Sesamoiditis: Causes, Diagnosis & Treatment | Podiatrist Howell MI

What Are the Sesamoid Bones?

If you have ever felt a tender, pea-sized area of pain directly under the ball of your foot at the base of the big toe, you have encountered the sesamoids. The sesamoid bones are two small, oval bones embedded within the flexor hallucis brevis tendon — one medial (tibial sesamoid) and one lateral (fibular sesamoid) — sitting just beneath the first metatarsal head. Unlike most bones, which articulate with other bones at synovial joints, sesamoids are embedded in tendons and serve a mechanical purpose: they act as pulleys, increasing the mechanical advantage of the flexor hallucis brevis and absorbing up to three times body weight during the push-off phase of gait.

This high mechanical load makes the sesamoids disproportionately vulnerable to cumulative stress. In our clinic at Balance Foot & Ankle, we see sesamoid injuries most commonly in dancers (the “ballet dancer’s heel”), distance runners, basketball players, and anyone who spends prolonged time in high heels or on hard surfaces. The medial (tibial) sesamoid bears more load and is injured far more frequently than the lateral.

Types of Sesamoid Injury

Not all sesamoid pain is the same. Distinguishing between these entities changes management significantly.

• Sesamoiditis (inflammation): Cumulative overuse producing peritendinous inflammation around the sesamoids without structural bone damage. The most common presentation. Responds well to conservative offloading and activity modification.
• Acute sesamoid fracture: A traumatic break from a sudden hyperextension injury (landing from a jump, stubbing the toe) or a direct crushing force. Identified on X-ray; MRI confirms non-displaced fractures invisible on plain film.
• Stress fracture: Gradual accumulation of microdamage in runners or dancers — a progressive rather than sudden onset. Bone edema on MRI is the key diagnostic finding when plain X-rays are normal.
• Bipartite sesamoid: A developmental variant in which the sesamoid failed to fuse during growth, producing two segments with a smooth, corticated interface. Present in roughly 10% of the population, usually bilateral and asymptomatic. Distinguishing a bipartite sesamoid from an acute fracture is critical — bipartite edges are rounded and smooth; fracture edges are irregular and sharp. Bilateral X-rays help (a contralateral bipartite sesamoid confirms the variant).
• Avascular necrosis (AVN): Loss of blood supply to the sesamoid producing progressive bone death. Rare, but seen in patients with diabetes, chronic steroid use, or following prolonged immobilization. MRI shows dark signal on T1 with surrounding edema on T2. May ultimately require surgical excision.
• Chondromalacia: Softening and degeneration of the sesamoid’s cartilaginous articulating surface — essentially arthritis of the sesamoid-metatarsal articulation. Produces chronic, deep aching rather than the sharp pain of acute injury.

Symptoms and Physical Examination

Sesamoiditis produces a characteristic symptom pattern: plantar forefoot pain at the first MTP joint that is aggravated by push-off (the toe-off phase of gait), going up stairs, wearing high heels, or walking barefoot on hard floors. The pain is localized — patients can often point to the exact spot — and is reproduced by palpating directly over the affected sesamoid on the plantar surface of the foot. Dorsiflexion of the great toe (loading the flexor hallucis brevis) reproduces the pain and distinguishes sesamoiditis from hallux rigidus (dorsal MTP pain) and gout (diffuse MTP swelling and warmth).

In acute fractures, swelling and bruising under the first metatarsal head may be visible. In chronic sesamoiditis, the examination is often surprisingly benign except for the point tenderness — a mismatch between reported pain severity and examination findings is characteristic.

Diagnosis

Standard weight-bearing foot X-rays in AP, lateral, and axial (sesamoid) views are the starting point. The axial sesamoid view is critical — it visualizes the sesamoid-metatarsal joint directly and is frequently omitted in non-specialist settings, leading to missed diagnoses. MRI is obtained for any sesamoid injury with normal X-rays or when stress fracture, AVN, or chondromalacia needs confirmation. Bone scan with SPECT imaging remains a sensitive alternative when MRI is unavailable. Ultrasound is useful for peritendinous fluid and soft-tissue swelling but cannot assess intrinsic bone pathology.

Differential diagnosis includes: hallux rigidus (dorsal, not plantar, MTP pain; stiffness), gout (acute onset, exquisitely tender diffuse MTP inflammation, responds to colchicine), plantar plate tear (pain at second MTP, not first), and bursitis of the first MTP (more diffuse, medial swelling). Getting sesamoiditis distinguished from a bipartite sesamoid is the single most important diagnostic question — unnecessary surgery on a bipartite variant can produce severe morbidity.

