Sesamoid Fracture - Comprehensive Review

1. Anatomy and Background

• The tibial (medial) sesamoid is larger, sits more directly beneath the first metatarsal head, and is the more commonly injured of the two
• The fibular (lateral) sesamoid is smaller and rarely bipartite
• Both bones are contained within a fibrocartilaginous plantar plate complex, along with the flexor tendon sheath and intersesamoid ligament
• They bear 300-400% of body weight during push-off activities
• Blood supply enters from the plantar aspect, making avascular necrosis a known complication of injury

2. Etiology and Predisposing Factors

Acute Fractures

• Falls from height with axial loading on the forefoot
• Direct trauma to the plantar foot
• Sudden, forceful push-off

Stress (Fatigue) Fractures

• Long-distance running, ballet dancing (especially the demi-pointe/relevé position)
• Soccer, basketball, tennis
• Military recruits (repetitive marching)
• Rapid escalation of training load

Risk Factors

• Campbell's Operative Orthopaedics 15th Ed 2026, p. 5221-5222
• Rockwood and Green's Fractures in Adults 10th Ed 2025, p. 868

3. Mechanism of Injury

Direct Mechanism (Axial Loading)

Indirect Mechanism (Hyperextension)

DIRECT MECHANISM:
    Ground → Sesamoid ← First Metatarsal Head
    (Axial compression → comminuted fracture)

INDIRECT MECHANISM (Hyperextension):
    FHB tension → Sesamoid → avulsion/transverse fracture
    (e.g., foot planted, body moves forward = forced dorsiflexion)

• Campbell's Operative Orthopaedics 15th Ed 2026, p. 5222

4. Associated Injuries

Turf Toe Grading (Anderson Classification):

• Miller's Review of Orthopaedics 9th Ed, p. 564

5. Signs and Symptoms

Acute Fracture

• Immediate, sharp, localized pain on the plantar aspect of the first metatarsal head (ball of foot)
• Point tenderness directly over the involved sesamoid (tibial or fibular)
• Swelling and ecchymosis/bruising plantar to the first MTP joint
• Antalgic gait - shortened stance phase on the affected foot
• Patient descends stairs with injured foot leading (to avoid push-off)
• Limited extension of the great toe (hallux)
• Pain on passive dorsiflexion of the great toe

Stress Fracture (Insidious Onset)

• Gradual onset of pain beneath the great toe with activity
• Initially pain only with vigorous activity; progresses to pain with walking
• Tenderness localized to the sesamoid (may need careful palpation to distinguish from diffuse MTP tenderness)
• Minimal swelling, usually no ecchymosis
• Pain relief with rest early in the course

Physical Examination Findings

• Diffuse MTP joint tenderness initially; careful palpation isolates to one sesamoid
• Plantar palpation test: direct pressure over the individual sesamoid reproduces pain
• Hyperextension test (dorsiflexion stress test): passive dorsiflexion of the hallux reproduces pain (stresses both FHB and sesamoid)
• Compare range of motion bilaterally
• Assess for hallux valgus or varus deformity

6. Investigations and Evaluation

6.1 Plain Radiographs (First-Line)

FIGURE: Standing AP view of both feet for sesamoid comparison - Campbell's Operative Orthopaedics 15th Ed

FIGURE: Oblique sesamoid views - tibial and fibular sesamoid profiling - Campbell's Operative Orthopaedics 15th Ed

Distinguishing Fracture from Bipartite Sesamoid

6.2 CT Scan

• Best modality to fully characterize fracture pattern (comminution, displacement, fragment number)
• Guides surgical planning for ORIF vs. sesamoidectomy
• Useful when plain X-rays are equivocal

6.3 MRI

• Best for soft tissue assessment: plantar plate integrity, FHB tendon, intersesamoid ligament
• Depicts avascular necrosis, stress fracture, osteochondritis dissecans, osteonecrosis
• Particularly useful when fibular sesamoid fracture is suspected (fibular sesamoid is rarely bipartite, so if clinical suspicion is high, MRI confirms fracture)
• Best for evaluating associated turf toe soft tissue injuries

6.4 Radionuclide Bone Scan

• Can confirm diagnosis of stress fracture with increased uptake
• However, use with caution: 26-29% of asymptomatic individuals show increased bone scan activity in the sesamoid region
• Largely superseded by MRI in clinical practice

6.5 Diagnostic Algorithm

Plantar 1st MTP pain
        |
  Weight-bearing X-rays (AP, lateral, oblique, axial)
        |
    ┌───┴───┐
  Fracture  Bipartite?
  confirmed   |
    |     Compare: fragment edges, sizes, bilaterality
    |         |
    |     Still unclear?
    |         |
    |       MRI / CT scan
    |
  Assess displacement
        |
  ┌─────┴─────┐
Non/minimally  Displaced
 displaced    (>5 mm) or MTP
    |           dislocation
Conservative  Surgical evaluation

• Campbell's Operative Orthopaedics 15th Ed 2026, p. 4821-4822
• Roberts and Hedges' Clinical Procedures in Emergency, p. 1213

7. Treatment

7.1 Conservative (Non-Operative) Treatment

• Short leg walking cast incorporating a toe plate, or a fracture boot to limit stress across the sesamoid - for 3 to 4 weeks initially
• Non-weight-bearing or protected weight-bearing with crutches
• NSAIDs for pain and inflammation
• Ice application to the plantar foot

