1. Direct injection of contrast material into bone indicates its extreme vascularity, particularly near an epiphysis, and emphasises the extraordinary capacity of the minute periosteal vessels. The nutrient artery of a long bone appears to play little part in its nourishment and may be regarded as a vestigeal structure.

2. The vascular pattern of bone tumours may be investigated by injection of the appropriate artery, and sometimes, if a haemangioma is suspected, by direct injection into the lesion.

3. The examination is easily and quickly carried out by direct arterial puncture under local anaesthesia and injection of 35 per cent diodone. A tourniquet applied distally at the appropriate level is often helpful.

4. A study of the vascular pattern of suspected bone tumours has provided useful information in a positive and negative way, assisting both the diagnosis and the planning of treatment. The pathological diagnosis of some tumours, notably osteosarcomas and haemangiomas, may be made with such assurance that possible dissemination of the tumour by biopsy may be avoided.

1. Synovectomy was carried out in thirty-four knees, of which thirty-one were certainly or probably afflicted by rheumatoid arthritis.

2. Synovectomy was considered only when adequate medical and physical treatment had failed to afford relief. Its purpose is to preserve useful function, and one of the principal factors influencing the decision to operate was the retention of a normal or good radiographic joint space in a persistently painful, warm and swollen knee.

3. Radiographic appearances constituted a useful but not infallible guide to the true state of the articular surfaces.

4. The method of operation, findings and subsequent care are described.

5. Up to two years after operation it appeared that improvement might be related to the state of the articular surfaces, but after two years this relationship was not evident and an attempt to explain this difference has been made.

6. It seems clear that the longer-term results are determined mainly by the course taken by the rheumatoid process. An unfavourable course was associated with considerably less satisfactory results than was a favourable course.

7. It is concluded that in rheumatoid arthritis which has resisted rest and medical treatment synovectomy of the knee is most likely to be successful when the radiographic joint space is good or normal, and when the rheumatoid process follows a favourable course. To undertake the operation at an early stage in the disease is to leave in doubt the outcome, as this is dependent upon the as yet undeclared general course of the disease. Even so, early synovectomy is worth considering when nothing else has given relief. The fact that arthrodesis has only once been necessary after synovectomy appears to justify the policy of salvage described.

1. The natural history and prognosis of progressive infantile idiopathic scoliosis are reviewed and twenty-eight cases are reported.

2. Resolving infantile idiopathic scoliosis is described and seven cases are reported.

3. The length of the curve, the degree of rotation, the age of onset of deterioration, and the rate of progression are the important factors in determining the type and severity of the deformity.

4. Infantile idiopathic scoliosis is briefly compared with congenital scoliosis.

1. The true deformity of kyphoscoliosis has received little attention. Twenty-one deformities of congenital origin, ten idiopathic, and two secondary to neurofibromatosis, are discussed. The diagnosis is established and usually first suspected by radiography.

2. The deformity was severe and progressive except in three cases; paraplegia occurred in five congenital cases.

3. Early correction and fusion are advocated in the hope of preventing paraplegia and because correction of the old-established deformity is difficult or impossible.

1. Sixty fractures of the tibial condyles have been reviewed. Fifty were treated by conservative measures and ten by operative reduction. The fractures are classified and the etiology, age incidence, mechanism of injury, methods of treatment, and results are discussed.

2. The indications for operative reduction are described.

3. The combined split and compression types of fracture give the least satisfactory results.

4. Age is no contra-indication to immobilisation in the treatment of these fractures.

5. Emphasis is laid upon the necessity for immobilisation in the treatment of the associated ligamentous injuries.

6. It is considered that the results justify the policy of treatment described.

A case of traumatic aneurysm of the peroneal artery at the level of its perforating branch is described. The intimate and variable relationship of this vessel to the flexor hallucis longus muscle and the tethering effect of its perforating branch predispose to its damage in operations through the postero-lateral approach to the region of the ankle.

1. Two cases of deposition of calcium on the outer side of the knee are described.

2. The condition is believed to be uncommon and does not appear to have been described before.

3. One case resolved with conservative treatment, the other after an operation at which the deposit was found in the tendon of popliteus.

A case of benign chondroblastoma in the upper end of the humerus is described. A plea is made that radiotherapy should be avoided in the treatment of this tumour. It is suggested that biopsy should be performed in every case.

1. The importance of accurate methods of measuring the strength of muscles and the amplitude of joint movements in man, both in clinical fields and as criteria of normal function, is discussed.

2. The advantages and disadvantages of subjective and objective methods are reviewed.

3. The main types of apparatus used for the assessment of muscle strength in both normal and clinical conditions are described. A dynamometer of the strain-gauge type is recommended.

4. Methods of measuring the amplitude of movements in man are also described. The protractor type arthrometer is thought to be the most suitable for routine clinical work, but for research purposes a radiographic method may be preferable.

5. The following factors, which must be considered if the measurements taken are to be of greatest use, are discussed: posture, test procedure, standards for comparison, nomenclature and normal variability.

Obviously these and other problems need much research, but the preliminary work already done is promising enough to indicate that a useful and dependable prosthesis could be developed to operate by the use of changes of muscle potential, and that such apparatus could be made light enough for practical use at the work-bench and in the home.