title: Comparison of histologic healing and biomechanical characteristics between repair techniques for a delaminated rotator cuff tear in rabbits.
abstract: BACKGROUND
  The purpose of this study was to compare histologic healing and biomechanical characteristics between 2 repair techniques (layer by layer, repair of each layer to bone separately; and whole layer, repair of each layer to the bone en masse) for delaminated rotator cuff tear.
  
  
  METHODS
  Rabbits were used as subjects and classified into 2 groups: group A, right side, the layer-by-layer repair group; and group B, left side, the whole-layer repair group. Histologic evaluations were done at 3 weeks (n = 7) and 6 weeks (n = 4) after operation. Biomechanical tests to evaluate the tensile property were done at time 0 (n = 5) and 3 weeks (n = 5) after operation.
  
  
  RESULTS
  Histologic healing improved in all groups. A smaller cleft was found between layers in group B compared with the cleft in group A at 3 weeks after operation. At time 0, group A showed a higher yield load and ultimate failure load (67 ± 10.5 N and 80 ± 7.8 N, respectively). However, at 3 weeks after operation, group B showed a higher yield load (48 ± 7.6 N).
  
  
  CONCLUSIONS
  In the delaminated rotator cuff tear model in the rabbit, the whole-layer repair showed a narrow gap between layers and a higher yield load at 3 weeks after operation. Surgical techniques that unite the cleft in a delaminated tear could improve biomechanical strength after operation.
authors.affiliation: Department of Orthopedic Surgery, Pusan National University Hospital, Pusan National University College of Medicine, Busan, Republic of Korea.
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Cheon
authors.affiliation: Department of Orthopedic Surgery, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea. Electronic address: kimjunghan74@gmail.com.
authors.forename: Jung-Han
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Heui-Chul
authors.initials: HC
authors.lastname: Gwak
authors.affiliation: Department of Orthopedic Surgery, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Chang-Wan
authors.initials: CW
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Jeon-Kyo
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Inje University Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea.
authors.forename: Ji-Hwan
authors.initials: JH
authors.lastname: Park
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D049109:Cell Proliferation; D003094:Collagen / Q000378:metabolism; D005337:Fibrin / Q000378:metabolism; D005347:Fibroblasts / Q000473:pathology; D023421:Models, Animal; D018919:Neovascularization, Physiologic; D019637:Orthopedic Procedures / Q000379:methods*; D011817:Rabbits; D000070636:Rotator Cuff Injuries / Q000473:pathology* / Q000601:surgery*; D013718:Tensile Strength; D014945:Wound Healing
chemical_list: D005337:Fibrin; D003094:Collagen
keywords: Delamination; biomechanical; histologic healing; layer-by-layer repair; rotator cuff tear; whole-layer repair