1. Five cases of involvement of vertebrae by growths classified as giant-cell tumours, and two cases of involvement by tumours classified as aneurysmal bone cysts are described. 2. The periods of observation after operation in the benign cases were in three cases six years, in one ten years and in one twenty-one years. 3. In one case malignant transformation developed four and a half years after operation and one patient, in whom a sacral tumour was already malignant at the time of operation, died five months later. 4. Four patients showed significant involvement of vertebral bodies. 5. The problems related to the removal of a vertebral body and the measures taken to stabilise the spine are discussed

We studied the various drill bits available for engineering purposes, and compared them with standard orthopaedic drill bits, using continuous temperature recording at 0.5 mm, 1.0 mm and 1.5 mm from the edge of a 2.5 mm hole as it was drilled in fresh cadaver human tibia. We found that some commercially available drill bits performed better than their orthopaedic equivalents, producing significantly less thermal injury to the surrounding bone and halving the force required for cortical penetration. Our work suggests that the optimal bit for orthopaedic purposes should have a split point and a quick helix. Theoretical knowledge of cutting technology predicts that the addition of a parabolic flute will further reduce thermal damage. Further work is being done on other drill sizes used in orthopaedic practice and on new custom-designed bits

We used dual-energy X-ray absorptiometry (DEXA) to measure the bone mineral content (BMC) of both tibiae in 13 patients who had been treated for a tibial fracture by rigid plate fixation. Within two weeks of plate removal the BMC was significantly greater in the bone that had been under the plate than at the same site in the control tibia. An unplated area of bone near the ankle showed a significant decrease in BMC at the time of plate removal with subsequent return to the level of the control tibia during the ensuing 18 months. We conclude that osteoinductive influences outweigh the potential causes of osteopenia, such as stress shielding and disuse, and that, contrary to expectation, demineralisation is not a factor in the diminished strength of the tibia after plating for fracture

The beneficial effect upon osteogenesis of imprenating bone grafts with autologous red marrow is well documented. The experimental findings reported in a previous paper suggested that prepared xenograft bone might provide a good medium for osteogenesis by marrow cells. This paper is a preliminary report of the first clinical attempt to use xenografts of bone combined with autologous red marrow. Kiel bone, which was found the most suitable, was impregnated with marrow aspirated from the iliac crest and, apart from one case of infection, gave excellent results in twenty-eight patients under conditions covering a wide range of indications for bone grafting. Further trials should allow a more valid assessment

Puppies in the second half of their growing period have been observed for one and a half to four and a half months after creation of a superficial femoral arteriovenous fistula on the right side. From measurements of the whole bone and from microradiographic and tetracycline-fluorophore studies of the diaphysial bone, it is believed that the following statistically significant phenomena may be attributed to the influence of the arteriovenous fistula. 1. All bones distal to the fistula are influenced in their growth. The tibia and metatarsals become heavier and larger, but retain normal shape. Although stimulation of longitudinal growth is small, it is significant for the tibiae and nearly significant for the femora in these short-term experiments. 2. The histological structure of the bones remains normal but quantitative changes are induced. The compact bone is more porous because of an increased number of osteones. Haversian turnover itself is affected in that the individual formation time of osteones tends to become longer, especially in the metatarsals. 3. Periosteal new bone formation is immediately stimulated, producing a flare of new bone. This accounts for the increase in diaphysial weight in the tibia but not in the metatarsals, where the same effect results from decreased resorption of old bone. 4. Endosteal new bone formation is depressed, especially in the metatarsals, resulting in an enlarged medullary cavity

1. Sixty-three fractures of the femur occurring in forty-eight patients with Paget's disease are presented. 2. In patients with Paget's disease the femur is the bone most often fractured, although the risk of fracture is probably not much greater than that of the normal population. 3. Many femoral fractures in Paget's disease are spontaneous and are preceded by pain. Extension of a stress fracture is the most likely cause. 4. All eleven femoral neck fractures in this series failed to unite; it is suggested that neither operation nor prolonged conservative treatment is indicated. 5. Subtrochanteric fractures, if severely displaced, are best treated by intramedullary nailing. 6. Most shaft fractures may be satisfactorily treated by conservative means. Deformity of the shaft can be corrected in fractures treated by external splintage. 7. The time required for union has been neither unduly short nor unduly prolonged. 8. The long-term results in this series have been acceptable. Sarcomatous change as a complication of fracture was not observed

Animal experiments are reported in which porous titanium plugs were used to secure a prosthetic tendon to bone. The plugs remained fixed under functional load and were colonised by healthy lamellar bone. These results suggest that such plugs form reliable anchorages

