Do corticosteroid injections improve plantar heel pain?
There is low-quality evidence that corticosteroid injections slightly reduce heel pain at one month, but they make no significant difference beyond that time. Patients treated with corticosteroid injections were less likely to experience treatment failure—a designation that was defined differently between studies (number needed to treat [NNT] = 3). Injections do not appear to provide any functional benefits.1 (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.)
Plantar heel pain is common, accounting for four in 1,000 outpatient physician visits and an estimated 1 million visits per year in the United States.2 Most plantar heel pain is caused by plantar fasciopathy, commonly called plantar fasciitis. Plantar fasciopathy is more likely in patients who are obese (odds ratio [OR] = 3.7; 95% confidence interval [CI], 2.9 to 5.6) and in those who have occupations in which the majority of time is spent standing (OR = 3.6; 95% CI, 1.3 to 10.1).3 Plantar fasciopathy is common in runners, with an incidence of 31% over five years in one study.4 The authors of this review sought to evaluate the effect of corticosteroid injections on plantar heel pain in adults.1
This Cochrane review included 39 randomized trials with 2,492 adults who had plantar heel pain.1 Studies ranged from one month to two years in duration. The studies were of low to very low quality and were judged to have high risk of bias. Eight studies compared local corticosteroid injections with placebo or no treatment. At one month, corticosteroid injections provided slight clinical benefit (mean difference [MD] on a visual analog scale [0 to 100 mm; higher scores indicate worse pain] = −6.38 mm; 95% CI, −11.13 to −1.64). Between one and six months, corticosteroid injections had no significant pain benefit (MD = −3.47 mm; 95% CI, −8.43 to 1.48). Two studies evaluated function, although neither revealed benefit at any time during follow-up.
Three very-low-quality studies with a total of 363 patients evaluated treatment failure, defined as persistent pain at eight weeks, the need for repeat treatment at 12 weeks, or no pain relief at six months. Treatment failure was significantly reduced by corticosteroid injections (absolute risk reduction = 33.7%; 95% CI, 27.2% to 38.7%; NNT = 3 [95% CI, 3 to 4]).
This review also included comparisons between corticosteroid injections and 15 other interventions. No useful comparisons could be made because of the small sample sizes for the different interventions.
Types and doses of corticosteroid varied between studies, with two studies not reporting the corticosteroid used. Injections generally included local anesthetic. Adverse effects included postinjection pain, injection-site infection, and, rarely, rupture of the plantar fascia.
A network systematic review published in 2016 included some of the studies from this Cochrane review and determined that corticosteroid injections significantly improved pain over placebo at two months, but showed no difference at six months after treatment.5 Guidelines from the American College of Foot and Ankle Surgeons from 2010 recommend corticosteroid injections as a first-tier intervention, along with weight loss, padding or strapping, orthotics, anti-inflammatory medication, and patient-directed Achilles and plantar fascia stretching.6
The practice recommendations in this activity are available at http://www.cochrane.org/CD009348.
Editor's Note: The number needed to treat for treatment failure reported in this Cochrane for Clinicians was calculated by the authors based on raw data provided in the original Cochrane review.
The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the U.S. government.