Treatment of proximal plantar fasciitis with ultrasound-guided steroid injection

Objective: To investigate the efficacy of ultrasound-guided steroid injecti on for the treatment of proximal plantar fasciitis and to evaluate mechanic al properties of the heel pad after steroid injection. Design: Proximal plantar fascia and heel pad were assessed with a 10-MHz li near array ultrasound transducer. Pain intensity was quantified with a tend erness threshold (TT) and visual analog scale (VAS). The transducer was inc orporated into a specially designed device to measure mechanical properties of the heel pad. Evaluations were performed before injection and at 2 week s and 3 months after injection. Setting: An outpatient clinic of a tertiary care center. Patients: Fourteen consecutive patients with unilateral proximal plantar fa sciitis. Intervention: Ultrasound-guided injection of 7 mg betamethasone and 0.5 mL of 1% lidocaine into the inflamed proximal plantar fascia. Main Outcome Measures: VAS, TT: heel pad and plantar fascia thickness, and echogenicity of the proximal plantar fascia on sonogram were assessed. Mech anical properties included unloaded heel pad thickness, compressibility ind ex, and energy dissipation ratio. Results: Both VAS score +/- standard deviation (SD, 5.43 +/- 2.03, 1.39 +/- 2.19, 0.57 +/- 1.40 at the 3 measurements, respectively) and TT +/- SD (5. 05 +/- 1.42, 9.34 +/- 1.84, 9.93 +/- 1.98 kg/cm(2) at the 3 measurements, r espectively) improved significantly (p < .001) after steroid injection. The mean thickness of the planter fascia was greater in the symptomatic side t han in the asymptomatic side before treatment (0.58 +/- 0.13 cm vs 0.40 +/- 0.11 cm. p < .001). The thickness had decreased significantly 3 months aft er injection (0.46 +/- 0.12 cm at 2 weeks, 0.42 +/- 0.10 cm at 3 months, p <.001). The hypoechogenicity at the proximal planter fascia disappeared aft er steroid injection (p < .001). Mechanical properties of the heel pad did not change 3 months after steroid injection (p > .05), Conclusion: Ultrasound offers an objective measurement of the therapeutic e ffect on proximal plantar fasciitis.-Accurate steroid injection under ultra sound guidance can effectively treat proximal plantar fasciitis without sig nificant deterioration of the mechanical properties of the heel pads.