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Biomedical subjects

C Delloye

Publications and source records attributed to C Delloye.

At least 37 records · Page 2Linked to original sources
PubMed1996

Induced healing of aneurysmal bone cysts by demineralized bone particles. A report of two cases.

Two cases of induced healing of aneurysmal bone cyst (ABC) following intralesional implantation of a bone paste made of autogeneic bone marrow and allogeneic bone powder are reported. The calcaneum in one case and the superior pubic ramus in the other were blown out by an ABC and would have required extensive surgery. Via a minimal exposure, the cyst was partially evacuated and filled with an admixture of a partially demineralized bone particles with bone marrow. Ossification of the peripheral shell was the first sign of healing and was observed within the first 3 postoperative months. Successful healing was observed in both cases. The rationale underlying this intralesional treatment was that the bone grafting material might reverse ABC expansion by promoting ossification through a bone induction mechanism. The concept of this treatment was to retain the ABC tissue, using its own intrinsic osteogenic potential to promote healing. By triggering intralesional new bone formation, the bone paste represented an effective means to reverse the expanding phase of ABC. The particulated bone allograft was easy to handle and to introduced in an irregular cavity. Moreover, as a complete cyst evacuation was not required, a minimal surgical approach could be used so that the risks and morbidity associated with an extensive approach were reduced. Its use is of particular interest in poorly accessible areas like the pelvis and spine.

Adolescent↗
PubMed1996

Comparative left-right mechanical testing of cancellous bone from normal femoral heads.

In order to assess the potential influence of various physical or chemical treatments on bone grafts, and in particular, on femoral heads to be used as bone grafts, the mechanical symmetry of the femoral head was investigated. Pairs of proximal human femora were harvested and transversally sliced using a coordinate system to orient correctly the head. After being embedded and polished, bone slices were loaded to failure between two steel columns (6 mm of diameter) in a sequential and symmetrical manner for both heads. From ten pairs, 592 mechanical assays on the cancellous bone of femoral heads were performed. There was a high variation in the mechanical properties of the specimens from the different donors. However, no statistical difference could be observed within each pair when side-to-side symmetry was tested for the different mechanical characteristics. Ultimate stress at failure and stiffness were also highly correlated for each mirror location of each pair. Provided that an accurate and reproducible method of slicing femoral head can be achieved, an excellent mechanical symmetry is observed using a static compressive test. Such a method could be used to determine the mechanical influence of any treatment applied to bone.

Aged↗
PubMed1995

Biodegradable implants for potential use in bone infection. An in vitro study of antibiotic-loaded calcium sulphate.

Local antibiotic therapy by diffusion from plaster of Paris beads has proved promising in bone surgery. Sustained local delivery depends on thermostability, so we tested the antibacterial activity of 11 antibiotic solutions after storage at 37 degrees C using a microbiological method. Cephalosporins and penicillins were unstable, but aminoglycosides remained fully stable with 100% activity after 2 weeks. About 60% of the initial bactericidal activity of quinolone, glycopeptides and sodium fusidate were still detectable after 2 weeks. Release of these antibiotics from plaster of Paris beads was evaluated in vitro. Even those in the same family differed in their release rate. Plaster beads with sodium fusidate were the most effective association. A therapeutic level of glycopeptides, aminoglycosides and amoxicillin was leached for about 3 weeks. Cephalosporins and sodium amoxicillin were released in 2 to 3 days, and quinolone beads were too brittle to be used. Plaster of Paris, which is cheap, biocompatible and biodegradable, is an excellent carrier for sodium fusidate, aminoglycosides and glycopeptides.

Aminoglycosides↗
PubMed1995

Tibial tubercle elevation with bone grafts. A comparative study of autograft and allograft.

We retrospectively investigated the fate of bone auto- and allografts in 64 patients who underwent a tibial tubercle elevation with bone graft. Half of them received an autograft and the other half, an allograft that had been processed and freeze-dried. The two groups had similar preoperative characteristics concerning age, sex and pathology. Roentgenograms were reviewed by three independent observers and scored for fusion, resorption and collapse. Clinical charts were analysed for different variables. The overall radiological score for both groups did not differ statistically. Comparison of graft fixation with one or two screws demonstrated more bone resorption in the case of a single-screw fixation. In such a case, the occurrence of a preoperative tubercle fracture had a significant adverse influence, due to a less stable fixation. From the clinical charts review, only the mean stay at hospital was significantly shorter when an allograft was performed. A bone allograft appears to be suitable to maintain an osteotomy but requires a more careful surgical technique fixation to obtain a similar result to an autograft.

