Reprint of: The Deadman Theory of Suture Anchors: Observations Along a South Texas Fence Line

Suture anchors are being increasingly reported as a means of fixation of torn rotator cuff tendons to bone. The author has developed a mechanical model for the suture anchor–rotator cuff construct based on an analogy to the deadman system used to stabilize a corner fence post. Using this model, one can demonstrate a mechanically favorable angle of insertion of the suture anchor (θ₁) such that the anchor's pullout strength is increased at low angles of θ₁. In addition, the angle that the suture makes with the direction of pull of the rotator cuff (θ₂) has a direct effect on tension in the suture. A low angle of θ₂ minimizes the total tension in the suture, thereby minimizing the chance of suture breakage.