Sesamoid Injuries of the Hallux

Introduction

Sesamoid injuries include
- 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
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
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

Surgical 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

TAG

(OBQ12.23) A 32-year-old female avid triathlete complains of left plantar great toe pain for the past 4 months. She has failed conservative management. Her radiographs and bone scan are shown in Figures A and B. Which of the following surgical options would most reliably return her to sporting activities in a timely fashion? Topic

Review Topic

FIGURES: A

1. Tibial sesamoidectomy
2. 1st metatarsophalangeal (MTP) plantar plate reconstruction
3. 1st metatarsophalangeal (MTP) arthroscopy and debridement
4. Open reduction internal fixation of sesamoid with autogenous calcaneus bone graft
5. Distal 1st metatarsal chevron osteotomy with proximal phalanx Akin procedure

PREFERRED RESPONSE ▶

DISCUSSION: The clinical scenario is consistent with a tibial sesamoid fracture recalcitrant to conservative management. Tibial sesamoidectomy would be the most appropriate and reliable treatment to return the patient back to sports.

Sesamoid fractures can occur in the foot as a result of forced dorsiflexion of first the first MTP. They can be distinguished from a bipartate sesamoid by increased activity on a bone scan.

Lee et al. evaluated hallux alignment and functional outcome after isolated tibial sesamoidectomy. They concluded that a hallux deformity after sesamoidectomy can be avoided by surgical repair of the soft tissues and that isolated tibial sesamoidectomy is a safe and effective treatment for recalcitrant tibial sesamoiditis.

Saxena et al. looked at the return to activity after sesamoidectomy in athletically active individuals. They found athletically active individuals were able to return to sports after a sesamoidectomy as early as 7.5 weeks. They concluded that sesamoidectomy of the first MTP joint in athletically active patients may be indicated in cases of chronic sesamoiditis resistant to nonsurgical care or symptomatic displaced fractures or nonunion.

Figure A shows a radiograph of a tibial sesamoid fracture. Figure B shows a bone scan of a sesamoid fracture showing increased activity.

Incorrect Answers:
Answer 2: This would be appropriate in the setting of a turf toe, by would not address the fractured tibial sesamoid.
Answer 3: This is a treatment option in the setting of mild arthritis for the 1st MTP joint.
Answer 4: This is a treatment option for a fractured tibial sesamoid, but would take more time to return athletes to sport compared to simple tibial sesamoidectomy.
Answer 5: This is a treatment option for bunion surgery.

REFERENCES:

1. Lee S, James WC, Cohen BE, Davis WH, Anderson RB. Evaluation of hallux alignment and functional outcome after isolated tibial sesamoidectomy. Foot Ankle Int. 2005 Oct;26(10):803-9. PMID:16221451 (Link to Abstract)

2. Saxena A, Krisdakumtorn T. Return to activity after sesamoidectomy in athletically active individuals. Foot Ankle Int. 2003 May;24(5):415-9. PMID:12801198 (Link to Abstract)

Question Authors:

David Abbasi MD, Derek Moore, Jan Szatkowski MD,

Please Rate Educational Value!

4.0

Average 4.0 of 3 Ratings

TAG

(OBQ06.111) What is the most common surgical complication of resection of both the medial (tibial) and lateral (fibular) hallucal sesamoids on the same foot for intractable keratosis? Topic

Review Topic

1. Hallux varus deformity
2. Neuroma
3. Toe cock-up deformity
4. Recurrence of keratosis
5. Hallux valgus deformity

PREFERRED RESPONSE ▶

DISCUSSION: Excision of both sesamoids should always be avoided since it can lead to a cock-up deformity, which is probably due to decreasing the moment arm of the flexor hallucis brevis. This MTP extension deformity leads to relative overpull of the flexors, causing IP joint flexion. Excision of the tibial sesamoid alone can lead to hallux valgus. Excision of the fibular sesamoid alone can lead to hallux varus.

The referenced article by Richardson is an excellent review of sesamoid pain and reviews the causes, diagnosis and treatment of this pathological condition.

REFERENCES:

1. Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 17-25.

2. Richardson EG. Hallucal sesamoid pain: causes and surgical treatment. J AmAcad Orthop Surg. 1999 Jul-Aug;7(4):270-8. PMID:10434081 (Link to Abstract)

Question Authors:

Ben Taylor MD, John Badylak MD, Michael Hughes MD,

Please Rate Educational Value!

3.0

Average 3.0 of 16 Ratings

Level of Evidence 4 (Case Series)

Lee S, James WC, Cohen BE, Davis WH, Anderson RB. Evaluation of hallux alignment and functional outcome after isolated tibial sesamoidectomy. Foot Ankle Int. 2005 Oct;26(10):803-9. PMID:16221451 (Link to Abstract)
Saxena A, Krisdakumtorn T. Return to activity after sesamoidectomy in athletically active individuals. Foot Ankle Int. 2003 May;24(5):415-9. PMID:12801198 (Link to Abstract)

Textbooks

Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
Orthopaedic Knowledge Update 10, John M Flyn. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2011
Hoppenfeld SP. Surgical Exposures in Orthopaedics: The Anatomic Approach. Lipponcott, Williams, and Wilkins, Philadelphia, PA, Copyright 2009
Orthopaedic In-training Examination (OITE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012
Self-Assessment Examination (SAE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012
Richardson EG (ed): Orthopaedic Knowledge Update: Foot and Ankle 3. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2004, pp 17-25.

Undefined

Richardson EG. Hallucal sesamoid pain: causes and surgical treatment. J AmAcad Orthop Surg. 1999 Jul-Aug;7(4):270-8. PMID:10434081 (Link to Abstract)

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