Trephine

Abstract: A system and method for anterior fixation of the spine utilizes a cylindrical implant engaged in the intra-disc space at the cephalad and caudal ends of the construct. The implants are cylindrical fusion devices (10) filled with bone material to promote ingrowth and fusion of the disc space. An attachment member is connected to each of the fusion devices (10) and bone screws (30) having similar attachment members (33) are engaged in the vertebral bodies of the intermediate vertebrae. A spinal rod (50) is connected to each of the attachment members using an eyebolt assembly (53-55). In a further inventive method, a revision of the construct is achieved by removing the fusion devices. Each fusion device is engaged by an elongated guide member (62) over which a cylindrical trephine (70) is advanced. The trephine (70) has an inner diameter larger than the diameter of the fusion implant.

Abstract: Aim To analyse the morbidity arising from autogenous bone graft harvesting, graft resorption and implant survival in grafted sites. Materials and methods Only comparative clinical trials on the harvest of autogenous bone grafts were selected. Studies were excluded if they compared autogenous bone grafts to bone substitutes or vascularised free bone grafts. Results A total of 24 studies were included in the review. Six intraoral or distant donor sites were identified. The highest level of evidence was reached by a randomised controlled trial. The mandibular ramus was the source of bone that was preferred by the patients. From this intraoral donor site bone was harvested under local anaesthesia on an outpatient basis. Patients' acceptance of chin bone harvesting was low. It led to a considerable morbidity that included pain, superficial skin sensitivity disorders and wound healing problems at the donor site. Patients even preferred iliac crest bone harvesting over bone harvesting from the chin, although this distant donor site required general anaesthesia and a hospital stay. The harvest of posterior iliac crest block led to less morbidity than the harvest of anterior iliac crest block grafts. When only cancellous bone was needed, percutaneous bone harvesting from the iliac crest led to less morbidity than an open approach to the iliac crest. Conclusions Dependent on the required graft structure and amount of bone needed, ramus grafts, block bone grafts from the posterior iliac crest and cancellous bone grafts harvested with a trephine from the anterior iliac crest should be chosen.

Abstract: The aim of the present study was to evaluate bone formation following maxillary sinus augmentation using bovine bone substitute material Bio-Oss in combination with venous blood by means of histologic and histomorphometric examination of human biopsies. This involved a total of 15 sinus floor elevation procedures being carried out on 11 patients (average age of 49.6 years) according to the technique described by Tatum (1986). The subantral sinus cavity was augmented using bovine apatite combined with venous blood. After an average healing phase of 6.8 months, trephine burrs were used to take 22 bone biopsies from the augmented sinus region. Then 38 Branemark implants were inserted in both the osteotomies resulting from bone sampling and in regular sites in the augmented posterior maxilla. Histomorphometric analysis of ground sections from the bone biopsies prepared according to the standard method of Donath & Breuner (1982) produced an average percentage of newly-formed bone of 14.7% (+/- 5.0%) and a proportion of residual xenogenic bone substitute material of 29.7% (+/- 7.8%). Some 29.1% (+/- 8.1%) of the surface of the Bio-Oss granulate was in direct contact with newly-formed bone. Histologically, newly-developed bone became evident, partly invaginating the particles of apatite and forming bridges in the form of trabeculae between the individual Bio-Oss particles. Despite the absence of osteoclastic activity, the inward growth of bone indicates slow resorption of the xenogenic bone graft material. When the implants were uncovered, after an average healing phase of 6 months, 4 of the 38 implants had become loose. Of these 4 implants, 1 had to be subsequently explanted, while the others remained as "sleeping implants" and were not included in the implants superstructure. Thus, the resulting clinical survival rate, prior to prosthetic loading, was 89.5%.

Abstract: We have evaluated the usefulness of bilateral rather than unilateral posterior iliac spine trephine biopsies in searching for lymphoma and other neoplastic diseases in the bone marrow. Two hundred and eighty-two patients with these diseases were studied. Tumor was found on only one side in 22% of patients with non-Hodgkin's malignant lymphoma, in 43% of patients with Hodgkin's disease, and in 36% of patients with other neoplastic processes. Thus, the second biopsy yields an additional 11% to 22% of positive biopsies. We conclude that bilateral trephine bone marrow biopsies should be routinely performed when searching for tumor in the bone marrow.