Fig. 2
From: Proximal femoral anatomy and collared stems in hip arthroplasty: is a single collar size sufficient?
Anatomic landmarks, axes and dimensions determined for each hip. The Femoral Head Center (FHC) is determined by fitting a ‘sphere of best fit’ to the femoral head. The Femoral Distal Diaphysis Center (FDDC) is determined by fitting an ellipse to the intramedullary cortex 120 mm below the FHC. The Femoral Proximal Diasphysis Center (FPDC) is determined by fitting an ellipse to the intramedullary cortex 20 mm above the superior margin of the lesser trochanter