Please see foot & ankle anatomy for more information about the big toe anatomy. 

The big toe joint (1st metatarsal and hallux) is big for a reason, it takes almost half of the weight transmitted through the toes when walking and standing. It is also commonly referred to as the first ray, referring to the 1st metatarsal, the sesamoid bones and the proximal and distal hallux.

Abnormalities of the first ray can prevent the big toe joint from working properly, such as 1st MTP joint arthritis (hallux rigidus) or bunions (hallux valgus).

Due to the first ray abnormal biomechanics and/or pain, the normal physiological load across the first ray is shifted across to the second toe and then the other lesser toes. This is called transfer metatarsalgia. Not surprisingly the second and other lesser toes are not designed to bear the extra load, and as a result, several complications can occur.

Illustration of how load is transferred from the big toe to the lesser toes in transfer metatarsalgia

Transfer metatarsalgia is essentially forefoot pain caused by dysfunction in another forefoot area. While the commonest presentation is 2nd MTP joint pain secondary to 1st MTP joint pathology, it is not exclusively the case.

Surgery to one part of the foot may alter the biomechanics sufficiently to cause a shift in load across the forefoot. This can result in painful symptoms and transfer metatarsalgia. This is an uncommon complication of most types of forefoot surgery.

The following are the commonest causes of transfer metatarsalgia:

• Big toe (1st MTP joint arthritis) also known as hallux rigidus
• Bunion (hallux valgus) deformity
• Sesamoid pathology
• Surgery of the forefoot 

Clinical picture of a patient with a painful bunion who is off loading the big toe and as a result, develops transfer metatarsalgia

Calf tightness results in increased forces going through the front of the foot “forefoot overload“.

This can cause or exacerbate problems in the forefoot. Please read about calf tightness for further information.

When considering treatment for a problem at the front of the foot, it is important to also treat the calf tightness to ensure a good outcome.

Patients with transfer metatarsalgia can develop problems in adjacent bones, joints and soft tissues such as:

• 2nd (midfoot) TMT joint arthritis
• 2nd MTP joint arthritis
• Lesser toe deformity such as hammer, claw or crossover toe
• Subluxation or dislocation at the lesser MTP joint
• Lesser metatarsal stress fracture

Investigations help confirm the underlying cause of the transfer metatarsalgia, grade the severity of the condition and where applicable, aid in pre operative planning.

Plain radiograph (x-ray)

Plain radiographs are a quick and effective way of confirming first ray pathology such as big toe (1st MTP) joint arthritis and bunion deformity in a foot. In the early stages of the condition, the deformity can be quite subtle. Most people however present when there is an obvious clinical and radiological deformity, often with additional complications such as lesser toe deformity.

Plain radiographs (x-rays) provide the following information:

• The degree of bunion deformity 
• Presence degenerative change in the 1st MTP joint
• Sesamoid pathology
• Evidence of transfer metatarsalgia
  • 2nd metatarsal stress fracture
  • 2nd (midfoot) TMT joint arthritis
  • Lesser toe deformity such as hammer, claw or crossover toe
  • Subluxation or dislocation at the lesser MTP joint
  • 2nd MTP joint arthritis

Ultrasound

Ultrasound is used to confirm swelling (synovitis) in the 2nd MTP joint, and to see if there is anything else that may be causing the symptoms of transfer metatarsalgia for example, Morton’s neuroma or intermetatarsal bursitis.

MRI

MRI is useful especially when x-rays appear normal. It provides excellent high definition static images.

MRI is particularly useful in assessing:

• Cartilage damage
• Reactive bone changes (stress response)
• Synovitis (inflammation and fluid in the joint)
• Damage to the plantar plate
• Other pathology

An MRI of the foot demonstrating inflammation (synovitis) in the 2nd MTP joint

If the underlying diagnosis is not clear an MRI can be a useful investigation.

Left untreated, the symptoms of transfer metatarsalgia can get worse.

The untreated abnormal biomechanics and subsequent overload of other parts of the forefoot can exacerbate or result in several different complications involving adjacent bones, joints and soft tissues such as:

• 2nd (midfoot) TMT joint arthritis
• 2nd MTP joint arthritis
• Lesser toe deformity such as hammer, claw or crossover toe
• Subluxation or dislocation at the lesser MTP joint
• Lesser metatarsal stress fracture
• Morton’s neuroma

Radiograph (x-ray) of the foot in a patient with a severe bunion deformity and arthritis in the midfoot

Radiograph (x-ray) of the foot, of a patient with a bunion deformity and 2nd MTP joint arthritis

Clinical picture of a foot in a patient with a bunion (hallux valgus) deformity with associated crossover toe deformity

A – AP, B – oblique and C – lateral radiographs (x-rays) of the foot demonstrating dislocation and crossover deformity of the 2nd toe

Serial radiographs (x-rays) of the foot demonstrating a 2nd metatarsal stress fracture in a patient with a hallux valgus deformity A – at initial presentation B – 6 weeks C – 3 months (healed)

Transfer metatarsalgia is treated by resolving the underlying pathology.

See relevant condition pages regarding the following for further information:

• Big toe (1st MTP) joint arthritis
• Bunion (hallux valgus) deformity
• Sesamoid problems
• Calf tightness