1 . Current theories of the etiology of chondromalacia patellae do not explain satisfactorily either its great frequency or its common site of origin on the medial patellar facet.

2. The etiology can be more logically explained by the presence of a ridge on the upper anterior border of the cartilage of the medial femoral condyle, in most knees. This ridge, consisting of cartilage, or cartilage and bone, varies considerably in height and, in normal knee joint movement, causes considerable friction on the medial patellar facet.

3. The degenerative changes were found to be greater in the presence of the larger ridges, and–because of longer wear and tear–in the older patients.

4. This study indicates that chondromalacia was more severe in women than in men, and in patients overweight. Although the activity of the individual and the power of the quadriceps mechanism must play an extremely important part in this condition, it was not possible to assess this.

5. Two factors previously considered to be important in the etiology of this condition, namely, the length of the patellar tendon and Wiberg's Type III patellar shape, have not been confirmed in this study.

6. Resulting from the present investigation certain precautions are suggested in rehabilitation after operations on the knee, and a surgical method for discouraging the progress of this common, and sometimes disabling, condition has been devised.

1 . The results of transplanting the greater trochanter in 225 "low-friction" arthroplasties of the hip have been examined.

2. Non-union occurred in an average of 7 per cent of cases.

3. When non-union occurred the results still showed improvement.

4. Four different methods of fixation were used, of which that using two wires, crossed in the horizontal and coronal planes, never failed to secure union.

5. Transplantation of the greater trochanter to the best position is only possible if the neck of the femur is shortened or if the centre of motion of the arthroplasty is displaced medially by deepening the acetabulum, or by a combination of both.

6. In the best position the transplanted trochanter considerably improved active abduction against gravity.

In this review of 106 cases it appears that immobilisation of a contracted, dislocated or subluxated hip in an extreme position in plaster as the initial treatment caused vascular damage to the femoral epiphysis in approximately 50 per cent of cases. Preliminary frame

reduction in the dislocated hips slowly stretches the soft tissues and allows adaptation of the vessels to the position required for reduction. Open reduction would seem to reduce the incidence of osteochondritic changes. When a hip is immobilised in plaster the extreme of any position, particularly with regard to rotation, should be avoided.

1 . A preliminary report is presented of a clinical trial to compare the results of early and late weight bearing in randomly selected patients of comparable age groups whose displaced femoral neck fractures were treated by internal fixation with a sliding nail-plate.

2. When 124 patients were assessed at three months and 107 at six months after operation there was no significant difference between those who started unguarded weight bearing two weeks after operation and those who avoided weight bearing for three months.

3. Early weight bearing appears to have no harmful effect on the early post-operative stability of this fracture when a sliding nail-plate is used for fixation.

4. Further information is necessary before any conclusion can be reached about the effect of early weight bearing on the ultimate fate of the fracture and of the femoral head. For this reason, and also to increase the numbers of patients in the series, the trial is continuing and the patients are being followed up for a three-year period.

Two hundred and thirty-two ankle fractures were treated in the orthopaedic department of the Royal Portsmouth Hospital between 1959 and 1960. Seventy-one fractures treated by internal fixation with screws have been seen at follow-up examination. Results show that open reduction, secure and accurate internal fixation and early movement without plaster or other splintage is a treatment which in most cases has been followed by a short convalescence, few post-operative complications, and a painless ankle and with good function.

1 . This case of post-traumatic osteochondritis of the lower tibial epiphysis is important because the condition is rare.

2. The similarity to osteochondritis in other sites dating from a single injury is noted.

3. The ankle joint bears more body weight per surface area of articular cartilage than other weight-bearing joint surfaces. It is of interest that regeneration took place in spite of the fact that the child continued to bear weight and that the joint was immobilised for only two months, beginning four months after the original injury.

1 . Two cases of chronic progressive dislocation of the talo-navicular joints are discussed.

2. Radiographs are presented showing the development of the lesions over a period of eighteen years.

3. It is thought that the lesion is caused by laxity of ligaments and subsequent osteoarthritic changes.

1 . A case of plantar Dupuytren's disease in a woman aged twenty-three is described.

2. A review of the literature has shown that the histology and rapid recurrence have led to an erroneous diagnosis of fibrosarcoma and treatment by amputation on several occasions.

1 . An epileptic patient with Dupuytren's contracture of the palms, severe plantar fibromatosis, prominent knuckle pads, periarthritis of the shoulders and hyperplasia of the gums is described.

