Strategy changes of neurotization before and after 2000

From 1986 to 2000, over 1000 adult patients with brachial plexus injury were operated on by the author. From 2000 to present, the author has performed an average of 66.7 brachial plexus operations every year. Seventy-five percent of patients sustained preganglionic root injuries that required a neurotization procedure either for nerve reconstruction or for functioning free muscle transfers. Strategy changes occurred before and after 2000 following retrospective study reviews, accumulation of experience, and knowledge from other centers.

For shoulder function

Although shoulder adduction was once thought more important than abduction, good recovery of shoulder abduction can provide greater range of motion for the arm and forearm, which is more appreciated by most patients. Shoulder adduction by fusion can increase shoulder grasp power but is technically difficult and also limits shoulder excursion. In nearly 1500 cases, fewer than 10 patients required shoulder fusion because of failed nerve reconstruction, but achieved elbow and hand function by functioning free muscle transfers.

For shoulder abduction, nerve reconstruction is always superior to local muscle(s) transfers. The donor nerves include the Ph nerve, XI nerve, CMB nerve, XII nerve, and some from C5 or C6 in three- or four-root avulsion injury. The priority choice for recipient nerves is first the distal C5 if it is available. If distal C5 is not healthy because of scarring, the suprascapular nerve, the dorsal division of the upper trunk, or finally the axillary nerve are considered for neurotization. From the author's experience, if the distal C5 is well reinnervated, the suprascapular, dorsal division of the upper trunk, axillary nerve, and some radial nerve function (especially ECRL) can be all recovered simultaneously. The use of three donor nerves (Ph + XI + CMB-to-distal C5) (Fig. 4A, B), or two donor nerves (Ph + XI-to-distal C5 [see Fig. 1]), or Xl-to-suprascapular plus Ph-to-dorsal division of the upper trunk (see Fig. 2) all yield good and reliable results for shoulder abduction and external rotation. The Ph nerve is so powerful that its transfer to the distal C5 or dorsal division of the upper trunk directly can also achieve acceptable results for shoulder abduction. Elongation of the Ph nerve, or XI nerve to the axillary nerve with a long nerve graft (>10 cm in length) is no longer my treatment of choice. The author has reviewed the recent 3 years' (2000 to 2003) experience of nerve transfer for shoulder abduction by single neurotization (single donor nerve transfer) (see Fig. 5), double neurot-ization (two donor nerves transfer) (see Figs. 1 and 2), and triple neurotization (three donor nerves transfer) (see Fig. 4). The results show triple neurotization achieving the best results (150° average, range, 90 to 180°); then double neurotization (86.8° average, range, 10 to 180°), and then single neurotization (68.84° on average, range, 10 to 180°). Double neurotization with one extraplexus donor nerve (Ph, XI, or CMB) combined with one intraplexus donor nerve (one part of C5 or C6) also generally produces good results for shoulder function.

Strategy changes of nerve transfer for shoulder abduction include the following:

1. for C5 alone, or C5-6 two-root avulsion; double or triple nerve neurotization is preferred for better and more reliable results; however,

2. for C5-C7 three-root avulsion, C6-T1 four-root avulsion, and C5-T1 total root avulsion; the author feels that single neurotization is adequate, leaving other donor nerves for other reconstructions. Since Doi's [24] double-functioning free muscle transfer (FFMT) technique using the XI nerve to innervate a FFMT for extensor digitorum communis (EDC) and elbow flexion replacement has become an accepted and reliable option; in patients with total root avulsion, the XI nerve is now spared as a reserve for the further enhancement reconstruction of finger extension and/or elbow flexion.

For elbow flexion

IC nerve transfer to the musculocutaneous nerve, either through mixed IC nerve to mixed MC nerve transfer [8] or from pure motor (deep central branches of the IC nerve) to the branch to the biceps [25] has proven to be effective. Partial ulnar nerve transfer to the musculocutaneous nerve or to the branch to the biceps [21-23] also yields good results. It is a short and easy surgical procedure with a quick recovery in rehabilitation. It has now become my first option for elbow

Fig. 5. (A) A 4-year-old boy suffered from C5 and C6 avulsion injury. (B) He achieved good shoulder elevation 2 years after single neurotization with XI nerve transfer to the suprascapular.

reconstruction if it is indicated (upper plexus avulsion), instead of choosing IC nerve transfer. CC7 transfer for elbow flexion is also one of my preferred options for elbow flexion in the case of total root avulsion and associated rib fractures where IC nerve transfer is unreliable and often fails. CC7 transfer with a vascularized ulnar nerve graft to the musculocutaneous and median nerves simultaneously in total root avulsion is another reconstructive option to achieve elbow flexion and finger flexion and sensation.

For elbow extension

Ph nerve transfer to the posterior division of the upper trunk or to the radial nerve with a nerve graft can restore elbow extension. Some authors describe using two or three IC nerve transfers to the branch to the long head of the triceps to achieve elbow extension [26], similar to three IC nerve transfers to the musculocutaneous nerve to achieve elbow flexion [8].

For finger flexion

Ipsilateral C5 or C6 transfer to the median nerve in C5 or C6 rupture associated with C7-T1 three-root or C6-T1 four-root avulsion, or CC7 transfer to the median nerve will achieve finger and wrist flexion and finger sensation. Both need a vascularized ulnar nerve graft and both constitute a one-stage complete reconstruction and may be combined with other nerve transfers for shoulder or elbow function [5-7]. However, CC7 nerve transfer should not be used in poor understanding or uncooperative patients because it usually ends with poor results.

For finger extension

The use of a dynamic interphalangeal extension splint or a long FFMT from the clavicle down to the extensor digitorum communis muscles innervated by the XI nerve have proven to be effective options to provide finger extension. Wrist and thumb arthrodesis are usually required for stability and grip [5-7].

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