1. Idiopathic necrosis of the femoral head is generally considered to be a rare disease but it appears to be rather frequent in France in view of the fact that 139 cases were recorded in the orthopaedic clinic of Hôpital Cochin between 1959 and 1963. Ninety cases treated by operation have been analysed in this paper. Men are nearly exclusively affected between the ages of eighteen and seventy, with the highest incidence between thirty and fifty years of age. Both hips are affected in 52 per cent of cases.

2. The etiology is unknown, but steroid therapy was noted in 36 per cent of the cases and some history of slight injury in 30 per cent. The sudden onset of pain in half the cases suggests the obliteration of one of the blood vessels supplying the femoral head.

3. Radiographs are often normal at the time of onset of the symptoms but later they show increased density of the head localised to the antero-superior aspect, and later still collapse of this weight-bearing region. The extent of the lesion appears to be determined from the very beginning rather than to be progressive. The superior joint space is never reduced and may in fact be widened.

4. Pathological examination of the head and neck confirms necrosis of the cancellous bone and the integrity of the overlying cartilage, but shows deep to the necrotic region a highly reactive zone characterised by hypervascularity and raised metabolism. These features have been demonstrated by injection of the blood vessels and also by the uptake of phosphorus 32 and by the succino-deshydrogenase test.

5. In six cases microscopic vascular lesions were found in the antero-lateral pedicle of the femoral head.

6. The high degree of activity of the tissue deep to the necrotic zone gives some hope for revascularisation of the necrotic segment. For this reason protection from pressure may be the way to prevent dramatic collapse of the head. Rest, medical treatment and freedom from weight bearing, however, do not achieve adequate protection. Varus or rotation osteotomy of the femoral neck not only gives relief from pain but appears to prevent collapse of the femoral head.

7. When destruction of the head has already taken place good results may be expected from the insertion of a metallic prosthesis, provided the acetabulum is sound. The results are less favourable when the acetabulum has been altered by secondary arthritic change, and arthrodesis may have to be considered if the disease is unilateral or when a prosthesis has been successfully inserted on the other side.

1. This paper presents a series of 135 patients with displaced ankle fractures treated by rigid internal fixation followed by early joint exercises in bed until movements were restored and followed then by full weight bearing in a plaster.

2. The advantages obtained are as follows: A high standard of reduction can be achieved and maintained. The joint movements are established before organisation of the traumatic exudate. Weight bearing in a plaster reduces the degree of disability and prevents osteoporosis. Further remedial treatment after removal of the plaster is usually unnecessary.

3. All but five of the fractures (3·7 per cent) could be classified in the manner described by Lauge-Hansen.

4. This classification is the most satisfactory of those available and is recommended for general use.

5. Anatomical reduction was obtained in 102 patients (77 per cent), with good objective clinical results in 108 patients (82 per cent).

6. The quality of the clinical result depends mostly on the accuracy of the reduction, to a lesser extent on the degree of initial displacement, and least on the type of fracture.

7. It is considered that the traditional concept of diastasis requires modification; it is felt that the term lateral ankle instability, which includes low fracture of the fibula (intraosseous diastasis) is preferable.

8. Internal fixation of the syndesmosis is to be avoided except in rare instances.

9. The incidence of arthritis is shown to depend mostly upon the accuracy of reduction; the initial degree of displacement is also of importance.

1. The results of three forms of treatment (mobilisation, immobilisation for six weeks, and suture with immobilisation for six weeks) for ruptures of the lateral ligament of the ankle have been compared in previously uninjured asymptomatic patients.

2. Only suture and immobilisation ensured final mechanical stability of the ankle as assessed by stress radiography. Unstable ankles were found after both mobilisation and immobilisation, but in these groups no ankle finally displayed more than 8 degrees of relative talar tilt.

3. The mean duration of disability in patients who finally became symptom-free was: after mobilisation, twelve weeks; after immobilisation, twenty-two weeks; and after suture and immobilisation, twenty-six weeks.

4. One year after injury 58 per cent of patients treated by mobilisation, 53 per cent of patients treated by immobilisation, but only 25 per cent of patients treated by suture and immobilisation, had become perfectly symptom-free.

