Transient osteoporosis of the hip is a disorder characterised by pain, and associated with temporary osteopaenia. Although osteopaenia is the essence of the condition, data do not exist about the local bone density of the femoral neck if no medication is administered. We describe three patients who were treated with limitation of weight-bearing only. Repeated bone mineral density measurements were obtained, and that at the femoral neck was lowest two months after the onset of the condition. The mean reduction in bone mineral density when compared with an age-matched control group was 13% (3% to 24%). Spontaneous recovery was observed in all patients

1. Measurements have been made of the relative calcification of different types of bone in tibia of the rabbit at the ages of six weeks, three and a half months and seven months by comparing their absorption of x-rays. 2. Calcified cartilage is between 8 and 10 per cet more highly calcified than periosteal and endosteal bone and about 20 per cent more highly calcified than bone formed immediately adjacent to cartilage. 3. Young and adult bones have a framework of approximately the same strength; that is, calcified cartilage, bone adjacent to cartilage and the interstitial areas of periosteal and endosteal bone have each approximately the same degree of calcification at all ages. 4. Adult rabbit bone approaches uniform calcification throughout, equal to the calcification of the interstitial areas of periosteal and endosteal bone. Evidence for this is the replacement of the lowly calcified epiphysial bone by osteones of higher calcification

We report the results of 79 patients (81 hips) who underwent impaction grafting at revision hip replacement using the Exeter femoral stem. Their mean age was 64 years (31 to 83). According to the Endoklinik classification, 20 hips had a type 2 bone defect, 40 had type 3, and 21 had type 4. The mean follow-up for unrevised stems was 10.4 years (5 to 17). . There were 12 re-operations due to intra- and post-operative fractures, infection (one hip) and aseptic loosening (one hip). All re-operations affected type 3 (6 hips) and 4 (6 hips) bone defects. The survival rate for re-operation for any cause was 100% for type 2, 81.2% (95% confidence interval (CI) 67.1 to 95.3) for type 3, and 70.8% (95% CI 51.1 to 90.5) for type 4 defects at 14 years. The survival rate with further revision for aseptic loosening as the end point was 98.6% (95% CI 95.8 to 100). The final clinical score was higher for patients with type 2 bone defects than type 4 regarding pain, function and range of movement. Limp was most frequent in the type 4 group (p < 0.001). The mean subsidence of the stem was 2.3 mm (. sd. 3.7) for hips with a type 2 defect, 4.3 mm (. sd. 7.2) for type 3 and 9.6 mm (. sd.  10.8) for type 4 (p = 0.022). The impacted bone grafting technique has good clinical results in femoral revision. However, major bone defects affect clinical outcome and also result in more operative complications

We implanted nails made of titanium (Ti6Al4V) and of two types of glass ceramic material (RKKP and AP40) into healthy and osteopenic rats. After two months, a histomorphometric analysis was performed and the affinity index calculated. In addition, osteoblasts from normal and osteopenic bone were cultured and the biomaterials were evaluated in vitro. In normal bone the rate of osseointegration was similar for all materials tested (p > 0.5) while in osteopenic bone AP40 did not osseointegrate (p > 0.0005). In vitro, no differences were observed for all biomaterials when cultured in normal bone-derived cells whereas in osteopenic-bone-derived cells there was a significant difference in some of the tested parameters when using AP40. Our findings suggest that osteopenic models may be used in vivo in the preclinical evaluation of orthopaedic biomaterials. We suggest that primary cell cultures from pathological models could be used as an experimental model in vitro

Coloured bone cements have been introduced to make the removal of cement debris easier at the time of primary and revision joint replacement. We evaluated the physical, mechanical and pharmacological effects of adding methylene blue to bone cement with or without antibiotics (gentamicin, vancomycin or both). The addition of methylene blue to plain cement significantly decreased its mean setting time (570 seconds (. sd. 4) vs 775 seconds (. sd. 11), p = 0.01), mean compression strength (95.4 MPa (. sd. 3) vs 100.1 MPa (. sd.  6), p = 0.03), and mean bending strength (65.2 MPa (. sd. 5) vs 76.6 MPa (. sd. 4), p < 0.001) as well as its mean elastic modulus (2744 MPa (. sd. 97) vs 3281 MPa (. sd. 110), p < 0.001). The supplementation of the coloured cement with vancomycin and gentamicin decreased its mean bending resistance (55.7 MPa (. sd. 4) vs 65.2 MPa (. sd . 5), p < 0.001).The methylene blue significantly decreased the mean release of gentamicin alone (228.2 µg (. sd. 24) vs 385.5 µg (. sd . 26), p < 0.001) or in combination with vancomycin (498.5 µg (. sd. 70) vs 613 µg (. sd. 25), p = 0.018) from the bone cement. This study demonstrates several theoretical disadvantages of the antibiotic-loaded bone cement coloured with methylene blue

The clinical, radiological and histological information on the fate of Kiel bone implants for anterior spinal fusion in four patients was evaluated. These implants were found to be unsatisfactory and further operations were required. Biopsies of the grafts showed that the Kiel bone was invaded by fibrous tissue but that it did not ossify or become incorporated into the underlying bone. However, it might provide temporary support to the grafted area. These findings indicate that the use of Kiel grafts does not seem to be justified in current orthopaedic practice

