What is Mortons Neuroma?
Although the codition is known as a neuroma it is not a tumour of the nerve. Mortons neuroma is actually a swelling of the nerve with occasional scar tissue formation around the site . it normally affects the nerve between the 3rd and 4th metatarsals of the foot.
A mortons toe is a shorter first metatatarsal , and therefore length of toe, compared to the second . This makes the 2nd toe appear longer than the first. It can also mean more difficulty with balancing as the balance platform made by the met heads are not even.
It is common to see a callus under the head of the 2nd met as more weight is taken on this area in walking as opposed to the first met.
Above the nerve is a structure called the deep transverse metatarsal ligament. This ligament is very strong, holds the metatarsal bones together, and creates the ceiling of the nerve compartment. With each step, the ground pushes up on the enlarged nerve and the deep transverse metatarsal ligament pushes down. This causes compression in a confined space.
Common symptoms of a mortons neuroma consist of Pain radiating to the toes. This can be accompanied with pins and needles, numbness, and a burning sensation.
Symptoms are usually worsened when the foot is compressed such as in a narrow fitting shoe or in high heels.
Such symptoms should ease off when the foot is at rest (non weight bearing)
There will normally be no bruising or effusion, but the area can be sore to touch.
A diagnosis can normally be made by a health professional on a subjective history and objective testing.
In clinic the therapist is looking for pain on compression of the foot, some local tenderness over the site of the swelling/scarring and response to weight bearing.
They will be looking at ant contributing factors such as foot placement and alignment, muscular asymmetries in the leg and dynamic control in the hip.
The therapist will need to differenciate between other common causes of foot and toe pain such as
Stress fractures, freibergs disease, capsulitis, bursitis and nerve realted problems from the back and pelvis.
An MRI scan can be preformed to rule out an actual tumour. By looking at an MRI we can determine the size of the neuroma which can indicate which treatment path will be best.
It is interesting to note however that a neuroma may be Present on MRI with no symptoms to the client at all.
Treatment can take one of 2 routes, conservative or surgical management.
With the conservative route we are looking to reduce irritation to the nerve and subsequent swelling. Simple icing can help here initially.
Off loading the foot with modalities such as orthotics or a met dome can also provide relief as they support the transverse arch of the foot and reduce the compressive pressure on the area. These types of aids can be issued by your physiotherapist in clinic.
It is then imperative to strengthen up the foot and maintain arch control in the transverse and longitudinal arches by use of the muscles within the foot. These specific exercises are taught in the clinic setting and then carried out at home. A constant sense of correct foot placement is required to build up endurance within the foot.
It is possible to have an Injection into the area to reduce the swelling, the effect will vary from patient to patient.
With a surgical method there can be 2 approaches wherein the nerve is resected.
1. The dorsal approach involves making an incision on the top of the foot. The benefit here is that you can walk soon after surgery because the stitches are not on the weight-bearing side of the foot. However, this procedure can lead to instability in the forefoot that may cause a problem in the future.
2.The second procedure involves a plantar approach, in which the incision is made on the sole of the foot. It is then required to use crutches for about 3 weeks and the scar that forms can make walking uncomfortable.
Surgery will run the risk of re occurance of swelling and scarring with a stump formation, bleeding, and loss of sensation from nerve damage.
A third procedure called Cryogeneic neuroablation is also an option. An initial study has shown that cryo neuroablation is equal in effectivenesss to surgery but does not have the risk of stump neuroma formation.
Recovery will be dependant on which treatment method was chosen. In either case foot strengthening exercises and correction of any lower limb weaknesses will be indicated.
If you have a mortons toe it will be beneficial to have a foot and lower limb assessment to commence with foot strengthening exercises and orthotic if required. It may even be of use to start with a met head dome early on in the prevention programme.