Peppering Injection for Plantar Heel Pain: A Double-Blind Randomized Feasibility Study (a Short Report)

Plantar heel pain affects up to 10% of individuals and often limits activity. Corticosteroid injections provide short-term relief, though emerging evidence suggests that benefits may derive from mechanical stimulation rather than pharmacologic effect. This pilot study evaluated the feasibility of a double-blind randomized trial comparing corticosteroid vs saline delivered via a standardized infracalcaneal peppering (fenestration) technique. Exploratory outcomes included short-term changes in Foot Function Index (FFI) and visual analog scale (VAS) pain scores.

A total of 495 adults were identified via electronic health record queries, research registries, and targeted outreach; 76 were screened (assessed for eligibility) and 41 were enrolled and randomized (21 corticosteroid; 20 saline). Feasibility metrics included recruitment yield, visit completion, protocol adherence, and data completeness. Exploratory analyses used unadjusted linear mixed effects models.

Feasibility was demonstrated through adequate recruitment, 76% study completion (31/41), high protocol adherence, and low missingness of scheduled outcome measurements (3%). Baseline characteristics were comparable. Exploratory unadjusted estimates favored saline: FFI change -3.2 points (95% CI: -6.1, -0.4), VAS First-Step Pain change -6.6 mm (95% CI: -10.7, -2.4), and VAS General Pain change -3.0 mm (95% CI: -6.6, 0.7); between-group differences were below published minimal important difference (MID) thresholds (≈7 points for FFI Total; ≈9 mm for VAS).

A randomized peppering-injection trial was feasible, and early unadjusted signals are consistent with a mechanically mediated effect independent of corticosteroid pharmacology. Larger, longer-term trials-including non-injection controls-are required to evaluate clinical effectiveness.

Level II, pilot feasibility study.