کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5891441 | 1153271 | 2013 | 9 صفحه PDF | دانلود رایگان |
ProblemThe physiological reconstruction of cancellous bone defects in surgery of the locomotor system is an unsatisfactorily solved problem.AimsThe aims of this study are to examine whether micro-chambered Ã-tricalcium-phosphate (Ã-TCP) beads provide a certain capillary force suctioning in blood and bone marrow thus forming a stable “negative”-replica of the bone marrow spaces. If so, a new approach for osteoconduction would yield primarily a scaffold of lamellar cancellous bone under load without a long-lasting remodeling process. Recombinant human bone morphogenetic protein (rhBMP) might even enhance all processes of defect healing, remodeling and Ã-TCP resorption; gentamicin-loaded ε-caprolactone might protect the implant.Material and methodsTen sheep were operated on; the patella-groove model and the tibial head were used. A defect of 9.4 Ã 20 mm was created using wet-grinding-diamond instruments. Micro-chambered Ã-TCP-beads of 4-6 mm with 0.35 mg rhBMP-7 + 0.1 g collagen per animal, or 1.5 g demineralized bone matrix (DBM) paste on the contra-lateral side were implanted. Both osteoinduction groups were compared with the defect in the tibial heads where plain micro-chambered ceramic beads were inserted. Added to the beads was 12.5 mg gentamicinsulphate in 12.5 mg ε-caprolactone-carrier. Outward diffusion was prevented using a 1-mm-thick press-fit inserted ceramic lid. The bone healing, remodeling and resorption of the ceramic in a right-left comparison of the patella groove and the tibial head was examined at 6 weeks, 2 and 3 months; one animal in reserve was followed for 14 months. The animals were perfusion-fixed, the vasculature micro-casted with an acrylate and nondemineralized processed, and with μ-CT and microscopically documented.ResultsA primary load-bearing spongiosa had developed around the beads, which shortened the remodeling process. The strong micro-chambered, resorbable Ã-TCP-beads demonstrate high capillary strength, resorb blood and bone marrow, and represent a stable formative material which, as a carrier for the controlled local release of BMP, that accelerates bone healing, shortens resorption and remodeling compared with plain and DBM loaded implants.ConclusionMicro-chambered beads represent the bone-forming element, BMP yields a fast defect healing and enhanced remodeling of bone and resorption of Ã-TCP compared to delayed and incomplete reconstruction and resorption of Ã-TCP on the DBM-side, the plain implants reached nearly the same reconstruction, but far later compared with the BMP loaded implants.
⺠We found primarily formed lamellar bone as a scaffold around ceramic beads in an animal experiment on sheep. ⺠We found that BMP accelerates the reabsorption of Ã-TCP enormously. ⺠We found that there is a speed up of the remodeling process by BMP. ⺠We found that capillary forces of micro-chambered beads suctioned in BMP, blood and bone marrow.
Journal: Bone - Volume 52, Issue 1, January 2013, Pages 465-473