Innovating innervation: how non-biological targets can revolutionize amputation care

Abstract

Amputation is a historically well-grounded procedure, but such a traumatic operation invites a litany of postoperative complications, such as the formation of agonizing neuromas. Developments in mitigating these complications include the clinically successful targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI), which showcased the potential for utilizing peripheral nerves' regenerative capabilities to circumvent neuroma formation and isolate neural activity for control of a sophisticated prosthetic device. Nevertheless, these techniques only record the aforementioned neural activity from the reinnervated muscle, not the nerve itself, which may ultimately limit the degree of functionality they can restore to amputees. Alternatively, regenerative sieve electrodes are non-biological end targets for reinnervation that utilize their porous structure to isolate regenerating axons into discrete transient zones lined with stimulating and recording electrodes. Albeit more invasive, such direct contact with the once-damaged nerve opens the door for highly selective, bi-directional neural interfaces with the capacity to restore higher degrees of sensorimotor functionality to patients for enhanced rehabilitation outcomes. By expanding the definition of innervation to include non-biological targets, clinicians can make room for these advancements in neural interfacing to revolutionize patient care.