1. The technique of the intra-articular surgery employed by the late Mr K. H. Pridie for osteoarthritis of the knee is described.

2. The results of sixty-two operations in sixty patients are analysed. The results in forty-eight knees (77 per cent) were pleasing to the patient. Forty knees (64 per cent) were rated as good at review.

3. The operation is most suitable for relatively active healthy people whose disability warrants a comparatively painful operation and lengthy rehabilitation.

4. The operation was most successful for relieving pain and improving stability. Functional improvement was less.

5. Results were remarkably permanent. The knees showed little tendency towards further deterioration.

6. Most of the bad results were associated with removal of the patella. A possible technical reason for this has been discussed.

Bilateral interlocking of the articular facets of the cervical spinal column results from excessive flexion. Unilateral interlocking (hemiluxation) results from simultaneous excessive flexion and rotation. Patients with hemiluxation of the cervical spine often have only mild complaints and the clinical signs may be slight. The diagnosis is made radiologically, but it is often overlooked.

Various forms of treatment may give good results. In recent hemiluxation, reduction is advisable to promote recovery of radicular symptoms. The effect of reduction on spinal cord symptoms is uncertain. Manual reduction under general anaesthesia is usually successful, with the possible exception of some cases of interlocking at C.6-C.7, or C.7-T.1. Skull traction with weights of 5 to 10 kilograms even when prolonged is hardly ever successful; with weights of 10 kilograms or more there is a chance of success. Surgical reduction is not always necessary. A hemiluxation of more than two weeks' standing may still be reduced but non-operative methods offer little chance of success. In this series there has been no aggravation of the neurological deficit after reduction. Although hemiluxation shows a tendency to spontaneous stabilisation it is wise in our opinion to apply some form of fixation. The selection of the method of fixation depends on the neurological picture and on the estimated degree of instability. The latter depends on the presence or absence of additional damage to the interlocked and adjacent vertebrae. Manual reduction by means of traction in the longitudinal axis of the cervical spine under general anaesthesia with muscle relaxation, followed by immobilisation in a plaster jacket (Minerva type) for three months is successful in many cases. If surgical stabilisation is considered necessary an attempt at manual reduction should be made before operation so that when the patient is placed on the table the cervical spinal canal has regained its normal shape. In general, sufficient stability will have been achieved after approximately three months, so that for hemiluxations of more than three months duration surgical treatment will only rarely be necessary. Figure 11 shows the methods of treatment that we advise.

1. The results of the treatment of 100 congenitally dislocated hips out of 102 treated consecutively are reported.

2. The follow-up has been from five to fifteen years and the treatment of all has been the same.

3. The importance of adequate growth potential which determines the future development of the hip is stressed.

1. The frequency of variable degrees of ischaemia of soft tissue in closed tibial and fibular shaft fractures is emphasised.

2. Two cases with ischaemia of calf musculature are described.

3. A follow-up study of 100 cases of closed tibial shaft fractures is analysed; ten patients were found to be affected.

4. The anatomical and pathological changes are discussed.

5. A plea is made for early surgical exploration in cases manifesting signs of ischaemia.

1. The results of excision of calcaneo-navicular bars in spasmodic flat feet are reported. The average follow-up was six years. Complete relief of symptoms was achieved in 68 per cent and over 25 degrees of subtalar inversion was restored in 58 per cent of the feet.

2. The results appear slightly more favourable than those of conservative treatment, but it is realised that the period of observation is short.

3. In a selected group of patients operation by a standard technique relieved symptoms and restored subtalar movement in all.

4. It is submitted that excision of the calcaneo-navicular bar is a justifiable procedure in the younger patient with painful spasmodic flat foot of recent origin.

1. Seven cases of old unreduced anterior dislocation of the hip are reported. Six were complicated by myositis ossificans.

2. Four cases resulted from the fall of a heavy object on the lower back of a stooping person.

3. Trochanteric osteotomy in five cases not only corrected the deformity but gave stable, serviceable hips.

1. The combination of femoral shaft fracture with dislocation of the hip in the same limb has been recorded in eighty-one patients since 1823.

