High myelomeningocele lesions do not preclude an acceptable level of functional walking provided that an integrated programme of surgical treatment and bracing is adopted. Clinical analysis of 100 patients with myelomeningocele shows that the development of the "swivel walker" and "hip guidance orthosis" has been associated with an improved level of function. Over 30 per cent of patients with thoracic lesions and 68 per cent of those with lumbar lesions achieved independent walking. For this reason the criteria used at present by paediatricians to govern the selection of infants for non-active treatment may require reconsideration.

Twenty-four children with infantile or juvenile idiopathic scoliosis had their spines corrected and solidly fused posteriorly before the age of eleven years. The growth of the fusion area was then accurately measured for a mean of 4.5 years during the adolescent growth spurt. During this period all longitudinal growth in the posterior elements ceased. The vertebral bodies continued to grow anteriorly, but the thick posterior fusion prevented the development of a lordosis. Initially the anterior growth was accommodated by narrowing of the intervertebral disc spaces, but eventually the vertebral bodies bulged laterally towards the convexity and pivoted on the posterior fusion, giving rise to loss of correction, increasing vertebral rotation and recurrence of the rib hump.

The operative and anaesthesic technique for 44 patients undergoing posterior spinal fusion with Harrington rod instrumentation for idiopathic scoliosis is described. There were two groups of 21 and 23 patients, matched for diagnosis and status before operation. The management of both groups was similar but in one group anaesthesia with induced hypotension was employed, using a mixture of sodium nitroprusside and trimetaphan. The mean blood loss at operation and after operation in this group was significantly lower than in the other group, with a consequent reduction in the transfusion requirement. No adverse sequelae were observed. All patients showed a drop in haemoglobin concentration after operation, despite clinically adequate blood transfusion.

This paper describes the relationship between post-myelographic symptoms and the timing of a subsequent spinal operation. A prospective study was performed comparing the post-operative symptoms of patients who underwent discectomy within 48 hours of myelography (Group 1) with those of patients who underwent discectomy at least seven days after myelography (Group 2). After myelography there was no statistical difference in the incidence of nausea and headache in the two groups. However, after operation the incidence of headache and nausea was significantly greater in patients who underwent early discectomy. The incidence of urinary retention was significantly greater in Group 1 at 24 hours after operation but not at 48 and 72 hours. We conclude that the temptation to perform discectomy shortly after myelography should be resisted until at least one week has elapsed between the two procedures, except in emergency situations.

One hundred and seven patients with intertrochanteric fractures of the femur treated with a Richards screw-plate were compared retrospectively with 103 patients treated with a Jewett nail-plate. The mortality and morbidity were similar in the two groups. In patients with comparable fractures, those treated with a Richards device mobilised more quickly and left hospital sooner, and more of them returned to their homes. Failures of stabilisation, both clinically and radiographically, were fewer in this group. The reliability of fixation with a correctly positioned Richards screw-plate could justify the omission of outpatient follow-up in all but a small group of patients with severe unstable fractures or grossly defective bone stock. The higher cost of a Richards implant and the slightly longer operative procedure were outweighed by savings in occupancy of acute and long-stay hospital beds.

Twenty-nine patients with avascular necrosis of the femoral head after injury have been treated by operation. Multiple drilling of the femoral head was performed, necrotic bone removed and a muscle-pedicle bone graft implanted into the head and neck of the femur. In 17 of the patients the necrosis was associated with an un-united femoral neck fracture, in 11 it occurred after the fracture had united, and one case followed reduction of a dislocated hip. The hips became painless soon after operation. The patients were young (average age 35 years), and full weight-bearing was not allowed for several months. The follow-up period ranged from 22 to 64 months. The results were excellent in 20 patients, good in five, fair in three and poor in one.

The case reports of four patients with breakage of the intramedullary nail of the femur are presented. In all four patients the nail broke after consolidation of the fracture of the femoral shaft. All the nails broke at the same place: the junction between the round cross-section and the cloverleaf cross-section.

