1. Forty-eight cases of causalgia are reviewed and the clinical features are briefly described.

2. Multiple nerve injuries are common and the pain is often associated with all the injured nerves. In the upper limb there was always an incomplete lesion of the lower trunk or medial cord of the brachial plexus, or of the median nerve. In the lower limb there was always an incomplete lesion of the medial popliteal division of the sciatic, the medial popliteal, or the posterior tibial nerve. These nerves carry most of the sympathetic fibres to the hand and foot. With two exceptions all the nerve lesions were at or above the level of the knee or elbow.

3. Sympathectomy gives marked relief of pain in most cases of causalgia. Prompt treatment is essential to prevent the crippling deformities which follow prolonged voluntary immobilisation of the painful limb. The results of preganglionic are superior to those of postganglionic sympathectomy.

4. The possible pain pathways are discussed, and an explanation is offered for the successful results of sympathectomy in the treatment of causalgia.

1. A new operation of body-to-body intervertebral fusion by grafts introduced through a posterior approach is described. This is a preliminary report of early results, with follow-up to two years, which seems to be encouraging.

2. In spondylolisthesis, abnormal mobility of the loose posterior neural arch is believed in itself to cause nerve root pressure, and excision of the arch is an important part of the operation.

3. In the few cases where spinal fusion is needed after removal of a prolapsed intervertebral disc—and the proportion is now very low—posterior intervertebral fusion has proved very satisfactory.

1. Ten cases are reported of subcapital fractures of the femoral neck with low fracture-shaft angles treated by wedge osteotomy and fixation by nail-plate.

2. A simple method of osteotomy to increase the fracture-shaft angle is described.

3. In eight fresh fractures bony union was obtained when nailing was followed by immediate osteotomy.

4. The alteration of the bony anatomy does not prejudice further reconstructive surgery should it become necessary.

Experiments have shown that the tension of the sciatic nerve roots is increased when the posterior tibial nerve is pressed upon in the popliteal space. A refinement of the straight leg raising test, based on this observation, is described.

1. The unreliable results of the conventional cup arthroplasty are attributed to mechanical imperfections in the reconstructed joint.

2. If its reliability can be improved, there will remain a place for cup arthroplasty, which, in relatively young and active patients, offers advantages over prosthetic replacement arthroplasty.

3. A technique of concentric cup arthroplasty is described. The new joint is shaped with precision to exact dimensions and lined with a cup designed to ensure stability, concentric movement and a uniform clearance between the moving parts.

4. The results so far are encouraging and justify continued clinical trial.

1. Experience in the treatment of tuberculous disease of the spine, hip and knee by combined constitutional, antibiotic and operative measures is described.

2. In patients with tuberculosis of the spine, especially in the thoracic region and when perispinal abscess formation is a prominent feature, the treatment helps to ensure stable ankylosis in the type of case in which it otherwise might not occur.

3. In children with tuberculosis of the hip and in adults and children with tuberculosis of the knee it is usually possible to save the joint and to restore function, provided the joint has not been destroyed before treatment is begun.

1. Five cases of calcified enchondroma are described. In all except one the condition was symptomless and was discovered accidentally.

2. The radiographic features are described and the differential diagnosis is discussed.

3. It is emphasised that when the diagnosis is in doubt biopsy should be undertaken.

1. One hundred and forty-nine cases of leontiasis ossea reported in the literature have been reviewed.

2. The clinical, radiographic and pathological features of the condition are discussed.

3. Four additional personal cases are reported in detail.

4. A new classification of leontiasis ossea is suggested, by which the condition is divided into true leontiasis and false (or symptomatic) leontiasis, True leontiasis is a clinical syndrome caused by two distinct types of disease, whose pathology, however, is related. False leontiasis gives a superficially similar picture but on detailed examination is found to be distinct; it may be caused by a variety of different conditions.

5. Classified in this way, ninety-seven of the total of 153 cases considered were classified as true leontiasis (forty-five Type 1 and fifty-two Type 2); forty were classified as false leontiasis; and sixteen did not fall into either category.

1. Thirty-six cases of tuberculous hip disease treated by the Trumble type of extra-articular arthrodesis are reviewed.

2. The size and position of the graft, and the results and complications, are tabulated.

3. It is concluded that a short wide graft, placed almost horizontally between femur and ischium, gives the best results, and that a long obliquely placed graft is less satisfactory, and more liable to fracture or non-union.

1. Five cases of bilateral glenoid hypoplasia are described. Flattening of the humeral heads and sometimes other skeletal abnormalities coexisted.

2. The condition is considered to be congenital.

3. The differential diagnosis and etiology are discussed.

1. A case of traumatic aneurysm in the popliteal fossa after a lateral meniscectomy is described.

2. Relevant factors in the surgical anatomy of the inferior genicular artery are discussed.

3. The value and limitations of angiography of the popliteal artery are considered.

4. Treatment is governed by the degree of involvement of the popliteal artery. In the case described cure of the aneurysm was obtained by endo-aneurysmorrhaphy.

1. The dynamics of synovial joints depends upon the geometry of the articular surfaces, which are always curved.

2. There are two types of articular curvature: ovoid (synclastic) and sellar (anticlastic).

3. The sellar type is mechanically more suited to movements in which sliding is combined with medial or lateral rotation (monodal conjunct rotation).

4. The movement of any hinge-joint is accompanied by a monodal conjunct rotation. This carries the moving part along a path that approximates (at least) to a path of minimal wear. The same is true of the paths of habitual effort-movement (ergodes) of other kinds of joint.

5. Evidence for the foregoing statements is drawn from both normal and abnormal joints, and a clinical application is suggested.