Silencing Neuroma Pain-Botulinum Toxin Versus Local Anesthetic Injection

SILENCE-NEUROMA Trial: Silencing Neuroma Pain-Botulinum Toxin Versus Local Anesthetic Injection in a Randomized Controlled Trial

Neuroma-related pain is a frequent and disabling condition after limb trauma and amputation. Available treatments often provide short-lasting or insufficient analgesia. The SILENCE-NEUROMA Trial is a multicenter, randomized, double-blind, active-controlled study designed to compare the efficacy and safety of botulinum toxin type A versus local anesthetic injection for the treatment of neuroma-related pain. The primary outcome is pain reduction at 8 weeks after treatment.

Neuroma pain following limb trauma or amputation is characterized by focal neuropathic pain, trigger-point tenderness, and significant functional impairment. Local anesthetic injections are commonly used for diagnostic and therapeutic purposes but typically provide only transient relief. Botulinum toxin type A has demonstrated analgesic properties through inhibition of neurotransmitter release and neurogenic inflammation, potentially offering longer-lasting pain relief.

This multicenter, randomized, double-blind, active-controlled trial will enroll adults with clinically and imaging-confirmed neuroma-related pain persisting for at least 3 months after limb trauma or amputation. Participants will be randomized in a 1:1 ratio to receive either ultrasound-guided botulinum toxin type A injection or ultrasound-guided local anesthetic injection using an identical technique and volume.

Participants will be followed for 24 weeks. Pain intensity will be assessed using a numerical rating scale at predefined intervals. Secondary outcomes include responder rates, neuropathic pain characteristics, pain interference, functional outcomes, analgesic consumption, durability of pain relief, and safety. The study aims to provide high-quality evidence to guide interventional pain management strategies for neuroma-related pain.

Inclusion Criteria:

• Age ≥18 years
• History of limb trauma and/or limb amputation at least 3 months prior to enrollment
• Clinical diagnosis of neuroma-related pain with focal tenderness and positive - - Tinel sign
• Imaging confirmation of neuroma by ultrasound or MRI
• Average pain intensity ≥4 on a 0-10 Numerical Rating Scale (NRS) during the week prior to screening
• Stable analgesic regimen for at least 14 days prior to enrollment
• Ability to provide written informed consent

Exclusion Criteria:

• Chronic pain condition unrelated to neuroma that predominates clinical symptoms
• infection at or near the planned injection site
• Known neuromuscular junction disorders (e.g., myasthenia gravis)
• Pregnancy or breastfeeding
• Botulinum toxin treatment within the previous 4-6 months
• Planned surgical neuroma revision during the study period
• allergy or hypersensitivity to botulinum toxin or local anesthetics