1. Radiographic changes in bone structure which follow the insertion of an unplasticised acrylic prosthesis of the Judet type are described. 2. Technical details of the operation and their relation to these changes are discussed. 3. Although the period of observation is short it is suggested that after initial loosening the prosthesis becomes stabilised owing to local bone reaction

We have made a retrospective study of 1001 custom-made prostheses used as replacements after surgery for bone tumours. There were 493 distal femoral, 263 proximal femoral and 245 proximal tibial prostheses. Aseptic loosening was shown to be the principal mode of failure of the implants, and 71 patients had revision for aseptic loosening of a cemented intramedullary stem. The probability of a patient surviving aseptic loosening for 120 months was 93.8% for a proximal femoral replacement, 67.4% for a distal femoral prosthesis and 58% for a proximal tibial implant. In patients with distal femoral replacements the age of the patient at the time of operation and the percentage of bone resected were related to the risk of aseptic loosening. Young patients with distal femoral prostheses in whom a high percentage of the femur had been replaced had the poorest prognosis for survival without aseptic loosening. The percentage of bone removed had a significant effect in the proximal tibial replacement group, but the age of the patient did not. By contrast, neither the age nor the percentage of bone removed was a factor after proximal femoral replacement. The significance of these findings is discussed in relation to mechanical factors

The Scottish National Blood Transfusion Service is the main provider of bone for grafting in Scotland. Bone is procured only from live donors, following very strict selection criteria, and we have investigated whether the amount being collected was adequate. Our current harvest of approximately 1700 femoral heads per year is shown not to be enough to meet the future demand for revision surgery of the hip. Many more of these operations are being undertaken, and impaction grafting is being used increasingly. We have calculated the predicted rates of collection and usage for the next four to five years so that we can expand our service in a controlled fashion

We performed a prospective, randomised double-blind study in 24 patients undergoing high tibial osteotomy to evaluate the effectiveness of human recombinant osteogenic protein (OP-1) on a collagen type-I carrier in a critically-sized fibular defect. The study had two phases, each evaluated by clinical, radiological and DEXA methods during the first postoperative year. The first concerned the validation of the model of the fibular defect, using positive (demineralised bone) and negative (untreated) controls. The second phase concerned the osteogenic potential of OP-1 on collagen type-I ν collagen type-I alone. The results of the first phase established the critically-sized nature of the defect. In the untreated group no bony changes were observed while, in the demineralised bone group, formation of new bone was visible from six weeks onwards. The results of the second phase showed no significant formation of new bone in the presence of collagen alone, while in the OP-1 group, all patients except one showed formation of new bone from six weeks onwards. This proved the osteogenic activity of OP-1 in a validated critically-sized human defect

We have investigated the effect of currents induced by electromagnetic fields on the healing of the tibia of sheep after osteotomy, using objective and quantifiable criteria wherever possible. A battery-powered, induction apparatus was developed and was enclosed within the cast applied to the limb, so that the treated fractures received pulsed magnetic fields for 24 hours a day while the animals were freely mobile. In all, 13 sheep were treated and 13 were used as controls. The response was assessed by radiography of the limb and of the excised bone, by histology, including measurement of the areas of callus, fibrocallus and cortical bone, and by measurement of the uptake and extraction of bone-seeking mineral. All the bones healed and no statistically significant differences between the treated animals and the controls were discovered except (at only P less than 0.05) in the uptake of bone-seeking mineral; this increased more rapidly in treated animals over the two to three weeks after osteotomy, although at six weeks the uptake in both groups was the same

We have managed 21 patients with a fracture of the tibia complicated by bone and soft-tissue loss as a result of an open fracture in 10, or following debridement of an infected nonunion in 11, by resection of all the devitalised tissues, acute limb shortening to close the defect, application of an external fixator and metaphyseal osteotomy for re-lengthening. The mean bone loss was 4.7 cm (3 to 11). The mean age of the patients was 28.8 years (12 to 54) and the mean follow-up was 34.8 months (24 to 75). All the fractures united with a well-aligned limb. The mean duration of treatment for the ten grade-III A+B open fractures (according to the Gustilo-Anderson classification) was 5.7 months (4.5 to 8) and for the nonunions, 7.6 months (5.5 to 12.5). Complications included one refracture, one transient palsy of the peroneal nerve and one equinus contracture of 10°

