Assessment Of The Accuracy Of The Sulcus Localization Method To Establish The Medial Patellofemoral Ligament Femoral Tunnel

Purpose Medial patellofemoral ligament(MPFL)injuries are always seen in patients with recurrent patella dislocations.Reconstruction of MPFL is very important to protect recurrence of the patella.Accurate positioning of the MPFL femoral tunnel in anatomical MPFL reconstruction.The present study aimed to investigate the accuracy of the sulcus localization method to establish the MPFL femoral tunnel.Methods This study was composed of two parts:a cadaveric study and a clinical study.A cadaveric study was first done on 12 knees to evaluate the accuracy of the sulcus localization method to establish the entry points of the MPFL femoral tunnel in comparison with the midpoint and fluoroscopic localization methods.The center of the native MPFL femoral attachment was served as the reference in the cadaveric study.A clinical study was then performed to further evaluate the accuracy of the sulcus localization method in 53 patients(60 knees).Schottle’s point was served as the reference in the clinical study.Femoral tunnel placement was defined as accurate when it was less than 5 mm from Schottle’s point.Results were shown was mean ± standard deviation.The accuracy of different localization methods was compared using analysis of variance,with P<0.05 being significant differences.Results In the cadaveric study,the mean distances from the native MPFL attachment to the femoral tunnel entry point were 2.9 ± 0.8 mm,4.4 ± 1.4 mm,4.2±1.0 mm,and using the sulcus,fluoroscopic,and midpoint localization methods,respectively;this distance significantly differed between the midpoint and sulcus localization methods,and between the fluoroscopic and sulcus localization methods(P<0.05).In the clinical study,accurate tunnel placement achieved in 49 of 60 cases by using sulcus localization methods(82%),and postoperative knee functional scores including IKDC、Lysholm,Tegner,and Kujala evaluating scales were significantly improved(P<0.01).Conclusion The accuracy of the sulcus localization method was more accurate than that of the fluoroscopic localization method and that of the midpoint localization method.In anatomical MPFL reconstruction,use of the sulcus localization method could achieve accurate placement of the MPFL femoral tunnel.