In certain medical procedures, there is a need to determine or measure the antetorsion angle of the human femur. Known methods for measuring the antetorsion angle of the human femur use different means, such as, for example, pre-operative X-ray images, CT data or intra-operative fluoroscopic images. Prior art references referring to such methods include: Egund, N., Palmer, J. “Femoral anatomy described in cylindrical coordinates using computed tomography”, Acta Radiol. Diagn 1984; 25:209-215; Herman, K L, Egund, N.: “Measuring anteversion in the femoral neck from routine radiographs”, Acta Radiol; 1998; 39:410-415; Herman, K. L., Egund, N: “CT measurement of anteversion in the femoral neck: the influence of femur positioning”, Acta Radiol 1997; 38:527-532; Murphy, S., Simon, S., Kijewski, P., et al. “Femoral anteversion”. Journal of Bone Joint Surgen 1987; 69A:1169-1176; Sugano, N., Noble, P., Kamaric E. “A comparison of alternative methods of measuring femoral anteversion”, Journal Computer Assisted Tomography 1998; 22(4):610-614; Hofstetter, R., Slomoczykowski, M., Krettek, C., et al.: “Computer-assisted fluoroscopy-based reduction of femoral fractures and antetorsion correction”, Computer Aided Surgery 2000; 5(5):311-325.
Another approach in the prior art relates to a measurement device which is inserted into an intramedullary canal of a human femur and, thus, involves major surgery. This measurement device is described in U.S. Pat. No. 5,728,128.
The above prior art methods for determining or measuring the antetorsion angle of the human femur seriously impact the body of a patient, either by means of high X-ray doses, a surgical operation and/or the like.