Abstract
BACKGROUND: The all-inside anterior cruciate ligament (ACL) reconstruction technique involves a graft with 2 adjustable loop devices at each end of a closed loop graft, made from folded tendon(s) with cerclage sutures along its length to enhance strength. There is no consensus on the optimal number of cerclage sutures, and this study evaluates their effect on graft strength. PURPOSE: To establish the effect of the number of cerclage sutures on graft strength. STUDY DESIGN: Controlled laboratory study. METHODS: A controlled cadaveric study of 27 graft specimens was conducted, with specimens standardized to 60 mm in length and 10 mm in diameter and divided into 3 groups: 2-cerclage, 3-cerclage, and 4-cerclage. They were tested using an Instron machine, and data on stiffness, ultimate load to failure (uLTF), and mode of failure were recorded. RESULTS: The 3- and 4-cerclage groups showed no significant difference in stiffness (P = .95) and uLTF (P = .81), but both were significantly stiffer with higher uLTF than the 2-cerclage group (3-cerclage, P = .002; 4-cerclage, P = .005). The double-tendon 3-cerclage specimens were significantly stiffer (P = .014) than single-tendon 3-cerclage specimens, but this was not seen in the 4- and 2-cerclage groups. No significant difference in mode of failure was found across the groups. CONCLUSION: A double-tendon 3-cerclage graft matches the stiffness and uLTF of a 4-cerclage graft for diameters ≥10 mm, whereas a 2-cerclage graft appears suboptimal relative to a 3- or 4-cerclage graft. This finding adds to the current literature on all-inside ACL graft techniques. CLINICAL RELEVANCE: The number of cerclages used in ACL graft preparation may play an important role in optimizing graft tension and stiffness. This potentially contributes to reduction of reinjury risk and a safe return to sports.