A personal experience is recounted of operations in cases of tumour involving the humerus or femur with restoration by endoprostheses. Twenty-four patients were treated in this way from 1950 to 1969 inclusive and have been followed up for between four and twenty-four years. The patients selected for treatment have presented chondrosarcoma (ten), so-called benign giant-cell tumour of bone, usually recurrent (nine), angiomatous osteolysis (two), seemingly single thyroid or renal metastasis (two), and ununited pathological fracture after irradiation of a tumour (one). Development of the prostheses from early beginnings is outlined. Some points in surgical management are referred to. The complications and results are recorded.

1. By questionnaire, an attempt has been made to ascertain the characteristics of a hundred cases of slipping of the upper femoral epiphysis.

2. The principal object has been to see whether an etiological classification would be possible pending an assessment of the results of treatment.

3. Proper statistical analysis has proved impossible because of the incompleteness of the data.

4. As usual, boys predominated and were usually affected as much as three years older than the girls.

5. It was exceptional to find epiphysial slipping in a girl once she had begun to menstruate.

6. Nearly a quarter of the cases were bilateral, or became so after six to twenty-four months or more.

7. Little information came from an enquiry about dietary fads, the estimation of urinary ketosteroid excretion in twenty-three of the patients, or some minor pathological investigations.

8. No convincing evidence was found of skeletal retardation or of general thickening of epiphysial discs, such as might perhaps be expected in a hormonal disturbance characterised by defective epiphysial maturation.

9. From each child with the necessary data, indices of height, weight and build were ascertained, which would indicate his expectation of finding a place among a hundred physically normal children of his own sex and age, and, if so, where that place would be. From these studies four groups of children seemed to emerge: I) what may be called abnormally heavy children who would not find a place among a hundred, or somestimes a thousand, physically "normal" children of their own age and sex; 2) unusually heavy children who would find a place in the heaviest minority of the normal hundred; 3) a very small group of abnormally small people, among whom might be expected the subjects of pituitary infantilism; and 4) a large group of children of average physique for their sex and age.

10. From this information and from clinical evidence in the case returns, it appeared that a quarter of the assessable boys and nearly two-thirds of the assessable girls showed evidence of endocrine defect, quite apart from those who were merely unusually fat.

11. By distinguishing these two groups of children from a third group of constitutionally "normal," an attempt has been made to see whether there is any correlation between evident endocrine defect and such characteristics as bilateral affection, delayed epiphysial maturation, a history of relevant injury and its nature, and sudden or gradual epiphysial slipping.

12. No relationship was established between any of these characteristics and endocrine type: bilateral affection was no commoner in the endocrine group; delayed maturation was not demonstrated in either; a history of relevant injury was equally common, and its nature identical, in both; slipping might be sudden or gradual in either indiscriminately.

13. There was a history of seemingly relevant injury in half the patients, and it was much commoner with sudden slipping than with gradual slipping. Sudden slipping was often preceded by symptoms of gradual slipping, or sudden slipping of one epiphysis was sometimes followed by gradual slipping of the other.

14. In gradual slipping the cardinal symptoms were pain and limp, usually starting synchronously and gradually; the pain was usually intermittent and referred much more often to the hip than the knee; the limp was usually continuous.

15. Of signs, demonstrable wasting seemed to be absent as often as present, but shortening was usual. Lateral rotation deformity was usually present, adduction often, and flexion sometimes. In more than a third of the cases limitation of movement was slight enough to be easily missed.

16. The radiographic observations confirmed the seeming widening at the affected epiphysial disc, the greater displacement revealed by the lateral view, and the difficulty of identifying avascular necrosis before collapse.

17. Treatment was delayed in thirty-four cases—a third of the whole; the reasons have been analysed; diagnostic failure was the cause in nineteen.

18. A few cases outside the series have been mentioned briefly because of special points of interest: slipping in gross pituitary disease—in pituitary giantism, and(at the age of thirty-three) in pituitary hypogonadism; slipping with defect of the opposite lower limb—infantile paralysis of the leg, and Legg-Calvé-Perthes disease of the hip; familial affection—slipping in two brothers.

19. The results of treatment in the present cases, supplemented by others, have been studied by Dr John Hall and related to some of the clinical features. His paper appears separately.

1. A defect of the middle of one tibial crest is described in young healthy ballet dancers.

2. The clinical and radiological characteristics have been studied in four cases, and the histological appearances in two.

3. The defect is concluded to be an incomplete fatigue fracture—a fatigue infraction.

4. A fifth, uncertain, case has been added tentatively, as presenting a possible serious complication, namely acute fracture from muscle action.

5. The diagnosis, treatment and prognosis are mentioned, with emphasis on the importance of adequate clinical and radiological examination in cases of obscure mid-tibial pain, tenderness or swelling.

1. It is suggested that replacement of the costo-clavicular ligament is mechanically an essential part of the operative treatment of recurrent sterno-clavicular dislocation.

2. Tenodesis of the subclavius appears to be the simplest and safest way of achieving such replacement.

3. Two cases are described of recurrent sterno-clavicular dislocation treated by this procedure and capsulorrhaphy.

4. Full function was restored in both cases; and there had been no recurrence at the times of follow-up—three years and six months after operation in the first case, and twelve months after operation in the second. In this case the joint had withstood violence that had shattered the clavicle.

5. Further trial in judiciously selected cases, with report, is suggested.

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.