Morton's disease (ICD code: G57.6) or Morton's neuroma refers to a disorder of the nerves on the underside of the foot. They are part of the nervous system and form a fine network with extensions to supply the little toes. This is not about the motor skills of the toes, but about their sensitivity. It is important that toes can feel and react to touch such as pressure or wetness.
In Morton's disease or Morton's neuralgia, this sensory perception is impaired. It does not simply fail. Morton's disease or Morton's neuroma is accompanied by severe nerve pain and other sensory disturbances. After some surgeons noticed the pain phenomenon as early as the 19th century, it was finally named after the doctor T. G. Morton.
Interaction of many bones: Anatomy of the feet © bilderzwerg / Fotolia
The condition is caused by a compression or other irritation of the nerves between the toes. The area affected is the metatarsophalangeal joints or the so-called heads on the metatarsal bones. Morton's disease usually occurs between the third and fourth metatarsal bones in the third interdigital space, occasionally also between the second and third interdigital space.
Multiple Morton's neuromas on the same foot are also possible, but rare. A permanent compression of these foot nerves exerts pressure . The associated pain leads to chronic incorrect loading of the foot or incorrect posture to relieve pressure on the nerves. Nodular thickening and tissue remodeling occur at the branches of the nerves: the neuroma.
Thickened nerves in Morton's disease © ellepigrafica / Fotolia
Morton's disease is characterized by sensory disturbances in the area of the forefoot or metatarsus. An initially diffuse, uncomfortable discomfort develops into severe pain that radiates from the midfoot to the toes. As the sole of the foot is also affected by forefoot nerve pain, Morton's disease is also known as (Morton's) metatarsalgia.
Patients suffering from Morton's neuroma complain of discomfort , particularly after prolonged walking and frequent rolling of the foot. In addition, there is often a feeling of numbness in the toes.
Both pain and numbness often occur in attacks. After initially being symptom-free, pain suddenly sets in. The nerve pain can also occur spontaneously while sitting or lying down, even while sleeping.
Excessive strain on the forefoot often leads to the development of Morton's neuroma. Regularly wearing shoes with high heels in particular promotes Morton's disease.
Other contributing factors are
- Hallux valgus (ball of the foot)
- Foot deformities: Bowlegged foot (flat foot), splayfoot, pointed foot and hollow foot
- Foot injuries
- Foot operations
Constant nerve stimulation caused by this causes nerve inflammation as well as scarring or thickening of the nerves, which further aggravates the condition.
If your feet are already misaligned or you are experiencing pain, it makes sense to talk to an orthopaedist about your foot health.
Pain-free feet - not a given with Morton's neuroma. © Valua Vitaly / Fotolia
The nature of the symptoms and the patient's description usually point clearly to Morton's neuroma. The doctor will also examine the foot thoroughly. There are standard tests that provide information about the disease.
The typical tenderness at the metatarsal heads and pain when squeezing the forefoot - the Gaenslen grip - indicate a well-founded suspicion of Morton's disease during the examination. Further certainty is provided by the Hohmann grip, which triggers pain when the metatarsal heads are displaced.
The doctor examines the painful foot with a firm grip. © JPC-PROD / Fotolia
The injection of a local anesthetic into the affected space between the metatarsal bones provides the final confirmation. X-rays remain unremarkable. Other imaging procedures such as sonography or magnetic resonance imaging(MRI) show the tissue growths present in Morton's neuroma, but are not usually necessary for diagnosis.
There are two treatment options for Morton's disease, namely conservative and surgical measures.
Conservative therapy
The first treatment approach is always outpatient conservative therapy. The inflammation of the foot nerves is treated first. Injections of cortisone preparations, which are diluted with a local anesthetic beforehand due to the highly sensitive, painful foot nerves, have proven effective here. One or two injections six weeks apart are almost always sufficient. After this, the patient is usually free of pain.
Conservative treatment with cortisone injections can lead to secondary bleeding or infections. After infections, painful bruising occasionally occurs, which subsides after one to three days. It is rare for the skin to become thinner or discolored. Some patients are hypersensitive or allergic to the cortisone or anesthetic.
Surgical therapy
If the nerve tissue shows scarring or thickening or if the cortisone injections have been unsuccessful, the next treatment step is surgery. You will usually be admitted to hospital for this. The surgeon will surgically treat the nerve inflammation and thickening with the aim of neurolysis (nerve removal) and decompression (pressure relief). The surgeon removes the Morton's neuroma. The majority of patients achieve freedom from symptoms or at least a satisfactory improvement in symptoms.
As with any other operation, Morton's neuroma can also have side effects. Postoperative bleeding, wound healing disorders and infections are possible. Pain at the nerve stump or scar discomfort are further conceivable undesirable consequences of the operation. There are also the usual surgical risks such as embolisms, thromboses or complications caused by previous illnesses. Before the operation, you will receive an information brochure about the planned procedure. You will also have the opportunity to clarify any unanswered questions with your doctor.
The dressing applied after the operation will be changed daily, the first few days by your doctor, later by yourself after you have been instructed accordingly. As the healing process progresses, a bandage or plaster will eventually suffice. If the incision was made under the sole of the foot, you will be given a relief shoe or bandage shoe for around three weeks. Once the wound has healed, your doctor will remove the stitches.
Immediately after the operation, pain may occur again despite the removal of the painful nerve tissue - so-called phantom pain. This almost always ends after a few weeks until the treated tissue has regenerated. The scar may also hurt a little at first. Overall, most treatments for Morton's disease are successful.
To ensure that the swelling subsides and the wound heals as quickly as possible, you should stand and walk as little as possible. Put your foot up when sitting. Keeping the foot elevated protects the foot and prevents thrombosis by improving blood circulation. Cooling packs help to reduce swelling and relieve pain caused by the operation.
Shoes, insoles and gymnastics
As a preventative measure, you should prefer flat shoes to high-heeled shoes. Soft or, if necessary, individually adapted orthopaedic insoles increase the load-bearing capacity of the forefoot when standing and walking.
Special foot exercises that strengthen the arch of the foot and tone the feet are a good preventative measure as long as you are pain-free. If you have existing complaints, you should first speak to a doctor or physiotherapist.
