[2] The lateral surface, quadrilateral in form, is broad, rough, convex, and marked by a diagonal impression, which extends from the postero-superior to the antero-inferior angle, and serves for the insertion of the tendon of the gluteus medius.
Below and behind the diagonal impression is a smooth triangular surface, over which the tendon of the gluteus maximus lies, a bursa being interposed.
The medial surface, of much less extent than the lateral, presents at its base a deep depression, the trochanteric fossa (digital fossa), for the insertion of the tendon of the obturator externus, and above and in front of this an impression for the insertion of the obturator internus and superior and inferior gemellus muscles.
The inferior border corresponds to the line of junction of the base of the trochanter with the lateral surface of the body; it is marked by a rough, prominent, slightly curved ridge, which gives origin to the upper part of the vastus lateralis.
The posterior border is very prominent and appears as a free, rounded edge, which bounds the back part of the trochanteric fossa.