1. The results of Chiari pelvic osteotomy have been examined two to six years after operation in a group of eighteen patients with persisting acetabular dysplasia in the second and third decades.

2. The analysis suggests that for a good clinical result it is essential to create a relationship of the new outer acetabular lip to the original lip so that the CE angle is between 20 and 40 degrees and the roof angle is between 10 degrees below and 20 degrees above the horizontal.

3. This may be achieved by a pelvic osteotomy immediately above the joint capsule, angled 10 degrees upwards and inwards and displaced by 50 per cent of the pelvic thickness.

4. Details of the operative technique using a Smith-Petersen approach are presented.

1. Prosthetic acetabular cups of the Charnley and McKee-Farrar designs were cemented into cadaveric pelves using different procedures for preparing the acetabulum.

2. The torsional moments needed to loosen these cups were measured.

3. The torsional moments so measured were found to be from about four to more than twenty times higher than the frictional moments measured in independent tests on the two designs of prosthesis.

4. It is argued that late looseness of the acetabular component after total hip replacement, in the absence of infection, seems most likely to be due to thermal damage to the bone occurring at the time of polymerisation of the cement, and to subsequent bone resorption.

5. Surgical preparation of the acetabulum should include removal of all the articular cartilage and cleaning of the acetabular fossa, but the drilling of additional holes in the floor of the acetabulum seems unimportant.

6. The possibility of fatigue fracture in bone as a factor contributing to late loosening is an argument in favour of metal-on-polyethylene prostheses with their lower frictional moments, although the importance of this factor cannot be estimated.

1. Nine cases of stress fracture of the pelvis after total hip replacement are reported, five after Ring replacement and four after a McKee. In none of the cases did the fractures unite.

2. In three cases infection was probably an important cause of the fracture. In six cases there was no infection. Only one presented a history of injury.

3. The combination of the various factors that might have caused the stress fractures is discussed.

1. The results of thirty-five acutely slipped upper femoral epiphyses, treated from 1950 to 1969, are presented. Avascular necrosis of the femoral head occurred in five cases.

2. Skin traction with medial rotation, followed in three to four days by internal fixation, without further manipulation, is recommended so that this iatrogenic complication may be avoided.

1. In a prospective controlled trial in patients undergoing hip operations, six out of thirty-three patients receiving prophylactic Dextran 70, and five out of thirty-three patients receiving only dextrose, were shown by ascending phlebography to have ilio-femoral thrombosis. Oedema was the only consistent clinical finding.

2. This study does not therefore support the conclusion of other reports that Dextran 70 is of value in preventing ilio-femoral thrombosis after operations on the hip joint.

3. It is suggested that patients needing operation on the hip joint are especially prone to major vein thrombosis and it may be that higher dosage of Dextran 70 is indicated.

4. This controlled investigation of sixty-six patients, now submitted as a preliminary report, is continuing.

1. The various methods of assessing the results of hip arthroplasties have been investigated.

2. The different results obtained by using different methods are very significant.

3. The importance of achieving a generally agreed assessment is obvious.

1. Three cases of cystic angiomatosis of bone are presented and the literature is reviewed.

2. The typical radiological appearances are described and illustrated.

3. The diagnosis must be confirmed by biopsy, and it is essential that the bone removed should be from an involved rib.

4. The prognosis is dependent upon extraskeletal visceral involvement and is not influenced by radiotherapy or chemotherapy. Splenectomy may improve the chance of survival when the spleen is the only viscus involved.

1. The history of microvascular surgery is reviewed; the necessary instruments and the technique of suture are described.

2. Modern trends in the experimental and clinical applications in orthopaedic surgery and traumatology are discussed.

3. The authors emphasise the usefulness of this technique in tissue transplantation and in the reconstruction of microvascular injuries of the musculoskeletal system.

1. Resolving infantile scoliosis is transient and unimportant; progressive infantile idiopathic scoliosis can be catastrophic.

2. To be able to differentiate the two at an early stage is a considerable advance. This is important for many reasons, but particularly for parents who are anxious for the future of an infant with a small curve which looks so innocent but which can be so malignant.

3. With the new observations reported by Mehta on the difference of the angles between the apical vertebra and its two ribs, and on the radiological relationship of these rib heads to the vertebral body, the prognosis is now almost wholly reliable.

4. Our former clinical impression that all cases with compensatory curves are progressive has now been verified.

5. At last an early distinction between progressive and resolving scoliosis can be made with confidence.

1. French in 1946 presented eight cases of arachnoiditis complicating a lumbar disc lesion; five further cases are reported here.

2. It is suggested that repeated minor persistent trauma produces the strictly localised changes in the arachnoid, in the same sort of way that it may produce ulnar neuritis at the elbow.

