1. Perthes' disease is an ischaemic lesion of the ossific nucleus of the head of the femur which may vary both in extent and degree. It is probably never quite complete.

2. When part of the ossific nucleus only is affected, as is usually the case, it is almost invariably the antero-lateral part.

3. The process of absorption of the damaged bone is complete radiologically before there is radiological evidence of reossification.

4. Reossification always occurs in Perthes' disease.

5. The aim of treatment must be to see that the mould in which the head is shaped is the right shape when ossification occurs.

6. The deformity of the head of the femur does not occur from pressure alone, but from pressure combined with subluxation. Full unrestricted weight-bearing can be allowed with safety on a femoral head in which there are ischaemic changes provided the femoral head is well contained.

7. The time of treatment can be very greatly reduced by using operation to correct the subluxation instead of relying on external splintage. This can be achieved by subtrochanteric osteotomy with rotation, or rotation combined with varus angulation.

8. Perthes' disease and avascular necrosis of the head of the femur are different conditions with different characteristics.

9. Suggestions are made as to the nature of the disease in relation to absorption, continued growth and reossification.

1. A simple technique of arthrodesis of the hip is described.

2. Two triflanged nails are driven across the joint. The joint is not opened. No bone graft and no extensive fixation is used.

3. Symptoms were relieved in 90 per cent of patients and bony union was achieved in 63 per cent. Backache after operation was not a problem.

4. The period of hospitalisation was short and rapid return to heavy work was common.

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 nature of flexion contractures of the knee joint is discussed.

2. It is suggested that division of the anterior cruciate ligament will help in the correction of the deformity when conservative methods have failed.

3. The results of the treatment of twelve such knees are mentioned and illustrative cases are described.

4. It must be emphasised that this method of treatment should be undertaken only when conservative methods have failed.

1. A brief description is given of normal epiphysial growth of the human femur.

2. Some ways in which abnormality of the growth plates may affect the shape and length of the human femur are described.

3. The influence of the blood supply on growth is discussed with particular reference to the etiology and treatment of congenital coxa vara.

1. Two types of paralytic dislocation of the hips are discussed.

2. The mechanics of dislocation and the methods of reduction are described, with emphasis on the importance of maintaining or increasing stability where possible.

1. A method of treatment of the congenitally dislocated hip is described.

2. The rationale of the treatment is considered.

3. The subsequent development of the hip generally, and of its individual components, is described.

4. Comparison between the results of other methods of treatment and of this method is not attempted for reasons stated.

5. The advantages of a shortened period of splintage are discussed.

6. The state of fifty completely dislocated hips treated consecutively is described at the end of a follow-up period of from three to seven and a half years.

1. The condition of persistent foetal alignment is discussed both as an entity and in its relationship to the development of a normal hip, and also to the varying degrees of congenital dislocation of the hip. A possible connection with osteoarthritis is also mentioned.

2. The secondary deformities to which it may give rise are discussed, and the way in which both primary and secondary deformities may be corrected is described.

3. The importance of estimating rotation with the hip in full extension is emphasised.

4. The results in eight patients so treated are mentioned.

Based on the constancy with which the limbus is inverted into the joint in a typical congenital dislocation of the hip, a hypothesis is presented which suggests that the sequence of events leading to established dislocation is: 1) lateral rotation aided and abetted by anteversion; 2) extension of the hips causing subluxation; 3) dislocation and inversion of the limbus; 4) secondary changes in the upper end of the femur, pelvis and acetabulum which will also develop if the deformity does not progress beyond a subluxation.

A pen picture is drawn showing how anteversion is either moulded away during growth to produce a normal hip, or persists with or without dislocation. The fate of the persistently inverted limbus is discussed and a line of treatment based on these findings is briefly considered.

1. It is suggested that the obstruction causing delayed reduction of the congenitally dislocated hip is the infolded limbus.

2. An operation is described by which the infolding limbus may be easily and safely removed.

3. The early results of the operation are reported.

4. The evidence for the original assumption is discussed.

This paper is a theoretical and experimental study of the processes involved in the development of curvature of the spine which we have come to call scoliosis. Reasons are advanced why the term scoliosis in its modern meaning may be misleading and an alternative title of Rotational Lordosis is suggested. It is admitted that it is more cumbersome, but I maintain that it is more accurately descriptive of the deformity under discussion and differentiates it from other curvatures which are produced differently but at present all of which come under the heading of scoliosis. I am conscious that many gaps still remain unfilled, especially the important but unexplained problem of the nature of the growth disturbance. If we could solve this we would be near to a solution of one of the most bizarre, mysterious and crippling deformities with which we are faced.