2. The plantar lesions recurred despite radical excision. The knuckle pads on one hand disappeared after radiotherapy.

3. The association of each of these conditions with epilepsy and with Dupuytren's contracture is reviewed, and it is suggested that the hyperplasia of the gums may be a hitherto unrecognised feature.

4. The characteristic histological appearances of the plantar lesions are described and the risk of confusion with fibrosarcoma is emphasised.

1. Delta phalanx is a rare congenital abnormality not to be confused with other forms of angular deformity of the phalanges.

2. The deformity needs radical treatment by repeated surgery because there is no tendency to spontaneous correction and growth of the phalanx is prevented by the epiphysial deformity.

A case of unilateral hypertrophy of the palmaris longus muscle in a girl of thirteen is described, associated with "simian" hands and feet and unusually coarse skin of the trunk. Symptoms of median nerve compression were relieved by excision of the muscle.

1 . Six patients have been presented in whom an established diagnosis of non-osteogenic fibroma of bone was made. Metaplastic bone was identified within the tumour tissues.

2. Three other patients are reported in whom the diagnosis appeared to be, on radiological and histological grounds, either fibrous dysplasia or non-osteogenic fibroma.

3. This evidence has convinced the author that the two lesions are frequently not distinctive and that they are, in fact, closely related. Because the natural history of the two conditions, especially in their simple or monostotic form, is also the same, there is good reason to consider them as varying histological manifestations of the same pathogenetic process.

1. Three patients with localised periosteal new bone formation associated with periosteal arteritis and other evidence of systemic lupus erythematosus are described.

2. Systemic steroid therapy was valuable in the management of this condition.

A brief review of the literature on malignant change occurring in fibrous dysplasia is given and a further case of a sarcoma arising in a patient with polyostotic fibrous dysplasia is reported.

1 . A case of posterior dislocation of the shoulder treated by open reduction and obliteration of the defect in the head of the humerus by implantation of the subscapularis tendon is reported.

2. It is suggested that this method is indicated in cases in which there is a deep V-shaped depression on the anterior aspect of the humeral head.

1 . The incidence of hydatid disease in bone is discussed and the relevant literature reviewed.

2. The parasitology and methods of control are described.

3. The pathology of hydatid disease affecting bone is described.

4. An analysis of fifty-three cases is made showing that the disease commonly occurs in the spine, the long bones, the ribs and scapula, and the pelvis and hip. The treatment and prognosis of each group is discussed.

5. Three cases of hydatid disease of bone occurring in animals are described.

1 . The arterial pattern and the histological features in the femoral head and neck were studied at necropsy in twenty-five specimens with intracapsular fractures. An improved visual-arteriographic method employing barium sulphate dyed with Prussian blue was used. Twenty-three of the fractures were from a few days to twenty-four weeks old and two were seven and ten years old. Nineteen had been nailed or nail-plated.

2. The results were divided into four groups according to the state of the femoral head. In the first group, four heads were histologically viable and had a normal vascular pattern; in the second group, four showed partial avascular necrosis with part of the head retaining a normal blood supply; in the third group, ten had avascular necrosis in all or most of the head and showed little or no revasculanisation; and in the fourth group, seven showed extensive revascularisation of grossly necrotic heads. Total or subtotal capital necrosis had occurred in 64 per cent and total or partial necrosis in 84 per cent of the specimens. The results indicated that interruption of the retinacular vessels was the cause of gross necrosis; and that in most cases an intact blood supply through the ligamentum teres cannot keep more than a part of the head alive when the other vessels are cut off. Occasionally the ligamentum teres is torn by the nail, or though intact, its blood supply is interrupted. This accounts for completion of avascular necrosis in most cases with total capital necrosis. Viability of the subfoveal area from an intact supply through the ligamentum teres was the main source of revascularisation after capital necrosis. Other sources–from across a uniting fracture line, from growth of soft tissue round the head and neck and from other small viable foci in the head and neck–were much less important and the degree of revascularisation was generally limited. Revascularisation was accompanied by fibrocellular invasion of the marrow, differentiation of cells and the formation of oil cysts whereby the necrotic fat is removed; but bony reconstitution was limited.

