A neuroma in the foot is a unique type of neuroma that is found in the interspaces located just in front of the balls of the forefoot (metatarsal heads).  The most common name used is a “Morton’s neuroma.”  This can be misleading because a Morton’s neuroma is only found in the 3rd interspace between the 3rd and 4th toes.  Neuromas that occur in the other interspaces have been given their own names, and are as follows:

1st interspace:                Heuter’s neuroma

2nd interspace:               Hauser’s neuroma

3rd interspace:                Morton’s neuroma

4th interspace:                Islen’s neuroma

 

“True Neuroma”
A true neuroma is caused from actual trauma to the nerve that is irreversible, usually occurring when the nerve has been cut.  When a true neuroma occurs, the treatment involves excising the traumatized nerve portion and implanting the nerve ending in a muscle.  This results in numbness and loss of sensation to the affected skin.  Currently, this neurectomy surgical procedure is what is done by the vast majority of foot surgeons for “Morton’s neuromas”.

Neuroma (Chronic Interdigital Nerve Compression)
The name of this condition, a “neuroma”, can be slightly misleading.  This is not a true neuroma.  This condition is caused from the repetitive compression of the common plantar digital nerve in the affected plantar interspace where the nerve lies between the heads of the metatarsal heads.  What occurs is not a true neuroma, but rather a chronic manifestation of the affected nerve becoming chronically compressed causing a chronic interdigital nerve compression.

Why is this important to know? 
The treatment of the chronic interdigital nerve compression is much different.  The initial treatment involves a series of corticosteroid injections around the compressed nerve which helps to break up any acute inflammation and relieves the compression around the affected nerve.  Other conservative treatments may include but are not limited to wearing shoes with a wider toe box to remove pressure against the metatarsal heads which will then remove pressure from the nerve, and/or the use of custom-made orthotic devices which biomechanically changes the way one walks and helps to remove pressure from the nerve.

Neurolysis
If the conservative options fail to resolve the condition, this is usually because the nerve is “stuck” in the plantar tissues secondary to its chronic compression and needs to be “unstuck”. 
This can be done surgically by releasing the deep transverse intermetatarsal ligament and decompressing the nerve from the plantar tissues from its intrinsic fibrosis or scarring.  The important issue is that the nerve is NOT cut or excised which will not cause any long-term numbness.  Also by decompressing the nerve any current numbness and loss of sensation should resolve with time as the nerve regenerates.

Recovery
The recovery from the surgical plantar interdigital nerve decompression (neurolysis) is relatively short.  The surgery is done under local anesthesia with IV sedation in a Day Surgery setting, and the surgical site is closed using internal absorbable sutures and the use of Dermabond which seals the surgical site.  You are able to leave the operating room with fairly quick recovery from the IV sedation without a large bulky dressing and are able to shower the next morning.  You can return to your normal daily activities within several days.