A small proportion of the total phosphate in normal bone salt occurs in the form of pyrophosphate. The deposit formed in vitro on incubation of rachitic cartilage with a calcifying medium does not contain pyrophosphate unless ATP is added to the medium, in which case the proportion of pyrophosphate is of the same order as that found in normal bone

Two cases of benign osteoblastic tumours of the spine, occurring in young patients, and presenting as expanding osteolytic lesions with some central calcification and ossification, are described. It is suggested that they represent a condition allied to, but usefully separated from, osteoid osteoma of bone. The name osteogenic fibroma of bone, proposed by Lichtenstein for this type of case, is accepted

1. Seven new cases of primary reticulo-sarcoma of bone are recorded, including one in which a full necropsy was carried out. 2. The literature of Ewing's tumour and reticulo-sarcoma of bone has been examined and the conclusion reached that the separation of these two tumours is an artificial one. 3. The investigation of our cases confirms this observation

1. Three cases of aneurysmal bone cyst are recorded. It is suggested that the condition is a type of cavernous haemangioma and the term haemangiomatous bone cyst is preferred. 2. A survey of the published cases suggests that in its early stages the lesion is amenable to local surgery, which is the treatment of choice, but for inaccessible lesions deep x-ray therapy may be effective

1. Ten cases are recorded of the entity known as non-osteogenic fibroma of bone. 2. We believe the evidence is in favour of the condition's being a localised disturbance of bone growth (metaphysial fibrous defect) rather than a true neoplasm. 3. The disorder usually pursues a symptomless course and in many instances the lesion disappears spontaneously

1. Chondrosarcoma is a malignant tumour of bone with clinical and morphological features which distinguish it from osteosarcoma. 2. Cartilage tumours present an unbroken spectrum in their clinical behaviour and histological appearances from the entirely benign to the frankly malignant. 3. A few chondrosarcomata, particularly those in children and young adults, run a rapidly fatal course but in general they metastasise late and some kill by local extension of the tumour. 4. "Secondary" chondrosarcomata arising from a pre-existing osteocartilaginous exostosis or enchondroma are mostly low grade tumours. 5. The first appearance of an osteocartilaginous exostosis after skeletal maturity, renewed growth, or pain unassociated with a fracture, should arouse suspicion of malignancy in any cartilage tumour. 6. Cartilage tumours of the trunk and upper end of femur and humerus are especially liable to sarcomatous change. 7. Although most benign cartilage tumours occur in the hand and foot they rarely become malignant with the exception of those in the calcaneus. 8. If biopsy is necessary it should be of the incisional type, a generous amount of material being removed from the edge of the tumour. Calcified, degenerate areas must be avoided. 9. In low grade tumours microscopic fields judged to be malignant by Lichtenstein and Jaffe's well established criteria may be scanty and many paraffin sections should be examined. Absence of mitotic figures, heavy calcification and poor vascularity are no guarantee of benignity. 10. Information as to the site of the tumour and age of the patient must be available to the pathologist if a useful report is to be given. 11 . In "borderline" tumours or where any difficulty in diagnosis arises the clinical, radiographic and histological features must all be taken into account and treatment based on the most unfavourable features. 12. Chondrosarcoma is a radio-resistant tumour and treatment is by radical excision or amputation. 13. Malignant cartilage cells implanted in the tissues at operation will often continue to grow and in all instances the biopsy wound and surrounding tissues must be removed en bloc with the tumour. 14. Small, low grade, readily accessible, peripheral tumours may be successfully treated by excision with a wide margin of healthy tissue. 15. In the limbs or pelvis large tumours and those of high grade malignancy should be treated by amputation. Since marrow permeation is often greater than the radiograph suggests amputation should, as a rule, not be performed through the bone in which the chondrosarcoma is situated. 16. Recurrence carries the danger that an initially accessible tumour becomes inaccessible and inoperable and, less frequently, a low grade tumour recurs in a metastasising form. 17. Recurrence is frequent after inadequate surgery; it indicates that the tumour is at least locally malignant and a cure can usually only then be achieved by more radical surgery

1. Three cases of cystic angiomatosis of bone are presented and the literature is reviewed. 2. The typical radiological appearances are described and illustrated. 3. The diagnosis must be confirmed by biopsy, and it is essential that the bone removed should be from an involved rib. 4. The prognosis is dependent upon extraskeletal visceral involvement and is not influenced by radiotherapy or chemotherapy. Splenectomy may improve the chance of survival when the spleen is the only viscus involved

We treated 13 children with histologically confirmed cystic tuberculosis of bone. Ten had solitary cystic lesions and three had the multicystic form. Signs and symptoms were related mainly to the joint adjacent to the cyst. Most lesions were in the metaphyses of long bones. They were radiolucent, round or oval, and resembled pyogenic infections, aneurysmal and simple bone cysts, cartilaginous tumours or osteoid osteoma. Only two of the children had pulmonary tuberculosis. The Mantoux skin test was negative in four children and the ESR was normal in five. Curettage followed by anti-tuberculosis therapy for one year resulted in good healing, but two children had residual joint contractures. Biopsy should be taken from the cystic area rather than from the synovium when a joint is involved

