1. Chondrosarcoma is a malignant tumour of bone with clinical and morphological features which distinguish it from osteosarcoma. 2. Cartilage tumours present an unbroken spectrum in their clinical behaviour and histological appearances from the entirely benign to the frankly malignant. 3. A few chondrosarcomata, particularly those in children and young adults, run a rapidly fatal course but in general they metastasise late and some kill by local extension of the tumour. 4. "Secondary" chondrosarcomata arising from a pre-existing osteocartilaginous exostosis or enchondroma are mostly low grade tumours. 5. The first appearance of an osteocartilaginous exostosis after skeletal maturity, renewed growth, or pain unassociated with a fracture, should arouse suspicion of malignancy in any cartilage tumour. 6. Cartilage tumours of the trunk and upper end of femur and humerus are especially liable to sarcomatous change. 7. Although most benign cartilage tumours occur in the hand and foot they rarely become malignant with the exception of those in the calcaneus. 8. If biopsy is necessary it should be of the incisional type, a generous amount of material being removed from the edge of the tumour. Calcified, degenerate areas must be avoided. 9. In low grade tumours microscopic fields judged to be malignant by Lichtenstein and Jaffe's well established criteria may be scanty and many paraffin sections should be examined. Absence of mitotic figures, heavy calcification and poor vascularity are no guarantee of benignity. 10. Information as to the site of the tumour and age of the patient must be available to the pathologist if a useful report is to be given. 11 . In "borderline" tumours or where any difficulty in diagnosis arises the clinical, radiographic and histological features must all be taken into account and treatment based on the most unfavourable features. 12. Chondrosarcoma is a radio-resistant tumour and treatment is by radical excision or amputation. 13. Malignant cartilage cells implanted in the tissues at operation will often continue to grow and in all instances the biopsy wound and surrounding tissues must be removed en bloc with the tumour. 14. Small, low grade, readily accessible, peripheral tumours may be successfully treated by excision with a wide margin of healthy tissue. 15. In the limbs or pelvis large tumours and those of high grade malignancy should be treated by amputation. Since marrow permeation is often greater than the radiograph suggests amputation should, as a rule, not be performed through the bone in which the chondrosarcoma is situated. 16. Recurrence carries the danger that an initially accessible tumour becomes inaccessible and inoperable and, less frequently, a low grade tumour recurs in a metastasising form. 17. Recurrence is frequent after inadequate surgery; it indicates that the tumour is at least locally malignant and a cure can usually only then be achieved by more radical surgery.
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. Forty-five patients with monarthritis of at least six months duration have been reviewed. Arthrotomy and synovial biopsy were carried out in every case. The period of follow-up varied from two to eight years from the time of biopsy. A re-examination of the biopsy material was made at the time of clinical assessment. 2. Twelve patients (27 per cent) were diagnosed as having definite or probable rheumatoid arthritis. Four patients (9 per cent) had psoriatic arthropathy and six (13 per cent) had a persistent monarthritis of undetermined type. A further four patients (9 per cent) had polyarthritis of undetermined type, ten (22 per cent) were diagnosed as having osteoarthritis and seven (16 per cent) were completely normal (self-limiting joint disease). 3. There was a moderately good relationship between biopsy findings suggestive of rheumatoid arthritis and the eventual clinical outcome. 4. Monarthritis of the wrist was followed in every case by the development of significant disease, either rheumatoid arthritis or psoriatic arthropathy. 5. Rheumatoid arthritis may remain monarticular for many years. 6. It is concluded that thorough investigation of patients with monarthritis is of considerable help in diagnosis and prognosis.
