We analysed the incidence of avascular necrosis in 101 hips of 90 infants with congenital dislocation treated with the Pavlik harness and followed up for more than one year. Using ultrasonography in the flexed-abducted position the hips were classified as type A when the femoral head was displaced posteriorly, but within the socket and making contact with the posterior inner wall of the acetabulum; type B when it was in contact with the posterior margin of the acetabulum, with its centre at this level or anterior to it; and type C when it was displaced out of the socket, with its centre posterior to the posterior rim of the acetabulum.

Eighty-seven hips were reduced by the harness (86%), and seven of these developed avascular necrosis (8%). All 69 hips with type-A dislocation were reduced, and only one (1.4%) showed slight avascular necrosis. Eighteen (78.3%) of 23 hips with type-B dislocation were reduced, and six developed avascular necrosis (33.3%). In one hip, the femoral head was severely damaged. None of the nine hips with type-C dislocation was reduced in the harness.

We conclude that the Pavlik harness is indicated for type-A, but not for type-B or type-C dislocations.

We studied 45 children who presented with an inversion injury of the ankle. The clinical signs suggested injury to the distal growth plate of the fibula, but the plain radiographs appeared normal. Ultrasound examination of the joint in 40 patients showed a subperiosteal haematoma consistent with a growth-plate injury in 23 (57.5%). Children who had been treated with a tubular bandage and crutches by random selection had a mean time to return of normal activity of 14.22 days compared with 21.60 days for those treated with a plaster-of-Paris cast (t = 3.60, p = 0.0032; d = 7.38, 95% CI 3.0 to 11.8).

We conclude that children with inversion ankle injuries who have clinical signs of injury to the distal fibular growth plate but a normal radiological appearance, should be treated with a tubular bandage and crutches.

We examined prospectively 4719 newborn infants to determine the congenital incidence of trigger thumb. No cases were found.

Fifteen other children aged from 15 to 51 months had surgery for this condition. The anomaly had not been seen at birth and all thumbs presented with a flexion contracture without triggering. The condition is usually seen after birth as a flexion contracture of the interphalangeal joint. The term ‘congenital’ is a misnomer because patients acquire the deformity after birth. The term ‘trigger’ is inaccurate as most thumbs show a fixed-flexion contracture without triggering.

We suggest that rather than ‘congenital trigger thumb’ a more appropriate description of this disorder is ‘acquired thumb flexion contracture in children’. If the contracture persists after one year of age, treatment by dividing the A-1 pulley is simple and effective.

We have studied retrospectively 37 hips in 36 children at an average of 91 months after simultaneous open reduction and Salter innominate osteotomy for developmental hip dysplasia. At the latest review 97.3% were clinically and 83.8% radiologically good or excellent. In three hips (8%) there were signs of avascular necrosis, but only one had been symptomatic. There were no cases of recurrent posterior displacement.

We report a postal survey of 59 families of children with osteogenesis imperfecta. From the 51 replies we collected data on developmental milestones and walking ability and related them to the Sillence and the Shapiro classifications of osteogenesis imperfecta. Twenty-four of the patients had been treated by intramedullary rodding.

Both classifications helped to predict eventual walking ability. We found that independent sitting by the age of ten months was a predictor for the use of walking as the main means of mobility with 76% attaining this. Of the patients who did not achieve sitting by ten months, walking became the main means of mobility in only 18%. The developmental pattern of mobility was similar in the rodded and non-rodded patients.

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.

We reviewed the results of anterior hip release for fixed flexion deformity in 57 hips in 38 children with spina bifida at an average follow-up of 8.9 years (2 to 22). The indication for this operation was a fixed flexion deformity of more than 30° which interfered with function.

In 43 hips there was a good outcome in that the fixed flexion deformity remained less than 30° at follow-up. Four hips had a good initial result but deteriorated after an average of five years, and ten had a poor outcome with deformity of over 30°. Six hips required a repeated anterior hip release and two of these were successful.

