Role of ultrasonography in the diagnosis and management of plantar fasciitis

ABSTRACT

To evaluate the sonographic features of plantar fasciitis and to investigate the efficacy of ultrasound-guided local steroid injection in its management. Forty patients, aged 25-55 years who had a clinical diagnosis of plantar fasciitis, 1-3 years previously and twenty age-matched healthy volunteers [control group], were evaluated with conventional x-rays then with ultrasound using a 7.0 MHZ linear-array transducer. All patients had calcaneal spurs in their X-rays. Heel pain was unilateral in 24 patients and bilateral in 16. Sagittal sonograms were obtained, and the thickness of plantar fascia was measured at its proximal end near its insertion into the calcaneus. Other findings including hypoechoic fascia, fiber rupture, perifascial fluid collections and calcifications were searched for. Evaluations were performed before, at 2 weeks and 3 months after a single dose of ultrasound-guided local steroid [7 mg Betamethasone and 0.5ml of 1% lidocaine] injection into the inflamed plantar fascia. Pain intensity was quantified with a tenderness threshold [TT] and visual analog scale [VAS]. Plantar fascia thickness was significantly increased in heels of patients with plantar fasciitis [mean 3.91 +/- 0.53] as compared to control [mean 2.13 +/- 0.18] [p<0.0005]. The mean thickness of the plantar fascia had decreased significantly on evaluation after 2 weeks [mean 3.73 +/- 0.53] [p<0.05]. While after 3 months there was a highly significant decrease [mean 2.39 +/- 0.43] [p<0.0005]. The mean VAS score and TT showed a highly significant improvement on evaluation after 2 weeks and 3 months [mean 4.57 +/- 0.98, 1.55 +/- 0.84 and 7.12 +/- 0.75, 9.47 +/- 1.66 respectively, p<0.0005]. The comparison between the second and third evaluations of all our parameters showed a highly significant improvement [p<0.0005]. The proximal plantar fascia was diffusely hypoechoic as compared to controls. No fascial rupture, perifascial fluid collection or calcifications were identified. Increased thickness of the fascia and hypoechoic fascia are sonographic findings of plantar fasciitis. Sonography provides sufficient information for the physician to confirm an initial diagnosis of plantar fasciitis and assess individual treatment regimens