Treatment

Treatment is matched to the type and severity of the sesamoid injury. The overarching principle is mechanical offloading — reducing the compressive and tensile forces transmitted through the sesamoid-metatarsal complex during gait.

• Sesamoid offloading orthotic: The cornerstone of conservative management. A custom or semi-custom orthotic with a sesamoid cutout (a relief cavity under the medial sesamoid) removes direct pressure from the injured bone with every step. This single intervention often provides dramatic immediate relief and should be initiated at the first visit.
• Dancer’s pad / J-pad: An adhesive felt or foam padding applied directly to the plantar forefoot, shaped to cushion around (not over) the sesamoid. Effective for acute pain management while an orthotic is being fabricated.
• Footwear modification: Flat, stiff-soled shoes (not high heels, not minimalist barefoot shoes) that minimize push-off dorsiflexion during gait. Rocker-bottom soles are ideal for acute sesamoiditis.
• Activity modification: Eliminating the provocative activity (dance, running, jumping) during the acute healing phase. Cross-training with swimming or cycling maintains fitness without sesamoid loading.
• Immobilization: For acute fractures or severe sesamoiditis, a short-leg walking boot or non-weight-bearing cast for 4–8 weeks reduces mechanical stress to allow bone healing. Stress fractures typically require 6–8 weeks of immobilization.
• Corticosteroid injection: An ultrasound-guided injection into the peritendinous sesamoid region reduces inflammation and provides pain relief for 4–12 weeks. We limit to two injections — aggressive repeated injections can lead to soft-tissue atrophy under the first metatarsal head.
• Physical therapy: Once acute pain is controlled, intrinsic foot muscle strengthening and flexor hallucis longus stretching restore the dynamic support system around the first MTP joint.
• Surgical excision (rare): Sesamoidectomy — removal of the affected sesamoid — is reserved for AVN, nonunion of an acute fracture after prolonged conservative care, or disabling chondromalacia that has failed all conservative measures. The medial sesamoid is excised more commonly than the lateral; excision of both sesamoids simultaneously is contraindicated due to risk of hallux valgus or cock-up toe deformity.

The Most Common Mistake We See

The most common mistake we see with sesamoid injuries is failure to obtain an axial sesamoid X-ray view. Standard AP and lateral foot X-rays frequently miss sesamoid fractures and chondromalacia. Patients arrive having been told their foot X-ray was “normal” when a sesamoid-specific view would have revealed the injury clearly. The second most common mistake is treating a bipartite sesamoid as an acute fracture — leading to unnecessary immobilization or, worse, unwarranted surgical excision. Every sesamoid presentation needs a proper axial view and, when the X-ray is equivocal, an MRI.

Frequently Asked Questions

How long does sesamoiditis take to heal?
Pure sesamoiditis (no fracture) with prompt initiation of offloading orthotics and activity modification typically resolves in 4–8 weeks. Acute stress fractures require 6–10 weeks of immobilization for bone healing. AVN has a more variable and often prolonged course that may ultimately require surgery.

Can I walk with sesamoiditis?
Walking is generally permissible with appropriate offloading — a sesamoid relief orthotic and supportive footwear reduce pain to manageable levels for most patients. Running and high-impact activity should be stopped until the injury has healed.

Is sesamoid surgery common?
No. The vast majority of sesamoid injuries — including many fractures — resolve with conservative management. Surgery is reserved for a small subset with confirmed AVN, fracture nonunion, or disabling chondromalacia that has genuinely failed all non-surgical options.

The Bottom Line

Sesamoiditis is an overuse injury of two small but mechanically essential bones under the first metatarsal head. Most cases respond well to a sesamoid offloading orthotic, footwear modification, and activity adjustment. The critical steps are obtaining proper X-ray views (including the axial sesamoid view), distinguishing a bipartite variant from a fracture, and using MRI to confirm stress fractures and AVN that plain X-rays miss. Come in early — sesamoid injuries caught and offloaded promptly heal far faster than those that have been walked on aggressively for months.

Related reading: sesamoiditis taping technique · broken big toe · podiatrist-recommended metatarsal pads

Related reading: sesamoiditis taping technique · broken big toe · podiatrist-recommended metatarsal pads

Suspect a bruise on the ball of your foot? See our guide: Stone Bruise on the Foot — Michigan podiatrist explains healing timelines and the best at-home and clinical treatment options.

For a complete clinical overview: Foot & Ankle Pain — Complete Guide — all common foot conditions explained by a board-certified podiatrist

Related Sesamoid Resources

• Sesamoiditis Taping Technique — KT tape and rigid taping methods that offload the sesamoids during activity.
• Best Shoes for Top-of-Foot Pain — low-drop, rocker-bottom shoes that reduce forefoot loading for sesamoiditis patients.

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