1. A series of 705 fractures of the tibia is reviewed, 674 of which were treated conservatively.

2. The factors most conducive to delayed or non-union are initial displacement, comminution, associated soft-tissue wound and infection. The extent to which these are combined in any fracture determines its "personality" and its inherent propensity for union.

3. Eight fracture types are differentiated based on the above "personality rating." The incidence of delayed union or non-union varies from 9 per cent in the most favourable type to 39 per cent in the least favourable. Infection raises the incidence to 60 per cent. Comparative statistics which fail to recognise these differences can be entirely misleading.

4. Continuous traction does not retard union.

5. The results of conservative treatment are analysed with regard to union, deformity, stiff joints and contractures and the conclusion is reached that no case has yet been made out for internal fixation as the method of choice in the treatment of this fracture.

1. Thirty cases of stiff knee treated by the operation of quadricepsplasty are reviewed.

2. The causes and morbid anatomy are analysed. The operative technique is based on an appreciation of the latter.

3. The after-care must be meticulous and prolonged. Manipulation under anaesthesia was used after operation in over half the cases.

4. The results were most gratifying. There were two technical failures but in the remaining twenty-eight cases the average gain of fiexion was 68 degrees. In twenty-one of these active extension was full and it was only 5 degrees short in another three. Permanent loss of active extension occurred when the rectus femoris tendon had to be divided or lengthened.

1. Almost all patients with osteoarthritis of the hip who consult the surgeon do so because they wish to be relieved of pain. They all have limitation of movement in varying degrees but most of them will be either unaware of it or will have accepted it. What is more important, they would not have sought medical advice because of stiffness if there had been no pain. The primary objective of operative treatment must therefore be to relieve pain.

2. Displacement osteotomy will give substantial relief from pain in a high proportion of cases and the relief is lasting. Perhaps that explains why this operation, advocated by McMurray and Malkin twenty-five years ago, is being practised more widely than ever to-day while its competitors (neurectomy, capsulectomy, arthroplasty) have steadily diminished in popularity.

3. The disadvantages of the operation are all related to post-operative immobilisation in plaster, which may induce further stiffness of the hip, even to the extent of ankylosis, or stiffness and pain in the knee. These disadvantages may be overcome to a considerable degree by internal fixation followed by sling suspension and early active movement. But when, under anaesthesia, the range of hip flexion is reduced to 45 degrees or less, the operation is always liable to result in ankylosis, and it is wise in these circumstances to take this possibility into account and warn the patient beforehand.

1. A method of bridging gaps in long bones is described, using cancellous insert grafts supplemented by internal fixation with a metal plate.

2. The experimental work on transplantation of bone is reviewed in so far as it affects the practical problem of bone grafting.

3. Twenty-seven cases have been treated, with no failures. Seven of these are presented as illustrations.

One hundred and sixty-four cases of intramedullary nailing of the long bones have been studied with special reference to the difficulties and complications encountered.

There was one death not attributable to the method.

Two cases of pulmonal fat embolism and one case of thrombosis occurred, all in fractures of the femur.

The lessons we have learned from our mistakes can be summarised as follows:

1 . The method requires technical experience and knowledge and is not suited to inexperienced surgeons or surgeons with little fracture material at their disposal.

2. Intramedullary nailing should only be used in fractures to which the method is suited. In general, comminuted fractures or fractures near a joint are unsuitable.

3. Open reduction is preferable to closed methods.

4. The nail should never be driven in with violence. It should be removed and replaced with a new one if difficulty is encountered when inserting it.

5. In fractures of the femur the nail should be driven in from the tip of the trochanter after careful determination of the direction.

6. The nail should be introduced only to the level of the fracture before exploring and reducing the fracture.

7. Distraction of the fragments must be avoided.

8. If the nail bends it should be replaced by a new one, at least in femoral fractures.

9. If union is delayed, the fracture should be explored and chip grafts of cancellous bone placed around it.

10. Improvised nails or nails which are not made of absolutely reliable material should never be used.

11 . Make sure that the nail is equipped with an extraction hole for removal.

1 . A series of 166 fractures and fracture-dislocations of the dorso-lumbar spine has been reviewed.

2. A new method of classifying these injuries is suggested.

3. A type of fracture with lateral wedging, previously unidentified, which has certain distinctive clinical and anatomical features is described.

4. The factors responsible for redisplacement are discussed and it is considered that in most cases this is predictable from the outset.

5. At the present time orthodox treatment is based on the assumption that a perfect anatomical result is indispensable to a perfect functional result. Analysis of the results in the series now reported shows that there are no grounds for this assumption.

6. Treatment is discussed in the light of the foregoing conclusions. This is based on a division of cases into stable and unstable types, the recognition of which is of crucial importance.