Sesamoiditis: Ball of Foot Pain Under the Big Toe — Causes & Treatment

Medically reviewed by Dr. Tom Biernacki, DPM — Balance Foot & Ankle, Howell & Bloomfield Hills, MI

What Is Sesamoiditis?

Sesamoiditis is inflammation of the sesamoid bones — two small, pea-sized bones embedded within the flexor hallucis brevis tendon beneath the first metatarsophalangeal joint (the ball of the foot at the base of the big toe). The sesamoids function as pulleys, improving the mechanical advantage of the tendons that flex the big toe and bearing significant compressive load during push-off. Sesamoiditis produces pain, tenderness, and sometimes swelling directly under the first metatarsal head — worse with walking, running, and any activity that loads the ball of the foot under the big toe. In our Howell and Bloomfield Hills clinics, sesamoiditis is a frequently seen cause of forefoot pain, particularly in dancers, runners, high heel wearers, and patients who bear unusually high forefoot load due to flat feet or metatarsal protrusion patterns.

Causes and Risk Factors

Sesamoiditis develops from repetitive overload of the sesamoid complex. Activities with highest risk include ballet and dance (demi-pointe and pointe positions concentrate enormous force on the sesamoids), long-distance running and sprinting, high-heel shoe wear (shifts weight distribution anteriorly, dramatically increasing sesamoid load), and occupations requiring prolonged forefoot weight-bearing. Structural risk factors include a plantarflexed first ray (the first metatarsal drops lower than the others, taking disproportionate force), high arch (pes cavus — concentrates forefoot load), and flat feet with hallux valgus (changes sesamoid tracking under the metatarsal head). Acute sesamoid fracture from a single impact (landing from a jump, stubbing the toe) produces a sudden-onset sesamoiditis presentation that requires fracture evaluation.

Sesamoiditis vs. Sesamoid Fracture: A Critical Distinction

The distinction matters significantly for management. Sesamoiditis (inflammation without fracture) is managed conservatively over 4–8 weeks with excellent outcomes. A sesamoid fracture requires strict non-weight-bearing or immobilization for 6–8 weeks and sometimes surgery for displaced fractures or bipartite sesamoid fractures that fail to heal. Bipartite sesamoid (a normal variant where the sesamoid is naturally in two parts, present in 10–30% of people) can be mistaken for a fracture on X-ray — the differentiating feature is that bipartite sesamoids have smooth, well-corticated edges while fracture edges are irregular and jagged. MRI is the gold standard when X-ray findings are uncertain; bone marrow edema on MRI confirms active stress injury requiring protection.

Symptoms and Physical Exam Findings

Sesamoiditis presents as focal pain and tenderness directly under the first metatarsal head, reproduced by direct palpation over the sesamoid bones and by passive dorsiflexion (upward bending) of the big toe, which increases tension on the sesamoid complex. Swelling may be visible under the first MTP joint in acute cases. The pain is typically dull during rest and increases sharply with any push-off activity — the toe-off phase of gait (when the heel lifts and the big toe joint bears full body weight) is characteristically the most painful moment. Patients often shift weight to the outer foot to avoid loading the sesamoids, producing secondary metatarsalgia of the lesser toes or lateral heel soreness.

Non-Surgical Treatment Protocol

The dancer’s pad is the cornerstone of sesamoiditis treatment — a felt or silicone pad with a cutout (aperture) under the first metatarsal head that offloads the sesamoids while maintaining forefoot contact. This is more effective than simply adding cushioning (which compresses the sesamoids rather than redirecting force). Dr. Biernacki pairs the dancer’s pad with a stiff-soled shoe that limits big toe joint motion (rocker-bottom sole shoes are ideal) to reduce the repetitive dorsiflexion loading that aggravates the condition. Custom orthotics with a first ray cutout and metatarsal redistribution bar address the underlying biomechanical factors for long-term management. Activity modification is essential — complete avoidance of barefoot walking, high heels, and impact activities during the acute phase (4–6 weeks minimum).

For persistent sesamoiditis not responding to 6–8 weeks of conservative care, a corticosteroid injection under the first MTP joint reduces inflammation effectively and is well-tolerated. Immobilization in a short leg cast or removable boot for 4–6 weeks can resolve cases that have failed pad modification and activity restriction alone.

Surgical Treatment: When Conservative Care Fails

Surgery for sesamoiditis is rare and reserved for specific situations: sesamoid fracture that has failed to heal after 4–6 months of conservative treatment, avascular necrosis (bone death) of the sesamoid confirmed on MRI, and chronic sesamoiditis with significant functional impairment after complete conservative care over 6+ months. The surgical procedure is sesamoidectomy — removal of one sesamoid (the fibular sesamoid is removed preferentially to preserve hallux valgus stability from the tibial sesamoid). Recovery requires 4–6 weeks non-weight-bearing. Sesamoidectomy has good outcomes but permanently alters first MTP joint mechanics, so it is truly a last resort. In dancers and elite athletes, surgical decision-making involves careful career-impact counseling.

Warning Signs Requiring Urgent Evaluation

See a podiatrist promptly for sesamoid pain if: pain appeared suddenly after a jump or direct blow (possible fracture), you have diabetes or poor circulation (sesamoid avascular necrosis risk), the pain is constant even at rest and not improving with offloading (MRI for avascular necrosis), or you are a dancer or athlete with worsening pain through a training cycle. Sesamoid avascular necrosis, though rare, requires early diagnosis to prevent complete bone collapse.

Sesamoiditis Treatment at Balance Foot & Ankle Michigan

Dr. Tom Biernacki evaluates and treats sesamoiditis at both Howell and Bloomfield Hills offices with in-office X-ray and diagnostic ultrasound. Custom dancer’s pads, orthotics, and cortisone injections are available at your first visit. Same-day appointments for acute forefoot pain. Book online or call (810) 206-1402.

Frequently Asked Questions — Sesamoiditis