Abstract:

BACKGROUND: The premise of model prediction of prosthesis is the full understanding and accurate measurement on proximal femur before total hip arthroplasty, but X-ray film only can provides a ground-plan, cannot understand the cross-sectional of proximal femur. However, the CT scan of the proximal femur can provide more information.
OBJECTIVE: To observe the effect of CT scan of proximal femur in the preoperative plan of total hip arthroplasty.
METHODS: A total of 61 patients with primary total hip arthroplasty underwent CT scan of proximal femur. The parameters were defined from the CT films taken at T20 (the neck at 20 mm higher than the apex of lesser trochanter), T0 (the level of the apex of lesser trochanter), and N level (the level of femoral isthmus). The length-diameter, wide diameter, medial diameter of plane medullary cavity in neck of femur, the length-diameter, medial diameter of plane medullary cavity in lesser trochanter, the length-diameter, wide diameter, cortical thickness of plane medullary cavity in femoral isthmus was measured.
RESULTS AND CONCLUSION: The length-diameter of the neck of femur at T20 level was 40.8-63.3, average (49.6±5.1) mm, wide diameter of the neck of femur at T20 level was 13.3-29.1, average (22.4±3.4) mm and medial diameter of the neck of femur at T20 level was 7.2-14.6, average (10.6±1.6) mm; the length-diameter of the intertrochanter region at T0 level was 20.5-40.2 mm, average (28.7±4.4) mm, medial diameter of intertrochanter region at T0 level was 4.3-13.0, average (8.1±1.7) mm; the length-diameter of femoral isthmus at N level was 8.2-22.4, average (14.1±3.1) mm, wide diameter of femoral isthmus at N level was 6.1-17.9, average (10.2±2.9) mm and cortical thickness on wide diameter at N level was 2.7-12.7, average (7.5±1.8) mm. The CT scan of proximal femur can provide more image information and more accurate measured data, which is helpful to the preoperative plan of total hip arthroplasty.