Metatarsalgia

NB This page is from the 2005 Hyperbook.
Last evidence check June 2006 but no substantial revisions since September 2004.

"Metatarsalgia" is an ill-defined condition. Scranton defined it as "pain in the fore part of the foot", but other definitions would be more precise in terms of nature and location of discomfort. Pain in the first ray is generally understood to be excluded.

Metatarsalgia should be understood as a symptom rather than a diagnosis. It is a diagnostic challenge and a good example of the importance of careful history taking and examination in the foot, as it has many causes and often more than one is present.

Causes

• generalised disease
  • obesity
  • diabetes
  • inflammatory arthritis
  • neurological problem, especially lumbosacral root entrapment or peripheral neuropathy
  • vascular insufficiency
• general and proximal foot problems
  • cavus
  • tight Achilles tendon
  • hyperpronation
  • tarsal tunnel syndrome
• 1st ray problems
  • 1st ray instability
  • previous 1st ray surgery
  • hallux valgus
  • hallux rigidus
• metatarsal problem
  • malalignment
  • non-functioning metatarsal
  • bony spike or prominent condyle on head
• MTPJ problems
  • synovitis
  • instability
  • Freiburg’s disease
• lesser toe problem
  • hammertoe
  • claw toe
  • corn
• interdigital neuralgia
• regional pain syndrome
• referred pain from hind/midfoot

Clinical assessment

In some patients the cause of metatarsalgia may be obvious and may even be presented as the problem: e.g. the rheumatoid forefoot. Generally the cause is less apparent and a full history and examination are essential.

Remember that there may be more than one factor in the development of metatarsalgia, and that the presence of a possible cause does not necessarily prove causation: there are a lot of people with hammertoes in the population but not all have metatarsalgia.

All patients with foot and ankle problems should be asked about:

• diabetes
• inflammatory arthropathy
• neurological disease
• vascular disease
• trauma

Ask about exactly where the pain is felt

• under metatarsal heads
• localised or generalised
• is there a corresponding callus?
• between the metatarsals - if so does the adjacent toe hurt, tingle, go numb or change colour (suggesting interdigital neuralgia)
• in the area of the MTPJs - suggesting Freiburg’s disease, arthritis or instability; pain felt directly under the MTP joint rather than the MT head suggests instability
• over the top of the metatarsus - often referred from proximal problems such as TMTJ OA
• diffusely under the toes with tingling - suggesting tarsal tunnel syndrome

Also ask:

• is there marked callus formation requiring chiropody, or is there even skin breakdown?
• has the patient recently taken up or increased athletic activities or walking - suggesting a stress fracture
• is the pain better on removing shoes - suggesting interdigital neuralgia or bursitis - or worse - suggesting pressure problems
• a long history of rather vague but severe symptoms localised to one or two toes suggests interdigital neuralgia
• if the patient has had 1st ray surgery, was the pain present before and has there been an obvious change in symptom level afterwards?

Look for evidence of systemic disease especially:

• diabetic neuropathy
• inflammatory arthropathy
• neurological disease
• vascular disease

Examination must begin proximally

• any stiffness or deformity (including length discrepancy) which might alter pressures on the forefoot?
• tight Achilles tendon or reduced ankle dorsiflexion, especially if there is fixed equinus (remember to examine in subtalar neutral position)
• pes cavus
• overpronated foot with unstable 1st ray
• peripheral neurological examination
• tenderness or a positive Tinel sign over the major nerve trunks
• hallux deformity or painful 1st MTPJ
• hammer or claw toes - if so, how flexible is the MTPJ. With the MTPJ reduced (if possible) is the fat pad reduced under the metatarsal heads?
• interdigital tenderness, palpable swelling or a positive Mulder's click
• interdigital corns
• tenderness and/or calluses under the metatarsal heads - check the relationship between the relative positions of heads and calluses. Most calluses are relatively diffuse although there may be increased thickening under the MT heads. However, a very localised callus should raise suspicions of a plantar condylar eminence
• metatarsophalangeal instability or irritability

Always screen the patient for diabetes - a urine test is usually enough

Radiology

• usually standing AP/lateral forefoot
• metatarsal skyline view if plantar condylar eminence suspected
• deformity views in the presence of overall foot deformity

Non-surgical management

The management of interdigital neuralgia and MTP instability are described in the relevant documents. For most patients with pressure problems there is a fairly standard regime which can be tailored to the individual patient as indicated:

• weight loss
• accommodative shoewear
• analgesics
• metatarsal insole - a dome insole is standard. It must be positioned just behind the metatarsal heads and should be just thick enough to transfer weight to the metatarsal necks. Many are too thick, unstable and uncomfortable.

About 2/3 of patients will be improved by this regime.

If non-surgical treatment fails, re-evaluate fully:

• is the diagnosis right?
• has a factor been missed?
• check the insoles - do they fit properly and transfer pressure correctly; is the patient wearing them?
• exclude inflammatory arthropathy if this has not already been done
• insist on satisfactory weight for height

Only if all of these conditions have been fulfilled should surgery be considered.

Surgery

The commonest surgery we do for metatarsalgia is correction of lesser toe deformities, sometimes with MTP stabilisation. Some patients also require treatment of hallux valgus or rigidus. Patients with severe rheumatoid forefoot disease would generally be offered a forefoot reconstruction, consisting of a 1st MTP fusion and Stainsby procedures to the lesser rays.

Patients who have failed conservative treatment of interdigital neuralgia may be offered an interdigital neurectomy.

Patients with pes cavus may need metatarsal, tarsal or calcaneal osteotomies, arthrodeses or tendon transfers in addition to toe straightening.

Occasionally a patient with a tight Achilles tendon may be offered a percutaneous Achilles lengthening.

Relatively few need isolated metatarsal surgery and these should be considered individually after adequate imaging as detailed above. Generally, patients with long 2nd or 3rd metatarsals would be offered Weil osteotomies and those with a plantarflexed metatarsal a modified Weil or BRT osteotomy. A short 1st ray may be improved with a scarf osteotomy or 1st MTP fusion with or without an intercalated bone graft.

References

• Davies MS, Saxby TS. Metatarsal neck osteotomy with rigid internal fixation for the treatment of lesser metatarsophalangeal joint pathology. FAI 1999; 20:630-5
• DiGiovanni CW et al. Isolated gastrocnemius tightness. JBJS 2002; 84A:962-70
• Iagnocco A et al. Sonography in the study of metatarsalgia. J Rheumatol 2001; 28:1338-40
• Miller SD. Technique tip: forefoot pain: diagnosing metatarsophalangeal joint synovitis from interdigital neuroma. FAI 2001; 22:914-5
• O’Kane C, Kilmartin TE. The surgical management of central metatarsalgia. FAI 2002; 23:415-9
• Trnka HJ et al. Comparison of the results of the Weil and Helal osteotomies for the treatment of metatarsalgia secondary to dislocation of the lesser metatarsophalangeal joints. FAI 1999; 20:72-9
• Trnka HJ et al. The Weil osteotomy for treatment of dislocated lesser metatarsophalangeal joints. AOS 2002; 73:190-4
• Vandeputte G et al. The Weil osteotomy of the lesser metatarsals: a clinical and pedobarographic follow-up study. FAI 2000; 21:370-4
• Waldecker U. Plantar fat pad atrophy: a cause of metatarsalgia? JFAS 2001; 40:21-7