Clinical Outcome And Kinematics Analysis Of 3D Printed Guide Plate-assisted Femoral Tunnel Positioning For Medial Patellofemoral Ligament Reconstruction

ObjectiveTo explore the clinical outcome and kinematics of knee joint in the treatment of recurrent patellar dislocation with 3D printed guide plate-assisted femoral tunnel positioning for medial patellofemoral ligament reconstruction.Methods1.Sixty patients with recurrent patella dislocation who visited the Sports Medicine Department of the First Affiliated Hospital of Kunming Medical University from January 2018 to December 2020 and met the inclusion criteria were selected and randomly divided into two groups according to different surgical methods:the 3D guide group and the conventional group.Among them,30 patients(14 males,16 females)were in the 3D guide group.The mean age was(27.7±7.9)years.Reconstruction of medial patellofemoral ligament using 3D printed guide plate to assist femoral tunnel positioning.In the conventional group,30 patients(including 15 males and 15 females)with an average age of(27.5±7.2)years were treated with traditional medial patellofemoral ligament reconstruction without 3D printing guide plate.2.Lysholm knee score,Kujula score,Tegner score and 2000 International Knee Literature Committee IKDC score were performed in 60 patients before operation,3 months after operation,6 months after operation,9 months after operation and 12 months after operation.The clinical outcome of the two groups was observed and compared.The Opti-Knee kinematics analysis system was used to measure and analyze the six degrees of freedom(flexion and extension Angle,inside and outside pronation Angle,inside and outside rotation Angle,front and back displacement,inside and outside displacement and up and down displacement)of the patients in the 3D guide plate group and the conventional group before,3 months,6 months,9 months and 12 months after operation.Preoperation and postoperation,intra-group and inter-group comparisons were made for the range of motion angles of patients in the two groups.Meanwhile,the knee kinematics data of 30 healthy adults were collected for a comparative study of the range of motion angles.ResultsThere were no statistical differences in preoperative gender,age,affected side,body mass index(BMI),duration of disease,frequency of dislocation,knee Lysholm score,Kujula score,Tegner score and IKDC score between two groups(P>0.05).Both groups were positive in lateral slip test and fear test before operation,and negative in the 3D guide group after operation.The positive rate in the 3D guide group was lower than that in the conventional group at the same time point after operation between the two groups(P<0.05),and there were statistically significant differences in the positive rate between the two groups before operation and after operation(P<0.05).Lysholm score,Kujula score,Tegner score and IKDC score of knee joint 3th,6thand 9th month after operation in the 3D guide plate group were significantly better than those in the conventional group(P<0.05),and there was no statistical significance in the scores of each scale 12th month after operation between the two groups(P>0.05).Lysholm score,Kujula score,Tegner score and IKDC score were gradually improved in both groups before operation and 3th,6th,9th and 12 months after operation,which were significantly better than before operation(P<0.05).There was no difference in the range of six degrees of freedom index of knee joint activity between the two groups(P>0.05),and there was a difference when the two groups were compared with healthy adults(P<0.05).Two groups of patients before and after the turning Angle of inside and outside,inside and outside the spiral Angle,both inside and outside,up and down displacement and displacement in there was no difference in March compared with healthy adults(P>0.05),between the two groups at the same time points after operation group before and after the turning Angle of inside and outside,inside and outside the spiral Angle,displacement,displacement and displacement range differences between up and down inside and outside has no statistical significance(P>0.05).There was no difference in the range of flexion and extension Angle between the two groups 3th month after operation(P>0.05),but both of them were smaller than that of healthy adults(P<0.05).The range of flexion and extension Angle in the 3D guide group was significantly better than that in the conventional group 6th and 9th month after operation(P<0.05),and there was no difference between the 3D guide group and healthy adults(P>0.05).The range of flexion and extension Angle in conventional group was smaller than that in healthy adults 6th and 9th month after operation(P<0.05).There was no significant difference in the range of six degrees of freedom index of knee joint activity between the two groups 12th month after operation(P>0.05),but it was similar to that of healthy adults(P>0.05).Conclusion①It is feasible to reconstruct the medial patellofemoral ligament with the aid of 3D printed guide plate for positioning the femoral tunnel.The 3D guide plate is safe effective;② Compared with conventional operation,the application of 3D printed guide plate to assist femoral tunnel positioning improves the accuracy of positioning;③ Compared with conventional medial patellofemoral ligament reconstruction,the application of 3D printed guide plate assisted femoral tunnel positioning for medial patellofemoral ligament reconstruction can be obtained More satisfactory knee joint subjective score and knee kinematics function;④ Knee kinematics analyzer can evaluate the kinematics and function of knee more objectively and dynamically.