In short
The sesamoids are two pea-sized bones under the big toe joint, inside the tendon that bends the toe. Sesamoiditis is painful irritation of these bones and the surrounding tissue from overload, and similar pain can come from a sesamoid stress fracture or arthritis. It causes pain under the ball of the foot beneath the big toe, worse when pushing off. Offloading pads and insoles, stiff-soled shoes and activity changes help most people; surgery is rarely needed.
What are the sesamoids?
Two small bones sit under the head of the first metatarsal, within the flexor hallucis brevis tendon. They act like pulleys, increasing the power of the big toe, and take a large share of body weight when you push off.
What causes sesamoid pain?
- Sesamoiditis: irritation and inflammation from repetitive loading
- Stress fractures or fractures after a fall or landing
- Avascular necrosis, where part of the bone loses its blood supply
- Arthritis between the sesamoids and the metatarsal
- High heels, high-impact sport (running, dancing, court sports) and a high-arched foot
- A bipartite sesamoid (in two pieces from birth), which can be mistaken for a fracture
Symptoms
- Pain under the big toe joint, worse when pushing off, on tiptoe or in heels
- Swelling or tenderness under the ball of the foot
- Pain bending the big toe upwards
Treatment without surgery
- Offloading pads (a “dancer’s pad”) and insoles that take pressure off the sesamoids
- Stiff-soled or rocker shoes, and avoiding high heels
- Taping to limit big toe movement
- Rest from high-impact activity, or a walking boot for more severe pain or stress fractures
- Pain relief, and sometimes an image-guided injection
Surgery
For pain that persists despite several months of treatment:
- Partial or complete removal of a sesamoid (sesamoidectomy)
- Bone grafting or fixation of a sesamoid fracture that has not healed
Common questions
How is sesamoiditis diagnosed?
From the pattern of pain and examination, with X-rays including a special view of the sesamoids. MRI or CT can show a stress fracture, avascular necrosis or arthritis.
Will I need an operation?
Rarely. Most people settle with offloading over a few months. Surgery to remove part or all of a sesamoid, or to fix a fracture that will not heal, is reserved for persistent pain.
Talk it through with a specialist
Consultations at Spire Liverpool, Salford and the Isle of Man. New patients £250.
Consultant Foot and Ankle Surgeon, MB BCh, PhD, FRCS (Tr&Orth), FRCS (Glasg), SFHEA, FFSTEd. GMC 6074953. Hunterian Professor, Royal College of Surgeons of England.
Page last reviewed 25 October 2026. This information is general and does not replace an assessment.
Prof Mason's published research on this topic
Peer-reviewed papers by Prof Mason and his colleagues. Links open the paper or its PubMed record.
- Mason LW, Digby G, Tanaka H. Complete agenesis of both metatarsophalangeal sesamoids with contralateral agenesis of fibular sesamoid associated with hallux valgus. Foot and Ankle Online Journal, 2012.