98 research outputs found
Design and management of an orthopaedic bone bank in the Netherlands
The design and management of an orthopaedic bone bank is a complex process in which medical organisation and legislation intertwine. Neither in the Netherlands, nor in any other European country, there are official guidelines for the organisation and management of an orthopaedic bone bank. In the Netherlands, the recently modified ālaw of security and quality for using human materialsā (WVKL) dictates requirements for technical and organisational aspects for the use of human tissue and cells. The bone bank procedures include a thorough questionnaire for donor selection, extensive serological, bacteriological and histopathological examination, as well as standard procedures for registration, processing, preservation, storage and distribution of bone allografts. This article describes the organisation of an accredited bone bank and can be used as a proposition for an official guideline or can be useful as an example for other orthopaedic bone banks in Europe
Freeze-thaw treatment effects on the dynamic mechanical properties of articular cartilage
BACKGROUND: As a relatively non-regenerative tissue, articular cartilage has been targeted for cryopreservation as a method of mitigating a lack of donor tissue availability for transplant surgeries. In addition, subzero storage of articular cartilage has long been used in biomedical studies using various storage temperatures. The current investigation studies the potential for freeze-thaw to affect the mechanical properties of articular cartilage through direct comparison of various subzero storage temperatures.
METHODS: Both subzero storage temperature as well as freezing rate were compared using control samples (4Ā°C) and samples stored at either -20Ā°C or -80Ā°C as well as samples first snap frozen in liquid nitrogen (-196Ā°C) prior to storage at -80Ā°C. All samples were thawed at 37.5Ā°C to testing temperature (22Ā°C). Complex stiffness and hysteresis characterized load resistance and damping properties using a non-destructive, low force magnitude, dynamic indentation protocol spanning a broad loading rate range to identify the dynamic viscoelastic properties of cartilage.
RESULTS: Stiffness levels remained unchanged with exposure to the various subzero temperatures. Hysteresis increased in samples snap frozen at -196Ā°C and stored at -80Ā°C, though remained unchanged with exposure to the other storage temperatures.
CONCLUSIONS: Mechanical changes shown are likely due to ice lens creation, where frost heave effects may have caused collagen damage. That storage to -20Ā°C and -80Ā°C did not alter the mechanical properties of articular cartilage shows that when combined with a rapid thawing protocol to 37.5Ā°C, the tissue may successfully be stored at subzero temperatures
B-cell lymphoma in retrieved femoral heads: a long term follow up
<p>Abstract</p> <p>Background</p> <p>A relatively high incidence of pathological conditions in retrieved femoral heads, including a group of patients having low grade B-cell lymphoma, has been described before. At short term follow up none of these patients with low-grade B-cell lymphoma showed evidence of systemic disease. However, the long term follow up of these patients is not known.</p> <p>Methods</p> <p>From November 1994 up to and including December 2005 we screened all femoral heads removed at the time of primary total hip replacement histopathologically and included them in the bone banking protocol according to the guidelines of the American Associations of Tissue Banks (AATB) and the European Association of Musculo-Skeletal Transplantation (EAMST). We determined the percentage of B-cell lymphoma in all femoral heads and in the group that fulfilled all criteria of the bone banking protocol and report on the long-term follow-up.</p> <p>Results</p> <p>Of 852 femoral heads fourteen (1.6%) were highly suspicious for low-grade B-cell lymphoma. Of these 852 femoral heads, 504 were eligible for bone transplantation according to the guidelines of the AATB and the EAMST. Six femoral heads of this group of 504 were highly suspicious for low-grade B-cell lymphoma (1.2%). At long term follow up two (0.2%) of all patients developed systemic malignant disease and one of them needed medical treatment for her condition.</p> <p>Conclusion</p> <p>In routine histopathological screening we found variable numbers of low-grade B-cell lymphoma throughout the years, even in a group of femoral heads that were eligible for bone transplantation. Allogenic transmission of malignancy has not yet been reported on, but surviving viruses are proven to be transmissible. Therefore, we recommend the routine histopathological evaluation of all femoral heads removed at primary total hip arthroplasty as a tool for quality control, whether the femoral head is used for bone banking or not.</p
Long-term outcomes of the use of allogeneic, radiation-sterilised bone blocks in reconstruction of the atrophied alveolar ridge in the maxilla and mandible
Der resorbierbare Knochenzement BiobonĀ®* im Tibiasegmentdefekt beim Schaf ā Biomechanische und Rƶntgenergebnisse nach 3,6 und 12 Monaten Beobachtungszeit
Reconstruction of a Lateral Femoral Condyle Articular Surface Defect with a Fresh Osteochondral Allograft
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Kinetics of cortical bone demineralization: controlled demineralization--a new method for modifying cortical bone allografts.
We investigated the kinetics of hydrochloric acid demineralization of human cortical bone with the objective of developing a method of controlled demineralization for structural bone allografts. It is known that the demineralization of cortical bone is a diffusion rate limited process with a sharp advancing reaction front. The demineralization kinetics of human cortical bone, described as the advance of the reaction front versus immersion time, were determined by measuring extraction of bone mineral in both planar and cylindrical geometries. Mathematical models based on diffusional mass transfer were developed to predict this process. The experimental data fit well with the behavior predicted by the model. The model for planar geometry is applicable to controlled demineralization of cortical bone allografts of irregular shapes such as cortical struts. The model for cylindrical geometry is appropriate when curved surfaces are involved such as in diaphyseal bone allografts. This method of demineralization has direct application to clinical modification of cortical bone allografts to potentially enhance their osteoinductive properties
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