1. The distribution of isotope following a single injection of either Ca. 45. or C. 14. -proline has been studied in young rats in which one tibia had previously been removed, killed and reimplanted. 2. The dead tibia took up about 25 per cent as much Ca. 45. or C. 14. as did the living tibia and the possible processes by which this occurred are discussed. 3. Determination of the "accretion rate " by kinetic analysis of the Ca. 45. data showed that this was much too high unless the physico-chemical process of uptake of isotope by bone was taken into account. 4. Under the conditions of the experiment it was not possible to estimate the rate of bone matrix formation using C. 14. -proline as a tracer

Bone loss around replacement prostheses may be related to the activation of mononuclear phagocytes (MNP) by prosthetic wear particles. We investigated how osteoblast-like cells were regulated by human MNP stimulated by particles of prosthetic material. Particles of titanium-6-aluminium-4-vanadium (TiAlV) stimulated MNP to release interleukin (IL)-1β, tumour necrosis factor (TNF)α, IL-6 and prostaglandin E. 2. (PGE. 2. ). All these mediators are implicated in regulating bone metabolism. Particle-activated MNP inhibited bone cell proliferation and stimulated release of IL-6 and PGE. 2. The number of cells expressing alkaline phosphatase, a marker associated with mature osteo-blastic cells, was reduced. Experiments with blocking antibodies showed that TNFα was responsible for the reduction in proliferation and the numbers of cells expressing alkaline phosphatase. By contrast, IL-1β stimulated cell proliferation and differentiation. Both IL-1β and TNFα stimulated IL-6 and PGE. 2. release from the osteoblast-like cells. Our results suggest that particle-activated mono-nuclear phagocytes can induce a change in the balance between bone formation and resorption by a number of mechanisms

We describe a 13-year-old boy with atrophic tibial pseudarthrosis associated with neurofibromatosis who had undergone nine unsuccessful operations. Eventually, union was obtained by the use of bone morphogenetic protein 7 in conjunction with intramedullary stabilisation and autologous bone graft

1. A case of multiple pseudo-cystic tuberculosis of bone presenting as a generalised disease of the skeleton in a child is reported. 2. The response to streptomycin and para-amino-salicylic acid is shown. 3. A possible explanation of the etiology of this rare disease is suggested

Of the 4172 patients in a survey of all cases of tuberculosis notified in a six-month period in England and Wales in 1978-79, 198 had a bone or joint lesion; 79 were white and 108 were of Indian subcontinent (Indian, Pakistani or Bangladeshi) ethnic origin. The estimated annual notification rates for orthopaedic tuberculosis were 29 per 100 000 for the Indian subcontinent group and 0.34 per 100 000 in the white group, a ratio of 85 to 1. Rates increased with age in both groups. The spine was the most common site, and was affected in 30% of the white patients and 43% of the Indian subcontinent patients; the distribution of other sites was similar in both groups. Positive culture from a bone or joint lesion was obtained in 99 (50%) of the 198 patients (58% of white patients and 47% of the Indian subcontinent patients). Bacteriological or histological confirmation of tuberculosis either from a bone or joint lesion or from another site was obtained in 68% of the patients. Mycobacterium tuberculosis was isolated from the orthopaedic lesions in 79 of the 82 patients with identification test results and M. bovis in the 3 remaining patients. Of the 61 patients with M. tuberculosis and with no history of previous chemotherapy, 5 had resistant strains compared with 1 of the 18 patients who had previously received chemotherapy. All 6 patients with resistant strains were of Indian subcontinent ethnic origin

Bone samples from the iliac crest of patients with no signs of bone disorder were treated with collagenase to remove the collagen component and so allow detailed observation of the mineral hydroxyapatite. Both polished and unpolished surfaces were studied in the scanning electron microscope and they showed that the mineral component of bone is composed of small rounded units about 10 nm across which are fused together to form larger spheroidal units roughly 100 nm in diameter. In the unpolished surfaces these 100 nm units are seen to aggregate to form columns approximately parallel to their neighbours and with numerous interconnections forming a continuous mineral phase. The polished sections also show the hydroxyapatite as a continuous phase of contiguous spheroids and the holes from which the collagen fibres were removed are clearly revealed. Lamellations in the surface are interpreted as resulting from adjacent layers of collagen fibres having orientations approximately perpendicular to each other

