Forefoot Pain (Metatarsalgia)
Has the patient noticed any particular change in the shape of their foot in particular separation of the toes, the formation of a hammertoe and does the patient suffer with a systemic condition such as rheumatoid arthritis or diabetes?Examination:
- Begin by observing the foot. Is there swelling dorsally? Is there separation of the toes? Is the foot red? Is there obvious deformity?
- Next ask the patient to walk on toes and on heels. Observe are they avoiding the forefoot. Do they have reasonable power in the musculature when walking?
- Firstly, feel for the patient’s dorsalis pedis and posterior tibial pulses.
- Next palpate the foot. Is the patient tender over bone? This would suggest a stress fracture. Is the patient tender at the 2, 3 or 3, 4 interspaces? This may suggest a neuroma. Is the patient tender at the second MTP joint or under the head of the second metatarsal? This may suggest a plantar plate problem.
- Is the second MTP joint unstable? Does the patient have an anterior drawer sign?
- Next check sensation in the toes. Is there any numbness at the adjacent borders of the second and third or third and fourth toes?
- Perform a plain x-ray of the foot weight bearing. I ask for an AP, and oblique view and then lateral view.
- Ultrasound of the foot and ankle is extremely operator dependent. MRI scan of the foot and ankle is just as operator dependent.
- An interdigital neuroma (Mortons neuroma) is often diagnosed by the history. The patient commonly a middle-aged woman presenting with a burning aching type pain in her forefoot. The pain is activity related and worse in tight or high-heeled shoes. The patient will classically describe taking their shoe off to rub their foot to relieve the pain.
- Examination as described above, the patient will be tender at the 3, 4 interspace (neuroma at the 2, 3 interspace is very rare). The patient will have altered sensation at the adjacent borders of the third and fourth toes. Often compressing the foot will elicit a click described as a Mulder’s click.
- Plain x-rays taken are usually normal. An ultrasound may or may not show enlargement of the nerve. An MRI scan may or may not show enlargement of the nerve or a bursa but is more useful to exclude the differential diagnoses of inflammatory arthropathy, stress fracture, tumour or third plantar plate tear.
- Nonsurgically neuromas can be treated by injection of cortisone, a metatarsal dome in the shoe and wider shoes. Whilst there has been a vogue for treating neuromas with radiofrequency ablation I have seen this technique cause avascular necrosis of the metatarsal head and plantar plate damage.
- In the right patient, surgery affords relief of pain in approximately 90% of cases. Removing the nerve is done as a day surgical procedure. I prefer a dorsal approach. The surgery is accompanied by numbness at the adjacent borders of the third and fourth toes but most patients are very grateful for the relief of pain and not bothered by this numbness.
- Following neuroma surgery footwear choice is often better.
Plantar plate tear:
- Tears of the plantar plate commonly occur in women in the sixth decade.
- The condition is frequently associated with hallux valgus. The common scenario is that a patient who has had a bunion for many years complains of a sensation of “walking on a stone” beneath the second metatarsal head.
- This sensation will often bring the patient to the doctor and the patient often states that the bunion is not what bothers them it is in fact the pain under the second metatarsal head.
- Associated with this pain there may be splaying of the second and third toes, in addition the patient may notice altered sensation on the lateral border of the second toe. This altered sensation together with a burning pain often results in a misdiagnosis of neuroma.
- When examining the patient they are tender at the second MTP joint, they often have a positive anterior drawer sign and there is often early hammering of the second toe.
- Plantar plate tears can occur in runners. It is unusual to tear a plantar plate in a young athlete. Indeed if one is contemplating a plantar plate tear as a diagnosis in a patient under 30, the diagnosis is more often an arthropathy. MRI can be very useful in this situation. Blood tests may be totally normal.
- I generally take a plain x-rays weight bearing. The diagnosis is usually obvious clinically.
- Ultrasound in the right hands is useful.
- MRI scan will exclude stress fracture, arthropathy and tumour.
- Unfortunately many radiologists are unaware of this condition and MRI scans are frequently misreported.
- In general with minimal deformity a trial of nonsurgical treatment is indicated. This would consist of taping the second toe in flexion and a metatarsal dome in the shoe.
- If unsuccessful plantar plate repair done from a dorsal approach associated with correction of the bunion will afford relief of pain in most patients. The surgery is inconvenient in terms of recovery necessitating a day in hospital and up to 6 weeks in a recovery shoe.
- The patient will experience stiffness and swelling in the second toe for approximately six months. The results of the surgery are good in approximately 80% of cases.
- At present there is an epidemic of stress fractures occurring in our community.
- Patients are increasingly running at older ages, going to the gym and performing impact.
- The common stress fractures occur in the metatarsals most often the second, third and fourth. The patient will present with swelling redness and pain on the dorsum of the foot and the diagnosis is usually clinically obvious.
- Occasionally patients will present with a stress fracture of a metatarsal head in which case the diagnosis is more difficult. The pain can be felt at the interspaces and can be confused with neuroma pain.
- Most stress fractures can be treated successfully nonsurgically with a period of rest and activity modification.
- It is imperative that the physician check the patient for issues with their bone density with various blood tests including serum calcium, vitamin D, parathyroid hormone and a biochemical profile. I often find it useful to refer the patient to an endocrinologist with an interest in bone metabolism.