Patients with combat-related amputations frequently experience chronic neuroma pain that may interfere with rehabilitation, prosthesis use, mobility, sleep, and quality of life. Ultrasound-guided botulinum toxin type A injection has emerged as a potential treatment option for persistent neuroma pain; however, the optimal injection technique remains unclear.

This prospective multicenter study aims to compare two ultrasound-guided botulinum toxin injection techniques for chronic neuroma pain after combat-related amputation: intraneuroma injection and perineuroma injection.

Participants with ultrasound-confirmed painful neuromas will undergo one of the two injection approaches based on the treating physician's clinical decision and local practice. Pain intensity, neuropathic pain characteristics, phantom limb pain, prosthesis tolerance, functional outcomes, and adverse events will be evaluated during follow-up.

The goal of the study is to evaluate the feasibility, safety, and potential clinical effectiveness of intraneuroma and perineuroma botulinum toxin type A injection techniques in patients with chronic neuroma pain following combat-related amputation.

Chronic neuroma pain is a common and disabling complication following combat-related limb trauma and amputation. Persistent neuroma pain may contribute to residual limb pain, phantom limb pain, impaired prosthesis tolerance, reduced mobility, sleep disturbance, and decreased quality of life. Ultrasound-guided botulinum toxin type A injection has emerged as a promising treatment option because of its potential effects on peripheral nociceptive signaling, neurogenic inflammation, and neuropathic pain modulation.

However, the optimal injection technique for botulinum toxin administration in painful neuromas remains unclear. Two commonly used approaches include direct intraneuroma injection and perineuroma injection surrounding the neuroma. Intraneuroma injection may provide more direct pharmacological modulation of pathological nerve tissue, whereas perineuroma injection may reduce the risk of mechanical nerve injury while still targeting peripheral sensitization mechanisms.

This prospective multicenter study is designed to evaluate the feasibility, safety, and clinical outcomes associated with intraneuroma and perineuroma ultrasound-guided botulinum toxin type A injection techniques in patients with chronic neuroma pain after combat-related amputation.

Patients with ultrasound-confirmed painful neuromas will undergo ultrasound-guided botulinum toxin type A injection using one of the two injection techniques according to local clinical practice and physician decision-making. Clinical follow-up will include assessment of neuroma pain intensity, neuropathic pain characteristics, phantom limb pain, residual limb pain, prosthesis tolerance, analgesic consumption, patient-reported improvement, and adverse events.

The study aims to improve understanding of ultrasound-guided botulinum toxin injection strategies for chronic neuroma pain and to identify potential differences in safety and clinical effectiveness between intraneuroma and perineuroma approaches in patients with combat-related amputations.

Inclusion Criteria:

• Age ≥18 years
• Combat-related limb amputation
• Chronic neuroma pain lasting ≥3 months
• Ultrasound-confirmed painful neuroma
• Average neuroma pain intensity ≥4/10 on the Numeric Rating Scale
• Ability to undergo ultrasound-guided injection
• Stable analgesic regimen for at least 14 days before enrollment
• Ability to provide written informed consent

Exclusion Criteria:

• Active infection at or near the injection site
• Open wound preventing safe injection
• Previous botulinum toxin injection for neuroma pain within 6 months
• Previous neuroma surgery within 3 months
• Known allergy to botulinum toxin type A
• Coagulopathy or anticoagulation contraindicating injection
• Severe uncontrolled systemic disease
• Inability to complete follow-up assessments

De-identified individual participant data including demographic characteristics, ultrasound findings, neuroma pain intensity scores, neuropathic pain assessments, phantom limb pain measures, residual limb pain outcomes, prosthesis tolerance assessments, adverse events, and follow-up clinical evaluations collected during the study will be available for sharing. The study protocol and statistical analysis plan may also be shared upon reasonable request.

Beginning 6 months after publication of the primary study results and ending 5 years after publication.

Outcome assessors and statisticians analyzing study data will remain blinded to the injection technique group whenever feasible. Treating clinicians performing the ultrasound-guided procedures will not be blinded because of the technical differences between intraneuroma and perineuroma injection approaches.