In a retrospective study we compared the results of 31 Wilson and 31 Hohmann osteotomies of the first metatarsal in the treatment of hallux valgus. There were no differences between the two operations in terms of patient satisfaction, pain relief, appearance, footwear and walking ability. First metatarsal shortening was the same after both operations, and the degree of shortening was unrelated to either the clinical or the pedobarographic findings. Although the long-term radiographic changes after the Hohmann osteotomy were more worrying, the pedobarographic patterns tended to be worse after the Wilson osteotomy. There were no poor results and the numbers of feet with the same final grade were identical in each group. However, there was abnormal loading of the lateral metatarsal heads after both osteotomies when compared with the normal foot, and hallux-contact time during the stance phase was also significantly reduced after osteotomy.

Quantitative polarised light microscopy was applied to sections of unfixed, undecalcified bone taken at operation from patients with two types of proximal femoral fracture, subcapital and trochanteric. Specimens were also taken from the equivalent sites in otherwise normal subjects at autopsy, and from various other sites of traumatic fractures; these two latter groups acted as controls. Analysis of the 57 specimens disclosed changes in the nature of the bone at the site of subcapital fractures, namely the presence of relatively large crystals of hydroxyapatite and a change in the molecular orientation, but not total content, of the acidic proteoglycans of the bone matrix. Our results have confirmed and extended the findings of others on subcapital fractures, and have also shown very similar changes in the trochanteric fractures. It thus appears that the bony changes in the two types of proximal femoral fracture are not as different as has been suggested.

In an attempt to improve the accuracy of diagnosis, 16 patients suffering from Morton's metatarsalgia were investigated clinically and electrophysiologically. The histological findings were related to these observations. The precise aetiology of Morton's metatarsalgia remains obscure, but the findings are compatible with an entrapment syndrome. Nerve conduction studies have a place in the investigation of patients with atypical presentation of pain in the foot. Further refinement of the electrophysiological technique should be possible.

The aim of this study was to try to elucidate the increased susceptibility of the neck of femur to fracture. Quantitative polarised light microscopy has been applied to fresh, undecalcified sections of samples of bone taken from the site of fracture, in specimens taken at operation from patients with fractures of the femoral neck or osteoarthritic femoral heads or from the equivalent site from otherwise normal subjects at necropsy. In all 21 specimens of fractured necks of femur, but in none of the other specimens, relatively large crystals (up to 2.5 X 0.5 micrometres) were found close to the site of fracture; the properties of these crystals were compatible with their being apatite. Measurement of the natural birefringence of the collagen showed no difference in the orientation of the collagen in all three types of specimen. However, the orientation of acidic glycosaminoglycans, measured by the birefringence of alcian blue bound to these moieties, was 45 per cent lower in the specimens from fractured necks of femur than in the other specimens, even though the total content of acidic glycosaminoglycans was unchanged. Although the decreased orientation was most marked close to the site of fracture, it was still apparent 15 millimetres from that site. These changes were unlikely to be simply the sequelae of fracture since they were not found in traumatic fractures of other bones. Thus it is conceivable that changes in the orientation of the ground substance allow formation of relatively large crystals of apatite and that such crystals, in the microcrystalline mass of apatite, are the cause of the increased fragility of such bones.

The effect of the application of a tourniquet to a limb and the release of the accumulated metabolites have been investigated with reference to the acid-base level in the blood from the limb and in the right atrium. Investigations have been carried out experimentally in rhesus monkeys and observations have been made on patients undergoing reconstructive operations on the knee. The acidotic blood from the ischaemic limb produces little systemic effect. The limb recovers in approximately 40 minutes after a tourniquet has been in place for four hours. Three hours is recommended as a reasonable upper limit for the safe application of a pneumatic tourniquet.

Experiments have been carried out on rhesus monkeys to determine the effect of the application of a pneumatic tourniquet on the ultrastructure of the muscles of the lower limb. Tourniquets were applied for periods lasting between one and five hours. The changes in the muscle lying immediately under the cuff of the tourniquet were more marked than those observed in muscle distal to the cuff. Three hours appears to be close to the limit of the time that a muscle can resist the sustained compression of a tourniquet.

The diffusion of Fucidin, gentamicin, and clindamycin from acrylic cement was tested in an in vitro system. The activity of Fucidin was very short-lived and only against gram-positive organisms; gentamicin inhibited gram-positive and gram-negative organisms for twenty-two and eleven days respectively; clindamycin had significant action only against gram-positive organisms and retained some activity for fifty-six days. We suggest that the destruction of organisms in the tissues is more likely to be achieved by topical and intravenous administration of antibiotics during the operation than by incorporation of antibiotic in the cement.

1. A case of anterior sacral meningocele is described in members of a family consisting of a woman, her father and his brother.

2. This is the first recorded case of this anomaly in members of the same family of different sex, and only the second recorded case of occurrence in the same family.

1. A study of fifty femoral heads removed at operation for primary prosthetic replacement showed a remarkable constancy of the fracture line.

2. It is suggested that two sub-groups of this fracture-subcapital and transcervical-have been described as a result of radiological interpretation without consideration of the effects of varying degrees of rotation.

1. Two girls with non-familial osteogenesis imperfecta who subsequently developed osteosarcoma of the femur are described. One is of special interest in that there were multiple bone metastases.

2. It is suggested that the tumours arose spontaneously and were not related to the underlying bone disorder.

3. Because of the relative frequency of hyperplastic callus formation in osteogenesis imperfecta it is most important that adequate biopsy material of any suspicious lesion is examined because the early clinical picture may be indistinguishable from a tumour.

1. Three patients with backache and spinal cord or cauda equina compression due to Paget's disease of the vertebrae are reported; all three were relieved by laminectomy.

2. One case is of particular interest because it is only the second one reported where compression was due to a single affected vertebra.

1. It appears that fracture of the humeral shaft occurs more often in persons over fifty. This incidence corresponds with that found in a study carried out by the Pennsylvania Orthopaedic Society in 1959.

2. The middle third of the bone is the most vulnerable portion of the shaft, where transverse fracture and radial nerve palsy most commonly occur.

3. Most fractures of the shaft of the humerus are best treated by simple splintage. The degree of radiological deformity that can be accepted is far greater than in other long bones. In this group anterior bowing of 20 degrees or varus of 30 degrees was present before it became clinically obvious and even then the function of the limb was good.

4. Internal fixation is only occasionally indicated but operation on the middle third of the bone increased the chances of delayed union.

5. In the treatment of delayed union intramedullary fixation and the application of slivers of iliac bone is effective in stimulating the fracture to join.

The history of surgery is to a large extent written around the record of its technical advances. A pneumatic tourniquet is a humble instrument, when compared with many of the more complicated mechanical devices in the modern operation theatre. Nevertheless, it has played a significant role in making possible the precise operations of present-day orthopaedics. Simple tool though the tourniquet may be, its application carries many potential dangers, and it should only he entrusted to skilled hands.

1. Four out of five patients with spondylolisthesis, four-fifths of whom were seen at least five years after operation, had their symptoms relieved after posterior spinal fusion.

2. In a small series of patients treated by anterior spinal fusion, the results were less successful.