Ultrasound-Guided Acupotomy at the Plantar Fascia–Flexor Digitorum Brevis Interface for Plantar Fasciitis: A Retrospective Case Series

Background: Chronic plantar fasciitis (PF) often involves fibrosis at the plantar fascia-flexor digitorum brevis (PF-FDB) interface, a key gliding layer implicated in heel pain.Despite its relevance, clinical interventions directly targeting this anatomical interface remain limited.Objectives: To evaluate the clinical effectiveness and safety of ultrasound-guided acupotomy targeting the PF-FDB interface without local anesthesia in patients with chronic or post-traumatic PF.Methods: This retrospective case series included three patients (mean age 59 years; mean symptom duration 16.3 months) with refractory PF.Acupotomy was performed under ultrasound guidance using a 0.5 mm miniscalpel needle to release adhesions at the PF-FDB interface.The procedure was done without local anesthesia, using real-time sensory feedback as a biological safety mechanism.Pain was assessed via the numeric rating scale (NRS) for morning and activity-related pain.Plantar fascia thickness and echotexture were evaluated before and after treatment.Results: All patients reported complete resolution of morning pain (mean NRS 9.0 to 0.0) and marked reduction in activity pain (mean NRS 8.0 to 1.7).Two showed reduced plantar fascia thickness (mean reduction 0.5 mm).One case showed unchanged thickness (6.7 mm) but improved echotexture with symptom relief.No adverse events or neurological complications occurred.Conclusion: Ultrasound-guided acupotomy targeting the PF-FDB interface without local anesthesia appears safe and effective for treating chronic or post-traumatic PF.The technique enables precise targeting while preserving neural safety through patient feedback.Controlled trials are warranted to validate these findings.