1. The phosphonates are simple chemical compounds containing P-C-P bonds which are resistant to the action of naturally occurring phosphatases and pyrophosphatases. They inhibit the formation and dissolution of apatite crystals in vitro and prevent ectopic mineralisation and bone resorption in animals.

2. In man one diphosphonate (EHDP) has been shown to reduce the excessive turnover of bone in Paget's disease and also appears to slow the mineralisation of ectopic bone matrix in myositis ossificans progressiva.

3. The possible uses of the diphosphonates in bone disorders with excessive resorption and in ectopic mineralisation are being further investigated.

Halo pelvic traction, a method of correcting the deformed spine, is discussed and experience with treatment of our first twenty-five patients presented.

1. Thirty-nine displaced fractures of the lateral humeral condyle in children are reported. In one-third of the children the injury was accompanied by postero-lateral dislocation of the elbow. In some cases there was evidence that dislocation had occurred even when there was little persistent displacement of the condylar fragment.

2. All the fractures were treated by internal fixation with a specially designed screw. Thirtyfive children attended for review.

3. lt is concluded that all displaced fractures should be treated by internal fixation and that the method described is simple and reliable. Undisplaced fractures, or those with little displacement, may be treated conservatively when there is no evidence of associated dislocation of the elbow.

1. Techniques are described for homografting intact or partly digested hyaline cartilage or isolated chondrocytes on to cancellous bone in rabbits.

2. Material which had been cooled to and thawed from -79 degrees Centigrade either in the presence or absence of the protective substance dimethyl sulphoxide was grafted in the same way. In control experiments samples were boiled before grafting.

3. Necropsies were performed at intervals varying from two to twenty-six weeks later and the graft sites were removed, fixed and decalcified. Paraffin sections were stained histologically.

4. Freshly isolated chondrocytes or chondrocytes which had been frozen in the presence of dimethyl suiphoxide formed new matrix within two weeks and did not succumb to a homograft reaction. By the sixth week they had become aligned in columns surrounded by well stained matrix. There were signs oferosion by invading capillaries and osteoblasts, but no lymphocytes were seen. By the twelfth week invasion by trabeculae of newly formed bone was well advanced and by the twenty-sixth week the grafts were difficult to find although there had been no sign at any stage of an immunological reaction.

5. New matrix was also formed in homografts of hyaline cartilage which had been treated with papain or with papain and collagenase. After freezing in the presence of dimethyl sulphoxide, small areas ofthe grafts seemed to contain living cells which had formed new matrix. Other areas were disintegrating.

6. The homografts of intact cartilage showed a variety of appearances suggesting that the old matrix was gradually leached out and that chondrocytes liberated in vivo formed a new matrix.

7. Intact or partly digested cartilage which had either been frozen without dimethyl suiphoxide or boiled disintegrated and was rapidly replaced by bone after grafting.

8. When specimens of partly digested cartilage or isolated chondrocytes were homografted On to sites denuded of cartilage on the articular surface of the rabbit humeral head, nodules of fresh cartilage were formed. They were embedded in fibrous tissue derived, presumably, from marrow cavities opened up at the time of operation.

1. An account of experiences in seventy-five cases with a new method of treatment of low back pain and sciatica caused by intervertebral disc lesions has been presented. The method is based on the fact that chymopapain, a proteolytic enzyme, can break down displaced intervertebral disc material without deleterious effects upon adjacent tissues.

2. Chymopapain was injected into intervertebral discs by the postero-lateral or preferably the lateral approach. Two milligrams per disc constitute an effective dose. The enzyme was administered to seventy-five patients who were potential candidates for laminectomy. These patients were followed for four to thirty months and results were graded as "good" (76 per cent), "fair" (15 per cent) and "poor" (9 per cent).

3. Although untoward reactions have been encountered, none of these has been attributable to chymopapain.

4. Our investigations have convinced us that enzymatic dissolution of a lumbar intervertebral disc lesion is a safe, effective method of relieving sciatica and low back pain in selected cases.

1. The results of treatment of 186 club feet have been reviewed.

2. Early strong repeated manipulation and splintage produced correction in all, but only sixty-five out of 186 remained acceptable at three years. The other 121 relapsed.

3. Relapse occurred in the first year in eight, between twelve and eighteen months in twenty-five, between eighteen and twenty-four months in twenty-three, and between twenty-four and thirty-six months in sixty-five.

4. Relapse was slightly commoner when treatment began after the first month of life.

5. Relapse was treated either by manipulation and plaster or by soft-tissue correction, leaving fifty-two out of 121 acceptable at three years and sixty-nine which were not acceptable (this includes those in plaster after soft-tissue correction, necessitated by relapse around the ages of two and a half and three and is thus adversely loaded).

6. The three year results in 186 feet were studied: 63 per cent were acceptable and 37 per cent were not. Five year results in eighty-seven feet were studied: 87·4 per cent were acceptable and 12·6 per cent were not.

7. Soft-tissue correction is described. It produced 89 per cent acceptable feet but 11 per cent relapses in 280 operations.