We report the contamination rate in the Cambridge bone bank of 35 consecutive allograft specimens, all harvested in a clean-air environment, using a strict aseptic technique and antibiotic cover. Five of 27 femoral heads taken from living donors and three of eight massive allografts taken from cadavers were found to be contaminated. The contaminated femoral heads were discarded. All massive allografts were rendered sterile by gamma-irradiation. It is important to exclude bacteriological contamination of harvested and banked bone

1. Experimental evidence suggests that the autogenous graft exhibits some advantage over refrigerated homogenous grafts in that healing takes place more rapidly but that in the end the results are the same. 2. Histological study of fragments of healing grafts, both autogenous and refrigerated, that have been removed from human hosts shows no significant difference in the rate or method of repair. 3. Study of the clinical results of the use of homogenous transplants in 307 operations shows the bone to be well tolerated. The rate of infection in clean cases was 2·6 per cent; loss of bone occurred in only two cases. 4. Follow-up studies of 248 cases showed successful results obtained in 210, or 85 per cent. These are comparable with the results obtained with autogenous grafts. The healing of cancellous transplants takes place more rapidly than with cortical grafts. Transplants that have been preserved for more than one year do not heal as well as those that have been preserved for a shorter period and the failure rate is higher. 5. The operation of a bone bank is safe and practical. It offers great advantages to the patient and the surgeon from the standpoint of availability, abundance and the elimination of the necessity of secondary operations to obtain bone. When a bone bank is available the number of operations in which bone transplants are used will show a sharp increase

We analysed the histological findings in 1146 osteoarthritic femoral heads which would have been considered suitable for bone-bank donation to determine whether pathological lesions, other than osteoarthritis, were present. We found that 91 femoral heads (8%) showed evidence of disease. The most common conditions noted were chondrocalcinosis (63 cases), avascular necrosis (13), osteomas (6) and malignant tumours (one case of low-grade chondrosarcoma and two of well-differentiated lymphocytic lymphoma). There were two with metabolic bone disease (Paget’s disease and hyperparathyroid bone disease) and four with inflammatory (rheumatoid-like) arthritis. Our findings indicate that occult pathological conditions are common and it is recommended that histological examination of this regularly used source of bone allograft should be included as part of the screening protocol for bone-bank collection

We identified eight patients of 2900 with a primary malignant bone tumour who had coexisting neurofibromatosis type 1. This was a much higher incidence than would be expected by chance. The patients had a mean age of 22.4 years (9 to 54): five were male. Two patients subsequently developed a second bone sarcoma, one of which was radiation induced. Four of the primary tumours were osteosarcomas, four were spindle-cell sarcomas and one a Ewing’s sarcoma. All the patients were treated with chemotherapy and surgery: six of the eight appear to be cured. This study suggests a possible relationship between neurofibromatosis type 1 and the development of a bone sarcoma, the increased risk being estimated at eight times that of the normal population. We recommend that further research into this possible link should be considered

Bone scanning with radioactive isotopes has been used to study a wide variety of disorders. Recently certain phosphate compounds, labelled with technetium, have been used as bone scanning agents. The comparative merits of three technetium-labelled phosphate compounds currently available for bone scanning–pyrophosphate, tripolyphosphate and ethylhydroxydiphosphonate (EHDP) have been compared in rabbits. Each substance was injected into ten rabbits and blood was withdrawn at regular intervals. The animals were killed at four hours and the blood and tissue samples were assayed for radioactivity. The results show that EHDP has a more rapid blood clearance than the other two agents, with a resultant improvement in the bone to soft-tissue ratio. Of the three substances investigated technetium-labelled EHDP was the best and might allow the technique of scanning to be used on a wide scale for the general study of bone and its pathology

We investigated the fracture-free survival of long bones stabilised by a telescopic intramedullary rod (TIMR) in patients with osteogenesis imperfecta with respect to the remodelling status of fracture or osteotomy sites and TIMR regions, in order to identify risk factors for fracture. A total of 44 femora and 28 tibiae in 25 patients with a mean age of 5.0 years (1.9 to 10.5) at presentation were studied. There were six patients with Sillence type I, five with type III, 13 with type IV and one with type V osteogenesis imperfecta. All received bisphosphonate treatment at the same stage during the mean follow-up of 7.3 years (0.5 to 18.1). The fracture-free survival was estimated at 6.2 years (95% confidence interval 5.1 to 7.3) by Kaplan-Meier analysis. More than half the fracture or osteotomy sites remained in a less-remodelled state at the latest follow-up or time of fracture. Of the 33 fractures, 29 (87.9%) occurred in long bones containing a less-remodelled site, and these fractures were located at this site. The relative fracture risk at the rod tip was significantly greater than in any other TIMR region (p < 0.001), and this was higher in bone segments having a less-remodelled site. This study shows a persistent fracture risk in TIMR-stabilised long bones, especially at less-remodelled fracture or osteotomy sites and at the rod tip