Radiological Analysis of the Proximal Femoral Geometry in Korean Adults and the Design of the Cementless Femoral Stem

Shon, W.Y.; Lee, S.H.; Chae, D.J.; Chang, O.S.

Abstract

We analyzed the endosteal morphology of the proximal femur in 300 Korean adults radiologically and assessed the proximal canal filling of the cementless anatomic stem in 100 patients with imaging analysis system. The cases were divided in six groups, according to age by the decades. The canal flare indices were 4.20, 3.82, 3.47, 3.40, 3.34 for each age group from third to eighty decades respectively. The shape of proximal cannal in the 300 cases, showed 234 cases(78%) to be normal, while 30 cases(10%) in the Stovepipe configuration and 36 cases(12%) in the Champagne flute appearance. The proximal canal filling rate in an AP view radiologically measured from the level of the lesser trochanter to 2cm distal to the lesser trochanter in 100 patients with cementless anatomic stem were s follow : 60 to 69% range in 9 cases(9%), 70 to 79% in 58 cases(58%), 80 to 89% in 31 cases(31%) and 90 to 100% in 2 cases(2%). With regard to the suitability of cementless femoral components, anatomic fitting, distal fitting, proximal fitting, undersized stem were 66%, 23%, 5%, 6%, respectively. It is difficult to achieve the optimal anatomic fitting to the femoral cannal with one design of the cementless femoral stem, because of the greater variation of proximal femoral anatomy in normal population.