The outcome of various types of treatment for femoral fracture in children with head injury was studied retrospectively in 51 patients with 56 fractures. Of these, 36 patients (71 per cent) were in deep coma and scored 5 to 7 on the Glasgow scale. Forty-three children (84 per cent) were eventually able to walk freely. Open reduction and internal fixation proved an attractive solution for femoral fractures in children with head injury who could tolerate general anaesthesia: intramedullary nailing was safe and gave satisfactory results in 16 fractures but infection complicated three of the five fractures which were plated.

A retrospective study of the development of the hip opposite a congenitally dislocated hip was carried out to identify at an early age those hips which would develop abnormally. Recognised radiological measurements were used showing the development of the joints with age. The development was compared with that of a control group of normal hips. Single measurements were shown to be unreliable in predicting the development of the hip. A simple hip ratio is proposed which predicts, at an early age and with a high degree of accuracy, the developmental outcome.

Certain features of the sagging rope sign recently analysed by Apley and Weintroub (1981) are examined in detail. Evidence is presented to show that the line is a radiological shadow cast by the lateral edge of a severely deformed femoral head rather than a condensation of the spongiosa within the neck. An explanation is offered to explain the common association of the presence of this radiological sign with premature epiphysial fusion.

Over 15 years (1967 to 1982) 140 uncomplicated femoral shaft fractures in children under four years of age were successfully treated using Bryant's traction. Forty of these children were treated after the introduction of the domiciliary management policy in 1976; 13 children were managed at hospital and 27 were managed at home. No significant complications occurred. The advantages to the family, and the safety and economy of domiciliary management lead us to recommend its adoption in favourable cases. Treatment at home relies on an efficient and experienced home nursing service. Possible complications of the injury and treatment with recommendations to prevent them are discussed.

A review is presented of 41 patients with traumatic tetraplegia on whom reconstructive surgery of the upper limb was carried out. Twelve patients were followed up for more than 10 years after operation and the average period overall was seven and a half years. Tendon transfers were made with the aim of providing extension of the elbow or restoring a useful grasp or a combination of both. The assessment was carried out on four main aspects: the function of the elbow, the function of the hand, the ability to carry out the activities of daily living and the effect of the surgical reconstruction on the personal and social achievement of the patient.

Out of 21 900 cases filed at the Latin-American Registry of Bone Pathology between April 1940 and July 1981, there were 987 with Paget's disease (4.51 per cent); 62 of these (6.28 per cent) were complicated by sarcoma and two were associated with giant-cell tumours of bone (osteoclastoma) without signs of malignancy. There was a slight predominance of men and the ages ranged from 45 to 87 years, with an average of 66 years. The most frequent sites were the femur (23 cases), the humerus (nine), the pelvis (10), and the tibia (nine). The low incidence of vertebral involvement (five cases) is noteworthy and is in sharp contrast to uncomplicated Paget's disease. The most common tumour type was osteosarcoma (39 cases), followed by fibrosarcoma (15 cases); other varieties (chondrosarcoma, malignant fibrous histiocytoma and reticulum-cell sarcoma) were much rarer. Most of the sarcomata occurred when the Paget's disease was polyostotic. Tumours often developed simultaneously, or at short time intervals, in the same or different bones; these bones had, in all cases, been affected by Paget's disease. The histological features of the osteosarcomata were characteristic, with large numbers of osteoclast giant cells, alternating with atypical osteoblasts, thus exaggerating the anarchic remodelling process of Paget's disease. The neighbouring areas of the pagetic bone showed an increased number of osteoclasts. These facts suggest a possible pathogenetic relationship between sarcoma and Paget's disease; the possibility of both processes having a viral aetiology is discussed.

