A security evaluation of the Rigid-fix crosses pin system used for anterior cruciate ligament reconstruction in tibial fixation site.

Our study aims to evaluate the safeness and feasibility that Rigid-fix cross pin system was used for hamstring graft anterior cruciate ligament (ACL) reconstruction in the tibial fixation site. In this study, eleven adult conservative cadaver knees were performed using the Rigid-fix Cross Pin device in the tibial fixation site for modeling the ACL reconstruction. The guide rod top was put through the tibial tunnel at the three horizontal positions: equal pace to articular facet (group A), the plane 5 mm below articular facet (group B), and the plane 10 mm below articular facet (group C). We gave four rotation positions to the cross-pin guide: 0°, 30°, 45°, 60° slope, referring to the parallel line of the posterior border of tibial plateau. We recorded the iatrogenic damages incidence, in the four different slope angle in the three groups, and then compare the incidence using Chi-Square test. Our results suggested that the incidence of chondral injury of tibial plateau in group B and group C was significantly lower compared to group A (χ (2) A-B = 27.077, χ (2) A-C 45.517, P = 0.000); However, there was no significant difference for the incidence penetrating the medial condyle of tibial plateau among the three groups (χ (2) = 5.733, P = 0.057); The highest incidence of injuring ligamentum transversum is in group A with 72.7%, especially at the 60° slope angle. In summary, our study suggested that in order to achieve the satisfactory clinical effect for the Rigid-fix system used in the tibia end fixation of ACL reconstruction surgery, the guide rod top should be put at the 5 mm below articular facet with a slope that parallel to the tibial medial plane at 30°-60° slope angle.