We have investigated whether the particle-stimulated release of inflammatory cytokines from human primary macrophages in vitro was dependent upon the type of bone cement used. Particles of clinically relevant size were produced from Palacos R without radio-opacifier, Palacos R with BaSO. 4. , Palacos R with ZrO. 2. and from CMW3 which contains BaSO. 4. All four preparations produced significantly greater release of tumour necrosis factor alpha, interleukin-6 and interleukin-1 beta than a negative control but there were no significant differences between them. The differences in the ability to stimulate bone resorption and in clinical performance between proprietary bone cements previously recorded are not explained by the release of the cytokines most commonly implicated in osteolysis

Twenty-three of 46 patients, aged 56 to 95 years, with fracture of the femoral neck (FNF) completed the first trial of 10 months treatment with oral sodium fluoride 60 mg and calcium 1800 mg on alternate days and 1 micrograms of vitamin D1 daily. Pre-treatment and post-treatment biopsy specimens and microradiographs of the iliac crest and metacarpal and spinal radiographs were evaluated together with biopsy material from seven untreated age-matched controls with FNF. In 17 patients the treatment improved the amount and quality of trabecular bone. Cortical thickness increased in nine patients and there were no losses of amount or mineralisation. The treatment was well tolerated by most patients and there were no major side-effects or signs of bone demineralisation. The study also revealed an unexpected rapid post-fracture deterioration of bone tissue in untreated FNF patients; thus there is an increased risk of further fractures which calls for the use of an effective treatment to increase bone mass

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

We have reviewed 41 patients with pustulotic arthro-osteopathy (PAO), all having both the typical skin rash of pustulosis palmaris et plantaris and bone lesions. The most common bones affected were the clavicle, sternum and ribs. Changes in the clavicle started, not as an enthesopathy, but with periosteal bone formation, indicative of a bone marrow disorder. About 30% of the patients also had lesions in the spine, sacroiliac region or the peripheral joints. Bone and joint lesions followed a variable and intermittent clinical course over a long period of time. Biopsies in eight cases showed similar inflammatory changes in skin, bone and synovium, with infiltration of lymphocytes and polymorphonuclear leucocytes. This suggests that there is a common pathogenesis in the three tissues

Glenoid replacement is technically challenging. Removal of a cemented glenoid component often results in a large osseous defect which makes the immediate introduction of a revision prosthesis almost impossible. We describe a two-stage revision procedure using a reversed shoulder prosthesis. Freeze-dried allograft with platelet-derived growth factor was used to fill the glenoid defect. Radiological incorporation of the allograft was seen and its consistency allowed the placement of a screwed glenoid component. There were no signs of new mature bone formation on histological examination. The addition of platelet-derived growth factor to the allograft seems to contribute to an increase in incorporation and hardness, but does not promote the growth of new bone

Treatment with corticosteroids is a risk factor for non-traumatic avascular necrosis of the femoral head, but the pathological mechanism is poorly understood. Short-term treatment with high doses of methylprednisolone is used in severe neurotrauma and after kidney and heart transplantation. We investigated the effect of such treatment on the pattern of perfusion of the femoral head and of bone in general in the pig. We allocated 15 immature pigs to treatment with high-dose methylprednisolone (20 mg/kg per day intramuscularly for three days, followed by 10 mg/kg intramuscularly for a further 11 days) and 15 to a control group. Perfusion of the systematically subdivided femoral head, proximal femur, acetabulum, humerus, and soft tissues was determined by the microsphere technique. Blood flow in bone was severely reduced in the steroid-treated group. The reduction of flow affected all the segments and the entire epiphysis of the femoral head. No changes in flow were found in non-osseous tissue. Short-term treatment with high-dose methylprednisolone causes reduction of osseous blood flow which may be the pathogenetic factor in the early stage of steroid-induced osteonecrosis

Congenital pseudarthrosis of the tibia is an uncommon manifestation of neurofibromatosis type 1 (NF1), but one that remains difficult to treat due to anabolic deficiency and catabolic excess. Bone grafting and more recently recombinant human bone morphogenetic proteins (rhBMPs) have been identified as pro-anabolic stimuli with the potential to improve the outcome after surgery. As an additional pharmaceutical intervention, we describe the combined use of rhBMP-2 and the bisphosphonate zoledronic acid in a mouse model of NF1-deficient fracture repair. Fractures were generated in the distal tibiae of neurofibromatosis type 1-deficient (Nf1. +/−. ) mice and control mice. Fractures were open and featured periosteal stripping. All mice received 10 μg rhBMP-2 delivered in a carboxymethylcellulose carrier around the fracture as an anabolic stimulus. Bisphosphonate-treated mice also received five doses of 0.02 mg/kg zoledronic acid given by intraperitoneal injection. When only rhBMP but no zoledronic acid was used to promote repair, 75% of fractures in Nf1. +/−. mice remained ununited at three weeks compared with 7% of controls (p < 0.001). Systemic post-operative administration of zoledronic acid halved the rate of ununited fractures to 37.5% (p < 0.07). These data support the concept that preventing bone loss in combination with anabolic stimulation may improve the outcome following surgical treatment for children with congenital pseudarthoris of the tibia and NF1

