Paleontology Wiki
Bone: Femur
Anterior view of the femur
Gray's subject #59 242
Origins Gastrocnemius , Vastus lateralis, Vastus medialis, Vastus intermedius
Insertions tensor fasciae latae, gluteus medius, gluteus minimus, Gluteus maximus, Iliopsoas
Articulations hip: acetabulum of pelvis superiorly
knee: with the tibia and patella inferiorly
MeSH A02.835.232.500.247

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."


The average length of the femur is 43.2 cm. The femur consists of a head and a neck proximally, a diaphysis (or shaft), and two condyles (medial and lateral) distally.

Proximal end

The proximal end of femur is composed by: head, neck, greater trochanter and lesser trochanter. The femur's head forms a ball-and-socket joint at the hip. The surface of the femoral head is smooth except in a small depresion named "fovea capitis femoris" that gives attachment to the "ligamentum teres", that joins femur with coxal acetabulum. One important function of the femoral head is the production of red blood cells within the bone marrow.

The femoral neck is located between head and trochanters. The femoral neck and the femoral diaphysis form the femoral neck angle that normally is about 125º. Other proximal features of the bone include the greater trochanter and the lesser trochanter, two bony projections that allow muscles to attach.


The body of the femur presents three borders: posterior, that corresponds to the linea aspera, lateral and medial. These borders delimit three surfaces: anterior, posteromedial and posterolateral.

The main anatomical structure in the femoral diaphysis (body) is the linea aspera.

Posteriorly the gluteal tuberosity is a rough surface that the 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


Distal end of the femur

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.

Muscle Attachments

Greater trochanter

  • hamstring part of adductor magnus
  • inferior gemellus
  • quadratus femoris
  • semitendinosus
  • semimembranosus
  • long head of biceps femoris
  • Vastus lateralis
  • piriformis

Lesser trochanter

  • Psoas major
  • Iliacus


Femur fractures, on occasion, are liable to cause permanent disability because the thigh muscles pull the fragments so they overlap, and the fragments re-unite incorrectly. To avoid this, femur fracture patients should be put into traction to keep the fragments pulled into proper alignment. With modern medical procedures, such as the insertion of rods and screws by way of surgery (known as Antegrade [through the hip] or Retrograde [through the knee] femoral rodding) those suffering from femur fractures can now generally expect to make a full recovery, though one that generally takes 3 to 6 months due to the bone's size. The thigh is generally not put in a cast since the surgical hardware does the job of straightening the bone and holding the fracture together while it heals. Permanent complications with this procedure include the risk of intra-articular sepsis, arthritis and knee stiffness. Patients can expect such hardware to be permanent and should not put weight on the leg without permission from an orthopedic surgeon since this can delay the healing process.

Hip fracture

Main article: 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. The Femur takes the longest to heal out of all the bones in the skeleton.

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