Abstract: Objective To study the F-s curve of transverse tensile and transverse displacement after porcine ACL reconstruction, and obtain the theoretical basis for the optimal measurement position of initial tension after ACL reconstruction. Methods Selection of 24 fresh porcine anterior cruciate ligament samples were randomly divided into three groups. Different measuring positions were performed including the edge position，quarter-position and middle position. Different location’s transverse tensile force and speed with the corresponding transverse displacement were recorded. F-s curves were drawn with computer and analyzed. Results The slopes of F-s curve were smaller when the hook were stretched at the middle position of ligament, the curve slopes at 1 / 4 position of ligament were the second, and the curve slopes at the edge position of ligament were the largest. Measured at the same point with initial tension 50, 75 and 100N, the slopes of the F-s curve were basically unchanged, but at the edge position of ligament the curve slopes were quite confused (group A). For group B and group C, the curve slopes variation of different forces were relatively regular. F-s curves of different transverse speed and corresponding displacement were same approximately. Conclusions After anterior cruciate ligament reconstruction, the middle position is optimal for measuring initial graft tension. It is easier for surgeon to grasp the F-s curves relationship and more likely to identify the current ligament tension. The transverse tensile speed has little effect on the result.

Key words: Anterior Cruciate Ligament Reconstruction, Initial graft tension, Optimal measuring position, Slack compensation