Morton’s Neuroma (Plantar Digital Neurofibroma) - Diagnosis
Morton's Neuroma is rather an odd condition, which we still don’t know much about. Essentially it is a soft tissue nerve entrapment usually in the space between the 3rd and 4th metatarsals when it is know as Morton’s Neuroma or neuralgia.
It causes a variety of symptoms such as numbness in the toes, burning pains, aching pains or shooting pains radiating into the toes and sometimes up the foot towards the midfoot. Taking off your shoes and rubbing the bottom of the foot often gives relief. It is usually first noted wearing tight fitting shoes, high heels, soccer boots, or after longer periods of hiking. Often the time it takes to come on slowly shortens. It is rare for any pain barefoot. Plantar digital neurofibroma or neuralgia is a better name for the condition, as you will see.
Morton’s Neuroma is the common name for the condition, but because the nerves between the other toes can also get irritated. Also other terms such as Morton’s toe or Morton’s foot are also used, but these named after a different Mr Morton actually to a foot where the big toe and 1st metatarsal are too short. The condition is caused by thickening of the insulating coat found around nerves between the metatarsals. However should the little sacks of fluid (called busae) between the metatarsals become inflamed they can press on the interdigital nerves creating the same symptoms. Therefore we tend to call the condition Plantar Digital Neuralgia until we know if we have a neurofibroma or bursitis from a diagnostic image such as a soft tissue ultrasound scan or MRI. X-rays will also come back as normal as they can show soft tissues well enough to see such conditions.
Fortunately there is a simple clinical test cause a Mulder’s click, which any competent clinician/therapist should be able to perform. When the foot is squeezed, pressure is applied under the intermetatarsal space to produce a clunk; which may or may not produce pain. Pain production is conclusive, whereas the painless clunk could be the cause of the symptoms. However, other types of metatarsalgia such as flexor plate strains can commonly occur together with neuralgia.
Morton’s Neuroma (Plantar Digital Neurofibroma) - Treatment
Very little research has been done on the treatment of intermetatarsal neuralgia. Surgery can be very successful, but is associated with quite a high complication rate. You will also be left with a numb area between the toes as the offending nerves are effectively cut out.
If other treatment fails, then surgery always remains an option. Again like most metatarsalgia the earlier it is treated the easier it is to sort out. For many just changing the lacing style, or buying wider walking boots or shoes will resolve the problem. Foot strengthening exercises can work very well, and as long as they don’t make the shoe tighter, insoles with metatarsal support can also be very helpful. But shoe tightness is probably the biggest problem associated with plantar digital neuralgia.
Should simple measures not prove successful then a steroid injection may help, but again we have no data as to how successful this actually is and probably shouldn’t be tried in isolation without recourse the shoe changes and exercises. Seek advice from a clinician/therapist with experience in dealing with this condition to get an accurate diagnosis and appropriate treatment plan.