title: A novel suture anchor constructed of cortical bone for rotator cuff repair: a biomechanical study on sheep humerus specimens.
abstract: The aim of this study was to evaluate biomechanical properties of a new type of suture anchors constructed of human cortical allograft bone and compare it with the similar standard titanium screw anchor for rotator cuff tears in sheep humerus model.
  
  
  
  Twenty-four paired sheep humeri were harvested from 12 male sheep aged 18 months. Specimens were divided into cortical bone anchor group and titanium screw anchor group. The anchors loaded with two sutures were placed at the footprint of infraspinatus tendon. Cyclic loading test was performed from 10 to 60 N at 1 Hz for 500 cycles and followed by a load-to-failure test at 33 mm/sec. A paired t-test was used to compare the biomechanical properties of the anchors of each type.
  
  
  
  No anchors failed during the cyclic phase, and the cortical bone anchors were all pulled out intact. The cyclic displacement of the cortical bone anchor was not significantly greater than that of the titanium screw anchor (P > 0.05). Student's t test showed no statistically significant difference between anchors in terms of failure load (cortical bone anchor: 304.74 ± 64.46 N versus titanium screw anchor: 328.45 ± 89.58 N; P = 0.213), ultimate load (cortical bone anchor: 325.82 ± 76.45 N versus titanium screw anchor: 345.61 ± 83.56 N; P = 0.183), yield load (cortical bone anchor: 273.78 ± 44.75 N versus titanium screw anchor: 284.72 ± 56.37 N; P = 0.326) or stiffness (cortical bone anchor: 52.97 ± 14.28 N/mm versus titanium screw anchor: 62.38 ± 18.35 N/mm; P = 0.112).
  
  
  
  In vitro, this experimental study suggested no statistically significant difference in initial fixation stability between the new type anchor and titanium screw anchor at a chosen level of significance (P < 0.05). The new type of suture anchor constructed of cortical bone provides comparable initial fixation strength to a similar metallic anchor for rotator cuff repair.
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China. guoqi_nku@163.com.|School of Medicine, Nankai University, Tianjin, 300071, China. guoqi_nku@163.com.
authors.forename: Qi
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China.
authors.forename: Chunbao
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Qi
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China.
authors.forename: Hongliang
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China.
authors.forename: Xuezhen
authors.initials: X
authors.lastname: Shen
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qu
authors.affiliation: Department of Orthopedics, Chinese PLA General Hospital, Beijing, 100853, China. liuyujie301@163.com.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D000071538:Cortical Bone; D006801:Humans; D006811:Humerus / Q000601:surgery*; D008297:Male; D017006:Rotator Cuff; D000070636:Rotator Cuff Injuries / Q000601:surgery*; D012756:Sheep; D053441:Suture Anchors; D013536:Suture Techniques
keywords: Biomechanical testing; Cortical allograft bone; Rotator cuff repair; Sheep; Suture anchor