Ultrasound guided steroid injection for plantar fasciitis

What is plantar fasciitis?

Plantar fasciitis is a term used to describe inflammation of the plantar fascia. The plantar fascia is a thick band of tissues that runs under the foot from the heel to the toes. It supports the sole and the feet during walking and running and provides extra energy that helps propel the feet forward during activities due to its mechanical recoil properties.

What are the causes of plantar fascia pain?

The Plantar Fascia (PF) is a thick tissue band that runs underneath the foot extending from the heel bone to the toes. The causes of plantar fascia pain include an increase in the intensity of exercise or activities or changes in the type of activity. The repeated stress upon the plantar fascia results in plantar fascia thickening and inflammation. The condition can be very painful and limiting to daily activities. There is no specific gender or age predilection, as both men and women can be affected. It is reported that 10% of the population can experience plantar fascia pain at some point. Repeated episodes of plantar fascia inflammation without adequate rest to allow tissue recovery will impair the normal healing process and can lead to chronic and long-standing plantar fascia pain. This is referred to as plantar fasciopathy, to differentiate it from the active and acute changes of plantar fasciitis.

What are the symptoms of plantar fasciitis?

Patients usually describe dull pain or ache in the heel area.
Typically, you'll feel the pain when you first step out of bed in the morning.
The pain also increases with activities like walking.
Other exacerbating pain factors include exercise, walking without shoes, and wearing flat footwear.

How to tell if I have Plantar fascia pain?

Plantar fascia pain characteristically affects the heel area, felt after walking or other activities and relieved by rest and using heel support. If the condition is left untreated without adequate periods of rest, repeated episodes of inflammation will interfere with plantar fascia healing resulting in chronic plantar fascia pain and inflammation which can be challenging.

How to diagnose plantar fasciitis?

The condition is usually first suspected after assessment by your doctor or a foot specialist. Following this, imaging is required to confirm the diagnosis and rule out other conditions like plantar fibromas or Baxter’s’ nerve entrapment.

Ultrasound is the most useful imaging modality for assessing patients with suspected plantar fasciitis. It will confirm the diagnosis and assess the degree of inflammation within the plantar fascia. It will also assess for any plantar fascia tears, which can require a different treatment. If the tear is severe, it can lead to the rupture of the plantar fascia. This often occurs during sports activities such as running, football, and rugby and is characterised by sudden onset heel pain. Ultrasound can be a helpful tool for assessing the extent of the injury.

Ultrasound can also assess for the presence of small bony spurs at the heel area, which is a predisposing factor for plantar fasciitis. An X-ray is also useful to assess for bony heel spurs. MRI is also useful for the assessment. It can detect inflammation or tears in the plantar fascia and any signs of oedema or inflammatory changes in the fat heel pad. Ultrasound also allows one to accurately perform a steroid or PRP injection into the plantar fascia under ultrasound guidance.

What other conditions can mimic plantar fascia pain?

Plantar fascia pain can be mistaken for other conditions, such as:

Midfoot arthritis.
Heel bursitis.
Achilles tendinopathy. The pain is usually located at the back rather than the bottom of the heel.
Baxter's nerve entrapment.

Baxter's nerve entrapment vs Plantar fasciitis

Baxter's Nerve Entrapment results from impingement or pressure upon a small nerve (called Baxter’s nerve) as it runs at the inside aspect of the heel. Nerve entrapment here can result in severe sharp pain, pins-and-needles or burning sensations around the inner side of the ankle. There could be a previous history of trauma, but often the condition starts spontaneously without an injury. On the other hand, plantar fascia pain is usually associated with predisposing factors like increased activity or a change in type of exercise. The site of pain is also an important differentiating factor. Plantar fasciitis pain is usually located underneath the heel area, while Baxter's neuropathy pain is more towards the heel's inside. Since it is a nerve-type pain, it can be associated with a pins and needles sensation, while plantar fascia pain tends to be duller.

What is the treatment for plantar fasciitis?

Treatment usually starts with conservative measures. A physiotherapist would recommend certain measures to help treat the condition. These include supervised and self-managed exercises and activity modification. A podiatrist can also help manage plantar fasciitis by ensuring you have the correct footwear and using orthotic/gel pads to provide heel support.

What if conservative management is not helping with plantar fasciitis?

If the above-mentioned conservative measures are not adequate for treating your plantar fascia pain, other treatment options include:

Extracorporeal Shockwave Therapy (ESWT)

Evidence shows that ESWT can help promote the healing of plantar fascia inflammation. It aims to desensitise the nerve endings transmitting the pain signal within the plantar fascia. In addition, it produces intentional micro-traumas aiming to change the long-standing and chronic condition of plantar fasciopathy to a more acute and active one. This, in turn, will start a natural healing process and promote healing.

Ultrasound-Guided steroid injection for plantar fasciitis

Ultrasound-guided injection therapy for plantar fasciitis is a very effective treatment option. The potent anti-inflammatory effect from a steroid injection will reduce the pain, swelling and inflammation in the area to enhance recovery and allow effective rehabilitation. Ultrasound guidance ensures accurate and safe injection delivery to the exact site of inflammation. There is significant evidence that ultrasound guidance results in better pain relief and fewer side effects when compared to injections done without imaging guidance. Usually, a combination of local anaesthetics (numbing medicine) and corticosteroids are administered using direct ultrasound guidance.

Ultrasound-guided Platelet-rich plasma injections.

These can sometimes be considered in resistant plantar fasciitis cases. To learn more, please see our article about PRP injections.

Surgical treatment is rarely indicated unless the plantar fascia has a significant tear or rupture. Also, if there is a significant bony spur, surgical removal might be considered to reduce the irritation of the plantar fascia.

Frequently asked questions about plantar fascia steroid/cortisone injections.

What is a cortisone injection?

Cortisone is a potent anti-inflammatory medicine routinely used to manage inflammatory conditions (like bursitis and arthritis). It reduces inflammation when injected into an area. In plantar fasciitis, it is injected around the inflamed plantar fascia to reduce pain and swelling. To learn more about steroid injections, please see our FAQs.

Should plantar fascia injections be done using ultrasound guidance?

This is our routine practice, as plenty of evidence supports ultrasound guidance when performing musculoskeletal injections. Performing plantar fascia injections under ultrasound guidance allows for direct visualisation of the needle to ensure accurate placement into the area of pain/inflammation. It is important for the medicine to be injected around the inflamed plantar fascia, and not directly into it. Direct steroid injections into the plantar fascia might cause weakening and tears. Ultrasound guidance results in more accurate, less painful, and faster procedures, with better outcomes than these injections without guidance.

How long will the effect of a cortisone injection last?

Current evidence suggests that cortisone can improve pain and function for up to 3 months, but in some cases, it can last longer. Pain relief duration depends on the severity of plantar fasciitis. The steroid injection will provide a window of opportunity to undergo effective rehabilitation and attempt to address the underlying cause to enhance the pain relief achieved from the injection.

How soon will a steroid injection start to work?

A steroid injection usually takes a few days before you notice the effect, although pain relief can sometimes start on the same day. The injected area can 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, usually by undergoing effective rehabilitation.

How many steroid injections can I have?

If possible, we advise reducing the number of cortisone injections by combining any injection therapy with other conservative measures to address the underlying cause. Repeated steroid injection into the same area should be avoided if the previous injection was less than 3-4 months ago.