• Transition to a stiff-soled shoe or rigid carbon fiber insole
• Dancer's pad (sesamoid relief orthotic): a full-length orthotic with a cutout or relief beneath the sesamoid to offload pressure; weight-bearing redistributed to surrounding metatarsals
• A bunion-type aperture pad (hole placed over the sesamoid, felt reinforced medially) achieves the same goal for tibial sesamoid injuries
• Gradual resumption of activity

• Full-length rigid carbon plate + orthotic with dancer's pad inside athletic shoe
• Gradual reconditioning: pool running → cycling → land running
• Athletes: cardiovascular fitness maintained during healing

FIGURE: Bunion shield/aperture pad with hole placed over fractured sesamoid to redistribute pressure - Roberts and Hedges' Clinical Procedures

7.2 Operative Treatment

Indications for Surgery:

• Displaced fracture (>5 mm) - especially with MTP dislocation or subluxation
• Widely displaced fracture with disruption of FHB musculotendinous unit
• Symptomatic nonunion after adequate conservative management (typically 6 months)
• Comminuted fracture with loss of articular cartilage
• Cases refractory to conservative care

Surgical Options:

• For fragments of roughly equal size with significant displacement (>5 mm)
• Mini-fragment screw fixation (most common)
• Figure-of-8 wire loop around proximal and distal poles over the sesamoid
• Bone grafting from the calcaneus or supramalleolar distal tibia may be added to achieve union
• Repair of the FHB mechanism is mandatory regardless of fixation method chosen

FIGURE: Pre and postoperative radiographs showing internal fixation of sesamoid/phalangeal fracture - Campbell's Operative Orthopaedics 15th Ed

FIGURE: Mini-fragment screw fixation of hallucal sesamoid fracture - Campbell's Operative Orthopaedics 15th Ed (Technique 93.18)

• Partial sesamoidectomy (pole excision): excision of proximal or distal pole - preferred when the fracture pattern allows; achieves best results
• Complete sesamoidectomy: for comminuted fractures with no large fragments, loss of articular cartilage on sesamoid or on the overlying metatarsal head surface
• A 6-month (lengthy) trial of conservative treatment should precede sesamoidectomy in non-athletes
• May be performed earlier in athletically active patients seeking faster return to sport

1. Medial longitudinal incision, plantar to midline; capsule incised longitudinally
2. Evaluate tibial sesamoid cartilage quality and fragment mobility intraoperatively
3. Inspect plantar surface of metatarsal head for cartilage damage
4. Extracapsular approach; protect the proper medial plantar nerve to the hallux (emerges plantarly at the abductor hallucis musculotendinous junction - retract plantarly)
5. Perform complete or partial sesamoidectomy
6. Repair the FHB defect with 2-0 nonabsorbable polyethylene suture; use suture anchor for partial excision

FIGURE: Series showing bipartite sesamoid (AP and axial X-rays, A-D), gross specimen (E), postoperative and 19-year follow-up radiographs (F-H) - Miller's Review of Orthopaedics 9th Ed

7.3 Outcomes

• Hallux valgus deformity after tibial sesamoidectomy (if soft tissue repair is inadequate)
• Hallux varus deformity after fibular sesamoidectomy
• Postoperative scarring / neuroma-like symptoms after fibular sesamoidectomy
• Cock-up toe deformity if both sesamoids are excised
• Inability to stand on tiptoes (does not typically affect ADLs)
• Campbell's Operative Orthopaedics 15th Ed 2026, p. 5222-5223
• Miller's Review of Orthopaedics 9th Ed, p. 565

8. Summary Diagram

SESAMOID FRACTURE - CLINICAL PATHWAY

ETIOLOGY
├── Direct: axial load (fall, jump) → comminuted fracture
└── Indirect: FHB traction / MTP hyperextension → transverse fracture

RISK FACTORS
├── High-arched foot, prominent 1st MT head
├── Athletes: dancers, runners, footballers
└── Female, osteoporosis, high heels

ASSOCIATED INJURIES
├── Turf toe (Grade 1/2/3)
├── MTP dislocation
├── Plantar plate tear
└── AVN of sesamoid

SIGNS & SYMPTOMS
├── Plantar 1st MTP pain (immediate in acute fracture)
├── Point tenderness over involved sesamoid
├── Swelling ± ecchymosis
├── Limited / painful great toe dorsiflexion
└── Shortened stance phase, toe-lead on stairs

INVESTIGATIONS
├── X-rays (AP bilateral, oblique, axial) - FIRST
├── CT - fracture characterization
└── MRI - soft tissue, AVN, stress fracture

TREATMENT
├── Conservative (nondisplaced / stress fractures)
│   ├── Cast/boot 3-6 weeks + toe plate
│   ├── NSAIDs, ice
│   └── Dancer's pad orthotic + gradual RTA
└── Operative (displaced >5mm, nonunion, comminuted)
    ├── ORIF (mini-screw / figure-8 wire + bone graft)
    └── Sesamoidectomy (partial pole or complete)
         + FHB repair (mandatory)

• Campbell's Operative Orthopaedics 15th Ed 2026, pp. 4821-4823, 5221-5223
• Rockwood and Green's Fractures in Adults 10th Ed 2025, p. 868
• Roberts and Hedges' Clinical Procedures in Emergency Medicine, pp. 1213-1214
• Miller's Review of Orthopaedics 9th Ed, pp. 564-565
• Imaging Anatomy Text and Atlas Vol. 3