Managing Major Peripheral Nerves in Forearm-Level Amputations With TMR and RPNI: What's the Best Recipe?

Area of Science:

• Amputation Surgery
• Neurology
• Regenerative Medicine

Background:

• Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) are used to prevent symptomatic neuroma formation in amputees.
• Forearm amputations present numerous muscle targets, complicating the selection of optimal TMR strategies.
• This study aimed to identify the best TMR targets, assess the role of RPNI, and define patient selection criteria for forearm amputations.

Purpose of the Study:

• To evaluate the efficacy of different TMR target locations (superficial/proximal vs. deep/distal) in preventing symptomatic neuroma formation.
• To determine the effectiveness of RPNI as an adjunct treatment for neuroma prevention.
• To investigate patient-selection criteria, particularly the impact of poorly controlled diabetes on neuroma development.

Main Methods:

• Retrospective analysis of forearm-level amputations performed between 2017 and 2022.
• Exclusion of patients with prior TMR by external providers, follow-up less than 6 months, or inadequate documentation.
• Comparison of symptomatic neuroma development between patients receiving superficial/proximal TMR versus deep/distal TMR.

Main Results:

• Out of 39 patients, 16 developed symptomatic neuromas.
• No symptomatic neuromas occurred in patients with deep or distal TMR targets.
• RPNI was successful in 11 out of 12 treated nerves, and no patient with poorly controlled diabetes developed a symptomatic neuroma.

Conclusions:

• Deep and distal TMR targets are superior to superficial and proximal targets in preventing symptomatic neuromas after forearm amputation.
• RPNI serves as a valuable adjunct for neuroma management, particularly for the radial sensory nerve.
• Patients with poorly controlled diabetes may not require advanced nerve management strategies for neuroma prevention.