Dr J. Robert Close has been good enough to point out a misquotation from his article, "Some Applications of the Functional Anatomy of the Ankle Joint"(Journal of Bone and Joint Surgery, 1956, 38-A, 761) in a later contribution by Mr M. G. H. Smith entitled "Inferior Tibio-fibular Diastasis Treated by Cross-screwing (Journal of Bone and Joint Surgery, 1963, 45-B, 737). Dr Close, in referring to tibio-fibular diastasis and deltoid ligament rupture with low fractures of the fibula, wrote (p. 780), "Treating diastasis therefore frequently means treatment for the deltoid lesion. When one realises that a certain amount of spreading apart of the malleoli and a certain amount of rotation of the fibula about the tibia are anatomical requirements for normal ankle motion the necessity for later removal of such internal fixation becomes obvious. Screws thus placed have been known to break during normal walking after the fractures have healed." In his paper Mr M. G. H. Smith, making mention of tibio-fibular movement, wrote, "This small range of movement of the fibula at the inferior tibio-fibular joint caused Close (1956) to recommend that screws placed across the joint to maintain reduction of diastasis be removed before weight bearing and movement were commenced. He stated that screws had broken when left in position." Further abbreviation by editorial staff led to the statement actually printed p. (737): "Close (1956) recommended the removal of screws that had been placed across the joint to maintain reduction of diastasis before movement was allowed, because the screws broke when left in position." The inadvertent change in sense unfortunately escaped attention, and we very much regret that Mr Close was thus misquoted.

1. A method is described by which the relative water contents of adjacent microscopic regions of bone can be assessed.

2. The water content is correlated with the inorganic and organic contents in regions of different age.

3. The results suggest that the age increase in the mineralisation of bone occurs at the expense of both the organic and water fractions.

1. The results in 211 fractures of the shaft of the femur in adults treated by internal fixation have been reviewed.

2. A comparison has been made between the effects of early internal fixation within the first six days of injury and delayed fixation.

3. Eighty-five fractures treated by early fixation gave a rate of non-union of 23 per cent; in 126 fractures treated by delayed fixation the rate was 0·8 per cent.

4. Delayed operation is therefore advocated for the majority of femoral shaft fractures for which internal fixation is indicated.

1. Two boys with osteochondritis of the humeral capitulum are described.

2. Similarities between this condition and Perthes' disease are noted.

3. From a review of the reported cases it is concluded 1) that osteochondritis of the capitulum occurs almost exclusively in boys between the ages of four and ten years; 2) that treatment and immobilisation are unnecessary; and 3) that advanced maturation of the epiphysis of the radial head is a possible sequel.

1. The relative concentrations of organic material in adjacent microscopic regions of bone have been studied by three methods, and the results suggest that this concentration varies considerably.

2. The variations in the organic concentration in bone have been correlated with the age of the bone and its inorganic concentration.

3. It is suggested that the progressive calcification of bone as its age increases, occurs, to some extent, at the expense of the organic fraction of the tissue.

1. Twenty-three patients were treated by cross screwing for diastasis of the tibia and fibula in fractures at the ankle.

2. It is suggested that limitation of ankle dorsiflexion after this treatment was caused by the presence of a mechanical block to dorsiflexion by spur formation at the margins of tibia and talus.

3. An ordinary bone screw controlled the diastasis satisfactorily in twenty patients.

4. The screw did not interfere with movement at the inferior tibio-fibular joint because bone resorption about that part of the screw in the fibula allowed a small range of movement.

5. Discomfort from the screw was relieved by its removal.

1. Twenty-eight cases of the infantile and three cases of the adolescent type of tibia vara occurring in West Indian Negroes are reported.

2. The condition is characterised by failure of growth of the postero-medial part of the upper tibial epiphysis.

3. The deformity produced is acute varus at the upper tibia with medial torsion and eventually flexion of the diaphysis on the epiphysis.

4. These deformities are considered to be due to a vicious circle set up by considerable alteration of the lines of force on the medial portion of the upper tibial epiphysial line.

1. The arrangement of collagen fibres in the secondary osteones in human femora and tibiae has been examined. The fibres were observed in paraffin sections stained by Weidenreich's method.

2. Three fibre patterns have been observed. They differ from one another in the relative numbers of longitudinal and circumferential fibres which they contain, and in the degree of lamellation which they exhibit.

3. The incidence of the three fibre patterns has been correlated with the relative ages of the regions of bone in which they occur.

4. The possibility of a correlation between variations in fibre pattern and certain recent microradiographic observations is discussed.

The place of internal fixation in the treatment of fractures of the shafts of the radius and ulna in adults is discussed, and the results in 130 fractures treated by internal fixation are reviewed.

Non-union was found to be the most frequent and serious complication after internal fixation.

The incidence of non-union can be greatly reduced if operation is delayed for at least one week, and preferably two to three weeks after injury.

Evidence is presented to support the value of delayed operation in the promotion of union of fractures.

1. The clinical and pathological features are given of an example of the rare syndrome of progressive and massive osteolysis associated with haemangiomatous changes in the bones affected.

2. Twenty-six cases have been previously reported, but this is only the second from Britain. Only one other patient is considered to have died as a direct result of the disease.

A case of fatal air embolism after Küntscher nailing of a fractured femur is described. Necropsy indicated that the only possible means of air entry was through the bone marrow. Subsequent discussion between the surgeon and the pathologist indicated that air must have been forced into the venous circulation through the marrow by repeated removal and reinsertion of nails, which allowed air to fill the punched-out marrow space when the nail was removed, the same air being forced into the marrow sinusoids when the nail was reinserted and hammered into position. This danger may be overcome 1) by allowing the site of operation to flood with blood by placing the patient in a "head up" position; 2) by flooding the operation site with saline; or 3) by assessing the calibre of nail required by radiological means rather than by trial and error.

The characteristics of enchondromata of long bones are mentioned and the special features of a malignant chondroma of the calcaneum are described. The management of such a case is discussed.

Sprain of the pisiform triquetral joint is a definite clinical entity. It presents as a "tenosynovitis" of the flexor carpi ulnaris muscle from which it can be distinguished by the tests described. The disability in most cases is such that operation is justifiable. Fusion of the pisiform-triquetral joint is preferred to excision of the pisiform because it restores stability to the wrist with the least disturbance to related structures.