Dysplasia of the hip is almost unknown in the Bantu peoples of Africa, except in cases of arthrogryposis and in those with partly European ancestry. Evidence is produced to show that the importance of intrinsic genetic factors in hip dysplasia far outweighs that of the extrinsic factors. These are of great importance only if allowed to act on a hip in which genetic factors have already determined dysplasia. Evidence is also produced to contradict the theory that the "piggyback" carrying method used by Bantu mothers is the reason for the immunity from dysplasia of the hip. The absence of "primary" osteoarthritis of the hip is noted, and the range of hip disorders leading to "secondary" osteoarthritis in the adult African is compared with that in the adult European. Three patients are described, one in each of the groups mentioned above, the third having an isolated "typical" congenital dislocation of one hip. The methods of study used were enquiry into obstetric history and into carrying methods, and arthrography to confirm clinical findings. The experience of other surgeons working in Africa is recorded.

Failure of normal acetabular development is inevitable in congenital dislocation of the hip when it is unrecognised until late infancy or early childhood. Numerous stabilising procedures have been described, one of the first being the shelf operation or acetabuloplasty. This procedure fell into disrepute because the shelf was often located too high or was too small to prevent upward migration of the femoral head. The technique described emphasises the importance of resecting the thickened capsule and exposing the lateral margin of the acetabulum to allow a substantial portion of the outer cortex of the ilium to be turned down both laterally and anteriorly over the femoral head. Twenty cases of acetabuloplasty have been followed up for an average period of nine years. The results have been assessed from the point of view of function, relief of pain, and degree of support of the femoral head as demonstrated radiologically. The shelf operation is a simple and safe procedure, and provided it gives adequate support to the subluxated femoral head it will ensure a stable, mobile joint capable of standing up to reasonable use for many years. If deterioration should occur in later life, total hip replacement may be undertaken more easily than if the joint had been allowed to undergo progressive subluxation.

The medial displacement osteotomy of Chiari has an established place in the management of older children and adults with severe hip dysplasia. The results claimed for the operation are, however, variable. There have also been reports of sciatic nerve lesions. In this study ten cadavers were operated upon. Chiari osteotomy was performed upon five, and five acted as controls. The hemipelvis was removed from each cadaver; each specimen was deep-frozen and sectioned transversely. The distance of the sciatic nerve from the nearest bony point was measured in each section and the results were recorded graphically. A further radiographic and photographic study was performed to determine whether apparent displacement at the osteotomy might be misleading. The conclusion was drawn that the sciatic nerve is angulated at the osteotomy and further endangered by the risk of bone splintering at the sciatic notch. The radiographic study suggested that some poor clinical results may be explained by a radiological artefact, because there is a tendency for the osteotomy to hinge posteriorly at the sciatic notch opening anteriorly like a book. Radiographs may suggest excellent medial displacement whereas in fact the femoral head is very poorly covered.

Four cases of slipped upper femoral epiphyses in patients with intracranial tumours causing hypopituitarism and chiasmal compression are presented. Detailed endocrine studies in three cases showed severe deficiencies of growth hormone as well as of gonadotrophin and sex hormones. The literature is reviewed and the aetiology is discussed with special reference to Harris's hypothesis that an increase in growth hormone relative to oestrogen predisposes to slipping of the upper femoral epiphysis in humans, which these cases do not seem to support. In all cases the slip was bilateral, and it is emphasised that surgical treatment can provide only temporary fixation because fusion is dependent on correct hormonal therapy.

The division of osteoarthritis into primary and secondary varieties implies that these are aetiologically distinct entities, the former being due to some intrinsic defect of cartilage and the latter resulting from previous articular damage. This traditional concept is questioned and the hypothesis is advanced that osteoarthritis is always secondary to some underlying abnormality of the joint. A detailed clinical, radiographic and morbid anatomical study of 327 cases of osteoarthritis of the hip is presented. In all but twenty-seven some predisposing abnormality of the joint was diagnosed: 107 (33%) were associated with major pathology such as Perthes' disease or epiphysiolysis; minor acetabular dysplasia was present in sixty-seven (20%), with a male: female ratio of 1:10; minimal femoral head tilt was demonstrated in fifty-nine (18%), the male: female ratio being 14:1; and in forty-three (13%) there were features suggesting an underlying inflammatory arthritis. On the basis of this study a new classification is proposed and osteoarthritis of the hip is divided into three pathogenetic groups: 1) failure of essentially normal cartilage subjected to abnormal or incongruous loading for long periods; 2) damaged or defective cartilage failing under normal conditions of loading; 3) break-up of articular cartilage due to defective subchondral bone.

A clinical study has been made of forty-three patients with symptoms arising from degenerative spondylolisthesis of the lumbar spine. Attention is drawn to the lower average level of the iliac crests in these patients, and to the high incidence of osteoarthritis of the hips. Many patients in this series had been referred specifically for operation and fourteen were so treated. The techniques of decompression and of spinal fusion are discussed. It is concluded that patients with back pain predominant are well treated by corsetry, only a minority needing fusion, and that patients with nerve root involvement or with symptoms of spinal stenosis need decompression. The place of spinal fusion is the main problem, but it seems reasonable, firstly, in younger patients with clear evidence of instability and degenerative change at a single level, and secondly, when radical decompression is judged to increase the risk of instability.

