Os Trigonum Syndrome

At the back of the ankle, there is a tiny additional bone called an Os Trigonum.

The common symptoms of Os Trigonum Syndrome include ankle discomfort and stiffness, which are frequently made worse by toe pointing.

You might feel a little lump behind the ankle that is frequently sensitive to the touch, and there is frequent swelling.

Only about 5–10% of people develop additional bone, making it a somewhat uncommon occurrence. It frequently goes overlooked and poses no issues.

Os Trigonum Syndrome, however, can manifest in athletes who play sports that frequently require ankle bendings, such as ballet dancers and football players, or when an ankle injury is present.

Os Trigonum, what is it?

A small, auxiliary bone called an Os Trigonum develops towards the back of the foot, behind the ankle joint.

The ankle joint includes the talus bone. A little bone fragment called the Os Trigonum grows right behind the talus as it expands during childhood. This often occurs between the ages of seven and eleven.

The lateral tubercle, a little lump on the talus, is formed by this small bone, which is originally connected to the talus by fibrous processes. Within one to three years, this small bone often fuses, or connects, with the talus bone.

But occasionally, it dissociates from the talus and continues to exist as a separate bone. It usually has a diameter of less than one centimeter and can take the form of a circle, an oval, or a triangle.

Normally, there are no problems if the bone does not fuse, but if the ankle is injured once or frequently, Os Trigonum Syndrome may appear. It is also known as impingement of the posterior talus.

The Os Trigonum Syndrome: What Causes It?

Os Trigonum Syndrome may manifest if the unfused bone is present in addition to an ankle injury. It is typically brought on by one of the following:

Ballet dancers who frequently plantarflex while e are more susceptible to Os Trigonum Syndrome.

From repetitive plantarflexion, overuse (foot pointing downwards). Runners, football players, and ballet dancers are frequently afflicted by Os Trigonum Syndrome.

Trauma: an ankle injury caused by severe plantar flexion of the foot

A "nutcracker injury" is when the unfused Os Trigonum bone and surrounding soft tissues become jammed between the ankle and heel bones. Either of these can result in this (tibia, talus and calcaneus). Pain and stiffness result from the inflammation of the soft tissues.

Typical Symptoms

Os Trigonum syndrome most frequently manifests as:

  • Ankle pain on the back of the foot is typical. The discomfort usually worsens with plantarflexion (pointing the toes) during the push-off stage of walking and subsides with rest.
  • Tenderness: The ankle's rear and outside side are typically sensitive to touch.
  • Swelling: Swelling may occur as a result of soft tissue inflammation.
  • You might occasionally be able to feel a little, firm lump close to the Achilles tendon. This bone is not fused.
  • Normally, just one foot is afflicted, but around one-third of the time, both feet are.

How is it identified?

Your symptoms and indicators will lead your doctor to believe you have this ailment. As the symptoms are frequently comparable to other disorders including Achilles tendonitis, peroneal tendonitis, tarsal tunnel syndrome, or a fracture, they may want to confirm the diagnosis with an x-ray or MRI scan.

It is crucial to receive an accurate diagnosis in order to receive the best possible care. This is reason why experts recommend wearing DrLuigi medical shoes. Quality footwear prevents the occurrence of foot diseases and relieves pain.


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