Adolescent↗
PubMed1994

Tissue allografts and health risks.

Like vascularized transplants, tissue allografts are able to transmit viral and bacterial diseases. Transmission of HIV (Human Immunodeficiency Virus) and HCV (Hepatitis C virus) has been proved for sterilized, unprocessed and deep-frozen allografts. It is the prime responsibility of the tissue bank to select the donor correctly and to perform careful biological screening. However, standard screening is not enough to detect a seronegative but contaminated donor. It is necessary to quarantine the tissues until complementary screening confirms the absence of viral disease. If secondary screening is not possible, the tissues should be discarded or should be processed. If donor selection, relevant and appropriate screening tests and adequate procurement of tissues are carefully made, then the risk of disease transmission from tissue allografts will remain remote.

Deltaretrovirus Infections↗
PubMed1993

[Multiple perforation in cryogenically preserved bone allografts. Comparative histological and microradiographic study of perforated and non-perforated allograft in sheep].

Incorporation of massive cortical bone allografts in the human is slow and remains incomplete. Late biopsies of implanted allografts or histological studies of explanted allografts always show the partial substitution of necrotic bone by new bone from the host. The aim of the present study was to evaluate the value of drilling the massive deep-frozen cortical allografts in order to induce osteogenesis. Thirteen sheep were operated on and a standard segment of the proximal ulna was removed and the gap filled either by an unperforated allograft or by a perforated one. Based on histological and microradiographic examination, a complete substitution of the perforated allografts was observed but in this model no statistically significant difference was observed between perforated and unperforated allografts. Further study is needed to assess the effect of the perforations.

Angiography↗
PubMed1992

[Value of multiple cortical perforations for the rehabilitation of massive deep-frozen bone allografts. Experimental study in sheep].

Incorporation of massive cortical bone allografts in human is slow and remains incomplete. Late biopsies of implanted allografts or histological studies of explanted allografts always show the partial substitution of necrotic bone by new bone from the host. The aim of the present study was to evaluate the effect of drilling the massive deep-frozen cortical allografts in order to induce osteogenesis. Thirteen sheep were operated on and a standard segment of the proximal ulna was removed and the gap filled either by an unperforated allograft or by a perforated one. Based on histological and microradiographic examination, a quite complete substitution of the perforated allografts was observed but in this model no statistically significant difference was observed between perforated and unperforated allografts. Further study is needed to assess the effect of the perforations.

Animals↗
PubMed1992

Morphometric and physical investigations of segmental cortical bone autografts and allografts in canine ulnar defects.

Cortical bone grafts were implanted for six months in mature dogs using an osteoperiosteal 3-cm defect in the ulna to evaluate their respective morphometric and physical values compared with autografts. The bone-grafting material included fresh auto- and allografts, frozen and thimerosal preserved allografts, and partially demineralized bone allografts. The grafts were evaluated by roentgenograms, microradiograms, photon absorptiometry, porosity, fluorescence labeling measurements, and torsional loading at failure. Autografts achieved a better union score than the allografts, but intracortical bone porosity, percentage of cumulative new bone, and mineral apposition rate were not variables with statistical significance. Lamellar bone was found earlier and in greater quantity in autografts. Within the graft, new bone was deposited at a slower rate than in the recipient bone. Autografts showed less peripheral resorption and a greater torsional resistance than allografts. Photon absorptiometry demonstrated that nondemineralized allografts underwent a substantial loss of peripheral bone. This marked reduction in the outer diameter of the graft had more influence on torsional resistance than did the intracortical porosity of the graft. Demineralized allografts were osteoinductive in only 28% of the cases and appeared to respond in an all-or-nothing pattern. Frozen and thimerosal preserved allografts were the most acceptable substitutes to autografts.

Absorptiometry, Photon↗
PubMed1991

Organizational and investigational aspects of bone banking in Belgium.

Our experience with the bone banking methodology that we have used over the last years is reported. The technical and investigational aspects of the procurement, storage and treatment of the donor bone and related tissues are presented. For different purposes, we have prepared sterile and nonsterile procured implants. Appropriate donor selection and sterility controls remain the two major concerns of bone banking activities.

Belgium↗
PubMed1991

Osteochondral allografts in arm and forearm surgery.

