Metatarsalgia

By Dr Andrew Mattin + Dr Rekha Ganeshalingam Accredited Orthopaedic Registrars

Metatarsalgia: pain in the area across the plantar forefoot beneath the second, third, and fourth metatarsal (MT) heads

Powerpoint Presentation

by Dr Rekha Ganeshalingam

Epidemiology

Metatarsalgia (metatarsal pain) is among the most common complaints in patients seeking care for foot problems.

Refers to a variety of painful conditions of the forefoot.

Aetiology

According to Rocker Mechanism

• First rocker metatarsalgia
  • causes
    • congenital deformity, cavus foot, or tight heel cord.
• Second rocker metatarsalgia
  • causes
    • Limited ankle motion
    • increased plantar flexion of the lesser MTs
• Thrid rocker metatarsalgia
  • Any progressive deformity of the MTP joints (e.g., subluxation) can produce third rocker metatarsalgia.
  • Metatarsalgia occurs most frequently in this phase of the gait cycle.

Primary vs Secondary

• Primary metatarsalgia.
  • Abnormalities that are related to:
    • the anatomy of the MT,
    • the relationships between the MTs
    • the relationships of the MTs to the rest of the foot \
• Secondary.
  • Trauma (e.g., MT malalignment),
  • hallux rigidus,
  • inflammatory arthropathy,
  • degenerative diseases
  • instability of the MTP joints,
  • interdigital neuroma,
  • tarsal tunnel syndrome,
  • Freiberg infraction.
  • Iatrogenic.
    • Malunion after MT osteotomy or resection of the MT head.
    • Nonunion or delayed union of MTs after reconstructive surgery
    • errors in positioning or fixation of an osteotomy may lead to MT overload under weight-bearing conditions.

Anatomy

Gait

• swing phase
  • 40% of the gait cycle
• stance phase
  • 60%.
• forefoot
  • is in permanent contact with the ground throughout approximately half the gait cycle.
• Stance Phase
  • three-rocker mechanism.
    • Provides physiologic balance between forward movement of the body and stability of the foot
  • First rocker
    • Heel acts as the first rocker
    • beginning with initial heel strike during the first 10% of the gait cycle.
    • First rocker metatarsalgia
      • causes
        • congenital deformity, cavus foot, or tight heel cord.
  • Second rocker
    • Ankle acts as the second rocker during the next 10-30% of the gait cycle.
    • The entire foot normally remains in contact with the ground (i.e., foot flat).
    • Second rocker metatarsalgia
      • causes
        • Limited ankle motion
        • increased plantar flexion of the lesser MTs
  • Third rocker
    • 30-60% of the gait cycle
    • only the forefoot is in contact with the ground, and the MTP joints are dorsiflexed.
    • Thrid rocker metatarsalgia
      • Any progressive deformity of the MTP joints (e.g., subluxation) can produce third rocker metatarsalgia.
      • Metatarsalgia occurs most frequently in this phase of the gait cycle.

Classification

• Primary
• Secondary

Examination

• Evaluate in weight-bearing and non–weight-bearing positions. 
• Look
  • Shoe wear
  • localized or diffuse patterns of hyperkeratosison the plantar skin.
  • Gait
    • 1st, 2nd, 3rd rocker progression
  • Pes Cavus
• Feel
  • tenderness
• Move
  • Lesser Metatarsals
    • abnormal plantar flexion of the lesser MTs
  • 1st Ray
    • elevated first MT
      • pushes the whole load of the second rocker onto the second MT, resulting in isolated keratosis underneath the second MT head
  • Ankle movement
    • Gastrocnemius muscle contracture and pes cavus
• Special Test
  • N/V status of limb.

Investigations

• Xrays
  • Dorsoplantar and lateral weight-bearing
    • asess the length of each MT
    • slope of each MT
    • the difference in diaphyseal inclination between the first and second MT are assessed on the lateral view.
    • subluxated or dislocated MTP joint

Treatment

Non operative

• Physiotherapy
  • Stretching exercises to decrease pressure at the forefoot.
• Walking aids.
• Shoe Modification
  • Wider toe box, correct length, a softer sole, lower heel, MT dome orthotic.
• Corticosteroid Injection
  • Local administration of corticosteroid mixed with a local anaesthetic may help decrease the inflammatory response (e.g., interdigital neuroma, bursitis).
• Shaving of the Callus
  • Chronic plantar keratosis.
  • Usually effective in the short-term however do not address underlying problem.

Operative Management

• Metatarsal Level
  • Distal Oblique Metatarsal Osteotomy
    • Weil osteotomy.
  • Midshaft Segmental Metatarsal Osteotomy
  • Proximal or Basal Metatarsal Osteotomy
  • First Tarsometatarsal Fusion
  • Metatarsal Head Resection
  • Plantar Condylectomy
  • Balancing the Soft Tissues. (Flexor/extensor transfer)
• Correcting the Foot and Ankle Ankle equinus
  • caused by contracture of either the Achilles tendon or the gastrocnemius-soleus complex can be addressed by tendon lengthening or resection of the gastrocnemius-soleus complex.
• Consider
  • Cause of metatarsalgia
    • cavus foot,
    • hindfoot, midfoot, and forefoot deformity must be addressed.
    • Severe hallux valgus deformity or malunion after fracture or osteotomy must be addressed or revised with corrective osteotomy.

Prognosis

Satisfactory results are achieved with nonsurgical management.

Surgical correction must be precise and include correction of all deformities producing the pain.

Variability of possible causative factors, treatment must be individualized.