to be 95% confident of including the true measurement. We found the most helpful measurements to be the acetabular index, up to the age of eight years; the centre-edge angle, over the age of five years; and Smith's c/b ratio and neck-shaft angle. We feel, however, that the change in value over a series of radiographs in the same child is much more valuable. Single readings of all the radiological measurements investigated in this study were unreliable.

We have reviewed the serial radiographs of 63 hips in 53 children treated by closed reduction for congenital dislocation with a view to finding a radiological measurement which can predict subsequent acetabular development. All had been followed for more than seven years, and at latest review, 34 hips were dysplastic. Failure to obtain concentric reduction or its loss by migration of the femoral head within one year of reduction were the best predictors of persisting acetabular dysplasia and were best quantitated by the h/b ratio (Smith et al. 1968). The acetabular index at reduction or its decrease in the first year were not reliable predictors. Late treatment was less likely to lead to normal acetabular development, but avascular necrosis did not appear to have a significant influence. The average age at which the acetabulum stopped developing was five years, but ranged from 17 months to eight years. The failure of a dysplastic acetabulum to improve in each annual radiograph after closed reduction should lead to consideration of operation on the acetabulum.

A protocol for the treatment of fractures of the middle third of the femur by the early application of a hip spica has been evaluated in 191 children aged 10 years or less. Children without other injuries spent only a few days in hospital for the application and later removal of the spica. At all ages, anterior angulation of less than 20 degrees and valgus angulation of less than 15 degrees were accepted at the one-week review. Acceptance of shortening varied with the age of the child and the stage of treatment, but was 10% or less of the femoral length at the time of spica removal. At late review leg-length discrepancy was rare and clinically insignificant. This method of treatment was simple and effective. It dramatically reduced the cost of care and freed a number of children's hospital beds.

Seven patients with Ewing's sarcoma of the pelvis were treated by chemotherapy followed by wide resection of the primary tumour. Although good function after operation is possible, survival in this series reflects the poor prognosis associated with the disease; two patients died, two are alive with local recurrence and metastases and three patients are alive with no evidence of disease.

We present three cases of a previously undescribed condition characterised by unilateral tibia vara associated with an area of focal fibrocartilaginous dysplasia in the medial aspect of the proximal tibia. The three children affected were aged 9, 15 and 27 months respectively. Two required tibial osteotomy, but in one the deformity resolved without treatment. The pathogenesis of the focal lesion remains conjectural; the most likely explanation is that the mesenchymal anlage of the tibial metaphysis has, for unknown reasons, developed abnormally at the insertion of the pes anserinus.

A protocol for the treatment of subacute haematogenous osteomyelitis has been used and evaluated in 71 children. A group of 26 children with a radiologically "aggressive" lesion had biopsy followed by antibiotics and immobilisation for six weeks. A group of 45 children with 48 cavities in the metaphysis or the epiphysis or both was further subdivided according to the presence or absence of clinical signs of pus at subperiosteal level or in a joint. Children with evidence of pus had operation followed by antibiotics and immobilisation while the remaining children were treated similarly but without operation. Intravenous cloxacillin or flucloxacillin and benzylpenicillin were given in hospital for 48 hours and oral antibiotics and immobilisation were then continued at home for six weeks. Staphylococcus aureus was the only pathogen cultured. In all, 91% were cured by a single course of treatment. Of the 48 metaphysial and epiphysial lesions, 77% were treated without operation; and of these, 87% were cured by a single course of treatment, this figure reaching 94% in children under 11 years old.

A programme for early mobilisation using a temporary prosthesis was evaluated in 17 children who had had an amputation above the knee for sarcomata. The temporary prosthesis had a performed adjustable polypropylene quadrilateral socket which was able to accommodate changes in the size of the stump during the first few months after amputation. The adjustable sockets were assembled onto wooden knee-shank-foot units or onto modular components covered with foam. The wooden units were better for routine use as more adjustment was possible between the socket and the knee and because they were more durable in active children. Prosthetic fitting usually took one hour and was carried out 10 days after the amputation to coincide with the start of the chemotherapy programme. The prosthesis was cosmetically acceptable, easy to use and provided a simple and economical way of rehabilitating the amputees and restoring their morale. After two to three months a new prosthesis with a laminated socket suspended by a waistband was supplied. The skin tolerated the closer fit of this socket and the small fluctuations in the size of the stump that occurred with each course of chemotherapy were easily accommodated by varying the thickness of the stump sock. A self-suspending laminated socket was provided after completion of the chemotherapy. The permanent sockets were assembled onto wooden components but the girls usually preferred the modular system covered with foam. The chemotherapy and rehabilitation programmes were successfully co-ordinated so that the children spent as little time as possible away from their normal activities.

A protocol of treatment for acute haematogenous osteomyelitis has been evaluated in 75 children. Intravenous cloxacillin and benzylpenicillin were given in hospital until the child had improved after which oral antibodies and immobilisation were continued at home for a total of six weeks. Oral cloxacillin was used most frequently as Staphylococcus aureus was the major pathogen. Simple drainage of subperiosteal pus was carried out in the 17 children with clinical evidence of an abscess. Ninety-two per cent of the 55 children with acute osteomyelitis diagnosed early were cured by a single course of antibiotics without an operation and with less than one week in hospital. Only 25 per cent of the 12 children with late-diagnosed acute osteomyelitis were cured with a single course of antibiotics and an operation. A longer period in hospital, a prolonged course of antibiotics, and secondary operations were required to cure the other children. Seven (88 per cent) of the eight neonates and infants with acute osteomyelitis were cured with a single course of antibiotics and an operation with only one to two weeks spent in hospital. The remaining infant was cured with a further course of antibiotics. The overall cure rate with a single course of treatment was 83 per cent, and the remaining children were cured with further treatment. More children would be cured with a single course of antibiotics and immobilisation without the need for surgical intervention if treated was started within one or two days of the onset of the illness rather than after four to five days when the disease is more advanced with the formation of and abscess.