Refixation of the anterior cruciate ligament: A biomechanical analysis of suture techniques in a porcine model

Abstract Purpose Refixation of acute anterior cruciate ligament (ACL) tears represents an increasingly popular treatment option. Systematic evaluations of various suture technique parameters are still pending. We therefore aimed to evaluate the mechanical pull‐out outcomes of various suture methods for optimization of ACL refixation. Methods Sixty fresh knees from mature domestic pigs were dissected and the femoral attachment of the ACL was peeled off. The 60 knees were divided in 10 groups and sutured as follows: (A) one suture (1, 2, 4 and 6 passes), (B) two sutures (2, 4 and 6 passes each; sutures knotted together as a loop) and (C) two sutures (2, 4 and 6 passes each, sutures knotted separately). The pull‐out test was conducted using a validated electrodynamic testing machine. First occurrence of failure, maximum pull‐out load and stiffness were measured. Suture failure was defined as pull‐out of the ACL. Results Two‐point fixation, using two sutures, with at least two passes, showed the most favourable biomechanical stability. The maximum pull‐out load was significantly higher with two sutures (529.5 N) used compared to one (310.4 N), p