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.

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, September 4, 2012 3:30 pm