title: Effects of interconnecting porous structure of hydroxyapatite ceramics on interface between grafted tendon and ceramics.
abstract: The purpose of this study was to evaluate histologically and biomechanically the interface between porous hydroxyapatite ceramics and a tendon grafted into ceramics, and to compare the interface in two ceramics with different porous structures: interconnected porous calcium hydroxyapatite ceramics (IP-CHA) with an effective porosity index (interpore diameter > 20 microm) of 63.6%, and porous calcium hydroxyapatite ceramics with less interconnection (HA-L) with an effective porosity index of 5.5%. The tendon-IP-CHA complex and the tendon-HA-L complex were implanted into the bone defects made in both knees of rabbits. With IP-CHA, abundant fibrous tissue, including vessels and collagen fiber continuity, was observed inside interface-region pores. The amount of osseous tissue in interface-region pores increased over time, and at 24 weeks after operation, the tendon was in direct contact with the osseous tissue in IP-CHA. With HA-L, the amount of fibrous tissue in interface-region pores was low and did not increase. The results of biomechanical analysis revealed that the maximum tendon pull-out load from IP-CHA was significantly higher than that from HA-L. With the porous hydroxyapatite ceramics having highly interconnecting porous structure, a bioactive interface was achieved between ceramics and grafted tendon. On the basis of these results, we conclude that bone defects, including tendon insertion, can be reconstructed using IP-CHA.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Hiroshima 734-8551, Japan. omae@hiroshima-u.ac.jp
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Omae
authors.forename: Yu
authors.initials: Y
authors.lastname: Mochizuki
authors.forename: Shin
authors.initials: S
authors.lastname: Yokoya
authors.forename: Nobuo
authors.initials: N
authors.lastname: Adachi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ochi
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001835:Body Weight; D001843:Bone Cements / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D017886:Durapatite / Q000737:chemistry*; D008628:Mercury / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D016062:Porosity; D011817:Rabbits; D013710:Tendons / Q000737:chemistry / Q000473:pathology*
chemical_list: D001672:Biocompatible Materials; D001843:Bone Cements; D018786:Bone Substitutes; D017886:Durapatite; D008628:Mercury