Interference Fit: A Novel Method for Strong Knotless Arthroscopic Fixation of Sutures to Bone

Abstract

Background The present study examined the strength of fixation of a knotless anchor system that relies on trapping the suture between an interference fit screw and its bone tunnel, a method familiar to orthopaedic surgeons during anterior cruciate ligament reconstruction. Type of study In vitro biomechanical single-pull load to failure study of fixation achieved by interference fit screws in porcine bone. A standard suture anchor with eyelet was used as a control. Methods A single-pull to failure test was carried out on a Hounsfield H20K digital tensiometer (Tinius Olsen, Hersham, PA, USA). Two suture materials were compared [braided polyester (Ethibond; Ethicon Ltd, Edinburgh, UK) and a new suture (Fibrewire; Arthrex Inc., Naples, FL, USA) that has a high molecular weight polyethylene core]. Two interference fit screws were compared: one metal and the other plastic (PEEK; Parkus Medical, Sturgeon Bay, WI, USA). Results The average values were between 262 N and 584 N. The average failure value for a standard anchor was 206 N. Clinical Relevance Interference fit fixation provides an elegant strong knotless method for securing multiple sutures to a single point.