Femur

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The femur or thigh bone is the longest, most voluminous, and strongest bone of the human body. It forms part of the hip and part of the knee.

The word "femur" is Latin for "thigh". In medical Latin its genitive is always femoris, but in classical Latin its genitive is often feminis, and should not be confused with case forms of femina = "woman."

Features

The femur consists of a head and a neck proximally, a diaphysis (or shaft), and two condyles (medial and lateral) distally.

Proximal end

The femur's head forms a ball-and-socket joint at the hip.

Other proximal features of the bone include the greater trochanter and the lesser trochanter, two bony projections that allow muscles to attach.

Posteriorly the gluteal tuberosity is a rough surface that gluteus maximus attaches to. Beneath this, the linea aspera runs down the back of the femur, which also provides an attachment for the biceps femoris muscle.

Distal end

The condyles at the knee form a condylar joint.

The medial and lateral condyles on the distal end, are bumps that fit into corresponding articular facets on the tibia. The gap between the two condyles is called the intercondylar fossa (or notch). Above the femoral condyles are the medial and lateral epicondyles, above the medial epicondyle is the adductor tubercle.

Fractures

Femur fractures are liable to cause permanent disability because the thigh muscles pull the fragments so they overlap, and the fragments re-unite wrongly. To avoid this, femur fracture patients should be put into traction to keep the fragments pulled into proper alignment.

Hip fracture

If bone is weakened, the proximal end of the femur near the hip joint is prone to fragility fracture. Most at risk are caucasian, post-menopausal women, and osteoporosis severely increases this risk.

In other animals

Parallel structures by the same name exist in other complex animals, such as the bone inside a ham or a leg of lamb.

The name femur is also given to the most proximal full-length jointed segment of an arthropod's leg.

External links

Image with major components labeled

Skeletal system | Lower limb anatomy