1. Twenty-three cases of tarsal anomaly—talo-calcaneal bridge or calcaneo-navicular bar—occurring among thirty cases of "peroneal spastic flat foot" have been studied.

2. The correlation between the clinical features and the mechanical defect is discussed.

The method of producing osteogenic sarcoma in rabbits by the injection of beryllium in the form of "zinc beryllium silicate" is presented. In five of ten animals which had such injections, osteogenic sarcomas developed several months later. There was new bone formation in the medullary cavities of the long bones before malignant changes were apparent. It is of particular interest to note that there was atrophy of the spleen in those animals in which bone tumours developed, whereas the spleen seemed to be quite normal in the rabbits which did not develop bone tumours. The tumours usually developed in the metaphysial regions. More than one tumour often developed in the same animal.

If conclusions are to be of any value they must be definite and one cannot draw definite conclusions from less than, say, fifty cases followed up for at least five years. However, few surgeons will ever see fifty patients requiring arthroplasty of the knee, let alone operate of them, even in five years. Accordingly, this account of a new approach to the problem of knee arthroplasty is submitted in the hope that other surgeons may care to try it and thereby learn, and thus be able to teach, tile modifications and improvements that all new techniques seem so surely to need.

All the cup and replacement arthroplasties of the hip at the Middlesex Hospital performed two or more years ago—110 cases—have been reviewed. Cup arthroplasty was the more successful.

1. Recent published reports of neonatal osteomyelitis in long bones are reviewed.

2. Six further cases are described.

3. The source of infection is usually the skin or the umbilicus, and the common organisms are the haemolytic streptococcus and staphylococcus aureus.

4. Cases fall into two groups: in one the patient is acutely ill with septicaemia and the bone lesion is of secondary importance; in the other the general condition is well maintained even though there may be multiple bone lesions.

5. Sequestration is uncommon; but when it occurs it prevents the rapid healing that is usually observed after drainage.

6. The most important complication is suppurative arthritis, which may lead to total destruction of a joint.

7. It is probable that the lowered mortality from infantile septicaemia will be matched by a corresponding increase in the cases of acute osteomyelitis encountered in clinical practice.

1. One hundred and one cases of cancellous chip bone grafting operations for filling of infected bone defects are reviewed.

2. Short-term follow-up showed primary or delayed primary healing in 87 per cent of the cases.

3. Observation after five years revealed a recurrence rate of 20 per cent. The recurrences were successfully overcome by minor procedures except in five patients, who suffer from repeated flare-ups of infection.

4. At the present time, 91 per cent of the lesions are satisfactorily healed with a partial or complete bone graft intact. There have been ten failures.

5. The criteria for successful cancellous chip bone grafting of osteomyelitic cavities are discussed.

1. Seven cases of localised lumbar spine defects in children associated with low back pain are described.

2. The importance is emphasised of the recognition and differentiation of the condition from tuberculosis, which it may resemble both clinically and radiographically.

1. A case of calcification in the intervertebral discs of a child is described.

2. The difference in the condition as it affects children and adults is discussed.

3. The etiology is considered but no definite conclusion is suggested.

Sprain of the pisiform triquetral joint is a definite clinical entity. It presents as a "tenosynovitis" of the flexor carpi ulnaris muscle from which it can be distinguished by the tests described. The disability in most cases is such that operation is justifiable. Fusion of the pisiform-triquetral joint is preferred to excision of the pisiform because it restores stability to the wrist with the least disturbance to related structures.

1. Details of clinical, radiological, biochemical and histological investigations of a case of metaphysial dysostosis are presented.

2. The patient was a boy of seven years, and showed widespread lesions (involving long bones of limbs, small bones of hands and feet, pelvis, clavicles, and ribs) characterised by retardation of growth and ossification with masses of partly calcified tissue in the metaphyses.

3. No radiological, clinical or histological evidence of renal osteodystrophy was found in the case described.

4. Metaphysial dysostosis is discussed in relation to other chondrodystrophies.

1. The literature of dislocation of the hip in childhood from 1922 to 1954 is reviewed. A total of eighty-eight cases have been recorded.

2. A further case, in a child of one year and eleven months, is described.

3. Nine of the children whose cases have been recorded developed Perthes' disease of the hip after the dislocation, an incidence of 10 per cent. A similar incidence of avascular necrosis of the femoral head has been reported after dislocation of the hip in adults.

1. A case of Fanconi's syndrome, with evidence of renal tubular dysfunction, is reported.

2. Healing of the rachitic lesions followed massive doses of calciferol. There was simultaneous improvement in the biochemical state. This case is probably unique in that the amino-aciduria disappeared.

3. Two-stage osteotomies were undertaken for the correction of severe bowing of the tibiae.

4. No toxic symptoms have developed so far from the calciferol therapy.

1. A case of multiple pseudo-cystic tuberculosis in an American Indian infant is described.

2. The extensive lesions in the skull of this infant are considered to be of particular interest.

3. The possible significance of a bony lesion present at birth is discussed.

1. A technique for bridging bone defects in the forearm with massive iliac graft and medullary nailing is described.

2. The results of fifteen operations are reviewed.

1. Five patients with seven fatigue fractures of the lower third of the tibia are described; two had bilateral fractures. There is a striking similarity in the site and appearance of these fractures.

2. All occurred in middle-aged or elderly people without a history of unusual activity or illness.

3. The fractures are so nearly identical as to constitute an entity which, as far as we are aware, has not been described before.

Results are given of a study of four cases of osteogenesis imperfecta using biophysical methods comprising microradiography, microscopy using polarised light, and x-ray diffraction. Rebuilding of bone tissue was infrequent in the material studied and has been shown to occur in an abnormal manner. The mineralisation of the bone is more uniform than is found in normal bone. The collagen has an abnormal organisation and is sparse. The ultrastructure of bone salts and their orientation are as in normal bone.