The plantar fascia is a fibrous band connecting the heel to the forefoot. Injury to the plantar fascia — plantar fasciitis — is common in athletes and weekend warriors, and most cases settle with stretching, footwear, and exercise. For severe or stubborn cases, an injection may be the next step. So, is a plantar fascia ultrasound injection worth it, and is a steroid injection for plantar fasciitis risky?

Dr Masci performs plantar fasciitis injections under ultrasound guidance at his London clinics as one-stop visits, using a nerve block to make them comfortable. Here’s what works, what doesn’t, and what to expect.

When do you need a plantar fasciitis injection?

Rarely as a first step. Most cases of plantar fasciitis settle with rest, stretching, footwear, and shockwave therapy — and evidence supports trying these before any injection. We reserve injections for cases that fail simple measures, and only after confirming the diagnosis, because not all heel pain is plantar fasciitis.

Is a cortisone injection for plantar fasciitis a good option?

Usually not as a first choice. Dr Masci co-authored the evidence review showing that ultrasound-guided injections work for plantar fasciitis, and that a steroid injection for plantar fasciitis relieves pain for a few months. But the risks are real: skin thinning, fat-pad atrophy, and plantar fascia rupture. And one randomised trial found cortisone added nothing to physiotherapy and heel cups.

Ultrasound guidance reduces the risk by keeping the steroid out of the fascia itself and the fat pad. A plantar fascia ultrasound injection also gives better pain relief than a blind injection. If you do have cortisone, have it under ultrasound — never blind.

PRP injection for plantar fasciitis

plantar fasciitis injection

PRP is our preferred injection. A review comparing PRP with cortisone found PRP more effective at 3 months and 1 year, with at least 15 studies showing better outcomes, and without cortisone’s risk of rupture or fat atrophy. In severe cases, PRP outperformed cortisone and proved safer than surgery. The trade-off: PRP works gradually, taking 2–3 months.

The formula matters. The optimal PRP for plantar fasciitis has a high platelet concentration and high white cell count — a double-spin, higher-volume system. Dr Masci uses Arthrex ACP Max, which delivers a superconcentrated dose in a single injection.

Do plantar fasciitis injections hurt? The tibial nerve block

Yes — heel injections can be painful. Two techniques reduce that. First, ultrasound guidance improves accuracy and lowers pain. Second, Dr Masci performs a tibial nerve block in the ankle about 15 minutes beforehand: a small dose of local anaesthetic around the tibial nerve, under ultrasound guidance, numbs the foot. It makes the plantar fascia injection much more comfortable. Few clinics offer this — it’s a genuine difference in the patient experience.

How much does a plantar fasciitis injection cost in London?

At Dr Masci’s Chelsea clinic, a cortisone plantar fascia injection costs £400, and ACP Max superconcentrated PRP costs £1,350, each as a one-stop visit — consultation, diagnostic ultrasound, and injection (with nerve block) in a single appointment. Other clinic locations cost more. Full fees here.

PRP recovery: what happens after the injection?

Plantar fascia pain tends to worsen before it improves, so offload the foot for about a week. A typical PRP recovery timeline:

  • Days 0–7: short walking boot; upper-body weights from day 2, swimming from day 3
  • Days 7–14: supportive trainers for gentle walking; start foot strengthening
  • Days 14–21: add cycling and the seated calf-raise machine; build walking to 10–15 minutes daily
  • Days 21–28: add standing weighted calf raises; faster walking over 20 minutes
  • Days 28–42: begin a progressive walk/run programme

If you have a nerve block, expect ankle and foot numbness for a few hours — don’t drive until it resolves.

Plantar fasciitis surgery: is it worth it?

A last resort. No surgical technique clearly beats the others, and since 80% of cases resolve within 12 months, we delay surgery at least that long. Cutting the fascia off the heel worries us — it weakens the arch and can cause a flat foot. If surgery is considered, a gastrocnemius (calf) fascia release shows more promise and avoids operating on the heel itself.

Frequently asked questions about plantar fasciitis injections

Cortisone or PRP — which should I choose?

For lasting benefit without the risk of rupture or fat-pad atrophy, PRP is our preference, with the understanding that it takes 2–3 months to work. Cortisone acts faster but offers only short-term relief and carries higher risks. The right choice depends on your circumstances — we discuss both at the consultation.

My injection hasn’t worked after two weeks. What now?

Wait. A cortisone shot can take up to 4 weeks to take effect, and PRP takes 2–3 months. If there’s still no benefit after that, the next options are shockwave or, if you had cortisone, a switch to PRP.

Should I have an injection if my heel is already improving?

Generally not. Injections carry risks, so if symptoms are settling on their own, it’s usually better to continue conservative treatment and keep the injection in reserve.

Could my heel pain not be plantar fasciitis at all?

Possibly. If imaging shows a normal plantar fascia, suspect Baxter’s nerve entrapment or another cause — a plantar fasciitis injection won’t help those. This is exactly why we scan before injecting.

Final word from Sport Doctor London about plantar fasciitis injections

Most cases of plantar fasciitis settle without an injection. For complex cases, shockwave comes first, then an injection — and the evidence increasingly favours PRP over cortisone for better, longer-lasting relief without the risks. Whatever the injection, insist on ultrasound guidance, ideally with a nerve block for comfort. And confirm the diagnosis first: not all heel pain is plantar fasciitis.

To book a one-stop plantar fasciitis injection in London, contact Dr Masci’s team here or call +44 (0) 203 488 0350.

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