In rabbits and goats, test implants with a porous surface of two layers of Tl-6A;-4V beads were examined at intervals for bond strength with bone. Half of the implants were coated with hydroxyapatite by plasma spray. The bonding strength with bone in the coated specimens was about four times greater than that of the uncoated specimens at two weeks, and twice as strong at six weeks. Twelve weeks after implantation, the strengths were similar. The hydroxyapatite coating of the beads provided earlier and stronger fixation

1. Fifteen cases of bone transplantation for fibrous union of fractures of long bones are described, using boiled minced cancellous bone from cadavers. One transplant became infected but the infection responded to treatment. 2. In one patient with non-union of the shaft of the humerus, bony union was not obtained, but a good functional result obviated further treatment. 3. It is suggested that this relatively simple method of bone transplantation could be used more widely if its potentialities were appreciated more fully

We treated 37 patients with chronic osteomyelitis of the tibia (25), femur (9), radius (2) and humerus (1) by a two-stage technique, comprising radical debridement of all infected bone and soft tissue with the provision of soft-tissue cover, and delayed autogenous bone grafting when necessary. All patients were reviewed at an average of 49 months (12 to 121). Infection-free bone union was achieved in 34. No patient required amputation. Wide excision of all compromised tissue and the closure of bone within a healthy vascularised soft-tissue envelope are essential if infection is to be eradicated. The combined assessment and management of such patients by an orthopaedic surgeon and a plastic surgeon are advocated

Loosening is a serious problem in total arthroplasty and early detection of bone loss in the vicinity of an implant would help in its investigation. We present a method for the objective evaluation of bone adjacent to metallic implants in which a modified technique of quantitative computed tomography (QCT) is used to reconstruct cross-sectional images with few artefacts. We have used this technique in 19 patients with knee arthroplasties to monitor the changes in bone density around the tibial stem of the prosthesis. In the first weeks after operation all patients showed a decrease in bone density ranging from 0.4% to 3.6% per month. One year after arthroplasty bone density had stabilised and only minor changes were observed. Our work indicates that modified QCT is a sensitive method for the long-term monitoring of the anchorage of implants and allows the early detection of osteolytic changes

This pilot study analysed the outcome of open versus endoscopic curettage and bone grafting for the treatment of simple calcaneal bone cysts. A total of 26 patients were evaluated into two equal groups: group 1 was treated with traditional open curettage and bone grafting and group 2 was treated with endoscopic curettage and percutaneous bone grafting. Cyst size, operating time, length of stay, time to healing, complications, further surgery and radiological healing were recorded and differences were statistically compared.

The mean age of the patients was 22.9 years (18 to 28) and the mean follow-up was 28.7 months (24 to 36). There were no statistically significant differences in regard to age of patients, cyst size and the follow-up periods in the two groups. The operating time and mean length of stay of group 2 patients was significantly shorter than group 1 patients (p <  0.001). The time to healing was similar in the two groups. The overall success rates for groups 1 and 2 were 92.3% (12 of 13) and 100% (13 of 13), respectively, and there were no statistically significant differences regarding radiological healing. This pilot study suggests that endoscopic curettage and percutaneous grafting is a simple and safe form of treatment, with similar results to those following open treatment.

1. A method is described of demonstrating in vivo the utilisation of radioactive sulphur. 35. and of radioactive phosphorus. 32. during bone growth and repair. 2. The relationship between labelled chondroitin sulphuric acid and labelled phosphate complexes has been studied, the importance and significance of vascularity and the localisation of the enzyme alkaline phosphatase being noted. 3. It was found that bone growth by external accretion, both epiphysial and periosteal, was accompanied by an increased utilisation of radioactive chondroitin sulphuric acid and calcium phosphate complexes. 4. During repair in a fracture site, although there was deposition of radioactive phosphate, no preferential localisation of radioactive sulphur was observed and the possible explanations of this are discussed

Patients suffering from generalised convulsions may dislocate their shoulders either anteriorly or posteriorly. Those with anterior dislocation are likely to have recurrent episodes because of secondary bony damage to the anterior rim of the glenoid and head of the humerus. In such patients there is high rate of failure of the standard soft-tissue stabilisation procedures. We have therefore devised a bone buttress operation in which autograft or allograft is secured to the deficient anterior glenoid and shaped to form an extension of its articular surface. We report our experience in 14 patients with grandmal epilepsy and recurrent anterior dislocation of the shoulder. After the bone buttress operation there were no further dislocations and all patients were satisfied despite a small restriction in their range of movement. We believe this to be the operation of choice for patients with this difficult problem

