Support of the anterior column with allografts in tuberculosis of the spine.
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Fresh-frozen allografts from the humerus were used to help to stabilise the spine after anterior decompression for tuberculosis in 47 children with a mean age of 4.2 years (2 to 9). The average angle of the gibbus, before operation, was 53 degrees; at follow-up, two years later, it was 15 degrees. Rejection of the graft or deep sepsis was not seen. Cross trabeculation between the allograft and the vertebral body was observed at six months, with remodelling occurring at approximately 30 months. (+info)
Mechanical considerations in impaction bone grafting.
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In impaction grafting of contained bone defects after revision joint arthroplasty the graft behaves as a friable aggregate and its resistance to complex forces depends on grading, normal load and compaction. Bone mills in current use produce a distribution of particle sizes more uniform than is desirable for maximising resistance to shear stresses. We have performed experiments in vitro using morsellised allograft bone from the femoral head which have shown that its mechanical properties improve with increasing normal load and with increasing shear strains (strain hardening). The mechanical strength also increases with increasing compaction energy, and with the addition of bioglass particles to make good the deficiency in small and very small fragments. Donor femoral heads may be milled while frozen without affecting the profile of the particle size. Osteoporotic femoral heads provide a similar grading of sizes, although fewer particles are obtained from each specimen. Our findings have implications for current practice and for the future development of materials and techniques. (+info)
Evaluation of the allograft-prosthesis composite technique for proximal femoral reconstruction after resection of a primary bone tumour.
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OBJECTIVE: To evaluate clinical and functional outcomes resulting from the allograft-composite technique used for proximal femoral osteoarticular reconstruction in patients who had limb salvage surgery for primary bone tumours. DESIGN: A retrospective review of a prospectively gathered database to provide a descriptive study. SETTING: A tertiary care musculoskeletal oncology unit in a university hospital. PATIENTS AND INTERVENTIONS: Patients treated between 1987 and 1993 were eligible for inclusion in this study if they met the following criteria: they were treated surgically for a primary malignant bone tumour; and a proximal femoral allograft-implant composite technique was used for the reconstruction. MAIN OUTCOME MEASURES: Major postoperative complications with emphasis on mechanical complications in the reconstructive composite implant. Functional outcome in a subset of patients using the 1987 and 1994 versions of the Musculoskeletal Tumor Society instrument, the Short-Form-36 and the Toronto Extremity Salvage Score. RESULTS: There were 5 mechanical and 2 infectious complications requiring surgical intervention. Functional scores were generally low. CONCLUSIONS: Our results suggest that the perceived benefits of the composite technique may accrue only to a few patients, partly owing to the risk of mechanical complications. Although these can be reduced by avoiding the use of cement in the host femur, the generally poor functional outcomes suggest that this technique needs to be studied further in this group of patients and compared with other reconstructive techniques, particularly the prosthetic implant. (+info)
Bone-peg grafting for osteochondritis dissecans of the elbow.
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In the treatment of osteochondritis dissecans involving the elbow, we have used a bone-peg graft taken from the proximal part of the ulna and inserted into the defect. Thirty-two patients were followed from 2 to 10.5 years. The graft was utilised in 20 elbows, and 6 of these also had concomitant removal of a loose body. Another 6 elbows had removal of a loose body only. Ten elbows were treated conservatively in 5 of these the outcome was unsatisfactory, including 4 in which a bone-peg graft was later necessary. The bone-peg graft gave the best short-term results. Bony union of the dissecans site and reconstitution of subchondral bone required an average of 6.5 months. In 15 patients followed for a minimum of 5 years, the bone-peg graft was effective in limiting the development of osteoarthritis. Bone-peg grafting is a reliable method for treating osteochondritis dissecans of the elbow. (+info)
Salvage of the head of the radius after fracture-dislocation of the elbow. A case report.
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We describe a patient with a Mason type-III fracture of the head of the radius associated with traumatic dislocation of the elbow. The radial head was intact throughout its circumference despite being completely detached from the shaft and devoid of any soft-tissue attachments. Severe comminution of the radial neck prevented reconstruction by internal fixation and precluded prosthetic replacement of the head. The head was fixed to the shaft with a tricortical iliac-crest bone graft which replaced the neck. Two years later, the patient had a stable elbow with flexion from 10 degrees to 130 degrees. Radiologically, the head of the radius appeared to be viable and the bone graft had incorporated. (+info)
The pathology of bone allograft.
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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. (+info)
Histopathology of retrieved allografts of the femoral head.
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From November 1994 to March 1997, we harvested 137 grafts of the femoral head from 125 patients for donation during total hip arthroplasty according to the guidelines of the American Associations of Tissue Banks (AATB) and the European Association of Musculo-Skeletal transplantation (EAMST). In addition to the standards recommended by these authorities, we performed histopathological examination of a core biopsy of the retrieved bone allograft and of the synovium. Of the 137 allografts, 48 (35.0%) fulfilled all criteria and were free for donation; 31 (22.6%) were not regarded as suitable for transplantation because the serological retests at six months were not yet complete and 58 (42.3%) were discarded because of incomplete data. Of those discarded, five showed abnormal histopathological findings; three were highly suspicious of low-grade B-cell lymphoma, one of monoclonal plasmacytosis and the other of non-specific inflammation of bone marrow. However, according to the standards of the AATB or EAMST they all met the criteria and were eligible for transplantation. Our findings indicate that the incidence of abnormal histopathology in these retrieved allografts was 3.6%. Since it is essential to confirm the quality of donor bones in bone banking, we advise that histopathological screening of donor bone should be performed to exclude abnormal allografts. (+info)
Multi-bracket appliance in management of mandibular reconstruction with vascularized bone graft.
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BACKGROUND: The most commonly used tool for maxillo-mandibular fixation to the patient who underwent reconstruction using a vascularized bone graft after mandibular resection is a dental arch-bar. However, the occlusal relationship achieved by this method is not ideal. Different from the dental arch-bar, the multi-bracket appliance which is frequently used in orthodontic treatment can control the position of each individual tooth three dimensionally. Thus, this appliance was applied for maxillo-mandibular fixation to patients who underwent mandibular reconstruction using a vascularized bone graft. METHODS: A multi-bracket appliance was applied to three patients. Prior to the surgery, standard edgewise brackets were bonded to the teeth in the maxilla and in the remaining mandible. After mandibular resection, wires for maxillo-mandibular fixation were applied. The harvested bone was then carefully fixed with miniplates to maintain the occlusion. The multi-bracket appliance was worn for 3 months when the wound contraction became mild. RESULTS: All three cases demonstrated stable and good occlusion. They also demonstrated satisfactory post-surgical facial appearance. CONCLUSIONS: Compared to conventional dental arch-bars, a multi-bracket appliance offers improved management of mandibular reconstruction. Firstly, its properties are helpful in maintaining occlusion of the remaining dentition accurately in bone grafting procedure as well as protecting against postsurgical wound contraction. Secondly, the multi-bracket appliance keeps the oral cavity clean without periodontal injury. As a result, stable occlusion of the residual teeth and good facial appearance were obtained. (+info)