What is a sesamoid fracture and how is it treated?
A sesamoid bone is a small bone found on the bottom (plantar surface) of the great toe joint. Each sesamoid bone is about the size of a pinto bean. The sesamoid bones derive their funny name from the Arabic word semsem, meaning sesame seed. (1) Sesamoid bones work in a pair and are named after the bones of the lower leg. The tibial sesamoid is named after the tibia, the large bone of the medial (inside) ankle and the fibular sesamoid is named after the fibula, the lateral (outside) bone of the ankle.
Sesamoid bones function to transfer mechanical load around the great toe joint as the joint moves. As an example, we can compare the sesamoids to the knee cap (patella). The patella transfers the mechanical force of the quadriceps (thigh) muscles around the knee as the knee moves. The sesamoid bones function in a similar manner, transferring the mechanical force of the extensor hallucis brevis tendon around the plantar surface of the great toe joint.
The sesamoid bones are susceptible to injuries that include:
Contributing factors to sesamoid fractures
Sesamoid fractures are found in younger, more active patients who are involved in bi-directional sports such as soccer or basketball. (2,3,4) Fractures of the often larger, tibial sesamoid are more common. Fractures of the fibular sesamoid are considered somewhat rare.
Symptoms of sesamoid fractures
The onset of a sesamoid fracture can be abrupt or insidious. Symptoms of a sesamoid fracture include pain on the plantar aspect of the great toe joint that is directly proportional to activities. For additional information regarding diagnostic modalities for sesamoid fractures, please refer to our knowledge base article on sesamoid fractures.
The majority of sesamoid fractures do not entirely heal, but heal instead with a fibrous union that holds the fracture fragments in place. This fibrous union is often sufficient to enable pain-free walking. In a more active population, the fibrous healing is insufficient and results in chronic pain with activities. The image at left shows a surgical specimen of a fibular sesamoid fracture and the fibrous union between fracture fragments.
Treatment of sesamoid fractures
Treatment of sesamoid fractures includes a period of off-loading of the fracture with pads or inserts. Pads are used to decrease direct load bearing to the sesamoid. Inserts are used to decrease the in-direct load bearing (mechanical pull) of the extensor hallucis brevis muscle.
Sesamoid fracture pads
Dancer’s pads are commonly used in the shoe or directly on the foot to decrease direct loading of the sesamoid. When possible, placing the dancer’s pad on the undersole of an insert is optimal. By doing so, the pad will stay in place and not need to be applied to the skin each day.
Reusable gel dancer’s pads are also helpful in that they can be worn both with, or without a shoe. Self-adherent dancer’s pads are a great way to off-load the sesamoid while walking around the house in just your socks. The amazing thing about these self-adherent pads is that they are reusable. When the sticky adhesive on the pad starts to lose its stickiness, simply wash the pad in soap and water and it becomes sticky again.
The following video shows how to apply a felt metatatsal pad (similar to a dancer's pad) to the bottom of the insole of your shoe.
Insoles and arch supports used to treat sesamoid fractures
In addition to off-loading the sesamoid with a pad, limiting the pull of the tendon (extensor hallucis brevis) attached to the sesamoid is imperative. A Morton’s extension is a semi-rigid to rigid extension built into the insert that limits the range of motion of the great toe. Use of a Morton’s extension significantly decreases tension placed on the sesamoid fracture during walking and running. Examples of inserts with a Morton’s extension include The Turf Toe Plate-molded glass fiber, Turf Toe Plate–flat glass fiber, the Hallux Trainer Sport Insoles and the Hallux Trainer Dress Insole.
Carbon fiber inserts are also commonly used in the treatment of sesamoid fractures. The benefit of the Carbon Fiber Spring Plate and Carbon Fiber Contour Plates is their ease of use in a shoe and the thin design that fits most shoes. The toe spring found in these inserts helps to eliminate flexion and extension of the great toe, thereby eliminating stress on the sesamoid fracture.
Which pad or insert is best for your needs? Be sure to contact our trained sales staff to understand more about how you can treat your sesamoid fracture with these simple to use and inexpensive in-shoe devices.
- van Dam Scott BE, Dye F, Wilbur Westin G. Etymology and the Orthopaedic Surgeon: Onomasticon (Vocabulary) Iowa Orthop J. 1991;11:84–90.
- Hillier JC, Peace K, Hulme A, Healy JC. Pictorial review: MRI features of foot and ankle injuries in ballet dancers. Br J Radiol. 2004;77:532–537.
- Karasick D, Schweitzer ME. Disorders of the hallux sesamoid complex: MR features. Skeletal Radiol. 1998;27:411–418.
- McBryde AM, Anderson RB. Sesamoid foot problems in the athlete. Clin Sports Med. 1988;7:51–60.