The invention relates to a method for automatically determining, on a bone comprising a head portion contiguous to a neck portion, parameters for characterizing a bump deformation on the head-neck junction of the bone from acquired 3D medical image, the method comprising the following steps: i) constructing a 3D surface model of the bone; ii) fitting a sphere on the spherical portion of the head of the bone; iii) determining a neck axis characterizing the neck portion of the bone; iv) determining from the fitted sphere and the neck axis, a clock face referential on the head of the bone rotating around the neck axis; v) determining a 3D curve on the 3D surface model characterizing the head-neck junction of the bone; vi) determining, from the 3D curve, the summit of the bump deformation of the head-neck junction of the bone; vii) determining, from said summit of the bump deformation, first and a second parameters (α3D, iMax) characterizing the maximum bump deformation of the head-neck junction of the bone.