The sesamoids — two small bones beneath the first metatarsal head — are among the most vulnerable structures in the athletic foot. In dancers, gymnasts, runners, and court sport athletes who repeatedly load the forefoot in a toe-off or demi-pointe position, sesamoid pathology is both common and notoriously difficult to treat. Understanding the full spectrum of sesamoid conditions helps athletes and their providers set realistic expectations and choose the right treatment path.

Why Athletes Are Uniquely Vulnerable

Athletes subject their sesamoids to forces far exceeding those of ordinary walking. During a ballet relevé, the full body weight passes through the sesamoids at the first metatarsophalangeal joint. A basketball player landing from a jump loads the sesamoids at 3–5 times body weight. A distance runner cumulates thousands of these loading cycles per training session. The medial (tibial) sesamoid bears more load than the lateral (fibular) sesamoid and is injured approximately twice as often.

Contributing factors in athletes: tight gastrocnemius-soleus complex (increasing forefoot loading by reducing heel contact time), hallux valgus deformity (shifting sesamoid loading pattern), hard training surfaces (eliminating impact absorption), and inadequate footwear or dance floor surface for the activity.

The Sesamoid Pathology Spectrum

Sesamoiditis is the inflammatory end of the spectrum — diffuse pain and tenderness around the sesamoid-tendon complex without discrete fracture or avascular changes. MRI may be normal or show peritendinous edema. It is an overuse injury that responds to load reduction and mechanical offloading but is often undertreated because athletes try to train through it, converting an early-stage condition into a more serious one.

Stress fractures of the sesamoid present with increasingly severe plantar first metatarsal pain that is reproduced by direct plantar compression and passive great toe extension. Initial X-rays are often negative; bone marrow edema on MRI confirms the diagnosis before radiographic changes appear. The distinction from bipartite sesamoid (a developmental variant) is critical — bipartite sesamoids have smooth corticated margins without marrow edema on MRI.

Avascular necrosis (AVN) of the sesamoid represents the most severe end, occurring after fracture disrupts blood supply or after repeated corticosteroid injections. T1 MRI signal loss within the sesamoid (dark where marrow should be bright) indicates AVN. AVN can ultimately require sesamoidectomy if conservative measures fail.

Conservative Treatment Protocol

The cardinal rule of sesamoid treatment: reduce load on the first metatarsal head. Dancer’s padding — a donut-shaped offloading pad with the hole positioned over the sesamoid — is the most effective orthotic intervention and should be placed in all footwear and pointe shoes. Custom orthotics with sesamoid cutout and first ray elevation (1st metatarsal head relief) redistribute load to the lesser metatarsals. Carbon fiber insoles or stiff-soled footwear reduce first MTP joint extension loading during push-off.

For acute stress fractures and AVN: non-weight-bearing in a cast boot for 6–8 weeks allows bone healing in stress fractures. Gradual return to dance or sport follows with aggressive offloading in all footwear. The rehabilitation timeline is frustratingly long — most sesamoid stress fractures require 3–6 months of modified activity before safe return to full training.

Surgical Treatment: When and What

Sesamoidectomy — surgical excision of the sesamoid — is reserved for non-healing fractures after 6+ months of conservative treatment, AVN with structural collapse, or sesamoiditis refractory to all non-surgical measures. The decision requires careful consideration: the medial sesamoid contributes to hallux flexion power and MTP joint stabilization; its removal can cause hallux valgus progression or transfer metatarsalgia. Partial sesamoidectomy and shaving procedures may preserve function better than complete excision for select cases.

At Balance Foot & Ankle, Dr. Biernacki evaluates sesamoid pathology with weight-bearing X-rays and MRI at both Bloomfield Hills and Howell offices, developing individualized treatment programs for athletes that minimize time away from activity. Call (810) 206-1402 for an evaluation.