Return to sport after transtibial amputation and targeted sensory reinnervation: a case report

Targeted sensory reinnervation (TSR) was introduced to avoid the painful phantom-limb syndrome that appears post-amputation in 60-90% of patients, compromising prosthesis tolerance and functional independence. With TSR, a sensory nerve of the amputated limb is connected with a sensory nerve that reinnervates an area of the skin of the residual limb, to regain sensitivity of the missing limb within 6-12 months after surgery. Our patient suffered a displaced fracture of the left leg, loss of substance and compartment syndrome during a motorcycle accident at the age of 23. After numerous operations to avoid amputation, Paralympic sport began. After 22 years, a further osteotomy caused disabling neuropathic pain for which he decided on trans-tibial amputation and TSR (re-innervation of the lateral femoral cutaneous nerve with the sural nerve). Six weeks after surgery, he received the first prosthesis, equipped with a pressure sensor in the sole of the shoe, which transmits to the actuator placed on the reinnervated skin area, allowing the signals coming from the prosthetic sole to be perceived as genuinely coming from the lost foot. Nine months after surgery, after rehabilitation and training with new prostheses, in absence of neuropathic pain, the results of an incremental test, walking uphill on a treadmill, showed V’O2max=51.4mL/kg/min, heart rate=102% of theoretical HRmax and aerobic threshold (2 mM lactate) at an ascent speed of 863 m of elevation gain per hour. Two years after amputation he covered the elevation of 8849 m (named Everesting) in 19h 53‘, climbing a mountain trail several times with an average ascent speed of 556 m/h, including stops. The TSR technique combined with transtibial amputation allowed the disappearance of neuropathic pain contributing to prosthesis embodiment. The new technology applied to the prosthesis allowed the return to sport, with significant improvement of the quality of life investigated with the SF-36 questionnaire.