3. The various causes of arachnoiditis are discussed.

4. The place of operation has been found difficult to assess.

1. Twenty-two feet injured at the tarso-metatarsal level are reviewed.

2. Experiments with eleven cadaveric feet are reported.

3. The injuries are caused by forced plantar-flexion combined with rotation in most cases. Crushing of the foot alone often does not produce dislocation.

4. A classification is suggested.

5. The results of various treatments in this small series are presented. It is concluded that anatomical reduction is important, achieved if necessary by operation and internal fixation.

1. One hundred and twenty-six metacarpo-phalangeal joints affected by rheumatoid arthritis were studied macroscopically at either synovectomy or arthroplasty.

2. The sites and extent of the initial erosion corresponded with the sites and size of the synovial pouches.

3. The areas of cartilage degeneration were related to the degree of flexion, ulnar deviation and subluxation of the proximal phalanx on the metacarpal head.

4. The routine radiographic findings were not a true reflection of all the pathological changes within the joint.

5. It is suggested that by encouraging joint movement and preventing deformity the degree of cartilage degeneration may be diminished.

1. Twelve cases of hydatid disease of bone seen in Kuwait over the last ten years are reported. Ten of the twelve patients were Bedouins.

2. Seven cases were followed up and the results of treatment are discussed.

3. Curettage, formalin swabbing and bone grafts were used as the treatment of choice.

4. There may be a place for a conservative approach in some cases ; one such case reported here has been followed up for ten years.

5. The problem of prevention, especially in a Bedouin area, is briefly discussed.

1. Joint compliance estimations were made on the knee joints of fourteen patients with rheumatoid arthritis, three patients with osteoarthritis and three healthy volunteers.

2. Diminishing values for capsular compliance were found in the normal volunteers, the patients under the age of thirty-five years with rheumatoid arthritis, the patients with osteoarthritis and the patients over the age of forty years with rheumatoid arthritis respectively.

3. In the young adult normal volunteers the average compliance was 8·1 cubic centimetres per millimetre of mercury at an intra-articular pressure of 5 millimetres of mercury and 0·7 cubic centimetre per millimetre of mercury at 50 millimetres of mercury. In the older patients with rheumatoid disease the average compliance was 2·1 cubic centimetres per millimetre of mercury at 5 millimetres of mercury and 0·4 cubic centimetre per millimetre of mercury at 50 millimetres of mercury.

4. Both the effects of ageing and the effects of disease appeared to be responsible for the low capsular compliance observed in patients over the age of forty years with rheumatoid arthritis, but duration of disease did not seem to be a contributing factor.

The case illustrated substantiates the explanation of the rare epiphysial separation of the head of the radius with 90 degrees backward tilting referred to above as Group 2. It suggests also that the initial fall on the hand may loosen the capital epiphysis.

The undesirability of reducing dislocations of the elbow merely by pulling on the hand of the injured limb is emphasised. The dislocation should be reduced by gentle traction accompanied by pressure with the thumbs on the front of the displaced olecranon.

A case of total dislocation of the ilium after disruption through the tri-radiate cartilage in a girl of thirteen years is described. No previous description of this injury has been found.

1. The femoral head has been examined in specimens taken from cadavers, patients suffering subcapital fracture of the femoral neck and patients undergoing total replacement arthroplasty for osteoarthrosis and rheumatoid arthritis.

2. Lesions have been seen, some of which appear to be uniting fatigue fractures of individual trabeculae.

3. It is suggested that excessive cyclical loading, sometimes leading to fatigue fractures, may represent a fundamental pathological process of general importance in the evolution of certain skeletal and articular diseases.

This experiment demonstrates that infiltration of hydrocortisone into rabbit calcaneal tendons has a direct effect on the tendon, producing necrosis of collagen at the site of injection. The repair of the lesion so produced is incomplete even after eight weeks, and is often complicated by dystrophic calcification. Similar morphological changes may account for spontaneous rupture of tendons in patients receiving steroid infiltration.

1. Into osseous defects cut in the pelvis of rats, Kiel bone grafts were implanted after impregnation with the animals' own fresh bone marrow, obtained by femoral puncture. Unimpregnated Kiel bone grafts and Kiel bone grafts impregnated with an antibiotic solution were implanted as controls.

2. Histological examination of the implant area showed that in the marrow-impregnated grafts new bone formation could be observed after twelve days, and that during an observation period of 135 days after implantation bone formation occurred in thirteen out of nineteen rats. In four of these cases a continuous bony bridge developed over the defect.

3. In the unimpregnated grafts no more than a small amount of new bone was seen in only one of seven rats. In the antibiotic-impregnated grafts no bone formation was found in six rats during the same period of observation.