1. Hereditary multiple exostosis has been studied in fifty-six patients and their relatives. In most cases previous records were available and the progress of the disease could be traced over many years. 2. The characteristic lesions are described and the complications encountered in the present series of cases are noted. The disease is inherited in approximately two-thirds of the cases and invariably produces detectable lesions in the heterozygote. 3. The cartilage-capped exostoses are confined to the endochondral skeleton where their incidence is closely related to the growth potential of the sites involved. 4. An attempt has been made to explain the curious distribution of the exostoses, and the likely theories of the pathogenesis of the disease are discussed

This paper describes the design, development and early surgical experience with a stereotactic device to allow closed retrieval and interchange of intramedullary rods in children with osteogenesis imperfecta. This relatively atraumatic procedure may allow more frequent rod interchange than with other techniques, lessening the likelihood of deformity and fracture in the unsupported skeleton when the bone has outgrown the intramedullary rod. The procedure was developed by design studies in vitro followed by intramedullary rodding of tibiae of New Zealand white rabbits. It has been used in children 12 times, in six tibiae and six femora: 11 rods have been successfully retrieved, with rod interchange in eight of these cases

Skeletal age was estimated by examination of radiographs of the carpus in 182 children suffering from Perthes' disease after the reliability of the Greulich and Pyle Atlas had been checked for a control group of British children. A striking tendency to delayed skeletal maturation was shown in the children with Perthes' disease. This trait was also found in ninety-three unaffected siblings of the patients. The velocity of skeletal ageing as the disease progressed was estimated. In some patients the carpal skeleton failed to mature at all for periods of up to three years and the term "skeletal standstill" is applied to this phenomenon. The significance of these findings is discussed and it is suggested that the maturation defect may have aetiological significance

Aims

The main advantage of 3D-printed, off-the-shelf acetabular implants is the potential to promote enhanced bony fixation due to their controllable porous structure. In this study we investigated the extent of osseointegration in retrieved 3D-printed acetabular implants.

Hemiarthroplasty of the hip and some other joints has been used for many years with satisfactory results, but the fate of articular cartilage when weight-bearing against metal has not been reported. Replacement of the head of the femur was carried out in one hip of each of 26 dogs, and the changes in acetabular cartilage studied at intervals of up to 24 weeks. There was early loss of proteoglycan, followed by surface damage to the cartilage, progressive degenerative changes, and growth of pannus from the articular margins. At 24 weeks after operation there was little remaining articular cartilage, while intense subchondral activity suggested that the bony skeleton was being remodelled to conform to the shape of the prosthesis. This study is not intended to suggest that hemiarthroplasty does not help patients

The shallow lateral recesses of the trefoil shape of the lumbar spinal canal have been implicated in the production of the spinal stenosis syndrome. In the present study, 485 skeletons of South African Blacks and Whites were examined in order to establish the incidence and possible genesis of the trefoil configuration. The overall incidence was 14 per cent, with little variation between the sexes or races. The incidence was not related to increasing age, measured stenosis of the spinal canal or osteophytosis. Of 74 trefoil-shaped vertebrae, 68 (92 per cent) were found at the fifth lumbar level. It is suggested that the trefoil configuration is a common non-pathological condition, usually of the fifth lumbar vertebral canal, and is probably a developmental variation of normal anatomy

1. The so-called adamantinoma of long bones is a clinico-pathological entity, the pathogenesis of which is still in doubt. The case for its being a synovial sarcoma showing epithelial differentiation is in our view unconvincing. 2. The tumour is slowly growing, and of low grade malignancy. Apparent cure has been effected in a third of the total cases recorded by amputation or resection of the diseased bone. 3. These means, however, have not prevented metastases to the lungs and skeleton in a similar number. 4. A case is presented in which a metastasis appeared in the chest twenty-two years after amputation of the leg. This was sensitive to telecobalt irradiation, and is the first case in which a distant metastasis has been proved microscopically

1. A case of solitary plasmocytoma of the thoracic part of the spine, verified by necropsy, is described. 2. A brief review is given of eighteen acceptable cases of solitary plasmocytoma of bone. 3. Of the eighteen patients, fifteen were men; the five spinal tumours were all in men. 4. Diagnosis requires: a) biopsy identification of plasmocytoma; b) exclusion of the possibility of generalised myelomatosis by complete radiography of the skeleton, repeated if necessary at intervals during the ensuing two or three years or longer. 5. A tumour of brief duration, proved to be solitary by careful necropsy, cannot be placed with certainty in the group of truly solitary plasmocytomas; it might have been a precocious first lesion of myelomatosis

