Fibula
Nicole Wendler holds a PhD in biology in the field of oncology and immunology. As a medical editor, author and proofreader, she works for various publishers, for whom she presents complex and extensive medical issues in a simple, concise and logical manner.
More about the experts All content is checked by medical journalists.Fibula is the Latin name for the fibula. The relatively thin and elastic bone begins below the knee joint and ends at the ankle. Together with the shin bone (tibia), the fibula forms the bony lower leg. Different structures ensure a close connection between the two bones and greater stability. Read everything you need to know about the fibula!
What is the fibula?
Fibula is the medical term for the fibula. This forms the bony lower leg with the shin (tibia). The relatively elastic tubular bone is about the same length as the shin, but appears much more delicate and slimmer in comparison. At its upper end, laterally below the knee joint, the so-called fibular head (caput fibulae) can easily be felt. Despite its proximity to the knee, the fibula - unlike the tibia - is not involved in the knee joint. However, ligaments, tendons and muscles that are important for the movement and stability of the knee joint attach to the fibula. The shaft of the fibula is thin and has three sharp edges. At the lower end, the bone widens and merges into the easily palpable outer ankle in the foot area.
What is the function of the fibula?
Most of the weight in the lower leg is carried by the shin. The fibula only takes on a small part of the load, but is still irreplaceable: The thin bone stabilizes the lower leg and at its lower end, together with the shin and ankle bone, forms the upper ankle joint. In addition, the fibula supports cushioning when jumping and serves as a starting point for the strong fibula muscles as well as tendons and ligaments.
Where is the fibula located?
The fibula sits next to the shin on the outside of the lower leg. The thin bone is connected to the tibia in a total of three places: At the upper end there is a tibia-fibula joint (articulatio tibiofibularis), which is barely movable due to tight ligaments, which fixes the head of the fibula to the shinbone.
In the ankle area, at the connection between the lower leg and foot, the inner ankle (part of the tibia) and the outer ankle (part of the fibula) form a fork (malleolar fork) in which the ankle bone (talus) is articulated. This hinge joint is known as the ankle joint. In particular, the anterior (anterior tibiofibular ligament) and the posterior tibiofibular ligament (posterior tibiofibular ligament) provide additional stability at this point.
In the shaft area, the tibia and fibula are closely connected by a strong interbone membrane, the interosseous membrane. This syndesmosis band, made of connective tissue, stabilizes the lower leg and ankle.
Numerous muscles, tendons and ligaments attach to the fibula or the head of the fibula. These include the long fibula muscle (peronaeus longus) and part of the thigh muscles (biceps femoris).
What problems can the fibula cause?
Fibula discomfort can have various causes. Often it is not the bone itself that is the cause, but rather the complaints originate from adjacent structures such as muscles, tendons and ligaments.
Muscular tension, cramps and strains tend to occur in the calves in particular. In sports accidents, the syndesmosis ligament or ligaments in the ankle area are often overstretched or torn. If a ligament is injured, this can be associated with a bony tear. As a result of falls, the rigid tibia-fibula joint can also cause problems.
Most severe pain is caused by a fracture. Depending on where the fibula breaks, it is one:
- Fibular head fracture or a
- Fibular shaft fracture.
In the case of a fibular shaft fracture, the shaft of the tibia is usually also broken at the same time. Doctors then speak of a lower leg fracture overall. In the case of a sole fracture of the fibula, the more stable tibia literally ensures the natural splinting of the fibula. A relatively common fracture involving the fibula is the ankle fracture.
Occasionally, benign or malignant tumors form on the fibula. They can put pressure on nerves and cause paralysis. These include, among others:
- Benign neoplasms: ganglion (overbone, spinner ganglion), enchondroma (cartilage tumor)
- Malignant bone changes: osteosarcoma, Ewing sarcoma
In rare cases, children are born with a malformation of the fibula. Examples are:
- Fibular aplasia: the fibula is missing.
- Fibular Hypoplasia: The fibula is not fully developed.
- Femur-Fibula-Ulna-Syndrome (FFU-Syndrome): Malformations of the femur (thigh bone), the fibula and / or the ulna (ulna).
