What is Sesamoiditis?

There are 2 sesamoid bones beneath your big toe.  These 2 bones function as a lever so that you can generate more force when you push off your toe as in running.  The sesamoids are attached to the flexor tendons in your foot.  These tendons transmit force which allows you to propel forward during activities like running or standing up on your toes as in ballet.  For these reasons sesamoiditis is common in runners and dancers.  In its truest sense sesamoiditis is inflammation of either the medial sesamoid or lateral sesamoid bone(s).   However, it is important to note that sesamoiditis is often misdiagnosed and in fact the patient is suffering from other conditions.

What are some conditions that are confused with sesamoiditis?

Sesamoid Stress Fracture – Because the sesamoids are weight bearing bones and can suffer from repetitive loading and impact they are susceptible to trauma. Stress fractures occur when the bone weakens from the inside out.  This type of injury requires non-weight bearing and rest from loading and impact to heal

Sesamoid Fracture – Fracture can occur from prolonged exposure to stress on the bone or a sudden moment in time where the sesamoid is exposed to more force than it can handle.  Sesamoid fractures are often misdiagnosed when a patient has a bipartite sesamoid bone.  A bipartite sesamoid is a normal variant where a person essentially has three sesamoids instead of two.


Sesamoid Bone Marrow Edema Bone marrow edema is also known as a pre-stress fracture.  This occurs when the sesamoid(s) are exposed to repeated stress.  Instead of fracturing swelling occurs inside the bone cavity and causes the marrow to swell.  This creates pressure and pain on the sesamoids.  This injury is treated similarly to stress fracture for effective healing.

Turf Toe, Big Toe Joint Sprain, 1st MTP Sprain – The first metatarsal-phalangeal joint is a fancy way of naming your 1st big toe joint in Latin.  For short it is referred to as the 1st MTP joint.  If exposed to repetitive, forceful bending the ligaments beneath the big toe joint can sprain or tear.  In football and soccer this injury is referred to as “Turf Toe”.  This injury needs to be immobilized to be treated effectively or it can worsen resulting in a more severe ligament tear.

Metatarsalgia, Plantar Plate SprainMetatarsalgia is a catch all term to describe pain in the metatarsal region which the sesamoid qualifies.  However, metatarsalgia simply means “pain in the ball of the foot” in Latin.  It is not a legitimate diagnosis.  In addition, it is commonly used to refer to pain in the 2nd-4th metatarsals and is the res