The success of anterior hip release could not be related to the neurological level or the age at operation. Successful surgery correlated with the walking ability of the child at the latest follow-up.

We reviewed 52 children, born between 1974 and 1985 with spina bifida affecting L3 and L4, who had dislocated hips. Their motor function was stable and they were able to walk at the time of dislocation. They were interviewed and examined physically and radiologically. Physical function was measured by the Rand Health Insurance Study questionnaire (HIS), the Childhood Health Assessment questionnaire (CHAQ), and by determining the functional level of ambulation according to Hoffer et al (1973). In a subgroup of 12 patients with L4 level of involvement from both treatment groups we measured the metabolic energy consumption while walking.

Thirty patients (49 hips) had been treated by operative relocation and 22 conservatively. Ten of the hips treated by operation subluxated or redislocated. The function in the two groups (conservative v operated) was similar (HIS score 7.8 v 8.0, p = 0.45; CHAQ 14 v 13, p = 0.2; level of mobility 0.61 v 0.63, p = 0.5). Patients in whom operation had failed had worse function than did those with successful surgery (HIS score 8.8 v 6.1, p = 0.025) and those with successful surgery had better function than patients treated conservatively (HIS score 8.8 v 8.0, p = 0.15). Function in patients with failed operations, however, was worse than in those who did not have surgical treatment (HIS score 6.6 v 7.8, p = 0.07). In the 12 so examined the operated group had a 30% more energy-efficient gait (0.271 v 0.361 ml O₂ kg/m, p = 0.05).

Patients with failed operations had worse function than those who were not operated on. The benefit of surgical relocation of the dislocated hips was marginal.

Most obstetric brachial plexus palsies are due to rupture of the upper roots in babies whose delivery was complicated by shoulder dystocia. If treated by early exploration and grafting, they have a favourable prognosis.

We reviewed 36 babies who had had an obstetric brachial plexus palsy after a breech delivery and found that they had a different pattern of injury; 81% had avulsion of the upper roots. This injury cannot be treated satisfactorily by exploration and microsurgical grafting and carries a considerably worse prognosis for shoulder function.

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.

We have reviewed 16 patients treated by leg lengthening for various forms of Turner dwarfism with regard to the long period of healing and the complications. We consider that Turner dwarfism is a suitable indication for leg lengthening because of the moderate length deficit and the morphological appearance of the patients, and have introduced an improved programme of management to deal with the problems encountered.

We describe three sisters in a family who presented with a clinical form of osteomesopycnosis which is a rare, benign osteosclerotic bone disorder limited to the axial skeleton. It must be distinguished from other osteosclerotic conditions which carry a worse prognosis. This is the first report of the condition in a Japanese family, and we believe it to be the first to be identified in Asian races.

Several authors have reported complications from screw removal after treatment of slipped upper femoral epiphysis by single screw fixation, and have attributed these to poor screw design. We have developed a simple and reliable method of screw removal which uses a cannulated 8.0 mm end-threaded cancellous screw (Smith & Nephew Richards Medical, Memphis, Tennessee) and a specially designed cannulated trephine.

The method has been successful, with minimal complications, and a limited surgical exposure.

We have used the Ilizarov technique for severe flexion deformity of the knee in 11 patients (13 knees) between 1986 and 1994 and have followed them up for an average of 4.1 years. The age of the patients at operation ranged from 1.7 to 18.8 years.

The femoral and tibial components were connected by two anterior hinges, medial and lateral, and two posterior distraction rods. The deformity was corrected to a femorotibial lateral shaft angle of less than 20°. A permanent orthosis was applied after removal of the fixator. Fractures occurred in four patients and paralysis of the common peroneal nerve in another. There was a recurrence of the deformity in four patients.

At the last review all patients were able to walk on their operated leg with or without an orthosis.

We have found the Ilizarov method to be helpful in correcting severe fixed flexion deformity of the knee, with relatively few complications, but the basic principles of the method must be carefully followed.