Distal sagittal groove of proximal phalanx

The distal extremity of the proximal phalanx, also called 'head' (Caput phalangis proximalis) or better trochlea is a bit inflated and presents an articular surface, extended on the palmar side, made of two condyloid reliefs a bit tilted on an intermediate groove: The distal sagittal groove of proximal phalanx (Sulcus sagitalis distalis phalangis proximalis).