Reduction of Phantom Limb Pain and Improved Proprioception through a TSR-Based Surgical Technique: A Case Series of Four Patients with Lower Limb Amputation

Abstract

Four patients underwent targeted sensory reinnervation (TSR), a surgical technique in which a defined skin area is first selectively denervated and then surgically reinnervated by another sensory nerve. In our case, either the area of the lateral femoral cutaneous nerve or the saphenous nerve was reinnervated by the sural nerve. Patients were then fitted with a special prosthetic device capable of transferring the sense of pressure from the sole of the prosthesis to the newly wired skin area. Pain reduction after TSR was highly significant in all patients. In three patients, permanent pain medication could even be discontinued, in one patient the pain medication has been significantly reduced. Two of the four patients were completely pain-free after the surgical intervention. Surgical rewiring of existing sensory nerves by TSR can provide the brain with new afferent signals seeming to originate from the missing limb. These signals help to reduce phantom limb pain and to restore a more normal body image. In combination with special prosthetic devices, the amputee can be provided with sensory feedback from the prosthesis, thus improving gait and balance.

Keywords: TSR; amputation; lower extremity; neuroma pain; phantom limb pain; targeted sensory reinnervation.

Figure 1

Prevention of neuroma recurrence: (A) nerve stump covering with an epineural cap; (B) transposition of this nerve stump into muscle (arrow).

Figure 2

Illustration of the surgical technique for a transtibial amputation: (A) resection of the stump neuroma; (B) transposition of the ipsilateral sural nerve to the cutaneous territory of the saphenous nerve; (C) medical device Suralis in place, providing sensory feedback from the sole to the reinnervated skin area.

Figure 3

Illustration of the surgical technique for a transfemoral amputation: (A) resection of the stump neuroma; (B) transplantation of the contralateral sural nerve as an autologous graft from the distal stump of the sciatic nerve to the cutaneous territory of the lateral femoral cutaneous nerve; (C) the medical device Suralis in place, providing sensory feedback from the sole to the reinnervated skin area.

Figure 4

(A) Numb skin area 4 weeks after denervation; (B) size reduction of the numb skin area 9 months after TSR surgery; (C) patient’s perception of the foot within the surgically reinnervated skin area (patient 2).

Figure 5

NRS scores before and after TSR surgery show a significant reduction in pain.

Figure 6

Comparison of mean test scores of the eight SF-36 subscales for TSR patients (blue bars) with the age-adjusted mean SF-36 scores of the general German population (navy blue line), lower extremity amputee population (orange line), and chronic neuropathic pain population (green line). Eight subscales measuring different domains of health-related quality of life: physical functioning (PF), role limitations—physical (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role limitations—emotional (RE), and mental health (MH). SD: Standard Deviation; LE: Lower Extremity.