2. A further fourteen cases are reported.

3. In over half the cases the hip dislocation was diagnosed late or not at all, and this error has occurred more often in modern times. The reasons for this are outlined.

4. The diagnostic physical signs of hip dislocation in the presence of a femoral shaft fracture are described.

5. The mechanism, sequels and treatment of this combined injury are discussed.

1. Thirty-seven hips with osteoarthritis underwent phlebography before intertrochanteric osteotomy. The results of this study were reported previously.

2. Thirty-two of the hips were studied and have had a clinical, radiological and phlebographic examination about one year after operation. Three of these were excluded because of technical failures.

3. Twenty-four hips had a normal pattern of venous drainage after operation; of these only two had normal patterns before operation and the rest had had many abnormalities of venous drainage. These hips had been completely or considerably relieved of pain at rest and on activity.

4. In the other five hips, although the venous drainage pattern was still abnormal, in only one was there significant deterioration in the venous pattern; in this group there was also some alleviation of rest pain.

5. The findings are discussed in relation to the pathology of osteoarthritis and the possible influences of intertrochanteric osteotomy.

6. The pain produced by the injection of radiopaque material into the femoral head was similar to the rest pain. This finding is discussed in relation to venous obstruction and congestion.

1. Shin splints in five horses is described as a stress fracture of the second metacarpal bone.

2. The value of this finding in relation to stress fracture of the tibia in man is discussed.

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. The operation of spinal fusion combined with Harrington rod instrumentation is often accompanied by severe blood loss. Factors affecting the degree of blood loss are discussed with emphasis on the adverse effects of partial or complete obstruction of the inferior vena cava during operation.

2. A new scoliosis operating frame is described which is designed to encourage normal venous return during spinal fusion with the patient prone. In addition, it stabilises the patient during the procedure.

3. A standard anaesthetic technique and method of supporting the patient have been used in forty major corrective operations in thirty-eight consecutive cases of scoliosis in the past nine months. The measured blood loss at operation encountered in this series compares favourably with the quantities lost in a previously reported series of cases in which alternative methods of anaesthesia and of support for the patients were used.

4. All operations in both series were performed by the same surgeon (J. E. H.). Although further experience with the surgical technique has helped in reducing the blood loss in the later series, the same basic method of exposure and performance of the instrumentation and fusion has been used in all cases.

1. In rabbit knees the effects of daily injections of saline, Varidase, blood, blood and Varidase simultaneously, and blood alternating with Varidase every third day have been compared.

2. Saline alone produces changes in joint cartilage comparable with a slight damage to the gel structure of the intercellular matrix.

3. The other four experiments resulted in changes in the articular cartilage comparable with the effects of a partial chemical degradation of the polysaccharide of the intercellular matrix.

4. Blood also induced hypertrophy of the synovial tissues. After the end of the injections healing of the cartilage was slower than with saline or with Varidase.

5. When blood and Varidase were given together the immediate effects were additive, but there was a considerable delay in healing.

1. The hypothesis is put forward that the cartilage of a developing epiphysis consists of two separate moieties. There is a superficial zone which from the first is destined to become articular cartilage and is incapable of ossification, whereas the deeper layers are concerned with the actual growth of the epiphysis and will eventually be converted totally to bone.

2. The results of an experiment which support this theory are described. A piece of developing joint cartilage was excised and replaced in its bed upside down. It was found that although the cartilage continued to proliferate at its normal rate, ossification of the original articular layer did not occur, so that there was a considerable increase in the thickness of the excised cartilage.

3. The supporting evidence for the hypothesis is discussed.

1. A method of finger dissection is described which provides a new approach to the anatomical study of structures in close relation to joints.

2. The volar part of the capsule of the finger joints is described, the attachment to the bones being particularly emphasised together with its form which is like that of a meniscus.

3. A gap between bone and tendon sheath is described.

4. Theoretical and clinical aspects of the local anatomy are discussed.