Osteochondral allografting can restore the skeletal continuity anatomically after a limb salvage procedure. Evaluation of the clinical function indicates that a good result can be anticipated. Fracture was the most frequent complication, and the fixation technique we used initially predisposed the problem. The major advantage of allograft is the possibility of reinsertion of soft tissue to help stabilize the new joint. In addition, any part of the limb can potentially be reconstructed with an allograft.

Adolescent↗
PubMed1990

Bone regenerate formation in cortical bone during distraction lengthening. An experimental study.

The aim of this study was to delineate the pattern of bone regeneration from cortical bone segments during distraction lengthening. The lengthening procedure was applied for various periods through the Ilizarov system on the forearms of mature dogs. Bone was sectioned either by corticotomy, preserving the nutrient artery integrity, or by osteotomy. When an osteotomy was performed, the marrow cavity was in some cases plugged with either resorbable bone wax or nonresorbable material. Under distraction, both periosteal and medullary callus on either side of the gap gave rise to new bone trabeculae. The trabeculae on either side were oriented along the direction of distraction and progressively approached one another. This striated callus emerging from both sides was the most characteristic pattern of bone regeneration subsequent to distraction lengthening. Fusion was achieved approximately four weeks after the end of the lengthening period. Most of the new bone was formed by membranous ossification; some cartilaginous nodules developed. Corticalization of the bone trabeculae that had begun at three months was not fully achieved at five months after the lengthening period. There were no differences found in the pattern of bone healing and the amount of newly formed bone after corticotomy or osteotomy with or without resorbable bone wax plugging.

Animals↗
PubMed1989

Bone sialoprotein II synthesized by cultured osteoblasts contains tyrosine sulfate.

Isolated mouse osteoblasts that retain their osteogenic activity in culture were incubated with [35S] sulfate. Two radiolabeled proteins, in addition to proteoglycans, were extracted from the calcified matrix of osteoblast cultures. All the sulfate label in both proteins was in the form of tyrosine sulfate as assessed by amino acid analysis and thin layer chromatography following alkaline hydrolysis. The elution behavior on DEAE-Sephacel of the major sulfated protein and the apparent Mr on sodium dodecyl sulfate gels were characteristic of bone sialoprotein II extracted from rat. This protein was shown to cross-react with an antiserum raised against bovine bone sialoprotein II, indicating that bone sialoprotein II synthesized by cultured mouse osteoblasts is a tyrosine-sulfated protein. The minor sulfated protein was tentatively identified as bone sialoprotein I or osteopontin based on its elution properties on DEAE-Sephacel and anomalous behavior on sodium dodecyl sulfate gels similar to those reported for rat bone sialoprotein I.

Animals↗
PubMed1989

Bone allografts in reconstructive middle ear surgery.

The authors present their current experience with stored bone grafts, using allografts shaped from the cortices of long bones for reconstructing the tympano-ossicular chain. The materials and the methods are described. The anatomical results have been good in 97% of the cases, while the functional results are as satisfactory as those obtained with bioceramics. In addition to ossiculoplasty, the bone allografts can also be used in otology for reconstructing large bony defects of the temporal bone.

Bone Transplantation↗
PubMed1989

Freeze-dried bank bone.

The authors present their experience with freeze-dried bone of human origin. Since 1983, 500 preserved allografts have been implanted in 228 patients. The implants were monitored radiographically and, based on perfect fusion with the recipient bone, the results were as follows: excellent: 78%; good: 8.6%; failure: 12.4%. In nearly all the cases of failure this was attributed to an erronous implant method or an improper use of the graft. Bank bone is only osteoconductive: thus, in the absence of osteogenetic properties, a perfect method of implant and its correct use are essential.

Belgium↗
PubMed1989

[Lyophilized homologous bone grafts in middle ear surgery: new perspectives].

The authors share their experience of the use of allografts in the reconstruction of the tympano-ossicular chain. The implants were cut from the cortical substance of the long bone in patients deceased for a maximum of six hours; the donors were tested for syphilis, hepatitis, AIDS, systemic diseases or a neoplasm. These bone allografts were cut to size, degreased, demineralized, frozen and then lyophilized in order to be presented to the surgeon in a sterile container (Bone Bank). The implants were all tolerated well. The anatomical results were satisfactory. Optical microscopic studies showed that the implant was: a) covered with mucosa, b) full of osteoblasts and c) the site of a bone neoformation. Experimental research is currently underway in order to perfect the implant preparation methodology.

Bone Transplantation↗