What conditions mimic Morton’s neuroma?
Morton’s neuroma often mimics other musculoskeletal and neurological conditions of the foot, which makes it quite challenging to accurately diagnose. Healthcare providers should adopt a multi-dimensional approach to identify and diagnose the Morton’s neuroma from common foot disorders like:
Metatarsophalangeal Joint Synovitis:
This condition is marked by swelling, inflammation and pain along the metatarsophalangeal joints that connect the toes to the metatarsals. Morton’s neuroma is differentiated from metatarsophalangeal synovitis due to relative lack of swelling and visible signs of inflammation.
Bursa are small fluid-filled sacs that are present along the surfaces of joints and are helpful in decreasing the risk of inflammation and friction during joint motion; however, in certain cases, these bursal sacs can become inflamed leading to bursitis. It is fairly challenging to differentiate Morton’s neuroma from bursitis on the basis of clinical examination alone. In many cases bursitis is present together with Morton’s neuroma. These can be seen with an ultrasound examination of the foot.
Fracture of toe may present with similar signs and symptoms as that of a Morton’s neuroma. A careful history together with an X Ray investigation is required to correctly identify/ diagnose the toe fractures. If the X Ray is normal and a fracture is still suspected, you may need a bone scan investigation.
Inflammation of joints is referred to as arthritis. Morton’s neuroma is often confused with arthritis pain and therefore accurate diagnosis is required for long term management. Arthritis usually occurs on multiple joints and may be worse at rest unlike Morton’s neuroma, which gets worse with weight bearing and activity.
Tarsal Tunnel Syndrome:
This is a condition where the tibial nerve is trapped as it passes under your inside ankle bone. The Tibial nerve, which is one of the main nerves of the foot, can become compressed as it passes through an anatomical tunnel in the inside ankle. In such cases the pain of Tarsal Tunnel Syndrome can be similar to Morton’s neuroma. A simple clinical test called the Tinel’s test can be used to evaluate for tarsal tunnel syndrome. The test involves tapping the Tibial nerve below the ankle, and a positive test produces tingling in the forefoot. See this video.
One of the the nerve roots which supply feeling to the foot can be squeezed as it leaves the spinal canal due to bone degenerative conditions. This can also present with severe pain, numbness and tingling sensation. Simple clinical testing (such as leg elevation tests) done by experienced providers can differentiate radiculopathy from Morton’s neuroma.
A Hammer Toe is an abnormal inward curving of the toe which can sometimes cause pain in the web space similar to Morton’s neuroma pain. Usually, the toe deformity is visible to the naked eye, and it can be diagnosed without further testing. In addition, pain in the area where the foot connects to the toes can be caused by arthritis of the metatarsal head joints. This is generally diagnosed once Morton’s neuroma is ruled out via diagnostic procedures, such as an ultrasound-guided injection or an MRI.