Algorithm for bionic hand reconstruction in patients with global brachial plexopathies

Abstract

OBJECTIVE Global brachial plexus lesions with multiple root avulsions are among the most severe nerve injuries, leading to lifelong disability. Fortunately, in most cases primary and secondary reconstructions provide a stable shoulder and restore sufficient arm function. Restoration of biological hand function, however, remains a reconstructive goal that is difficult to reach. The recently introduced concept of bionic reconstruction overcomes biological limitations of classic reconstructive surgery to restore hand function by combining selective nerve and muscle transfers with elective amputation of the functionless hand and its replacement with a prosthetic device. The authors present their treatment algorithm for bionic hand reconstruction and report on the management and long-term functional outcomes of patients with global brachial plexopathies who have undergone this innovative treatment. METHODS Thirty-four patients with posttraumatic global brachial plexopathies leading to loss of hand function consulted the Center for Advanced Restoration of Extremity Function between 2011 and 2015. Of these patients, 16 (47%) qualified for bionic reconstruction due to lack of treatment alternatives. The treatment algorithm included progressive steps with the intent of improving the biotechnological interface to allow optimal prosthetic hand replacement. In 5 patients, final functional outcome measurements were obtained with the Action Arm Research Test (ARAT), the Southampton Hand Assessment Procedure (SHAP), and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. RESULTS In all 5 patients who completed functional assessments, partial hand function was restored with bionic reconstruction. ARAT scores improved from 3.4 ± 4.3 to 25.4 ± 12.7 (p = 0.043; mean ± SD) and SHAP scores improved from 10.0 ± 1.6 to 55 ± 19.7 (p = 0.042). DASH scores decreased from 57.9 ± 20.6 to 32 ± 28.6 (p = 0.042), indicating decreased disability. CONCLUSIONS The authors present an algorithm for bionic reconstruction leading to useful hand function in patients who lack biological treatment alternatives for a stiff, functionless, and insensate hand resulting from global brachial plexopathies.

Bionic Upper Limb Reconstruction: A Valuable Alternative in Global Brachial Plexus Avulsion Injuries—A Case Series

“…Global upper extremity function using two objective functional tests was assessed at three time points: before bionic reconstruction using the functionless arm; shortly before amputation using a hybrid prosthetic arm [15,16] mounted on the functionless arm of the patient; and after successful prosthetic reconstruction.…”

“…Following complex brachial plexus injuries, nerve regeneration often leads to partial re-innervation of muscles in the affected arm. Although without clinical significance to the patient, faint muscle activity may therefore still be detectable with transcutaneous electromyographic (EMG) sensors [15]. Recently, it has been shown that this residual myoactivity suffices to translate into dexterous prosthetic hand control after elective amputation and prosthetic replacement of the functionless plexus hand, a concept today known as bionic reconstruction [16].…”

“…Recently, it has been shown that this residual myoactivity suffices to translate into dexterous prosthetic hand control after elective amputation and prosthetic replacement of the functionless plexus hand, a concept today known as bionic reconstruction [16]. So far, it has only been described for the transradial level in BPI patients [15,16]. Prerequisites were a sufficient shoulder and elbow function to move the prosthetic hand in three-dimensional space as well as two separable EMG signals in the forearm to reliably control the prosthetic hand [15].…”

“…So far, it has only been described for the transradial level in BPI patients [15,16]. Prerequisites were a sufficient shoulder and elbow function to move the prosthetic hand in three-dimensional space as well as two separable EMG signals in the forearm to reliably control the prosthetic hand [15]. Patients with global brachial plexus avulsion injuries, however, may lack useful shoulder and elbow function as well as detectable myoactivity in their forearm muscles.…”

“…A limited number of functional axons, however, may still be present within the respective muscle branches of the cardinal upper limb nerves, amenable for nerve transfer surgery. With an intra-operative fast staining technique developed in our group nerve biopsies can therefore be screened for single fascicles containing viable motor axons [15]. These few motor axons may then be used to re-innervate a free muscle transplant transferred to the patient s arm, which will not have the functional capacity or power of a biological muscle but instead serve as an additional EMG signal for future prosthetic control (given that a sufficient number of axons regenerate into the transferred muscle target).…”