Thirty-nine patients underwent reconstruction of the anterior cruciate ligament with carbon-fibre and a MacIntosh repair; all had a negative pivot shift test after operation. Some patients had persistent pain, mild effusion and synovial thickening; in 10 of these patients the symptoms warranted arthroscopic examination and biopsy at a mean of 16.9 months after the repair. Arthroscopy revealed that the carbon-fibre had not induced the formation of a "new ligament" and that the repair was merely covered by a thin, fibrous sheath. Histological investigations confirmed this finding, with only a suggestion of a fibroblastic response to carbon-fibre found in two patients. Particles of carbon-fibre were found scattered through the knees. Synovitis and breakdown of the skin over subcutaneous carbon-fibre complicated treatment. Failure of the carbon-fibre to bond to bone was detected radiographically.

Three cases of isolated anterior dislocation in the proximal tibiofibular joint are presented. The common aetiological feature was that injury occurred with the knee in hyperflexion and the foot inverted and extended. The symptoms of locking, pain and giving way may lead to an erroneous diagnosis of meniscal injury. Early diagnosis in the acute case enabled easy reduction. In the inveterate cases, resection of the head of the fibula gave complete relief of symptoms.

Test results on carbon-fibre-reinforced plastic plates are presented, all of which had been used as semi-rigid fixation in a series of fractures of the middle third of the human tibia. Symptoms of pain experienced by the patients were found to be related to the stiffness of the plates and it is suggested that a stiffness of 2.0 newton-metres per degree is most suitable for this type of fixation of the tibia.

Congenital dislocation of the peroneal tendons is a rare and infrequently reported deformity of the foot in the neonate. Four cases of this deformity associated with a congenital calcaneovalgus deformity of the foot have been treated and followed to the resolution of both of the deformities. The calcaneovalgus foot proved more resistant to correction and required more prolonged and aggressive treatment than was usual when it was found as an isolated deformity. All four patients demonstrated other stigmata of intra-uterine malposition and oligohydramnios or both. Our anatomical studies suggested that the superior peroneal retinacular ligament was the critical stabilising structure for the peroneal tendons. A concept of the pathogenesis of this deformity is discussed and a proven regimen for its treatment presented.

A total of 67 patients with 94 resistant club feet were treated operatively as soon after birth as all other postnatal problems could be excluded, the mean age of the patients being 12 days. No treatment was attempted before operation. The results, after a follow-up period of a minimum of two years (mean 4.4 years) are comparable with the best published results. This method of treatment has many advantages but cannot be recommended for general use without reservations.

One hundred patients who had sustained a fracture of the tibial shaft and had been treated by internal fixation were reviewed to obtain information on residual ankle and subtalar disability. This study reinforces the belief that early mobilisation of patients with tibial shaft fractures does help to preserve subtalar movement.

A review is presented of the results of treatment in 126 patients over 50 years of age who had suffered a displaced fracture of the ankle. Operative fixation achieved better fracture positions than conservative management, but was associated with a very high complication rate in women. Examination of 86 of the patients more than two years after injury showed little difference in function after conservative or operative treatment.

Two cases of idiopathic avascular necrosis of the scaphoid are reported and it is suggested that the aetiology could be the same as that recently described for Keinboeck's disease by Beckenbaugh et al. (1980). The condition described in this paper is a different entity from that described by Preiser (1910), which was probably not an osteochondritis but an undiagnosed fracture.

The effect of the pneumatic tourniquet on the incidence of postoperative deep venous thrombosis is uncertain. We carried out a controlled study comparing the incidence of deep venous thrombosis when a tourniquet was used with the incidence when a tourniquet was not used. Thrombosis was detected by radioisotope venography. The results of the study showed no difference in incidence and we concluded that the pneumatic tourniquet has no influence on the formation of a thrombus in a deep vein.

