Neuroma – An Injury of the Forefoot
A neuroma is a benign growth of nerve tissue in the forefoot between the metatarsal bones. It is caused by forces that pinch the relevant branch of the nerve, usually as it passes the narrow gap between the metatarsal heads.
The classic symptoms of this condition can include pain in the forefoot, usually in the bottom of the ball of the feet, though it can be felt on top too; with intermittent shooting pains into the affected toes. Burning and tingling, as well as sensations of numbness, are often reported.
This nerve in question is caused to grow by any force that places too much friction or shear forces between the metatarsal heads. Your natural biomechanics (the way you walk or run) may put excess forces through this area over time. Common external causes and/or aggravators of this condition include improperly fitting footwear (e.g. insufficiently wide or with a higher heel), walking on uneven surfaces (e.g. sand), pivoting or changing direction, or any activity that places more forces through the forefoot (e.g. running).
This condition is more common between the middle toes (i.e. between the third and fourth, or between the second and third toes) although it can occur between any or all metatarsals or even from the pressure to the nerves on the sides of the forefoot. The neuroma site in question is technically preceded by different surnames depending on the inter-metatarsal site (e.g. Joplin’s, Heuter’s, or Houser’s Neuromas). Although a ‘Morton’s Neuroma’ is most commonly cited as referring to any neuroma, this technically only includes a neuroma between the third and fourth metatarsals.
A neuroma between the 3rd and 4th metatarsal heads, commonly known as Morton's Neuroma
In addition to the above signs of a neuroma, there are other diagnostic tests your podiatrist will do in the clinic to determine the likelihood of a neuroma. In rare cases, an ultrasound scan may be suggested to confirm its presence and/or to check for other injured tissues in the area.
If believed to be a neuroma, there are several methods of treatment your podiatrist may recommend to treat the issue. The over-arching principle of management involves releasing pressure on the neuroma. This can be achieved in different ways. Selecting appropriate footwear is often key; as a minimum, the ‘toe box’ in the forefoot of the footwear must be wide enough; a firm massage to the area or the rolling of a golf ball between the metatarsal heads in the forefoot – if tolerated well – can sometimes help reduce pain; a soft ‘metatarsal dome’ device may be attached by your podiatrist to your foot or your shoe insole to lift up and separate the relevant metatarsals; taping and/or padding can help re-distribute pressures away from the effected area.
Based on the relief achieved from some of these strategies, pressure-redistributing features can be incorporated within a pre-made or custom-made orthotic which you can then change between appropriate footwear. Hands-on foot joint mobilisation, or the use of acupuncture needles in the appropriate trigger points by your podiatrist can also help. Failing these more conservative strategies, and in a bid to avoid neurectomy (surgery to remove the nerve), referral for a cortisone steroid injection can be arranged.
A 'U-shaped plantar metatarsal pad can ease forces on an inter-metatarsal neuroma
By Mark Dooley - 4 Life Podiatrist