Comparative Effectiveness of Ultrasound-Guided Corticosteroid Injection and Radial Extracorporeal Shock Wave Therapy for Plantar Fasciitis: A Double-Blind Randomized Controlled Trial.

Introduction: Plantar fasciitis (PF) is one of the most prevalent causes of heel pain, involving inflammation of the plantar fascia leading to pain and functional disability. The treatment options of PF include conservative, minimally invasive procedures, and surgery. Of these, radial extracorporeal shock wave therapy (rESWT) and corticosteroid injections (CSI) are widely practised treatments for PF, but its treatment outcome is often debated. Understanding the treatment course, symptom improvement rate, and cure of the underlying pathology is always essential to choose a treatment modality. This study is aimed to evaluate the early effectiveness of ultrasound-guided CSI and rESWT in the treatment of PF.

Methodology: A hospital-based, randomized, double-blind interventional study was conducted in our tertiary center to evaluate the efficacy of CSI and rESWT in participants presenting with plantar heel pain. A total of 170 participants were enrolled and randomly assigned to either the CSI or rESWT group. After treatment completion, follow-up was completed in the 70 participants in each group. The CSI group received an injection comprising 2 mL of methyl prednisolone acetate (40 mg/mL) combined with 2 ml of 2% lignocaine, while the rESWT group received 2000 shock impulses at a pressure of 2.5 bars and a frequency of 15 Hz for three consecutive weeks. The participants were assessed at baseline (week 0), 4 weeks, and 8 weeks post-treatment as this study is aimed to focus mainly on the early outcome of both primary modalities. Outcome measures included the visual analogue scale (VAS) at three instances of a day such as 'first step in the morning', 'at rest' and 'during activities of daily living' for pain assessment, the Foot and Ankle Ability Measure (FAAM) with Activities of Daily Living (ADL) and Sports subscales for functional evaluation, and ultrasonographic measurement of plantar fascia thickness.

Results: After 4 weeks and 8 weeks, VAS score continued to decrease in all the three time instances in the CSI group, whereas even though it started reducing for rESWT at 4 weeks, pain with respect to VAS score showed an increasing trend by 8 weeks. By 4 weeks, significant differences appeared within the CSI group compared to rESWT in all three instances. By 8 weeks, these differences became even more pronounced and statistically significant (p < 0.05). In terms of the FAAM scale, both groups showed increase in the score, where a higher score indicates better function. CSI resulted in more significant improvement in terms of ADL (p = 0.0001) and Sports subscale (p = 0.01). rESWT, while showing some improvement, was less effective than CSI, especially in the ADL subscale at 8 weeks. In terms of plantar fascia thickness, both groups showcased reduction in thickness, but there was no statistically significant difference between the two groups at 4 weeks (p = 0.163). At 8 weeks, the study showed a statistically significant difference between the two groups (p = 0.042). At this point of time, the reduction in plantar fascia thickness appeared to be greater in CSI compared to the rESWT group.

Conclusion: The study indicates that ultrasound-guided CSI and rESWT are both effective in PF treatment, where CSI is more effective with immediate recovery and progressive symptom improvement in contrast to the rESWT.

Clinical trial registry: Institutional ethics committee approval was obtained, and the study was registered with the Clinical Trials Registry of India (CTRI) under the registration number CTRI/2024/01/061283.