The internal calcar septum (femoral thigh spur) in computed tomography and conventional radiography.

Objective. The femoral ”thigh spur”, a cortical septum in the region of the lesser trochanter of the human femur, was first described and named by the German anatomist Merkel in 1874, but it was never examined in detail. To evaluate the frequency and the shape of this structure, a combined anatomical and radiological study was performed using saw-cuts from specimens, high-resolution CT and conventional radiography.