summary Sesamoid injuries of the Hallux consist of a constellation of injuries to the sesamoid complex consisting of fractures, tendonitis, and ligamentous injuries. Diagnosis is suspected with hallux pain that is worse with hyperextension and can be confirmed with MRI studies. Treatment depends on the specific injury to the sesamoid complex, chronicity and patient activity demands. Etiology Specific injuries fracture (caused by hyperextension and axial loading) dislocation sprain "turf toe" sesamoiditis (trauma or infection) chondromalacia osteochondritis dissecans FHB tendonitis Epidemiology Tibial sesamoid more commonly injured has greater weight bearing status larger than lateral sesamoid Etiology Mechanism forced dorsiflexion of first MTP most common potential avulsion of plantar plate off base of phalanx proximal migration of sesamoids Associated conditions bilateral sesamoiditis should raise alarm and concern for reiter's disease (urethritis, conjuctivitis / iritis, inflammatory bowel disease) psoriatic arthritis seronegative RA Anatomy Osteology sesamoids play important role in function of great toes by absorbing weight-bearing pressure reducing friction at MT head protect FHL tendon glides between sesamoids provide fulcrum for flexor hallucis brevis that increases MTP flexion power bipartite sesamoid present in 10-25% 97% are in the tibial sesamoid 25% bilateral Attachments FHB attaches to both tibial and fibular sesamoid sesamoids are connected to each other by intersesamoid ligament and plantar plate abductor hallucis is connected to tibial sesamoid adductor hallucis is connected to fibular sesamoid Biomechanics sesamoid function is analogous to the patella as they increase the mechanical advantage of the FHB Presentation Symptoms generalized big toe pain worse in terminal part of stance phase Physical exam possible plantar-flexed MTP with cavus foot Imaging Radiographs recommended views AP and lateral of foot medial oblique (sesamoid view) axial sesamoid view findings proximal migration of sesamoids be suspicious of intrinsic minus hallux Bone scan helps distinguish a bipartite sesamoid from a fracture use caution with interpretation as 25%-30% of asymptomatic patients can have increased uptake increased uptake compared to uninjured side helps diagnosis Treatment Nonoperative NSAIDs, reduced weightbearing, activity modification, orthoses indications indicated as first line of treatment short leg cast with toe extension indication acute fracture (controversial) shaving keratotic lesion indications keratotic lesion present increasing pressure on sesamoids Operative partial or complete sesamoidectomy indications nonoperative management fails after 3-12 months technique (see below) autologous bone grafting indications nonunion or fracture dorsiflexion osteotomy indication plantar-flexed first ray with sesamoid injury Techniques Complete or Partial Sesamoidectomy approaches approach to tibial sesamoid medial-plantar approach high risk of injuring proper branch of medial plantar nerve approach to fibular sesamoid plantar approach beware for proper branch to lateral side of hallux first common branch to first web space technique may be partial or complete sesamoidectomy sesamoid shaving (contraindicated in a patient with a plantar flexed 1st MT) Complications Cock-up deformity removal of both sesamoids is associated with a high incidence of cock-up deformity of the great toe caused by weakening of the flexor hallucis brevis tendon, which should be meticulously repaired after sesamoid excision excision of both sesamoids should be avoided Hallux valgus may be caused from tibial sesamoid excision Hallux varus may be caused by fibular sesamoid excision