The role of ultrasonography in the diagnosis and management of idiopathic plantar fasciitis.

OBJECTIVE: To compare ultrasonography with bone scintigraphy in the diagnosis of plantar fasciitis and to compare ultrasound-guided injection with palpation-guided injection in the management of idiopathic plantar fasciitis.

METHODS: Twenty-three patients with a clinical diagnosis of idiopathic plantar fasciitis in 28 heels underwent ultrasonography and bone scintigraphy of both heels at baseline. The patients were randomized to ultrasound- or palpation-guided injection of triamcinolone hexacetonide and xylocaine into the plantar fascia. The 100 mm visual analogue scale (VAS) of pain, the heel tenderness index (HTI), and ultrasonography were performed at baseline and follow-up (mean=13.4 weeks).

RESULTS: The mean thickness (+/-standard error of the mean) of the plantar fascia, measured by ultrasonography, was 5.7+/-0.3 mm in symptomatic heels as compared with 3.8+/-0.2 mm in asymptomatic heels (P<0.001). Ultrasonography findings correlated with bone scintigraphic findings in the diagnosis of plantar fasciitis (P<0.001). Fourteen heels were randomized to ultrasound-guided injection, 10 heels were randomized to palpation-guided injection and four heels were not injected. Ultrasound- and palpation-guided injection resulted in significant mean improvements in VAS [39.6+/-9.2 (ultrasound) vs 41.5+/-8 (palpation)] and HTI [1.35+/-0.2 (ultrasound) vs 1.3+/-0.4 (palpation)]. There was no significant difference in the response rate following corticosteroid injection by either modality (ultrasound=13/14, palpation=8/10). Following injection, the mean thickness of the plantar fascia decreased from 5.7+/-0.3 mm to 4.65+/-0.4 mm (P<0.01).

CONCLUSION: Ultrasonography and bone scintigraphy are equally effective in the diagnosis of plantar fasciitis. Ultrasound-guided injection is effective in the management of plantar fasciitis but is not more effective than palpation-guided injection. Ultrasonography may be used as an objective measure of response to treatment in plantar fasciitis.