No one likes getting shots, but sometimes injections are necessary. A patient asked me what percentage of patients had success with the injection we’d recommended for her. Unfortunately, being young in my practice, and not having data of my own, nor having read a published paper outlining the exact statistics, I didn’t have the peer-reviewed answer I wanted at the time. This post will serve as both apology and answer for that patient. Luckily, there is recently published data from a group in England that shared details on what worked, and what did not for them and their patient population.1 (see below)
Why would I need an injection?
First, why would the doctor recommend an injection? Why would anyone suggest sticking a needle in someone else’s foot? The idea being an injection is two fold: decrease pain and decrease inflammation. Most of the time, the inflammatory process is causing the pain. Injections are used prior to procedures and can also be used to diagnose a condition,
What is a Corticosteroid?
A corticosteroid is a naturally produced steroid hormone in adrenal gland. These steroids can be produced synthetically produced and prepared for injection. The corticosteroids that are commonly injected for orthopedic concerns work to regulate inflammation.
This group looked at the effectiveness of foot and ankle corticosteroid injections on 365 patients over a period of at least two years.
Ankle Injection: 74% of the patients noted complete relief with the injection and 46% were still pain free at the 2 year follow up point. Only one of the 134 patients wouldn’t have another ankle injection if it were needed. These are the most promising results from the study and the authors concluded that ankle injections for synovitis, or inflammation of the joint capsule, are the most effective injections.
Morton’s neuroma: 87% of patients either had complete or partial relief after the injection. Essentially the numbers were split into thirds. One third of the patients had no symptoms after two years, one third were improved and the last third end up with surgery. Other researchers found similar results, reporting 51% of patients needing more injections or surgery, with success rates between 77% and 93%
*Less promising results were found for the following three clinical entities:
Midfoot/Hindfoot Osteoarthritis: Patients with this wear and tear joint disease reported significant improvement 82% of the time. Yet, after six months, only 32% had benefit, and only 12% after 2 years. Of the 73 patients who received injections, 30% ended up with surgery anyway.
Hallux Rigidus: Injections to treat painful, stiff big toe joints also had limited sucess. The injection was effective in 92% of patients, but only 14% maintained the positive effects for longer than three months. In this scenario, this injection could be saved for a “band-aid” therapy prior to a trip or vacation preceding surgery, but at the two year follow-up 55% of patients had surgery.
Plantar fasciitis: To treat the elusive heel pain that stems from inflammation at the origin of the plantar fascia at the inferior heel bone (calcaneus), 92% of patients had relief with the injection, but only 8% had any benefit lasting longer than 3 months.
Lesser toe joints: 50% of patients had no pain post injection, but 3 out of 16 developed a plantar plate rupture. I have been to many seminars where lecturers have abandoned this injection altogether, in favor of a more reliable and less risky and invasive treatments such as orthotics or taping.
Not all shots are created equal. Different conditions result in different results. The benefits from an injection will last longest with ankle pain and neuroma, but otherwise the results are fleeting and provide only temporary relief. This doesn’t mean that injections can’t be very beneficial even with these results, but they aren’t always a permanent fix.
Is the injection beneficial?
Ankle joint – 74%
Neuroma – 87%
Plantar fasciitis – 92%
Midfoot/hindfoot osteoarthritis – 82%
Hallux Rigidus – 92%
Will it last?
Ankle joint – 46% at two years
Neuroma – 31% at two years
Plantar fasciitis – 8% at 3 months
Midfoot/hindfoot osteoarthritis – 32% at 6 months, 12% at two years
Hallux Rigidus – 14% at 3 months
1. Grice et al. “Efficacy of Foot and Ankle Corticosteroid injections” – Foot & Ankle International. 2017, Vol. 38(1) 8-13.