The zona conoidea comprises the area of the lateral
trochlear ridge of the humerus. The purpose of this study is to reintroduce
this term ‘zona conoidea’ to the discussion of the human elbow and
to investigate its significance in the development of osteoarthritis
of the elbow. The upper extremities of 12 cadavers were prepared. With the
forearm in neutral, pronation and supination, the distance between
the bevel of the radial head and zona conoidea was inspected. A
total of 12 healthy volunteers had a CT scan. The distance between
the zona conoidea and the bevelled rim of the radial head was measured
in these positions. In the anatomical specimens, early osteo-arthritic changes were
identified in the posteromedial bevelled rim of the radial head,
and the corresponding zona conoidea in supination. Measurement in
the CT study showed that in full supination, the distance between
the bevel of the radial head and the zona conoidea was at a minimum. This study suggests that the significant contact between the
bevel of the radial head and the zona conoidea in supination is
associated with the initiation of osteoarthritis of the elbow in
this area.