An experimental study performed in 16 mongrel dogs is presented, which shows that when venous stasis is combined with the local injection of non-esterified fatty acid an intense thrombosis results. This response is not produced by venous stasis alone, nor by the combination of venous stasis and triacylglycerol. Histologically it is quite different from the response produced by an inert intraluminal foreign body. It does resemble venous thrombosis described experimentally and in patients. The clinical relevance of these findings is that during accidental or operative trauma to a long bone, fat is commonly forced into the local venous circulation. If this event is combined with venous stasis or a tourniquet is used, then the circumstances of this experiment are reproduced. It is suggested that the venous thrombosis which commonly complicates long-bone injury or operation is in part caused by the thrombogenic nature of the introduced fat.

A long-term review of 131 children fitted with upper limb prostheses at the Ontario Crippled Children's Centre between 1965 and 1975 is reported. There were 116 children with congenital deficiencies and 15 who had had amputations. Follow-up ranged from 7 to 17 years. A total of 42 children had abandoned their prostheses, 37 of whom had congenital deformities and five were amputees. The level of deficiency was of fundamental importance in determining whether the prosthesis would be accepted; in the forearm, the longer the stump, the more likely it was that the child would discard the prosthesis. Overall, 50 per cent of children fitted over the age of two years abandoned their prostheses compared with only 22 per cent of patients who had been fitted before the age of two years. The highest drop-out rate was at the age of 13 years when the children became more conscious of their cosmetic appearance. Suggestions for reducing the high drop-out rate in the early teens are put forward.

The clinical features of nine new patients with dysplasia epiphysialis hemimelica are reported, with a long-term follow-up on a further seven patients who were described in the earliest case reports of this disease. Each of these 16 patients had only one leg involved, but 12 had multiple epiphyses affected. The distal femur, distal tibia and talus were the commonest sites and most patients presented with painless swelling or deformity. Wasting of the muscles of the affected leg was a common finding, and was occasionally disproportionate to the degree of disuse. One patient had the unique combination of involvement of the lateral and medial halves of different epiphyses in the same limb and another had unusual metaphysial changes. Diagnosis was often delayed despite typical radiographic appearances. There was no evidence for a genetic component in the aetiology nor was any common environmental factor identified. Treatment by local excision was generally effective for lesions in the vicinity of the knee, but some patients with involvement of the talus required arthrodesis around the ankle. The long-term prognosis appears to be good and so far only two of these patients have developed premature osteoarthritis.

The elbow flexor muscles of four men were trained using maximal voluntary isometric contractions. Thirty contractions a day were performed for five weeks. The four men and four control subjects were tested once a week: measurements of the supramaximally stimulated isometric twitch force, the time taken for the twitch force to peak and the tetanic force were carried out; simultaneously, measurements of the force of maximal voluntary isometric contraction and resistance to fatigue were made. The testing sessions produced no training effect on control subjects. Training produced a 20 per cent increase in the force of maximal voluntary isometric contraction after five weeks, but the forces of electrically evoked twitch and tetanus showed no increase. It was concluded that the increase in the force of maximal voluntary isometric contraction must be related to factors other than the force-generating capacity of the muscle fibres themselves.

We report two cases of aneurysm of the external iliac artery after arthroplasty of the hip. In each case the patients suffered from severe, seropositive, rheumatoid arthritis, had been treated with oral corticosteroids and had defects in the acetabular floor which were complicated by sepsis. In these circumstances bleeding from the wound in the hip should be investigated by immediate arteriography with anteroposterior and lateral views. Though vascular injury during operations on the hip is rare, recognition is important as safe and satisfactory treatment can be achieved. In the surgical management of these cases the following points should be noted: an alternative blood supply to the limb must be established using separate surgical incisions; to reduce the risk of sepsis these incisions should be closed and dressed before exploring the aneurysm; the aneurysmal vessel must be isolated and ligated, no attempt being made at primary repair; the aneurysm should be opened longitudinally to avoid damaging the femoral nerve which overlies it; and all foreign material should be removed from the hip.