The midsagittal and interpedicular diameters and the trefoil shape of lumbar vertebrae of known age at death were measured in skeletons from a population aged between 1 and 70 years. All the trefoil configurations were at L5 with the exception of one at L4. The overall prevalence was 25%, but this shape was not generally apparent until adulthood. The midsagittal diameter in the trefoil canals was found to be significantly smaller than that in the unaffected canals. This did not change significantly after six years of age indicating that the cause of the trefoil configuration is probably present early in life. The trefoil shape was no more common in the spines of the elderly subjects. Our findings indicate that the trefoil configuration of the lumbar vertebral canal has a developmental origin and is not a consequence of degenerative processes

1. The source of nutrition of articular cartilage still remains a subject of controversy. 2. Experiments are described in which an attempt to demonstrate the direct transfer of fluid from the subchondral bone has been made using 355 and an autoradiographic technique. These experiments were based on ones originally performed by Ekholm (1951), except that two distinct groups of animals were used : immature rabbits and adult rabbits whose skeletons were mature. 3. The transfer of fluid to the cartilage could be demonstrated only in the immature rabbits. 4. It is suggested that some of the conflicting opinions which have been advanced on this subject stem from a failure to distinguish between mature and immature joint cartilage. Subchondral nutrition is a feature only of the immature animal

We reviewed lesions of the femoral condyles seen in 5,000 knee arthroscopies, recording the findings and the age and sex of the patients. We were able to distinguish the characteristics of developing and late osteochondritis dissecans, acute and old osteochondral fractures, chondral separations, chondral flaps and idiopathic osteonecrosis, and suggest that these are separate distinct conditions. Haemarthrosis was associated only with acute osteochondral fractures. The characteristic feature of osteochondritis dissecans was an expanding concentric lesion at the 'classical' site on the medial femoral condyle which appeared during the second decade of life and progressed to a concave steep-sided defect in the mature skeleton. Caffey's (1958) classification of epiphyseal dysplasias could not be applied to osteochondritis dissecans, which appeared to have a gradual onset without acute trauma. Much of the controversy about the cause of osteochondritis dissecans is the result of imprecise nomenclature

Six patients are described with idiopathic osteoporosis which began between the ages of 4 and 16 years. In four children the disorder was mild with pain in the back, vertebral collapse, qualitatively normal iliac bone biopsies, variable calcium balance and spontaneous recovery. The two remaining patients had progressive bone disease with deformity. One with a previously normal skeleton developed changes similar to those of osteogenesis imperfecta; in the other patient, who rapidly developed structural collapse associated with severe metaphysial osteoporosis, treatment was ineffective and the histological appearances of the bone suggested osteoblastic failure. Quantitative bone histology in four patients showed no evidence of excessive active resorption; and the ratio of Type III to Type I collagen in the skin was normal, in contrast to the findings in osteogenesis imperfecta. The significance of this study in relation to previous accounts is reviewed

1. Four cases of true congenital vertical talus are described; in three of the four cases there were other major deformities of the skeleton. All were treated by open operation; the operation sacrificed part of the substance of the navicular bone, which was placed between the forepart of the calcaneus and the head of the talus. 2. The results five to ten years after operation show that stable reduction was maintained without any further treatment. They suggest, however, that more of the navicular bone could have been removed or that the whole navicular might be excised, at least in the more severe deformities. 3. Congenital vertical talus resembles club foot (equino-cavo-varus) in that difficulty in reduction and in maintenance of the reduction results from the tension in the medial pillar of the foot. Easing of the tension can result in recurrence of the dislocation or, alternatively, a reversal of the deformity

