Intramedullary rods manufactured from polyacetal were used to fix diaphyseal fractures in osteoporotic bone. They are pliable and can be introduced without further damage to such bone. Their low elastic modulus induces abundant callus. They can be locked with cortical bone screws without the need of jigs or radiographic control. Nine femoral and five tibial fractures were fixed in 10 patients, all with osteoporosis; 13 united primarily; one required bone grafting. No implant broke; however, no ambulant patient weighed more than 75 kg. The rods offer a promising treatment for diaphyseal fractures in osteoporotic bone

In a prospective study of 14 patients undergoing total hip replacement we have used dual-energy X-ray absorptiometry (DEXA) to investigate remodelling of the bone around two different designs of cementless femoral prosthesis. The bone mineral density (BMD) was measured at 12-weekly intervals for a year. Eight patients (group A) had a stiff, collarless implant and six (group B) a flexible isoelastic implant. Patients in group A showed a decrease in BMD from 14 weeks after operation. By 12 months, the mean loss in BMD was 27%, both medially and laterally to the proximal part of the implant. Those in group B showed an overall increase in BMD which reached a mean of 12.6% on the lateral side of the distal portion of the implant. Our results support the current concepts of the effects of stem stiffness and flexibility on periprosthetic remodelling

We analysed the effects of commonly used medications on human osteoblastic cell activity in vitro, specifically proliferation and tissue mineralisation. A list of medications was retrieved from the records of patients aged > 65 years filed in the database of the largest health maintenance organisation in our country (> two million members). Proliferation and mineralisation assays were performed on the following drugs: rosuvastatin (statin), metformin (antidiabetic), metoprolol (β-blocker), citalopram (selective serotonin reuptake inhibitor [SSRI]), and omeprazole (proton pump inhibitor (PPI)). All tested drugs significantly stimulated DNA synthesis to varying degrees, with rosuvastatin 5 µg/ml being the most effective among them (mean 225% (. sd. 20)), compared with metformin 10 µg/ml (185% (. sd.  10)), metoprolol 0.25 µg/ml (190% (. sd. 20)), citalopram 0.05 µg/ml (150% (. sd. 10)) and omeprazole 0.001 µg/ml (145% (. sd. 5)). Metformin and metoprolol (to a small extent) and rosuvastatin (to a much higher extent) inhibited cell mineralisation (85% (. sd. 5)). Our results indicate the need to evaluate the medications prescribed to patients in terms of their potential action on osteoblasts. Appropriate evaluation and prophylactic treatment (when necessary) might lower the incidence and costs associated with potential medication-induced osteoporosis. Cite this article: Bone Joint J 2013;95-B:1575–80

1. Twenty-five lower limbs, amputated above the knee for senile atherosclerosis with peripheral gangrene, have been investigated radiologically and histologically to determine the vascular patterns in ischaemic bone with particular reference to the tibia. These have been contrasted with the patterns found in non-atherosclerotic tubular bone. 2. The principal changes are the development of a diffuse vascularisation of compact and spongy bone; a widening of Haversian spaces which come to contain a variable number of sinusoidal blood vessels; and an increasing periosteal participation in cortical nutrition which is related to the severity and chronicity of the ischaemic process. 3. Views on the normal blood supply of long bones are discussed, and evidence is presented for regarding this as discrete and end-arterial in nature; in particular it is suggested that the normal cortex has a wholly medullary, centrifugal, arterial supply

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model. Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30mW/cm. 2. ) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group. We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis

The long-term effect of stainless steel and titanium alloy plates on structural remodelling and bone mass of osteotomised canine femora was studied and the effects of early and late removal of plates were compared in 27 adult Beagles. Radiological, histological, histomorphometric and tetracycline fluorescence studies led to three conclusions. First, the continuous (60 weeks) presence of plates, irrespective of their composition, delays remodelling and leads to a reduction of bone mass. This loss is significantly greater under stainless steel plates. Secondly, the removal of plates at eight weeks leads during the 52 ensuing weeks to a marked and widespread structural remodelling and to a return to normal bone mass, irrespective of the type of plate used. However, remodelling is more intense after titanium alloy plates have been used; it is not complete 60 weeks after osteotomy. Thirdly, removal of plates at 40 weeks activates remodelling during the ensuing 20 weeks to a lesser degree and to a more limited extent than early plate removal. The clinical significance of this study is that less rigid but stable internal fixation permits the radiological assessment of healing and thus the determination of the optimal moment for removal of the plates. It also reduces the degree of bone loss should the plate be left in situ for any reason

It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised into two groups to receive either a resurfacing or a THR and were followed for two years. One patient’s resurfacing subsequently failed, leaving 19 patients in each group. Resurfaced replacements maintained proximal femoral BMD and, compared with THR, had an increased bone mineral density in Gruen zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95% confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6% (95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD of the medial femoral neck and increased that in the lateral zones between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6). On the acetabular side, BMD was similar in every zone at each point in time. The mean BMD of all acetabular regions in the resurfaced group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863). A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8 to 9.0) of BMD was found above the acetabular component in W1 and 10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial to the implant in W2 for resurfaced replacements and THRs respectively. Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to 12.7) in W3 but the BMD inferior to the acetabular component was maintained in both groups. These results suggest that the ability of a resurfacing hip replacement to preserve BMD only applies to the femoral side

Of fifteen patients treated by excision of the lunate bone and prosthetic replacement twelve had no pain at all or slight discomfort after exceptionally heavy work. All these were able to return to and continue at heavy manual jobs. Two patients continued to experience pain with vigorous use of the wrist but were none the less satisfied with their improvement. In one patient the operation failed and pain persisted unrelieved. We believe that the radiographs show that the prosthesis greatly minimises the distortion of the carpus after excision of the lunate bone and that the maintenance of a normal carpal architecture is important in the avoidance of osteoarthritis of the remaining joints. The results suggest that when the operation is technically successful degenerative changes do not occur despite prolonged and heavy use. The presence of osteoarthritis in the wrist before operation is not a contra-indication to prosthetic replacement because the degenerative process may remain stationary for several years after removal of the damaged lunate bone. The prosthesis has proved durable over many years and none of our patients having attained a good wrist has suffered a relapse. The operation entails a month off work for a heavy labourer and as little as a fortnight for those who do lighter jobs. These considerations prompt us to suggest its wider use in the treatment of Kienböck's disease

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

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

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

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

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. 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