The femur is the longest, most voluminous and strongest bone in the human body.
It is composed of the upper extremity, body and lower extremity and provides several muscular origins and insertions.
Femoral head and neck
The femoral head is supported by the neck of femur. It is globular and forms rather more than a hemisphere. It is directed caudally, medially and anteriorly. Its surface is smooth and coated in cartilage except for an ovoid depression (the fovea capitis femoris) which is situated a little below and behind the centre of the head. The fovea allows for the attachment of the ligament of head of femur.
If there is a fracture of the neck of femur, the blood supply through the ligament becomes crucial. Where this occurs, there is a risk of insufficient blood supply to the head and avascular necrosis may occur. It is for this reason that the treatment of choice is total hip replacement rather than dynamic hip screwing.
Greater and lesser trochanter
The greater trochanter is a large, irregular, quadrilateral eminence attached to the proximal end of the femur. It is directed laterally and posteriorly and, in the adult, is about 1cm lower than the femoral head. It has two surfaces and four borders two which several muscles are attached.
The lesser trochanter is a conical eminence which is of variable size. It projects from the posterior surface of the neck of femur. It is continuous with the middle division of the linea aspera (the prominent ridge along the femur) and the intertrochanteric crest. Like the greater trochanter, it is also involved in muscular attachment.
- gluteus medius
- gluteus minimus
- obturator internus
- obturator externus
- quadratus femoris
- vastus lateralis
The femoral shaft is almost cylindrical in form, is a little broader superiorly and is slightly arched such that it is convex anteriorly and concave posteriorly where it is strengthened by a prominent longitudinal ridge of bone, the linea aspera. A variety of muscles have their origins at and insert into the femoral shaft (all, apart from gluteus maximus and vastus intermedius, interact with the posterior surface of the bone):
- gluteus maximus
- adductorl longus
- adductor brevis
- adductor magnus
- adductor minimus
- vastus medialis
- vastus lateralis
- vastus intermedius
- biceps femoris
The lower extremity is composed of the medial and lateral condyles, adductor tubercle, patellar surface and intercondylar fossa. It is larger than the upper extremity and articulates with the tibia and patella at the knee.
Anteriorly, the condyles are slightly prominent and separated from oneanother by the patellar surface. Posteriorly, they project considerably and the interval between them forms a deep notch, the intercondylar fossa. The lateral condyle is more prominent than the medial.
The articular surface of the lower end of the femur occupies the anterior, inferior and psoteriro surfaces of the condyles.
The bones of the upper limb are part of the appendicular skeleton.
- 1. Thieme Atlas of Anatomy (General Anatomy and Musculoskeletal system): ISBN 3131420812
- 2. Gray's Anatomy 39th Edition, Elsevier
- 3. Wikipedia: Femur