Objective: To evaluate the long-term efficacy of steroid injection for plantar fasciitis using clinical parameters and high-resolution ultrasonography.
Material and methods: Thirty patients (27 female and three male) with plantar fasciitis and 30 healthy controls matched by age, gender and body mass index (BMI), were enrolled in this study. Seventeen of the patients had bilateral and 13 had unilateral (six right, seven left) plantar fasciitis. Palpation-guided steroid injection was applied to the 47 heels of 30 plantar fasciitis patients. Ultrasound examination and pain intensity with visual analog scale (VAS) were assessed three times in each plantar fasciitis patients; before injection and at 1 and 6 months after steroid injection. Ultrasonography was performed to the controls at initial assessment.
Results: The plantar fascia was remarkably thicker in the plantar fasciitis group than in controls (P < 0.001). The thickness of the plantar fascia and mean VAS values in the plantar fasciitis group decreased significantly 1 month after steroid injection (P < 0.001, P < 0.001, respectively) and a further decrease was noted 6 months postinjection (P < 0.001, P < 0.001, respectively). Strong correlation was found between the changes of plantar fascia thickness and VAS values 1 month after (P < 0.001, r: 0.61) and 6 months after (P < 0.001, r: 0.49) steroid injection. The incidence of hypoechoic fascia was 73% in the plantar fasciitis group before steroid injection. It decreased significantly at 1 and 6 months postinjection (33% and 7%, respectively, P < 0.001). Gross fascia disruption or other side effects were not observed after steroid injection.
Conclusion: Steroid injection could be used in plantar fasciitis treatment for its positive long-term effects.