5. For these reasons, and because simple sprains are satisfactorily treated by mobilisation, it is suggested that mobilisation may be the treatment of choice for most, perhaps all, ruptures of the lateral ligament of the ankle.

1. Forty-two previously asymptomatic patients presenting with a recent rupture of the lateral ligament of the ankle, and twenty similar patients with a simple sprain of this ligament, have been followed for one year. The physical and radiological findings upon the completion of treatment have been related to functional instability of the foot one year later.

2. Persistent mechanical varus instability of the talus in the ankle mortise was a possible cause of functional instability one year after injury in four (or perhaps six) patients.

3. Adhesion formation was a possible cause of functional instability in one patient.

4. Seventeen patients finally displayed no clinical or radiological abnormality after injury, but noted functional instability of the foot one year later.

5. It is concluded that the pathological process which is usually responsible for functional instability of the foot after a lateral ligament injury is at present unknown.

1. Eighty-five patients have been studied soon after a ligamentous injury at the foot or ankle. These patients were treated in one of three ways, and in fifty-six patients the results were evaluated six to fifteen months after injury.

2. It is concluded: a) that ligamentous injuries at the foot and ankle frequently produce a proprioceptive deficit affecting the muscles of the injured leg; b) that such a deficit is responsible for the symptom of "giving way" of the foot; and c) that the incidence of both the proprioceptive deficit and the symptom of "giving way" can substantially be reduced by treatment after injury with the coordination exercises described in this study.

3. The mechanism of production of the proprioceptive defect is discussed.

1. An account is given of twenty patients who had sustained accidental division of one or more foot tendons (other than tendo calcaneus).

2. Severe deformities occur when these injuries are neglected in children.

1. A method of hip fusion with the aid of a straight intramedullary nail through the ilium and the femur is presented.

2. If properly done, no external fixation is necessary and the patient can be allowed up with crutches ten days after the operation.

3. The method has been used on eighteen hips between 1958 and 1960. There was one case of delayed union due to faulty technique and one case of exacerbation of an old tuberculous infection. Otherwise the follow-up study of the patients revealed good bony fusion in all cases, with no pain in the back or knee.

1. Central dislocation of the hip combined with ilio-femoral intramedullary nailing is a technically difficult operation, but one which, if well done, provides a high percentage of hip fusion without external fixation.

2. Fifteen hips have been operated upon. Twelve have fused; two cannot yet be assessed as the time since operation is too short; and one failed, presumably due to osteoporosis resulting from rheumatoid arthritis.

1. Five cases of involvement of vertebrae by growths classified as giant-cell tumours, and two cases of involvement by tumours classified as aneurysmal bone cysts are described.

2. The periods of observation after operation in the benign cases were in three cases six years, in one ten years and in one twenty-one years.

3. In one case malignant transformation developed four and a half years after operation and one patient, in whom a sacral tumour was already malignant at the time of operation, died five months later.

4. Four patients showed significant involvement of vertebral bodies.

5. The problems related to the removal of a vertebral body and the measures taken to stabilise the spine are discussed.

1. Six cases of malunited anterior Monteggia fracture have been treated, five of them successfully, by open reduction and reconstruction of the orbicular ligament by turning down a slip from the triceps tendon.

2. One relapse occurred after a slight injury; this was because of an unsuitable triceps tendon.

3. A slip from the triceps tendon has retained reduction of the head of the radius in a patient with congenital dislocation of the radial head.

1. A method of treating Smith's fracture and Barton's anterior fracture-dislocation of the wrist by internal splintage is described.

2. The application of a special buttress plate fixed to the lower anterior aspect of the radius is advocated; no external splintage is used.

1. Stress fractures of the femoral neck in twenty-five patients are described.

2. Two distinct radiological types, compression fractures and transverse fractures, are described. A clinical distinction cannot be made in the early stages.

3. The importance of the early differential diagnosis between the two types is emphasised because the transverse stress fracture of the femoral neck will become displaced.

