Comparative evaluation of bone suture anchor to bone tunnel fixation of tibialis anterior tendon in cadaveric cuboid bone: a biomechanical investigation.

A multiphase biomechanical study was performed using human tibialis anterior tendons and cuboid bones, comparing the fixation of the tendon to the bone using bone anchors and bone tunnels. Twenty-six specimens were tested for ultimate load to failure comparing Mitek Superanchor fixation with no. 1 and no. 5 braided polyethelyne suture to bone tunnel fixation. Mitek Superanchor with no. 5 suture failed at 223 N, compared with Mitek Superanchor with no. 1 suture at 134 N and bone tunnel at 143 N (P = 0.033). Mitek with no. 1 suture versus bone tunnel was not significantly different. The Mitek with no. 5 suture failed at the tendon/suture interface (75%), the Mitek with no. 1 suture failed at the suture/anchor interface (56%), and bone tunnel fixation failed most commonly by fracture of the tunnel (76%). This study is the first biomechanical analysis of the pullout strengths of bone tunnels or suture anchors in the cuboid bone. We have shown that the suture anchor has a pullout strength comparable or superior to a conventional bone tunnel in an in vitro situation. We believe it is a viable alternative to fixation of the tibialis anterior tendon to the cuboid when there is insufficient tendon length or failure of the bone tunnel.