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Prairie Path Foot & Ankle Clinic

What are those two things on my x-ray??

The foot is comprised of 28 bones.  Two of them are what are called 'sesamoids.'  These bones are named for their shape, which resembles a sesame seed.  Everyone has two of these bones in each foot and sometimes one or both can naturally occur in two pieces (called bipartite).  The term sesamoid refers to a bone which serves as an insertion point for a tendon.  Your knee cap (patella) is also a sesamoid bone, serving as an attachment for your quadriceps tendon. 

In your foot, the sesamoid bones serve as insertion points for the tendon which helps you curl your big toe down (plantarflexion).  These bones articulate with the metatarsal head, sitting underneath the big toe joint.  These bones normally are present without any way to notice that they are there at all.  However, in certain circumstances and with certain activities, these little bones can be the source of a lot of pain!  People who are active an on the balls of their feet a lot can suffer from injury or overuse of the sesamoid bones.  The generic term for this condition is sesamoiditis - which simply states that there is inflammation (or irritation) of the sesamoid bones.

Dancers and catchers are especially susceptible to sesamoid injury from having constant or repetitive pressure placed on these sesamoid bones.  Pressure on these bones can cause a bone contusion (or bruise) and if this injury is sustained and the area is not rested, this can lead to a very painful condition called avascular necrosis.  In avascular necrosis, the bone is traumatized to the point that the blood supply is disrupted and the bone itself can die.  When this condition occurs, treatment includes taking pressure off of this painful area - and in some cases surgery to remove the painful bone.  Runners can also experience sesamoiditis, depending upon their running gait and style. 

If treated at its onset, the condition of sesamoiditis can resolve with some simple rest, padding and offloading and anti-inflammatories.  The longer you wait to treat sesamoid pain, the more difficult it is to get rid of.  Traumatic injuries of the sesamoid bones can also occur in the form of fractures.  These fractures often are difficult to heal, as the sesamoid bones do not have a very reliable and well-intact blood supply.  If the fractured sesamoid does not heal, it can be painful chronically.  However, in some instances, allowing rest after this injury can help to prevent chronic pain.

The sesamoid bones can also be affected by arthritis.  The great toe joint can very commonly become arthritic, as we use this joint with every step we take every single day.  Depending upon the alignment of joints and flexibility in certain parts of the foot, some people develop arthritis in this joint as early as in their 30's or 40's.  When motion in the great toe joint is restricted, the sesamoid bones are not allowed to freely glide along the metatarsal bone and this can cause irritation and arthritis of the sesamoid bones.  In extreme cases, the sesamoid bones can fuse to the metatarsal head and become an irritating pressure point while walking.

If you have pain in the ball of the foot near the great toe joint, you may be suffering from sesamoiditis.  To treat this quickly and prevent it from coming back, come see one of the doctors at Prarie Path Foot and Ankle Clinic today!  We can determine the source of your pain and treat you quickly and with compassion and care - and we can determine the reason this pain may have started and help to prevent it from being a regular occurence.  Call today!