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What is a Syndesmosis?

Shelby Miller
Shelby Miller

A syndesmosis is a type of articulation, or joint, in which two adjacent bones are joined by an interosseous membrane. Along with symphysis joints, syndesmoses are classified as amphiarthrosis joints in that they allow slight movement. Joints of this kind are found at several points in the human body, including the intermediate radioulnar joint, where the radius and ulna meet above the wrist; in the spine between the spinous processes of various adjacent vertebra; and above the ankle joint where the tibia and fibula converge.

To illustrate the structure of a syndesmosis joint, the ankle articulation is a prime example. Located directly above the ankle joint, a synovial hinge joint, the ankle syndesmosis is held together by four ligaments. The anterior inferior tibiofibular ligament (AITFL) crosses in front of the tibia and fibula bones; the posterior inferior tibiofibular ligament (PITFL) and the transverse ligament connect the two bones from behind; and the interosseous ligament runs between the contiguous bony surfaces of the two bones.

Ligament injuries in the ankles are common.
Ligament injuries in the ankles are common.

Due to the lack of flexibility in these joint structures, ligament injuries in these joints are not uncommon, particularly at the wrist and ankle. When the wrist or ankle joint is bent beyond its normal range of motion, a sprain or even a tear in these ligaments can occur. Mild syndesmosis injury may involve the sprain of a single ligament; more severe injuries can involve damage to multiple ligaments at once, or even the separating of the bones at the joint — known as diastasis.

Football players are susceptible to experiencing ankle syndesmosis injuries.
Football players are susceptible to experiencing ankle syndesmosis injuries.

Ankle syndesmosis injury is perhaps the most common and is referred to as a high ankle sprain, as the injury occurs just above, or superior to, the ankle joint. Orthopedists report a frequency of such injuries in athletes, such as football players and snow skiers, where the foot is bent outward at the ankle joint — these injuries are often misdiagnosed as an ankle sprain. The result of such an injury is a joint that is unstable and in some cases may require surgery to repair the ligament damage. Additionally, injuries can be more painful and take longer to heal than regular sprains, and high-impact activities, such as jogging and jumping, should generally be avoided until advised otherwise by a physician.

Discussion Comments

Certlerant

The syndesmosis screw is a metal screw designed to replace the syndesmosis of a human, generally short term. When there is a break in a bone causing issues with the syndesmosis a doctor may use this screw to hold the parts together while the bone heals.

It is a disturbing thought, the idea of having a surgery that fuses body parts together with a screw, but the procedure is very common.

When the bones have healed and it is safe, the screw can usually be removed.

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    • Ligament injuries in the ankles are common.
      By: Von Schonertagen
      Ligament injuries in the ankles are common.
    • Football players are susceptible to experiencing ankle syndesmosis injuries.
      By: Brocreative
      Football players are susceptible to experiencing ankle syndesmosis injuries.
    • Skiers may be susceptible to experiencing ankle syndesmosis injuries.
      By: Marina Karkalicheva
      Skiers may be susceptible to experiencing ankle syndesmosis injuries.
    • People who have experienced syndesmosis injuries should avoid activities such as jogging.
      By: Gorilla
      People who have experienced syndesmosis injuries should avoid activities such as jogging.
    • Ligament injuries in syndesmosis joints like the wrist are common.
      By: Shakzu
      Ligament injuries in syndesmosis joints like the wrist are common.