In this study the direct relationship between the type of bone implant used, the vascular reaction caused to the host and the revascularisation of the implant has been studied. It was found that the best graft was that which was the most rapidly and permanently vascularised. Not only was the biological affinity between the graft and the bed important, but the structural facilities offered by the implant for the "penetration" by the host vessels were also of paramount importance. Thus small, fresh, cancellous bone grafts offered the best chance of rapid incorporation provided they were not crushed to the point of making vascular progress difficult. The findings from this investigation so strongly suggest that the rapid revascularisation of the bone grafts was because of an end-to-end anastomosis of the vessels of the host with those in the implant that it seems justified to consider that the best bone graft is that which is richest in vessels. Apart from a recent short paper by Graf (1960), we have not found this assertion before. It is this which seems to make the fresh, autogenous, cancellous implant so superior to all others. We believe that any new material for bone grafts should be tested by the technique described here. The material which one day may replace fresh, autogenous, cancellous implants will have to show the same readiness to vascular penetration, vascular osteogenesis and vascular permanency that at present is exhibited only by the cancellous autograft

1. The use of the Metals Research Macrotome for cutting 100 μ thick sections of fresh, unfixed specimens of arthritic human femoral heads and normal goat condyles is described. 2. A technique for isolating living cells from these slices by decalcification followed by enzymic digestion is reported. 3. The microscopic appearances of the fresh slices, the decalcified slices and the isolated cells as seen by incident or transmitted fluorescent lighting, by phase-contrast microscopy, by scanning electron microscopy and by histological and cytological techniques are illustrated. 4. These techniques might be applicable to the examination of biopsy specimens of pathological bone or to basic research on bone cells

The role of inflammatory cells in aseptic loosening and failure of cemented joint replacements is unclear. Inflammatory cells from the revision joint capsule of four failed hip arthroplasties were examined to determine their nature and resorptive capacity. The capsules contained numerous macrophages and abundant foreign-body macrophage polykaryons, distinguished from osteoclasts by their antigenic phenotype and lack of response to calcitonin. When cultured on cortical bone slices in vitro, both macrophages and macrophage polykaryons produced small resorption pits and were associated with areas of superficial resorption of the bone surface. These results indicate that foreign-body induced macrophages and macrophage polykaryons are capable of a type of low-grade bone resorption which may be of pathogenic significance in the loosening of cemented joint prosthetic components

1. When cortisone is administered to rabbits there is early rapid resorption of bone and a partial inhibition of new bone formation. After a few days the effect becomes less obvious, so that, if observations are made at later stages, the results may be ascribed then to simple inhibition of bone growth. 2. The effect of mechanical stress has been studied in the jaw. When tooth movement is induced mechanically there is, in ordinary circumstances, a resorption of bone on the side to which the tooth is moving (the "pressure" side) and bone formation on the opposite side (the "tension" side). After administration of cortisone there is increased resorption on the "pressure" side and there is greater resorption of connective tissues here. On the "tension" side there is resorption and inhibition of bone formation. 3. In the areas of stress, when cortisone is administered, collagen fibres are no longer in apposition, being separated by spaces presumably filled with altered ground substance; this kind of change may be responsible for many of the observed phenomena. 4. A.C.T.H. does not produce a demonstrable resorptive effect on bone or connective tissue until it has been administered for periods longer than is required for cortisone (three weeks); even then the change is not pronounced. 5. In the guinea pig there is slight delay in bone formation with large doses of both cortisone and A.C.T.H., but no significant bone resorption occurs

In a preliminary experiment the paired radii and femora of dogs were tested for bone mineral mass and mechanical properties including the load at break, the ultimate bending strength and the modulus of elasticity; symmetry was observed for most of the parameters determined. The influence of the elasticity of materials used for the internal splintage of bone and its relationship to bone remodeling were then investigated for stainless steel and plastic plates applied to the femora of dogs. A significant decrease in bone mineral mass per centimetre length of bone and in mechanical properties was demonstrated for the femora plated with steel, and microradiography showed that this was due to massive endosteal resorption. A model for determining the influence of protection from stress in bone is presented