1. The bone changes are described in fifty-one cases of sickle cell anaemia. nineteen cases of sickle cell haemoglobin C disease and two cases of sickle cell thalassaemia. 2. Avascular necrosis of the head of the femur has been found in all three types of sickle cell disease. These responded to treatment. 3. The changes found in six cases of Perthes' disease in the negro are compared with the changes in avascular necrosis of the head of the femur in sickle cell disease. 4. Hyperplastic bone changes are seen only in true sickle cell anaemia and not in the variants. 5. Secondary osteomyelitis appears to be fairly common in sickle cell anaemia. Organisms of the salmonella group have often been found in these cases

When amputation just below the knee becomes necessary after extensive loss of bone from the tibia and of anterior soft tissue in the treatment of tumours, fractures or infection, the remaining proximal tibia may be too short for a below-knee prosthesis, although the knee may be normal. We have included the distal tibia or foot in a long posterior flap by turning it up thus increasing the length of a very short proximal tibial stump. The knee is thereby saved, allowing satisfactory use of a below-knee prosthesis. This technique is particularly applicable when the distal leg is normal and well vascularised. Five procedures have been undertaken. We present two illustrative cases

1. Evidence is presented which suggests that after total joint replacement bone necrosis and consequent loosening of the prosthesis may be due to the development of sensitivity to the metals used. 2. Nine patients, from a total of fourteen with loose prostheses, were found to be metal sensitive by skin-patch testing. In twenty-four patients with intact prostheses no sensitivity was demonstrated. 3. In material from the joints of sensitive patients the metal content was raised. 4. Examination of this material showed necrosis of bone and soft tissue following obliterative changes in the vascular supply. 5. Similar reactions were found following the injection of cobalt into a sensitive patient. 6. The release of metal around a prosthesis is greatest where metal rubs against itself. 7. We conclude that prostheses in which metal articulates with polyethylene should be preferred; that any patient in whom loosening or fragmentation occurs should be patch tested; and that if sensitivity is found the implant should be removed

Osteonecrosis of the femoral head usually affects young individuals and is responsible for up to 12% of total hip arthroplasties. The underlying pathophysiology of the death of the bone cells remains uncertain. We have investigated nitric oxide mediated apoptosis as a potential mechanism and found that steroid- and alcohol-induced osteonecrosis is accompanied by widespread apoptosis of osteoblasts and osteocytes. Certain drugs or their metabolites may have a direct cytotoxic effect on cancellous bone of the femoral head leading to apoptosis rather than purely necrosis

A case of unusually extensive pigmented villonodular synovitis of the wrist with involvement of bone, particularly of the distal end of the radius, is reported. The clinical and radiographic evidence suggested a diagnosis of primary bone tumour, possibly a giant-cell tumour with sarcomatous transformation

Out of 21 900 cases filed at the Latin-American Registry of Bone Pathology between April 1940 and July 1981, there were 987 with Paget's disease (4.51 per cent); 62 of these (6.28 per cent) were complicated by sarcoma and two were associated with giant-cell tumours of bone (osteoclastoma) without signs of malignancy. There was a slight predominance of men and the ages ranged from 45 to 87 years, with an average of 66 years. The most frequent sites were the femur (23 cases), the humerus (nine), the pelvis (10), and the tibia (nine). The low incidence of vertebral involvement (five cases) is noteworthy and is in sharp contrast to uncomplicated Paget's disease. The most common tumour type was osteosarcoma (39 cases), followed by fibrosarcoma (15 cases); other varieties (chondrosarcoma, malignant fibrous histiocytoma and reticulum-cell sarcoma) were much rarer. Most of the sarcomata occurred when the Paget's disease was polyostotic. Tumours often developed simultaneously, or at short time intervals, in the same or different bones; these bones had, in all cases, been affected by Paget's disease. The histological features of the osteosarcomata were characteristic, with large numbers of osteoclast giant cells, alternating with atypical osteoblasts, thus exaggerating the anarchic remodelling process of Paget's disease. The neighbouring areas of the pagetic bone showed an increased number of osteoclasts. These facts suggest a possible pathogenetic relationship between sarcoma and Paget's disease; the possibility of both processes having a viral aetiology is discussed