4. The morbidity after a displaced transverse fracture of the femoral neck can be severe.

1. A case of actinomycosis of the metacarpal bone of the right little finger from a punch injury is described.

2. The infection lasted five months and responded to prolonged courses of antibiotics and iodine preparations and drainage of recurrent abscesses.

1. A child with a rigid valgus foot caused by fibrous contracture of the peronei muscles is described.

2. The probable cause of the contracture is discussed.

1. Loss of osteocytes in the bone trabeculae of the femoral heads of "normal" elderly patients was patchy and distinguishable from that resulting from avascular necrosis after fracture.

2. Changes in the haemopoietic marrow were the earliest and most sensitive indicators of ischaemia, loss of osteocytes rarely being complete until three or four weeks after fracture.

3. In 109 femoral heads removed more than sixteen days after fracture the viability could be determined by histological means. All of these had suffered some damage to the vascular supply but in a number the head remained alive apart from the region of the fracture line. These heads were nourished by the blood vessels of the ligamentum teres and sometimes by retinacular arteries, usually of the inferior group.

4. Some femoral heads became completely necrotic following fracture, others were only partly affected. A variable amount of the subfoveal region commonly remained alive and it was from this site that revascularisation spread into the head. The upper segment of the femoral head least often remained alive and its subchondral region was usually the last to revascularise.

5. In a group of unselected femoral heads a third remained alive following fracture and two-thirds were partly or completely necrotic.

6. Femoral heads which were partly necrotic appeared capable of uniting and completely revascularising, there being invasion of the necrotic bone by vessels from across the fracture line and from the ligamentum teres. This contrasted with the completely necrotic femoral heads described elsewhere in this issue which united but in the absence of proliferation of ligamenturn teres vessels failed to revascularise completely and developed late segmental collapse.

7. Avascular necrosis did not appear to be the sole cause of non-union.

8. Necrotic bone showed no alteration in radiological density. Reossifying bone in areas of revascularisation sometimes caused an absolute increase of radiodensity especially when associated with halted revascularisation. This increase of radiological opacity was the result of deposition of new on dead bone with broadening of the trabeculae. Marrow calcification was minimal.

9. Obliterative sclerosis of venules in the ligamentum teres was found in "normal" patients even in infancy. No thrombosis was seen in the ligaments following fracture but where the femoral heads were completely necrotic and not revascularised the ligaments were often also necrotic.

10. There appeared to be no increase in degenerative changes in the articular cartilage of the femoral heads following fracture compared with fifty elderly controls. Some loss of chondrocytes in the deep zone of the weight-bearing area was found in about a quarter of the femoral heads. In only one head was the cartilage almost completely acellular. An almost normal depth and a smooth contour of the articular cartilage were retained.

1. A study of late segmental collapse in twelve femoral heads shows that it may not develop until two and a half years after the fracture.

2. Until the articular surfaces had collapsed the patients usually had no symptoms. The fractures were united and there was no obvious radiographic evidence of ischaemic necrosis.

3. There was histological evidence that the whole of the femoral heads had been necrotic at one time. The term late segmental collapse is more appropriate than late segmental necrosis.

4. The blood vessels of the ligamentum teres played little or no part in revascularisation which, when it occurred, was almost entirely across the fracture line.

5. In only one femoral head was revascularisation approaching completion and apparently continuing. In the other eleven much of the head remained necrotic and the process appeared to have halted.

6. An increase in radiological density was caused by new bone laid down on unresorbed necrotic trabeculae and was most prominent behind the line of revascularisation when the process had halted.

7. Trabecular collapse was evident within dead bone. In ten of the femoral heads it occurred in the subchondral region and in four just beyond the junction of reossified and dead bone.

8. Osteoarthritic changes occurred in the cartilage covering revascularised bone at the periphery of the head, especially when collapse was severe.

1. Dislocation and subluxation of the hip has been produced in young rats by application of splints reaching from the hip to the foot, bringing the hip into extension.

2. Progressive acetabular dysplasia and anatomical abnormalities of the head and neck of the femur occurred.

3. Results of the experiments suggest that post-natal extension of the hip is of importance in the pathogenesis of congenital dislocation of the hip in man.