Influence Of The Position Of The Femoral And Tibial Tunnels On The Stability Of The Patellofemoral Joint During Anterior Cruciate Ligament Reconstruction

Objective: To analyze the relationship between different combinations of tibial vs.femoral tunnel positioning and the stability of the patellofemoral joint,further clarifying the optimal combination of tibial vs.femoral tunnels that has the least effect on patellofemoral stability.Methods: Forty-eight patients with complete rupture of the anterior cruciate ligament and no remaining ligament injury were clearly identified by preoperative examination and imaging,and the coordinates of each localization point were derived by establishing a plane right angle coordinate system according to the Bernard quadrant method.The patients were divided into AA,AP,PA,and PP groups based on the femoral and tibial equations derived from the mean localization points.The correlation of postoperative TT-TG,patellar valgus angle,and Insall-Salvati index was compared between each group.Results: There were no significant differences in patient age,BMI,gender,affected limb side,or time to injury between the AA,AP,PA,and PP groups.there were significant differences in TT-TG values(P<0.001)and patellar valgus angle(P<0.05)between the AA,AP,PA,and PP groups,and no significant differences in Insall-Salvati index(P=0.179 P>0.05).The TT-TG values in the AA group were smaller than those in the other three groups,and the patellar camber did not appear to open inward.Conclusion:When performing a single bundle ACL reconstruction of the knee.Better patellofemoral stability is obtained when the tibiofemoral tunnel is positioned close to the tibiofemoral attachment point of the AMB.Secondly,better patellofemoral stability is achieved when the femoral tunnel is positioned at the AMB attachment point and the tibial tunnel is positioned at the PLB attachment point.The positioning of the femoral tunnel has more priority than the positioning of the tibial tunnel.In clinical work,we cannot position the femoral tunnel too far forward when reconstructing the ACL,and can position the femoral tunnel posteriorly and upward at the lateral femoral condyle appropriately,thus reducing patellofemoral instability.