The Hip
Home » Bones » Tibia and Fibula » Sesamoid Fractures

Sesamoid Fractures



- 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.

 Stress fractures of the medial great toe sesamoids in athletes.