The Biomechanical Study Of The Initial Stability Of Intertrochanic Fractures Treated With Cemented Femoral Stems

1.BackgroundMost of the intertrochanic fractures in elderly occur by minor trauma and may present many complications which are thought to be related to initial stability of fixation.In order to promote the early full weight-bearing,some studies suggest the use of femoral stem prosthesis in the treating of intertrochanic fractures in elderly.2.ObjectiveThe purpose of this study was to provide the mechanical evidences for the arthroplasty in treatment of communited intertrochanic fractures in elderly by assessing the initial stability which received the conventional femoral stem prosthesis,with the use of third-generation cementing techniques.3.Material and method 12 cadaveric femurs were selected in this study and divided into 2 groups randomly.Group A were fractures at the femoral necks simulated with a osteotomy at the neck and group B were communited intertrochanic fractures(classified Typeâ…£by Evans-Jensen)simulated with a osteotomy at the intertrochanic region.Both of the groups were treated with cemented femoral prosthesis following the standard total hip arthroplasty procedure.The specimens were tested mechanically WDS-100in vertical and rotational loading from 100 N to 1000 N by applying the loading along the perpendicular axis of the femurs or set the torque on the pins which were passed the dilled holes located the distal to the femoral stems on coronal planes.The generated displacement magnitudes of the prosthesis when applying the loading were recorded.The differences of displacement magnitudes between the group A and group B were analyzed with the Student t test.4.ResultsThere were two spicemens failed at 800 N when applied the rotational loading in group A,respectively.No significant differences of the displacement magnitudes were found between the two groups either in vertical and rotational loading. 5.ConclusionThe initial mechanical stability of the conventional femoral stem prosthesis in the treatment of communited intertrochanic fractures is acceptable and similar to femoral necks treated with the same procedure.The use of femoral stem prosthesis is an alternative choice in the treatment of elderly patients with communited intertrochanic fractures.