title: Biomechanical evaluation of a novel application of a fixation device for bone-tendon-bone graft (EndoButton CL BTB) to soft-tissue grafts in anatomic double-bundle anterior cruciate ligament reconstruction.
abstract: OBJECTIVE
  The purpose of this biomechanical study was to compare the structural properties of the flexor tendon graft connected to the EndoButton CL BTB (ECL-BTB) (Smith & Nephew Endoscopy, Andover, MA), which is newly developed to fix the bone-tendon-bone graft, with those of the same graft connected to the EndoButton CL (ECL) (Smith & Nephew Endoscopy), which is commonly used as a standard fixation device.
  
  
  METHODS
  We randomly divided 40 porcine flexor digitorum profundus tendons into 4 groups. An ECL and an ECL-BTB were attached to the doubled tendon measuring 6 mm in diameter in groups I and II, respectively. An ECL and an ECL-BTB were attached to the doubled tendon measuring 7 mm in diameter in the same manner in groups III and IV, respectively. Tensile testing was performed with a tensile tester.
  
  
  RESULTS
  The linear stiffness of the tendon-device composite (mean +/- SD) was 131.8 +/- 18.3 N/mm, 109.7 +/- 14.9 N/mm, 132.4 +/- 20.5 N/mm, and 123.8 +/- 10.7 N/mm in groups I, II, III, and IV, respectively. The 2-way analysis of variance (ANOVA) showed a significant difference (P = .0058) between the ECL and the ECL-BTB. Concerning the maximum load and the elongation at failure of the tendon-device composite, the 2-way ANOVA showed no significant difference between the 2 fixation devices. Regarding the cross-sectional area, the 2-way ANOVA indicated no significant difference between the 2 fixation devices.
  
  
  CONCLUSIONS
  This study has shown that the maximum load of the flexor tendon graft connected to the ECL-BTB is similar to that of the ECL whereas the stiffness of the ECL-BTB is inferior to that of the ECL.
  
  
  CONCLUSIONS
  This study has suggested that patients should not be permitted to perform vigorous activities in the early period after anterior cruciate ligament reconstruction by use of the ECL-BTB fixation technique, because of its low stiffness compared with the ECL device.
authors.affiliation: Department of Sports Medicine and Joint Reconstruction Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Miyatake
authors.forename: Eiji
authors.initials: E
authors.lastname: Kondo
authors.forename: Harukazu
authors.initials: H
authors.lastname: Tohyama
authors.forename: Nobuto
authors.initials: N
authors.lastname: Kitamura
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yasuda
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D001696:Biomechanical Phenomena; D050376:Bone-Patellar Tendon-Bone Grafting / Q000295:instrumentation*; D002102:Cadaver; D004868:Equipment Failure; D020007:Implants, Experimental; D008422:Materials Testing; D011897:Random Allocation; D034421:Sus scrofa; D013552:Swine; D013710:Tendons / Q000637:transplantation*; D013718:Tensile Strength; D016474:Weight-Bearing