Assessment Of Proximal Femoral Geometry And Clinical Significance Based On 3D Reconstruction

ObjectiveTo detect the reliability of the relationship between the tip of greater trochanter and the center of femoral head in restoring leg length discrepancy during hip replacement. Through the study of the anatomical parameters of proximal femoral medullary cavity to provide evidence to the selection of geometric types and design of artificial femoral prosthesis. MethodsPelvic radiograph was performed using digital diagnose DR radiography system in the affiliated hospital of Pu Tian university radiology department. The shooting range covered the mid-upper femur. Excluding the patients with obvious femur disease. The CT image data of chinese proximal femurs were collected in this study. Using mimics 14.0 software,computerized approach for 3D-reconstruction measurement of proximal femurs,various parameters were measured which included the femoral offset, femoral neck anteversion(FNA). We analyzed whether there were differences between left and right side. 3D-reconstruction method was used to analyze the canal shape of the proximal femur.Results1.The femoral offset is 31.84±7.11mm(range,20.54mm~47.12mm),greater trochanter height is 6.71±7.11mm(range,1.45mm~14.11mm), femoral neck anteversion is 12.76±2.73°(range,7.65°~18.31°).Width of canal at the lesser trochanter for lateral view is 19.98±3.74 mm.Intracortical width of isthmus is 10.10±1.80 mm. There is no significant difference between the left and right side.2.Overall morphological characteristics of the the proximal femoral medullary cavity,there are large to small, irregular circular evolution to the class. Conclusions1.The tip of greater trochanter is not at the same level as the center of femoral head, in most of the conditions, at 6.71 mm above the center of femoral head. Femoral offset and femoral neck anteversion has no significant difference between left and right side. The measurement of the relationship between the tip of greater trochanter and the center of femoral head has an important reference significance to total hip replacement in adjust the leg length2. Proximal femoral parameters of Chinese population are significantly different,with the bending characteristics. The length of femoral prosthesis should not exceed the point of maximum curvature.The length of prosthetic femoral stem can not exceed 175 mm.There-dimensional reconstruction of medullary cavity can be more detailed,fully reflect its forms. Different forms of femoral marrow cavity could provide reference for the reasonable choice of prosthesis.