Ultrasound guided Morton's neuroma steroid injection

What is Morton's Neuroma?

Morton's Neuroma is a condition characterised by thickening and irritation of the small nerves between the toes at the front of the foot. Its exact cause is not fully understood, but it is believed that wearing high-heeled shoes that are narrow at the front may contribute to its development. This is because these shoes can pressure the bones at the front of the foot, leading to nerve irritation and discomfort. Morton’s Neuromas are more common in the 2nd and 3rd webspace and are often accompanied by inflammation of small sacs of fluid between the toes, known as intermetatarsal bursitis. While it can affect anyone, it is more commonly seen in women and is not typically found in children and adolescents.

Morton’s neuroma anatomy

Morton's neuroma is caused by swelling and irritation of a small nerve (called the plantar interdigital nerve) that runs at the front of the foot. It is most seen between the third to fourth toes.

What are the symptoms of Morton's Neuroma?

The clinical features of Morton’s neuroma include:

You may experience a sharp pain in the forefoot, often compared to an electric shock or walking on pebbles, between the bones at the site of Morton's neuroma, typically located between the 3rd and 4th toe.
A feeling of pins and needles in the ball of the foot at the neuroma site, radiating between the toes.
The symptoms of Morton’s neuroma can be exacerbated by activities like running or wearing tight shoes.

What is Morton's Neuroma Pain?

Morton's neuroma pain is a type of neurogenic pain, which means it stems from the nerves. It can be described as a tingling or electric sensation, but many patients often describe it as feeling like they are walking on a pebble.

What other conditions can cause forefoot pain and mimic Morton's Neuroma?

Other medical conditions that can result in forefoot pain and could be mistaken for Morton’s neuroma include:

Morton's neuroma vs intermetatarsal bursitis

Morton's neuroma and intermetatarsal bursitis are two conditions that are frequently observed together. Morton's neuroma refers to the thickened and irritated nerve located between the toes, while intermetatarsal bursitis is the inflammation of a small sac in the same area. An ultrasound-guided steroid injection can effectively treat both conditions.

Morton's neuroma vs osteoarthritis of the midfoot

The two conditions are very different. Wear and tear changes to the joints within the foot cause the latter. It can be mistaken for Morton’s neuroma. Imaging, particularly foot X-rays and ultrasound, are very useful in differentiating the two conditions.

Morton's neuroma vs plantar plate injury.

The plantar plate is a small structure that runs underneath the joints at the front foot. It is a very important stabilising structure. Plantar plate injury can happen due to repeated stress upon the joint without a specific injury history. It can lead to forefoot pain and is mistaken for Morton’s neuroma. Ultrasound assessment is very useful in differentiating the two conditions as the treatment tends to differ completely.

How to diagnose Morton’s neuroma?

Morton’s neuroma is initially suspected after clinical assessment by a foot specialist. Imaging is usually required. Ultrasound is an excellent tool for assessment when a neuroma is suspected. Usually, dynamic assessment is performed by pressing on the top of your foot and on the sides of the foot (lateral squeeze test) during the scan. This will help visualise small neuromas and differentiate them from intermetatarsal bursal fluid (fluid within the small, inflamed sacs between the toes). MRI can also be useful for the assessment, especially if the ultrasound is negative and there is clinical concern regarding other conditions like a stress fracture.

If Morton's neuroma is suspected, a foot specialist will conduct a clinical assessment and imaging is usually required. Ultrasound is an excellent tool for diagnosis, as it allows for dynamic assessment by pressing on different parts of the foot during the scan. This helps visualise small neuromas and differentiate them from intermetatarsal bursitis. If ultrasound is negative and there is still a concern, an MRI may be useful to rule out other conditions that can cause pain at the forefoot, like a stress fracture.

What is the treatment for Morton’s neuroma?

Initial steps to treat Morton's neuromas involve conservative measures to improve foot biomechanics and address muscle imbalance or tightness. Physiotherapists typically handle these measures. On the other hand, podiatrists can review footwear to ensure its suitability and not put pressure on the forefoot. They may also suggest using insoles, orthotic shoes, or metatarsal pads to support the forefoot.

Can ultrasound guided cortisone injections help with Morton’s neuroma?

Ultrasound-guided steroid injections are a common treatment option for Morton’s neuroma. First, an ultrasound assessment will confirm the diagnosis and rule out other causes of forefoot pain like intermetatarsal bursitis, capsulitis/injury to the plantar plate or a stress fracture. Ultrasound allows direct visualisation of the needle during the injection to ensure accuracy and safety.

Is ultrasound needed in Morton’s neuroma injections?

There is significant evidence that ultrasound guidance results in better outcomes, less pain and fewer side effects compared to non-guided injections.

Ultrasound-guided cortisone injection for Morton’s neuroma

Cortisone is a strong anti-inflammatory medicine routinely used to manage inflammatory conditions (like bursitis and arthritis). It reduces the swelling and inflammation within the intermetatarsal bursa. To learn more about steroid injections, please see our FAQs.

How long will the effect of a cortisone injection last?

Current evidence suggests that cortisone can improve pain and swelling for up to 3 months, but in some cases, it can last longer. Using ultrasound guidance ensures accuracy. A steroid injection will reduce inflammation and enhance the effect of other conservative measures. If this is adhered to, most patients notice prolonged pain relief.

How soon will a steroid injection start to work?

A steroid injection usually takes a few days (1-3) before you notice the effect, although sometimes the pain relief can start on the same day. The injected area will often feel sore for the first few days. This is referred to as (steroid flare) and can be seen after a steroid injection.

Do steroid injections just hide/mask the pain?

Steroid injections do not just mask or hide the pain, but they act by reducing the inflammation in the targeted area, thus providing a strong and local anti-inflammatory effect to help control the symptoms and allow the patient to manage the condition, in combination with other conservative measures.

How many steroid injections can I have?

If possible, we advise reducing the number of cortisone injections by combining any injection therapy with effective conservative measures. Repeated steroid injection into the same area should be avoided if the previous injection was less than 3-4 months ago. Especially, with Morton's neuroma, we aim to reduce the number of injections to 1 or 2, before considering other treatment options.

What are other treatment options for Morton's neuroma?

If conservative management and ultrasound-guided injection treatment do not offer relief, confirming the diagnosis by reviewing imaging is necessary. Surgical excision or cryotherapy are additional treatment options. Cryotherapy involves using a special needle to freeze the neuroma under ultrasound guidance, which has shown promising results despite being a new treatment.