1. Tarsal bone disintegration is a progressive disorder that affects a high proportion of leprosy patients. 2. Early detection and treatment by immobilisation permit healing with minimal deformity or disability. 3. Feet with advanced lesions can be similarly treated with a satisfactory outcome and amputation is not needed

1. Eight cases of solitary eosinophilic granuloma of bone are described, along with two possible complications. 2. The main pathological, clinical, and radiographic features of the condition, and its treatment, are discussed. 3. The essentially benign course of the solitary lesion, even in the presence of complications, is confirmed

1. A case of total dislocation of the cuboid bone without fracture is described. This is an uncommon injury and to our knowledge has not previously been reported. 2. Its rarity is explained in the light of the structural anatomy and function of the foot. 3. A mechanism of injury is postulated and a method of reduction and fixation described

1. Rosette strain gauges placed on the lateral surface of the right calcaneus of eight sheep allowed recordings of bone deformation to be made during walking and trotting on a moving belt. From these recordings the changing direction and magnitude of the principal strains and the maximum shear strain could be calculated. 2. The cancellous architecture of the ovine calcaneus, when viewed in lateral radiographs, is arranged in two trabecular tracts which intersect in the form of an arch. in all cases during the main weight-bearing period the direction of the principal strains varied little, and at the time of maximum deformation coincided with the direction of the underlying trabeculae. The principal compressive strain coincided with the direction of the trabeculae in the dorsal tract, The principal tensile strain with those in the plantar tract. At the point of trabecular intersection the principal strains were more nearly equal but they maintained their alignment with their respective trabecular tracts. 3. in this particular site the trajectorial theory of bone structure has found some experimental support

1. Direct injection of contrast material into bone indicates its extreme vascularity, particularly near an epiphysis, and emphasises the extraordinary capacity of the minute periosteal vessels. The nutrient artery of a long bone appears to play little part in its nourishment and may be regarded as a vestigeal structure. 2. The vascular pattern of bone tumours may be investigated by injection of the appropriate artery, and sometimes, if a haemangioma is suspected, by direct injection into the lesion. 3. The examination is easily and quickly carried out by direct arterial puncture under local anaesthesia and injection of 35 per cent diodone. A tourniquet applied distally at the appropriate level is often helpful. 4. A study of the vascular pattern of suspected bone tumours has provided useful information in a positive and negative way, assisting both the diagnosis and the planning of treatment. The pathological diagnosis of some tumours, notably osteosarcomas and haemangiomas, may be made with such assurance that possible dissemination of the tumour by biopsy may be avoided

1. A case of hydatidosis of the innominate bone is described. 2. The disease was treated by local resection combined with instillation of supersaturated salt solution. 3. The disease appears to have been arrested and the functional result is good. 4. The lethal effect of supersaturated salt solution on the parasite is stressed. 5. The experience of other workers in the field of hydatid disease is described

We have developed a bioactive bone cement (BA cement) consisting of Bis-GMA resin and bioactive glass powder. It has high compressive and tensile strengths, a low curing temperature and its bioactivity allows it to bond directly with bone. We operated on the 18 femora of nine mongrel dogs for intercalary replacement of part of the bone by a metal prosthesis using either PMMA cement or BA cement for fixation. Three dogs were killed at each of 4, 12 and 26 weeks after surgery for the evaluation of fixation strength by a push-out test and for histological examination by Giemsa surface staining and SEM. Fixation strengths with PMMA cement at 4, 12 and 26 weeks after surgery were 46.8 ± 18.9, 50.0 ± 24.7, and 58.2 ± 28.9 kgf (mean ±SD), respectively. Those with BA cement were 56.8 ± 26.1, 67.2 ± 19.2, and 72.8 ± 22.2 kgf, respectively. Fibrous tissue intervened between bone and PMMA cement but BA cement had bonded directly to bone at 12 and 26 weeks. This suggests that BA cement will be useful in providing long-lasting fixation of implants to bone under weight-bearing conditions

1. Twenty-five cases of benign giant-cell tumour of bone, treated at Westminster Hospital, London, are reported. 2. The diagnosis can often be made on clinical and radiographic grounds alone but biopsy is sometimes necessary and seldom, if ever, contra-indicated. 3. Some cases may best be treated by excision, but in general irradiation is the treatment of choice. 4. Details of treatment by irradiation are given

Aneurysmal bone cysts are uncommon lesions, especially in the spine. Seventy-eight cases have been previously documented in the English literature and an additional fourteen cases are now reported. There is a definite predilection for the lumbar region and the neural arch is the part of the vertebra most commonly affected. It is recommended that treatment should consist of total excision or when this is not possible, curettage. Radiotherapy should be reserved for those few cases where operation is inadvisable