Continuous strontium administration first induces typical "rickets" in young rats receiving adequate calcium phosphorus and vitamin D but later the widened cartilage spontaneously calcifies intermittently leaving transverse bands consisting largely of osteoid tissue in the metaphysis; in addition to intermittent calcification bone changes indicate that skeletal growth is not uniformly progressive. Subsequently areas of the epiphysial cartilage fail to calcify and localised defects develop; among these are wedge-shaped metaphysial osteoid tissue masses, "invagination" of the epiphysial plate to form multiple nodules of cartilage with proliferating cells in the middle and hypertrophic ones at the periphery, perforation and fragmentation of the epiphysial plate with formation of large cartilage nodules. Multiple cartilage nodules of different sizes appear in the epiphysis, metaphysis and bone shaft. Most bone margins are lined by osteoid seams which only slowly calcify and concomitantly resorption is decreased so that the rate of remodelling of the skeleton is diminished. This type of process may help to explain the results of treatment of osteoporosis by strontium administration

1. The detailed anatomy and calcification of the upper half of the tibia in rabbits varying in age from six weeks to twelve months has been studied. 2. The structure of the bone varies at different levels, but a section taken from the same level in the tibia from animals of the same age presents a reasonably constant picture. 3. It has been shown that this variation in structure at different levels is directly related to a difference between the axis of growth and the bone axis. This difference is a result of the unique shape of the tibia. 4. Autoradiographic studies confirm the localised concentration of radioactive strontium in areas of active bone formation where uptake is rapid. 5. The long retention of radioactive strontium in the skeleton (that is, the slow turnover) is a result of the slowness of resorption of bone (endosteal, periosteal or Haversian) in the cortex. Not only is the process slow but it is extremely localised. 6. The significance of these anatomical and physiological characteristics in relation to radiation injury is discussed

Aims

Chondrosarcoma is the second most common primary sarcoma of bone: conventional chondrosarcoma accounts for 85% of all cases. Conventional chondrosarcoma may be central or peripheral. Most studies group central and peripheral chondrosarcomas together, although there is growing evidence that their clinical behaviour and prognosis differ. The aims of this study were to analyze any differences in characteristics between central and peripheral chondrosarcomas and to investigate the incidence and role of different syndromes.

A girl aged ten, of Cape Coloured stock, with typical features of parastremmatic dwarfism has been investigated. The clinical manifestations included disproportionate dwarfism, limb deformity, a short stiff neck, and marked thoracic kyphosis. The radiographic changes were dramatic, the skeleton having a "flocky" appearance due to patches of radiolucency in an irregular lattice of sclerosis. The metaphyses and epiphyses of the long bones were grossly expanded, and the vertebrae were flattened and distorted. The clinical and radiographic features of five other previously reported individuals with parastremmatic dwarfism were very similar to those of our patient. The differential diagnosis of this condition includes metatrophic dwarfism, diatrophic dwarfism and the spondylo-epiphysial dysplasias. However, the unique "flocky" radiographic appearance of the bones permits diagnostic precision. There is some evidence to indicate that parastremmatic dwarfism might be transmitted as an autosomal dominant, although this is by no means certain. The fact that our patient had seven normal siblings and unaffected parents would be compatible woth autosomal recessive inheritance

1. Sections were cut from the third metacarpal, the radius, the femur and the third lumbar vertebra of thirty-four male and twenty-one female cadavera. The mineral content of these different specimens was measured by ashing and the relationships between the quantity of bone mineral present at these sites were examined. 2. In the females the whole bone density and mineral/unit length at both the midshaft metacarpal and the midshaft radius correlated significantly with the whole bone density at all the other sites. 3. In the males these correlations were much less significant and no significant correlation was found between the whole bone density of either the metacarpal midshaft or the radial midshaft and that of the third lumbar vertebra or the distal femur, although a highly significant correlation was found between those of the distal femur and the lumbar vertebra. 4. It is suggested that in women, measurements of either mineral/unit length or whole bone density of both the midshaft metacarpal and radius provide useful information on the whole bone densities at other sites throughout the skeleton. This work was supported by the Scottish Hospital Endowments Research Trust, the National Fund for Research into Crippling Diseases and G. D. Searle and Co. Ltd., High Wycombe

Aims

In recent conflicts, most injuries to the limbs are due to blasts resulting in a large number of lower limb amputations. These lead to heterotopic ossification (HO), phantom limb pain (PLP), and functional deficit. The mechanism of blast loading produces a combined fracture and amputation. Therefore, to study these conditions, in vivo models that replicate this combined effect are required. The aim of this study is to develop a preclinical model of blast-induced lower limb amputation.