Description

• Metatarsalgia is defined as pain in the forefoot under one or more metatarsal heads.
• There are three groups:
  • Primary: due to anatomic issues between the metatarsal and other parts of the foot
  • Secondary: due to conditions that increase metatarsal loading via indirect mechanisms, such as chronic synovitis or fracture or injury to the metatarsophalangeal (MTP) joint
  • Iatrogenic usually after a prior forefoot surgery, such as with halux valgus surgery

Epidemiology

Incidence
The overall incidence in the general population is 5–36%; especially common in athletes engaging in high-impact sports (running, jumping, dancing), in rock climbers (12.5%), and in older active adults; most common in women aged 3 to 60 years.

Prevalence
Common

Etiology and Pathophysiology

• The 1st metatarsal head bears significant weight when walking or running. A normal metatarsal arch ensures this balance. The 1st metatarsal head normally has adequate padding to accommodate increased forces.
• Reactive tissue can build a callus around the metatarsal head, compounding the pain.
  • Excessive or repetitive stress; Forces are transmitted to the forefoot during several stages (midstance and push off) of walking and running. These forces are translated across the metatarsal heads at nearly 3 times the body weight.
  • A pronated splayfoot disturbs this balance, causing equal weight-bearing on all metatarsal heads.
  • Any foot deformity changes distribution of weight, impacting areas of the foot that do not have sufficient padding.
  • Soft tissue dysfunction: intrinsic muscle weakness, laxity in the Lisfranc ligament
  • Abnormal foot posture: forefoot varus or valgus, cavus or equinus deformities, loss of the metatarsal arch, splayfoot, pronated foot, inappropriate footwear
  • Dermatologic: warts, calluses (1)[C]
• Great toe
  • Hallux valgus (bunion), either varus or rigidus
• Lesser metatarsals
  • Freiberg infraction (i.e., aseptic necrosis of the metatarsal head usually due to trauma in adolescents who jump or sprint)
  • Hammer toe or claw toe
  • Morton syndrome (i.e., long 2nd metatarsal)

Risk Factors

• Obesity
• Forefoot surgery or trauma
• High heels, narrow shoes, or overly tight-fitting shoes (rock climbers typically wear small shoes)
• Competitive athletes in weight-bearing sports (e.g., ballet, basketball, running, soccer, baseball, football)
• Foot deformities or changes in range of motion (ROM) (e.g., pes planus, pes cavus, tight Achilles tendon, tarsal tunnel syndrome, hallux valgus, prominent metatarsal heads, excessive pronation, hammer toe deformity, tight toe extensors) (1)[C]

Geriatric Considerations

• Concomitant arthritis
• Metatarsalgia is common in older athletes.
• Age-related atrophy of the metatarsal fat pad may increase the risk for metatarsalgia.

Pediatric Considerations

• Muscle imbalance disorders (e.g., Duchenne muscular dystrophy) causing foot deformities in children.
• In adolescent girls, consider Freiberg infraction.
• Salter-Harris type I injuries may affect subsequent growth and healing of the epiphysis.

Pregnancy Considerations

• Forefoot pain during pregnancy usually results from change in gait, center of mass, and joint laxity.
• Wear properly fitted low-heeled shoes.

General Prevention

• Wear properly fitted shoes with good padding.
• Start weight-bearing exercise programs gradually.
• Adequate stretching, particularly of the calf muscles
• Weight loss, if overweight

Commonly Associated Conditions

• Arthritis
• Morton neuroma
• Sesamoiditis
• Plantar keratosis—callus formation