3. Six fractures were uniting and another had united by bone making an overall union frequency of 50 per cent considering only the nailed fractures older than two weeks. Four of them (57 per cent) showed total or subtotal capital necrosis. In fractures older than two weeks the frequency of union among the eleven nailed fractures with avascular necrosis was 36 per cent, and it was 100 per cent among the three nailed ones with viable or substantially viable heads. Necrosis of the neck side of the fracture was unrelated to non-union because it soon becomes invaded by fibrovascular tissue and new bone.

4. Fibrosis was the basis of union when the head was dead but examination of older fractures at necropsy is needed to assess the long-term results of revascularisation and union. The clinical desirability or otherwise of capital revascularisation after necrosis also needs to be studied.

1. A method of constricting sciatic nerves of rats was devised which produced lesions resembling macroscopically and electromyographically those of carpal tunnel and related syndromes.

2. The nerves became swollen and hyperaemic proximal and distal to the constriction. The swellings were largely caused by an accumulation of fluid between the axons, but the axons themselves were also increased in size.

3. This accumulation of fluid was an oedema secondary to a partial obstruction of the vasa nervorum.

1. The menisco-femoral ligaments, extending from the posterior horn of the lateral meniscus to the lateral aspect of the medial femoral condyle, were found in ninety-nine (71 per cent) of the 140 knees examined. Fifty per cent of the ligaments were identified as the anterior menisco-femoral ligament while the remaining 50 per cent were of the posterior type.

2. During flexion of the knee with the foot fixed the menisco-femoral ligaments pull the posterior horn medially and slightly anteriorly, increasing the congruity between the meniscotibial socket and the lateral femoral condyle.

3. During lateral rotation of the femur with the knee flexed the menisco-femoral ligament pulls the posterior horn medially and slightly anteriorly, in this way increasing the risk of the posterior horn being crushed by the lateral femoral condyle. It is suggested that this is prevented by the contraction of the tibio-meniscal portion of the popliteus muscle which pulls the posterior horn of the lateral meniscus posteriorly.

4. When removing the lateral meniscus it may be advisable to make another incision in order to free the posterior horn from its attachment to the popliteus muscle and then to cut the menisco-femoral ligaments under direct vision.

1. Radiographs of both shoulders were performed on 106 unselected necropsy subjects and those found to be abnormal were examined pathologically.

2. Radiological abnormalities were found in sixty-eight shoulders of thirty-eight subjects. Pathological examination showed rotator cuff tears and associated abnormalities in thirty-five of these, rheumatoid arthritis in one, a previous fracture in one, and one was not examined.

3. The criteria for radiological diagnosis of rotator cuff tears are examined and discussed.

4. The radiological changes give little indication of the severity of the tears or associated abnormalities except in the case of complete rupture of the cuff when acromio-humeral articulation occurs.

5. The lesions are all explicable on a traumatic basis. There is no correlation with the presence or absence of osteoarthritic disease of the joint.

6. The biceps tendon may become damaged or even ruptured in this condition.

7. Villous synovial proliferation was found in fourteen cases, in five of which it was pigmented with histological appearances resembling pigmented villonodular synovitis. The significance of this finding is briefly discussed.

1. Experimental defects in the cranial vaults of young adult rabbits were implanted with decalcified, deproteinised and deep frozen homogenous whole bone. The experiments were similar to those of Ray and Holloway (1957) except that these workers used rats as the experimental animals. In addition, six control defects were made and not implanted.

2. All animals were killed six weeks after operation and thirty-four defects were studied by radiology and by histology.

3. All implants became surrounded by connective tissue and in all cases some new bone formed in apposition to implanted fragments. The degree of incorporation of the implants in new bone varied widely, not only between the three implanted groups, but also within each group. In general, new bone formation was greatest in defects implanted with deproteinised and whole bone, least in defects implanted with decalcified bone.

4. The fate of bone implants and the extent to which they can be said to induce osteogenesis are discussed.

1. The results of the present investigation indicate that in the foetal rat the juxta-epiphysial vascular bed consists of a dense irregular network of sinusoids in direct contact with the growth cartilage, supplied by end-arteries, and drained by a profusion of metaphysial sinusoids.

2. The circulation is a closed one–that is, the endothelium is unbroken in its continuity and microhaemorrhages do not occur against the cartilage.

3. It is possible that juxta-epiphysial endothelial cells or their derivatives are chondrolytic, and that they participate directly, together with other mesenchymal derivatives, in the removal of cartilage as a preparatory stage in enchondral bone formation.