A system is presented for the analysis of failure after spinal operations: 1) outright failure; 2) temporary relief; 3) failure in spondylolisthesis; and 4) infections. With this system it is possible to trace the causes of failure and to correct some of them. When they are used as a guide before operation, the recommendations made should help to prevent many failures.

At the apex of an idiopathic scoliotic curve there is a greater proportion of "slow twitch" muscle fibres in multifidus on the convex as compared to the concave side. To determine whether this represents a primary muscular imbalance relevant to the aetiology of idiopathic scoliosis or merely a secondary change, the lengths of multifidus on opposite sides of the curve were measured. Multifidus is shorter on the convex side. This is consistent with the theory of primary muscular imbalance, in which the more tonically acting muscle with its higher proportion of "slow twitch" fibres contracts and shortens as the deformity is produced. The paradox of multifidus being shorter on the convex rather than on the concave side is explained by consideration of its action.

The clinical, radiographic and pathological features are described of eight cases of a bone tumour which we propose to classify as "malignant osteoblastoma". It presents the characteristics of genuine osteoblastoma but of an aggressive pattern, with more abundant and often plump hyperchromatic nuclei, greater nuclear atypia, and numerous giant cells of osteoclastic type. This rare tumour is regarded as the malignant counterpart of osteoblastoma and appears to be only locally aggressive. It should be separated from conventional osteosarcoma not only because of its peculiar histological pattern, but also because of its different clinical and radiological features and better prognosis. Thus seven of the eight patients were alive and free of disease from one and a half to eleven years after the initial surgical treatment, which in only two cases included amputation. Excision or block resection is the preferred method of treatment.

Eighteen cases of bone and joint tuberculosis in children were diagnosed in the Stockholm region (about 1,500,000 population) over the period 1961-1974. BCG infection was verified by culture and identification of bacterial type in seven, all after 1968. The same origin can be presumed in most of the remaining eleven cases, in spite of the absence of bacterial verification. The increased frequency of complications after BCG vaccination may necessitate a revision of the vaccination programme. We recommend operative treatment, which has not led to any growth disturbances or impairment of joint function, although the lesions were invariably localised close to growth zones and joints.

A new technique of tibialis posterior transfer is described which has been used in a wide variety of conditions producing muscular imbalance in the foot. The results in eighty-five feet are reviewed in terms of range of motion, power and voluntary control of the transfer. The effect of the transfer on shoe wear, on the necessity for bracing and on the child's or his parents' assessment of the results are used to allocate an overall evaluation of the operation. Recommendations on the indications for the operation are given.

We have considered the indications for and results of transplanting pronator teres to extensor carpi radialis brevis in cerebral palsy. The operation has some virtue but a very limited application. We achieved satisfactory functional results in six of nine patients and some improvement in one. Two operations failed because of poor selection. In all patients the appearance of the limb was improved.

Paralytic clawing of the hallux may occur in children with congenital disorders of the neuraxis. Tenodesis of flexor hallucis longus allows correction of this deformity in early childhood. Seventeen of these procedures have been reviewed and good results were obtained in fifteen.

The results of ten excision arthroplasties of the elbow for rheumatoid disease are described. The operation may afford good relief of pain and a useful increase both of hinge motion and of forearm rotation. Instability is not a serious problem unless the patient has to bear weight on crutches. To increase stability after arthroplasty it appears that Kirschner wire fixation is advisable as well as a plaster cast. For advanced rheumatoid disease unilateral excision arthroplasty has a definite value, especially for patients confined to a wheelchair.

The effects of splintage, suture and excision of the tendon sheath on the healing of incompletely transected flexor tendons in the rabbit have been evaluated separately and in various combinations. When all procedures were done together, repair was accompanied by dense adhesion formation with little evidence of any healing activity by the tendon cells. The experiments indicated that the adhesions were the result not of any one single factor studied but of all three contributing in varying degrees. Suturing produced the most adhesions but synovial sheath excision and immobilisation also contributed. It is suggested that these factors are also responsible for the adhesions which occur after flexor tendon repair in clinical practice.

Eighteen patients with acute dislocation of the patella had associated osteochondral fractures. This fracture complicates approximately 5% of all acute dislocations of the patella occurring in children. Three types of fracture patterns were noted. All patients who were treated by immediate arthrotomy and excision or replacement of the osteochondral fragment and repair of the acute dislocation of the patella made an uneventful recovery with no recurrence of the dislocation. In those patients in whom the osteochondral fragment was removed but with no repair the dislocation recurred.

Eight patients had symptoms from ganglia arising from the superior tibio-fibular joint with physical signs that resembled the anterior tibial and peroneal compartment syndromes. Five ganglia were in the peroneus longus muscle in which they produced only an ill-defined firmness. Histologically the ganglia showed much cellular activity which must not be mistaken for malignant change.

A rare case of intra-osseous glomus tumour is described, together with a review of eight other reported cases. Electron microscopic studies suggest that glomus cells, the histogenesis of which has not been completely resolved, originate from smooth muscle. Studies in this case support that hypothesis: they showed the important role of contraction of the glomus cells in eliciting the peculiar type of pain.

The localisation of acute haematogenous pyogenic osteomyelitis following a local injury is well known. Whilst there is often a history of trauma in patients developing bone and joint tuberculosis, its role is obscure. Two patients are reported who developed histologically proven tuberculosis in the vicinity of closed fractures during the healing process. These two patients make a total of four so far reported.