Double-plating of ovine critical sized defects of the tibia: a low morbidity model enabling continuous in vivo monitoring of bone healing

<p>Abstract</p> <p>Background</p> <p>Recent studies using sheep critical sized defect models to test tissue engineered products report high morbidity and complications rates. This study evaluates a large bone defect model in the sheep tibia, stabilized with two, a novel Carbon fibre Poly-ether-ether-ketone (CF-PEEK) and a locking compression plate (LCP) which could sustain duration for up to 6 month with an acceptable low complication rate.</p> <p>Methods</p> <p>A large bone defect of 3 cm was performed in the mid diaphysis of the right tibia in 33 sheep. The defect was stabilised with the CF - PEEK plate and an LCP. All sheep were supported with slings for 8 weeks after surgery. The study was carried out for 3 months in 6 and for 6 months in 27 animals.</p> <p>Results</p> <p>The surgical procedure could easily be performed in all sheep and continuous in vivo radiographic evaluation of the defect was possible. This long bone critical sized defect model shows with 6.1% a low rate of complications compared with numbers mentioned in the literature.</p> <p>Conclusions</p> <p>This experimental animal model could serve as a standard model in comparative research. A well defined standard model would reduce the number of experimental animals needed in future studies and would therefore add to ethical considerations.</p

実験的ウサギ下顎欠損のrhBMP-2とアテロコラーゲンゲルによる再構築 in vivo μCTによる観察と組織学的検索

A rabbit experimental mandibular defect was reconstructed with rhBMP-2 and atelocollagen gel, and examined using μCT (R_mCT, Rigaku Mechatronics, Tokyo) in vivo and histological techniques. Using eight rabbits, we made an experimental mandibular defect and filled it with 1% atelocollagen gel including rhBMP-2 10ìg (Astellas Pharma Inc.). In μCT observation, the density was slightly elevated at the bone marrow side at one week, and the phenomenon gradually expanded during the course of this experiment. Histologically, mesenchymal cell proliferation and immature bone formation occurred at one week, and mature bone gradually increased and filled in at four weeks.ウサギ8羽の下顎を実験的に欠損させ、欠損部位を組換えヒト骨形態発生蛋白を含む1%アテロコラーゲンゲルで満たした。1週間後にこの部位をμCTで観察したところ、密度が骨髄側で軽度上昇していた。この現象は経時的に広がっていくことが示された。組織学的検索では、1週間後に間葉細胞の増殖と未熟骨細胞の形成が認められ、4週間後には成熟細胞が徐々に増加して下顎欠損部位を満たしていた