Using Traditional Measurement Methods And Arthroscopic Landmarks To Study PCL Anatomy Based On Three-dimensional Fusion Technology

ObjectiveTo reconstruct three-dimensional knee joint fusion image including PCL,and to study PCL attachment anatomy on the fusion images,so as to provide a unified imaging method and anatomical data for individualized and accurate PCL reconstruction.MethodsTwenty healthy adults were enrolled and examined by CT and MRI.A three-dimensional fusion model of knee joint was established by using the modified MIMIMICS software and image fusion software.On the fused image,Measuring the area of the PCL footprint in the femur and tibia of both knees.The anatomy of the center of the PCL footprint was measured using the common conventional imaging methods.On the femur,Measuring the distance from the center of the PCL to the medial edge of the medial femoral condyle,the vertical distance from the center of the PCL to the Blumensaat line,and the distance from the center of the PCL to the anterior cortex of the medial femoral condyle(parallel to the Blumensaat line).On the tibial,Measuring the distance from PCL center to medial edge of tibial plateau,the distance from PCL center to anterior edge of tibial plateau,the vertical distance from PCL center to the lowest plane of tibial plateau and the percentage of the distance from platform to medial condyle rotation angle,the length of the PCL slope and the distance from the PCL center to the nearest end of the PCL slope as a percentage of the length of the PCL ramp.Measuring the distance from the PCL center to the PCL attachment-related landmark under arthroscopy.On the femur,Measuring the distance from the PCL center to the trochlear point,the shallow point,and the posterior point of the trochlear.On the tibial,Measuring the PCL center to the medial groove,champagne-glass drop-off and the tip of medial intercondylar.The paired t-test was used to compare the difference between the left and right knee PCL footprint area and the difference between the left and right knee of the distance from the PCL center to the PCL attachment-related landmark.Statistical significance was accepted for probabilities of<5%(p<0.05).ResultsAll the 20 subjects successfully achieved image fusion modeling and measurement,with an average time of 12 hours.The distance from the PCL center(femoral)to themedial edge of the medial femoral condyle,to the Blumensaat line,and t to the anterior cortex of the medial femoral condyle were 32.1±1.8 mm,6.8±2.5 mm,and 23.3±2.1mm,respectively.The distance from the PCL center(tibia)to the medial edge of the tibial plateau,the anterior edge of the tibial plateau,and the lowest plane of the tibial plateau were 37.3±3.3 mm,45.6±5.3 mm,and 6.0±1.2 mm,respectively.The PCL slope length was 24.2±2.06mm.The average location of the PCL center on the 3-dimensional fusion model method was 65.2±7.2%along the PCL slope from anterior/proximal to posterior/distal.The center of left knee PCL(femoral)to the trochlear point,shallow point and posterior point were 11.8±2.2 mm,9.5±1.5 mm and 18.2±1.8 mm respectively,the right knee were 12.1±2.4mm,10.3±1.8mm,18.1±2.0mm,respectively.The PCL center of the left knee(tibial)to the medial groove,champagne-glass drop-off and the tip of medial intercondylar were 8.4±2.4 mm,9.2±1.8 mm and 15.3±1.4 mm,respectively,the right knee were 8.0±2.0mm,9.4±2.2mm and 16.1±1.8mm respectively.There was no difference between the right and left about the distance from the PCL center to the PCL attachment-related landmark under arthroscopy(P>0.05).The area of PCL footprint on the femoral and tibial of the left knee were 115.3±33.5mm~2 and146.6±24.4mm~2,respectively,the right knee were 121.8+35.6mm~2 and 142.8+19.5mm~2,respectively.There was no difference between the right and left about the area of PCL footprint(P>0.05).Conclusion1.MRI and CT three-dimensional image fusion technology can well reconstruct the knee joint model including PCL,and the PCL anatomical data measured on the model can be used to guide clinical PCL reconstruction;2.Anatomical parameters of left and right PCL footprints in healthy subjects were bilaterally symmetric in MRI and CT three-dimensional fusion images,supporting the use of contralateral knee data to guide PCL reconstruction of the affected knee;3.PCL-related landmarks under arthroscopy can be recognized and measured in fusion images of MRI and CT,which can guide PCL reconstruction to locate tunnels accurately under arthroscope.