Abstract. Objective. Radial to axillary nerve and spinal accessory (XI) to suprascapular nerve (SSN) transfers are standard procedures to restore function after C5 brachial plexus dysfunction. The anterior approach to the SSN may miss concomitant pathology at the suprascapular notch and sacrifices lateral trapezius function, resulting in poor restoration of shoulder external rotation. A posterior approach allows decompression and visualisation of the SSN at the notch and distal coaptation of the medial XI branch. The medial triceps has a double fascicle structure that may be coapted to both the anterior and posterior division of the axillary nerve, whilst preserving the stabilising effect of the long head of triceps at the glenohumeral joint. Reinnervation of two shoulder abductors and two external rotators may confer advantages over previous approaches with improved external rotation range of motion and strength. Methods. Review of the clinical outcomes of 22 patients who underwent a double nerve transfer from XI and radial nerves. Motor strength was evaluated using the MRC scale and grade 4 was defined as the threshold for success. Results. 18/22 patients had adequate follow-up (Mean: 29.5 months). Of these, 72.2% achieved ≥grade 4 power of shoulder abduction and a mean range of motion of 103°. 64.7% achieved ≥grade 4 external rotation with a mean range of motion of 99.6°. Conclusions. The results suggest the use of the combined nerve transfer for restoration of shoulder function via a posterior approach, involving the medial head branch of triceps to the axillary nerve and the XI to SSN

Supercharged end-to-side nerve transfer for severe cubital tunnel syndrome is a recently developed technique which involves augmenting the ulnar motor branch with anterior interosseous nerve (AIN). Previous studies suggested that this technique augments or “babysits” the motor end plates until reinnervation occurs, however, some authors suggested possible reinnervation by the donor nerve. We present two cases where this transfer was done for rapid progressive (6–9 months) cubital tunnel syndrome. The first case was a 57 year-old right hand dominant female who presented to us with severe right cubital tunnel syndrome clinically, including intrinsic wasting and claw deformity. The patient had significant loss of function and visible atrophy to her hand intrinsics over the last few months. Electrodiagnostic studies confirmed the diagnosis of severe cubital tunnel syndrome demonstrating axonal loss, positive sharp waves and fibrillations in the ulnar nerve distribution distally. The patient underwent cubital tunnel ulnar nerve release, subcutaneous anterior transposition, Guyon's canal release along with an AIN to ulnar motor nerve end-to-side transfer. Patient-based functional outcome instruments were prospectively collected with improved overall pain and function as demonstrated from a quickDASH score of 9.1 1 year post-op in comparison to a score of 34.1 pre-op. Recovery was monitored clinically and electrodiagnostic studies at 6 months and 1 year post-operatively. She demonstrated improved intrinsic muscle bulk and strength. The nerve studies at one year showed reinnervation with large amplitude motor unit potentials in the 1st dorsal interosseous and abductor digiti minimi but the 5th finger sensory response remained absent. The second case was a 58 year-old right hand dominant male diagnosed with severe and progressive right cubital tunnel syndrome. Clinically, he had significant muscle wasting and weakness and confirmed denervation on electrodiagnostic studies. He underwent the same surgical procedure as described for the first case and follow-up regimen. The patient demonstrated improved pain score and significant overall function recovery with a quickDASH score of 11.4 one year post-op in comparison to 72.7 pre-op. Nerve studies at one year confirmed our clinical impression, showing ulnar nerve reinnervation with large amplitude motor unit potentials in the 1st dorsal interosseous, while sensory response remained absent. It is yet unclear if end-to-side nerve transfers allow reinnervation of the target muscles. Previous studies have demonstrated clinical improvement with this transfer, however we are unaware of any electrodiagnostic studies demonstrating this effect. These two cases support the notion of reinnervation after an end-to-side procedure. Further studies are needed to assess outcomes of such nerve transfers

In combined high median and ulnar nerve injury, transfer of extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) nerve branches to restore intrinsic hand function is previously described. A segment of nerve graft is required in this operation. The aim of this study was to evaluate the feasibility of using the sensory branch of radial nerve (SRN) as an “in situ vascular nerve bridge'” (IVNB) instead of sural nerve graft. Twenty fresh cadavers were dissected. In proximal forearm incision, the feasibility of transferring the EDM/ECU branches to the distal stump of transected SRN was evaluated. In distal forearm incision, the two distal branches of the SRN were transected near the radial styloid process to determine whether transfer of the proximal stumps of these branches to the motor branches of the median (MMN) and ulnar (MUN) nerves is possible. The number of axons in each nerve was determined. The size of the dissected nerves and their location demonstrate that tension free nerve coaptation is easily possible in both proximal and distal incisions. Utilisation of the SRN as an IVNB instead of the conventional sural nerve graft has some advantages. Firstly, the sural nerve graft is a single branch and could be sutured to either the MMN or MUN, whereas the SRN has two terminal branches and can address both of them. Secondly, the IVNB has live Schwann cells and may accelerate the regeneration. Finally, this IVNB does not require leg incision and could be performed under regional anesthesia. The SRN as an IVNB is a viable option which can be used instead of conventional nerve graft in some brachial plexus or high median and ulnar nerve injuries when restoration of intrinsic hand function by transfer of EDM/ECU branches is attempted