Targeted muscle reinnervation to improve electromyography signals for advanced myoelectric prosthetic limbs: a series of seven patients.

BACKGROUND: Upper limb amputation is a devastating injury. Patients may choose to use a passive prosthesis, a traditional body-powered prosthesis or a myoelectric prosthesis driven by electromyography (EMG) signals generated by underlying muscles. Targeted muscle reinnervation (TMR) aims to surgically create strong and reliable signals to permit the intuitive use of a myoelectric prosthesis with the greatest number of movements possible. We review the Alfred Hospital experience of using TMR to improve upper limb prosthesis control.
METHODS: A retrospective review of all cases of TMR performed at the Alfred Hospital was undertaken. Patient demographics, injury, surgical complications and outcomes were examined. Comparison was made to preoperative prosthesis use.
RESULTS: Seven patients have undergone TMR to improve upper limb prosthesis control at the Alfred Hospital between 2015 and 2018. Within the patient group, pre-TMR EMG signal numbers ranged from 1 to 2, and post-TMR signal numbers ranged from 3 to 5. Six patients were able to achieve six degrees of freedom post-operatively, and one patient achieved four degrees. No patients required the use of co-contraction to switch function post-operatively. There were no significant surgical complications.
CONCLUSION: The use of TMR to improve and increase the number of EMG signals has been successful in generating more degrees of freedom for upper limb amputees with myoelectric prostheses.