We reviewed the clinical and radiological results of 131 patients who underwent acetabular revision for aseptic loosening with impacted bone allograft and a cemented acetabular component. The mean follow-up was 51.7 months (24 to 156). The mean post-operative Merle D’Aubigné and Postel scores were 5.7 points (4 to 6) for pain, 5.2 (3 to 6) for gait and 4.5 (2 to 6) for mobility. Radiological evaluation revealed migration greater than 5 mm in four acetabular components. Radiological failure matched clinical failure. Asymptomatic radiolucent lines were observed in 31 of 426 areas assessed (7%). Further revision was required in six patients (4.5%), this was due to infection in three and mechanical failure in three. The survival rate for the reconstruction was 95.8% (95% confidence interval 92.3 to 99.1) overall, and 98%, excluding revision due to sepsis. Our study, from an independent centre, has reproduced the results of the originators of the method

Two cases of malignant angioblastoma of tibia are described, one finally treated by amputation and the other by segmental resection and grafting. They have remained free from signs of local recurrence or distant metastasis for five and a half and ten and a half years respectively. Both showed prominent areas of neoplastic mesenchymal angioblastic tissue which closely imitates solitary fibrous dysplasia. The natural history and radiological characteristics of these little-known tumours, long thought to be "adamantinoma" of bone, are described

1. Cell differentiation around screws manufactured by two American and two Swiss companies and inserted into seventy femora in forty-one adult mongrel dogs has been observed over periods varying between two weeks and nine months. 2. This study reveals that, despite their excellent holding power, such screws are not everywhere in firm contact with the surrounding bone at the time of insertion. Indeed, only part of the thread surface facing the head of the screw touches the compact bone, all other surfaces being separated by a space up to 150 µ in thickness. 3. These spaces result both from the surgical technique employed and from the inaccurate measurements of drills, screws and taps. 4. Migrating cells invade these spaces during the first two weeks. In the absence of movement, these cells differentiate into osteogenic cells; movement leads to differentiation into fibroblasts, chondroblasts and osteoclasts, and failure of fixation ensues. In contrast, callus formation by osteogenic cells firmly anchors screws in four to five weeks, well before callus uniting the bone fragments has been established. 5. Extremities should be protected from undue stresses during those first few weeks after osteosynthesis, whatever the technique. 6. This study clearly demonstrates the importance oftesting screws in living bone to ascertain their holding power at all stages of fracture healing

In patients with traumatic brain injury and fractures of long bones, it is often clinically observed that the rate of bone healing and extent of callus formation are increased. However, the evidence has been unconvincing and an association between such an injury and enhanced fracture healing remains unclear. We performed a retrospective cohort study of 74 young adult patients with a mean age of 24.2 years (16 to 40) who sustained a femoral shaft fracture (AO/OTA type 32A or 32B) with or without a brain injury. All the fractures were treated with closed intramedullary nailing. The main outcome measures included the time required for bridging callus formation (BCF) and the mean callus thickness (MCT) at the final follow-up. Comparative analyses were made between the 20 patients with a brain injury and the 54 without brain injury. Subgroup comparisons were performed among the patients with a brain injury in terms of the severity of head injury, the types of intracranial haemorrhage and gender. Patients with a brain injury had an earlier appearance of BCF (p < 0.001) and a greater final MCT value (p < 0.001) than those without. There were no significant differences with respect to the time required for BCF and final MCT values in terms of the severity of head injury (p = 0.521 and p = 0.153, respectively), the types of intracranial haemorrhage (p = 0.308 and p = 0.189, respectively) and gender (p = 0.383 and p = 0.662, respectively). These results confirm that an injury to the brain may be associated with accelerated fracture healing and enhanced callus formation. However, the severity of the injury to the brain, the type of intracranial haemorrhage and gender were not statistically significant factors in predicting the rate of bone healing and extent of final callus formation

1. Seven cases of massive osteoarticular transplant for conditions affecting major joints are described. In one case the whole femur was replaced. 2. The transplants were well accepted, though there was a varying degree of absorption of bone and necrosis of articular cartilage. 3. The functional results were very satisfactory, and movements of joints were well preserved. 4. In these cases recurrence of the original disease was not seen. 5. Such operations are still in an experimental stage, but they are likely to have a permanent place in treatment in certain carefully selected cases