- Discussion:
- inflammation and swelling around the sesamoid (tibial > fibular) and FHB can be secondary to trauma, infection, AVN, stress fractures, or a systemic disorder;
- sesamoiditis may also be precipitated by a cavus foot w/ excessive wt bearing under the first metatarsal;
- sesamoid shape may vary and in some cases may be especially thick or pointed;
- a sharp pointed sesamoid might cause a deep seated callus to form under it, and extra-articular shaving or partial excision of the plantar half may afford relief;
- Clinical Findings:
- symptoms include pain on wt bearing and with dorsiflexion of the great toe and pain with direct palplation;
- determine whether the medial or the lateral sesamoid is involved;
- first MTP joint may show swelling;
- Non-Operative Treatment:
- non operative treatment may start with extra-soft shoe inserts and shoe modification;
- if simple inserts do not work, then consider insertion of a semi-rigid fiberglass insert placed below a soft inset (this limits great toe dorsiflexion and therefore takes the stress off of the sesamoids);
- Operative Treatment:
- best indication for surgical treatment is a tibial sesamoid non union (or bipartite sesamoid) which has remained symptomatic despite non op treatment;
- in this case the smaller sesamoid fragment is removed (cutting thru the synchondrosis), and FHB tendon is then re-secured to the remaining sesamoid;
- complications:
- excision of both sesamoids is always avoided since it will lead to a "cock up" deformity;
- removal of only the fibular sesamoid can lead to hallux varus;
- removal of the tibial sesamoid can result in hallux valgus;
- nerve injury:
- plantar-medial cutaneous nerve is at risk with the surgical approach to the medial sesamoid;
- it is located underlying an incision made at the junction of the glabrous skin of the hallux and needs to be identified before approach can proceed
- reference:
- Sesamoid disorders and treatment. An update.
- Tibial sesamoid shaving for treatment of intractable plantar keratosis.
Injuries to the hallucal sesamoids in the athlete.
Anatomic variations in the first ray: Part II. Disorders of the sesamoids.