Prediction of Rotationally Neutral State of the Femur by Comparing with the Shape of Contra-lateral Lesser Trohanter / 대한정형외과학회잡지

ABSTRACT

PURPOSE: To evaluate the accuracy and reliability of method for prediction of rotationally neutral state of the femur by comparing with contra-lateral lesser trochanter. MATERIALS AND METHODS: The rotationally neutral state of the femur was measured by comparing the shape of the opposite side of the lesser trochanter in a normal group of 100 adult. Each examination was performed independently by three observers. The observers predicted a position presumed to be neutral by comparing the shape of lesser trochanter with that of contra-lateral side previously recorded by the C-arm image intensifier. We evaluated the mean angular discrepancy that is different from the neutral point and assessed the inter-observer variations. RESULTS: The mean angular discrepancy (SD) was 3.4 degree(+/-2.4); 3.5 degree(+/-2.4) by observer-1,3.5 degree (+/-2.8) by observer-2, 3.2 degree(+/-2.2) by observer-3. There was no inter-observer variation (p=0.87). 77% of all observers indicated below 4 degree and no one over 15 degree. CONCLUSIONS: The method of comparing the shape of both lesser trochanters is considered to be effective in determining the rotational status of the femur. It could be used as a practical method in the operation of the femoral fracture for prevention of rotational deformity intra-operatively