title: The role of an octacalcium phosphate in the re-formation of infraspinatus tendon insertion.
abstract: BACKGROUND
  To improve the success rate of rotator cuff repair, we investigated whether octacalcium phosphate (OCP) with gelatin (Gel) vehicle had a positive effect on tendon-to-bone healing.
  
  
  METHODS
  We assessed the histologic characteristics of the tendon-to-bone healing using the rabbit rotator cuff repair model. We divided the shoulders into 3 groups: control (without OCP/Gel composite), OCP/Gel composite (OCP+group), and Gel alone without OCP (Gel group) to evaluate the effectiveness of gelatin.
  
  
  RESULTS
  Both the number of newly formed tendon fibers and the Sharpey fibers at the repair site increased in the OCP+group compared with those in the other 2 groups on hematoxylin-eosin staining (P < .05). On immunohistochemical evaluation, both the bone and the fibers in the OCP+group demonstrated that type I collagen was picked up, whereas the newly formed tendon fibers and Sharpey fibers revealed type III collagen.
  
  
  CONCLUSIONS
  Treatment with OCP made collagen fibers and the Sharpey fibers, constituted by type I and type III collagens, increase at the tendon-to-bone insertion. It might be beneficial for the healing of rotator cuff tendon to bone.
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan; Department of Orthopaedic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Itoigawa
authors.affiliation: Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai, Japan. Electronic address: suzuki-o@m.tohoku.ac.jp.
authors.forename: Osamu
authors.initials: O
authors.lastname: Suzuki
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sano
authors.affiliation: Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Anada
authors.affiliation: Yokushukai Dental Clinic, Nishi-Murayama, Japan.
authors.forename: Takuto
authors.initials: T
authors.lastname: Handa
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Hatta
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kuwahara
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
authors.affiliation: Division of Craniofacial Function Engineering, Tohoku University Graduate School of Dentistry, Sendai, Japan; Division of Oral and Maxillofacial Surgery, Tohoku University Graduate School of Dentistry, Sendai, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ezoe
authors.affiliation: Department of Orthopaedic Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kaneko
authors.affiliation: Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Itoi
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology*; D024042:Collagen Type I / Q000187:drug effects / Q000502:physiology; D024061:Collagen Type III / Q000187:drug effects / Q000502:physiology; D023421:Models, Animal; D010012:Osteogenesis / Q000187:drug effects*; D011817:Rabbits; D012038:Regeneration / Q000187:drug effects*; D017006:Rotator Cuff / Q000601:surgery*; D013710:Tendons / Q000502:physiology
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D024042:Collagen Type I; D024061:Collagen Type III; C022045:octacalcium phosphate
keywords: Rotator cuff repair; Sharpey fibers; collagen fibers; enthesis; octacalcium phosphate (OCP); shoulder; tendon-to-bone healing