Sesamoid Bones: Tiny Bones That Cause Big Problems

Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Hills, MI. Last updated April 2026.

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The Sesamoids: Small Bones, Big Impact

Most people have never heard of the sesamoid bones — two small, pea-sized bones embedded within the flexor hallucis brevis tendon beneath the first metatarsal head (the big toe joint). Despite their small size, the sesamoids play an outsized role in foot function and are a surprising source of significant pain and disability when injured.

At Balance Foot & Ankle in Howell and Bloomfield Township, Michigan, we diagnose and treat the full spectrum of sesamoid pathology, from simple sesamoiditis to complex sesamoid fractures requiring surgical management.

What Do the Sesamoids Do?

The sesamoid bones serve several important functions. They act as a pulley for the flexor hallucis brevis tendon, increasing its mechanical advantage when plantarflexing (pushing down) the big toe. They absorb and distribute the substantial compressive loads placed on the first metatarsal head — particularly during the push-off phase of gait and during activities like running, jumping, and dancing. They protect the tendon from excessive friction. The medial (tibial) sesamoid bears more load than the lateral (fibular) sesamoid and is more commonly injured as a result.

Sesamoiditis

Sesamoiditis refers to inflammation of the sesamoid bones or their surrounding tendons and bursae without fracture. It develops from overuse — particularly in runners, dancers, and athletes who perform repetitive forefoot push-off. High-arched feet with a plantarflexed first metatarsal concentrate excessive load on the sesamoids. Sesamoiditis presents as localized pain and tenderness directly beneath the first MTP joint that worsens with push-off and wearing heeled shoes. Initial treatment: sesamoid offloading pads (a U-shaped cutout takes direct pressure off the sesamoids), stiff-soled footwear, activity modification, and anti-inflammatory measures. Most cases resolve with 4-8 weeks of consistent offloading.

Sesamoid Stress Fractures

Stress fractures of the sesamoids are among the most difficult foot injuries to manage. The medial sesamoid is more commonly fractured. Distinguishing a stress fracture from a bipartite sesamoid — a normal anatomical variant where the sesamoid has two parts separated by a fibrous junction — requires clinical correlation and MRI or bone scan, since X-rays alone cannot reliably differentiate the two. Sesamoid stress fractures require prolonged, strict offloading — typically 8-12 weeks in a non-weight-bearing boot or cast — to allow healing. Non-union (failure to heal) is common, particularly in athletes who continue loading during healing.

Avascular Necrosis of the Sesamoid

Like other small bones with limited blood supply, sesamoids are vulnerable to avascular necrosis (bone death from disrupted blood flow) following fracture or repetitive trauma. AVN of the sesamoid produces chronic, refractory pain that doesn’t respond to standard treatment. MRI demonstrates the characteristic signal changes of AVN. Persistent pain from AVN may ultimately require surgical sesamoidectomy (removal of the affected sesamoid).

Surgical Treatment

Sesamoidectomy — surgical removal of the problematic sesamoid — is reserved for chronic, painful sesamoid conditions that have failed prolonged conservative management. Results are generally good, though it requires careful surgical technique to avoid destabilizing the first MTP joint. Partial sesamoidectomy preserves some of the sesamoid’s function. Most patients return to normal activity within 3-4 months of sesamoidectomy.

Foot or Ankle Pain? We Can Help.

Balance Foot & Ankle — Howell & Bloomfield Township, MI

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Sesamoid Pain Under Your Big Toe? Expert Treatment Available

The sesamoid bones under the big toe are tiny but can cause significant pain from fractures, inflammation, and avascular necrosis. Dr. Tom Biernacki diagnoses sesamoid problems accurately and provides conservative and surgical solutions.

Learn About Sesamoid Treatment | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Cohen BE. Hallux sesamoid disorders. Foot and Ankle Clinics. 2009;14(1):91-104.
2. Boike A, et al. Sesamoid disorders of the first metatarsophalangeal joint. Clinics in Podiatric Medicine and Surgery. 2011;28(2):269-285.
3. Sims AL, Kurup HV. Painful sesamoid of the great toe. World Journal of Orthopedics. 2014;5(2):146-150.

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Dr. Tom Biernacki, DPM

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Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.