- See:
Sesamoid Bones of Foot:
- Discussion:
- type of fatigue frx which usually involves tibial sesamoid;
- tibial sesamoid is more likely to fracture because normally it receives most of the wt transmitted by the first metatarsal;
- fracture is usually transverse or comminuted;
- these may be either acute or chronic;
- there usually is no swelling, but there is marked tenderness to pressure over involved sesamoid;
- Differential Diagnosis:
- sesamoiditis:
-
hallux rigidus:
- bipartite sesamoid;
- in a true frx, line of division is irregular & jagged, whereas in bifurcation the line
is regualar and division is smooth;
- Radiographs:
- anteroposterior, lateral, oblique
& axial sesamoid radiographs;
- need to consider bipartite, sesamoid, osteochondritis dissecans of sesamoid, or fracture of the sesmoid;
- bipartite sesamoid: (versus sesamoid frx)
- only 25 % of pts w/ a bipartite sesamoid will have it bilaterally;
- bipartite sesamoid has narrow & distinct regular edges;
- bipartite sesamoids also are usually larger than single sesamoid;
- bipartite sesamoids have smooth margins whereas frx demonstrate irregular frx lines;
- bone scan is also helpful;
- Acute Treatment:
- includes immobilization for 6 weeks, although sesamoid removal is often required (esp if
the initial treatment is delayed);
- goal of management is to unload the sesamoid;
- initial treatment is always conservative;
- extended steel shank & rocker sole eliminates stress on MTP joint area while heel wedge &
Morton's extension will increase wt bearing in this area;
- resection of medial sesamoid may weaken medial
FHB insertion into proximal phalanx;
- this imbalance allows the toe to drift into valgus;
- Treatment of Stress Frx:
- cessation of sports activity & avoid excision;
- shoe orthotics: hard - soled shoe, Morton bar, or cast immobilization;
- frx often take months to heal;
- Excision of Sesamoids:
- when symptoms persist for 6 months after a sesamoid fracture and cause functional disability, the most
accepted form of treatment is total excision of the offending sesamoid;
- however, avoid excision of sesamoid in the athelete:
- resection of both sesamoids leads to intrinsic minus, cock-up deformity;
- removal of only the fibular sesamoid can lead to hallux varus;
- removal of the tibial sesamoid can result in
hallux valgus;
Injuries to the hallucal sesamoids in the athlete.
Richardson G: Foot Ankle 1987;7:234.
Stress fractures of the medial great toe sesamoids in athletes.
