Sinus Tarsi Implants (Stents)
The Doctors at Michigan Podiatry have been providing this type of minimally invasive procedure for over 20 years. The insertion of this titanium stent into the sinus tarsi helps stabilize the foot joints and relieves pain associated with flexible flat foot conditions.
A few basic tips about your misaligned feet.
- Misaligned feet:
Misaligned feet are the result of the ankle bone sliding off of the heel bone causing the small, naturally occurring space in between (called the Sinus Tarsi) to collapse. Standing on misaligned feet causes a chain reaction of misalignment throughout the body. Strain is placed on your ankles, knees, hips, and back as the body tries to compensate.
- Misaligned feet statistics:
Across all ages, almost half of all people have misaligned feet. Although relatively common, it can be misdiagnosed oftentimes due to unrelated symptoms like pain in the back, knee, and hip.
- Stents Can Help
Procedures to insert stents into the Sinus Tarsi Implants are FDA cleared and shown to be a proven solution to misaligned feet. These implants can reduce, or even eliminate, your symptoms and improve your quality of life. The doctors at Michigan Podiatry Foot & Ankle Surgeons can help you decide what type of Sinus Tarsi Stent is best for your condition.
“A Sinus Tarsi Implant (Stent) is typically a titanium spacer-implant that is placed into the naturally occurring space (Sinus Tarsi) between the ankle and heel bones.”
What is the heel bone?
One of the toughest bones of the body, the heel bone is designed to take the forces generated by the body on the ground below. The heel bone has 3 different joint surfaces that come into contact with the ankle bone.
What is the ankle bone?
Separating the leg and the foot, the ankle bone is one of the most complex bones of the body. It is responsible for directing the forces from the body above on the back and front surfaces of the heel bone. The joint surfaces of the ankle bone should always be in constant alignment with the matching surfaces on the heel bone.
What is the function of the sinus tarsi space?
Marking a dividing line between the transfer of forces onto the back of the heel and into the front of the foot, the sinus tarsi space has a very important function. Supporting more than ½ of the force from the ankle bone, the joint surface on the back of the heel is the largest of the three.
What do Sinus Tarsi Implants (Stents) Fix?
Simply stated, Sinus Tarsi Stents fix ankle bone instability, an unnatural condition in which the ankle bone (talus) has lost its stability and alignment on the heel bone.
However, what these implants actually does is much more complex in that it deals with the many secondary orthopedic deformities that are caused by the partial dislocation of the ankle bone.
When the ankle bone falls forward and downward it shifts the forces that should be acting on the back of the heel bone to the inner arch. This shift in alignment causes the joints to lose their stability which causes the creation of excessive force on the weakened joints within not only the feet but also the knees, hips, and spine.
This excessive force ultimately places strain on the ligaments within the joints causing the body to react with muscle contractions and tendons attempting to stabilize the weakened joints.
Age requirements
In order to be considered for Sinus Tarsi Implants, a patient must be at least three years old.
When we are born our bones remain soft while they are growing and shaping. The walls of the sinus tarsi chamber do not become fully hardened (ossified) until three years of age. Waiting until a patient has reached age three guarantees that the sinus tarsi space is fully transformed from the “soft” bone into the “hard” bone.
However, most surgeons will wait until the child is several years older. With that being said, there is no cutoff age as long as the ankle bone can be repositioned on the heel bone and the sinus tarsi space is open.
The oldest person on record to have a Sinus Tarsi Implant inserted into their foot was 94 years old.
Example of an acceptable amount of the sub-ankle bone motion (left) and excessive motion (right):
