%0 Journal Article
%T Adjustable
%A Dayne T. Mickelson
%A Jonathan C. Riboh
%A Ken Gall
%A Thomas Lefebvre
%J The American Journal of Sports Medicine
%@ 1552-3365
%D 2018
%R 10.1177/0363546518771365
%X Adjustable-loop cortical buttons for femoral fixation of bone-tendon-bone grafts have potential advantages over interference screw fixation; however, these devices have not been benchmarked biomechanically against interference screws. The purpose was to compare the time zero biomechanical properties of commercially available, adjustable-loop cortical button and metallic interference screws for femoral fixation of bone-tendon-bone grafts. It was hypothesized that no significant differences would be found in biomechanical properties between fixation techniques. Controlled laboratory study. Adjustable-loop cortical buttons (n = 8) and metallic interference screws (n = 8) were used to fix matched pairs of human bone-tendon-bone allografts in porcine distal femurs. These constructs were preconditioned (10 N to 50 N at 1 Hz, 10 cycles), subjected to cyclic loading (50 N to 250 N at 1 Hz, 500 cycles), and then pulled to failure at 20 mm/min. The loads to failure (mean ¡À SD, 700 ¡À 256 N vs 688 ¡À 215 N, P = .92) and linear stiffnesses (219 ¡À 48 N/mm vs 218 ¡À 49 N/mm, P = .97) for the adjustable-loop cortical button and metallic interference screws, respectively, were not significantly different. Cyclic displacement was higher in the adjustable-loop cortical button group (2.1 ¡À 0.6 mm vs 1.3 ¡À 0.4 mm, P = .01). The mechanism of failure was different between groups, with bone block slippage occurring most commonly in the interference screw group (n = 5) and fracture of the bone block through the suture hole occurring most commonly in the adjustable-loop cortical button group (n = 6). Adjustable-loop cortical buttons and interference screws have similar time zero failure loads, although cyclic displacement was higher with the adjustable-loop cortical buttons. The mean difference in displacement was less than 1 mm compared with the interference screw. Adjustable-loop cortical buttons may be an acceptable alternative to an interference screw for femoral fixation of bone-tendon-bone grafts in anterior cruciate ligament reconstruction. The clinical relevance of the observed differences in cyclic displacement is unknown and should be evaluated in future studies
%K ACL reconstruction
%K bone-tendon-bone graft
%K suspensory fixation
%K adjustable loop
%K interference screw
%K biomechanics
%U https://journals.sagepub.com/doi/full/10.1177/0363546518771365