Nerve transfers for the upper and lower extremities

Surgery for mononeuropathies

Advancement in microsurgical techniques and innovative approaches including greater use of nerve and tendon transfers have resulted in better peripheral nerve injury (PNI) surgical outcomes. Clinical evaluation of the patient and their injury factors along with a shift toward earlier time frame for intervention remain key. A better understanding of the pathophysiology and biology involved in PNI and specifically mononeuropathies along with advances in ultrasound and magnetic resonance imaging allow us, nowadays, to provide our patients with a logical and sophisticated approach. While functional outcomes are constantly being refined through different surgical techniques, basic scientific concepts are being advanced and translated to clinical practice on a continuous basis. Finally, a combination of nerve transfers and technological advances in nerve/brain and machine interfaces are expanding the scope of nerve surgery to help patients with amputations, spinal cord, and brain lesions.

Motor Nerve Transfers

Brachial plexus and peripheral nerve injuries are exceedingly common. Traditional nerve grafting reconstruction strategies and techniques have not changed significantly over the last 3 decades. Increased experience and wider adoption of nerve transfers as part of the reconstructive strategy have resulted in a marked improvement in clinical outcomes. We review the options, outcomes, and indications for nerve transfers to treat brachial plexus and upper- and lower-extremity peripheral nerve injuries, and we explore the increasing use of nerve transfers for facial nerve and spinal cord injuries. Each section provides an overview of donor and recipient options for nerve transfer and of the relevant anatomy specific to the desired function.

Median and/or Ulnar Nerve Fascicle Transfer for the Restoration of Elbow Flexion in Upper Neonatal Brachial Plexus Palsy

Introduction

Transfer of a fascicle of the ulnar and/or median nerve to the musculocutaneous nerve in order to reinnervate the biceps and/or brachialis muscles has a high success rate and a low rate of complications in infants with upper (C5-C6) or extended upper (C5-C7) neonatal brachial plexus palsy.

Step 1 Make the Incision

Make a longitudinal incision along the midline of the middle third of the medial brachium.

Step 2 Mobilize the Musculocutaneous Nerve

The musculocutaneous nerve is typically found on the undersurface of the biceps muscle.

Step 3 Mobilize the Median Nerve

The median nerve runs along the neurovascular sheath medial to the brachial artery.

Step 4 Mobilize the Ulnar Nerve

The ulnar nerve lies posterior to the intermuscular septum.

Step 5 Transfer the Donor Nerve to the Recipient Nerve

Cut the donor fascicles distally and the recipient fascicles proximally to facilitate transfer.

Step 6 Close the Wound

Irrigate the wound, and close it in layers.

Step 7 Postoperative Protocol

Remove the bandages two weeks postoperatively, and encourage passive range-of-motion exercises.

Results

In our series, thirty-one patients underwent single or combined nerve fascicle transfer; twenty-seven (87%) obtained functional elbow flexion recovery (Active Movement Scale [AMS] score ≥ 6) while twenty-four (77%) obtained full elbow flexion recovery (AMS score = 7). Indications Contraindications Pitfalls & Challenges.

Early functional recovery of elbow flexion and supination following median and/or ulnar nerve fascicle transfer in upper neonatal brachial plexus palsy

BACKGROUND

Nerve transfers using ulnar and/or median nerve fascicles to restore elbow flexion have been widely used following traumatic brachial plexus injury, but their utility following neonatal brachial plexus palsy remains unclear. The present multicenter study tested the hypothesis that these transfers can restore elbow flexion and supination in infants with neonatal brachial plexus palsy.

METHODS

We retrospectively reviewed the cases of thirty-one patients at three institutions who had undergone ulnar and/or median nerve fascicle transfer to the biceps and/or brachialis branches of the musculocutaneous nerve after neonatal brachial plexus palsy. The primary outcome measures were postoperative elbow flexion and supination as measured with the Active Movement Scale (AMS). Patients were followed for at least eighteen months postoperatively unless they obtained full elbow flexion or supination (AMS = 7) prior to eighteen months of follow-up.

RESULTS

Twenty-seven (87%) of the thirty-one patients obtained functional elbow flexion (AMS ≥ 6), and twenty-four (77%) obtained full recovery of elbow flexion against gravity (AMS = 7). Of the twenty-four patients for whom recovery of supination was recorded, five (21%) obtained functional recovery. Combined ulnar and median nerve fascicle transfers were performed in five patients and resulted in full recovery of elbow flexion against gravity and supination of AMS ≥ 5 for all five. Single-fascicle transfer was performed in twenty-six patients and resulted in functional flexion in 85% (twenty-two of twenty-six) and functional supination in 15% (three of twenty). Patients with nerve root avulsion were treated at a younger age (p < 0.01), had poorer preoperative elbow flexion (p < 0.01), and recovered greater supination (p < 0.01) compared with patients with dissociative recovery. Younger patients (p < 0.01) and patients with C5-C6 avulsion (p < 0.02) recovered the greatest supination. One patient sustained a transient anterior interosseous nerve palsy after median nerve fascicle transfer.

CONCLUSIONS

Ulnar and/or median nerve fascicle transfers were able to effectively restore functional elbow flexion in patients with nerve root avulsion, dissociative recovery, or late presentation following neonatal brachial plexus palsy. Recovery of supination was less, with greater success noted in younger patients with nerve root avulsion.

Acute transfer of superficial radial nerve to the medial nerve: case report

Distal nerve transfers have proven to be an important addition to the armamentarium for reconstruction of peripheral nerve injuries. As new nerve transfer procedures are developed, the indications for their uses continue to broaden. We report a case of a 77-year-old male who had a 9-cm-long gap of the median nerve after experiencing an avulsion injury to his right forearm. This was successfully treated by transferring superficial radial nerve to the median nerve at the carpal tunnel level, thus restoring thumb, index, and first web sensation. Our report emphasizes that nerve transfers in the emergency setting may be the treatment of first choice in cases where conventional nerve grafting is known to result in poorer outcomes such as in long nerve gaps or in the elderly patient population.

Repair of a median nerve transection injury using multiple nerve transfers, with long-term functional recovery

Complete loss of median nerve motor function is a rare but devastating injury. Loss of median motor hand function and upper-extremity pronation can significantly impact a patient's ability to perform many activities of daily living independently. The authors report the long-term follow-up in a case of median nerve motor fiber transection that occurred during an arthroscopic elbow procedure, which was then treated with multiple nerve transfers. Motor reconstruction used the nerves to the supinator and extensor carpi radialis brevis to transfer to the anterior interosseous nerve and pronator. Sensory sensation was restored using the lateral antebrachial cutaneous (LABC) nerve to transfer to a portion of the sensory component of the median nerve, and a second cable of LABC nerve as a direct median nerve sensory graft. The patient ultimately recovered near normal motor function of the median nerve, but had persistent pain symptoms 4 years postinjury.

Nerve reconstruction in the hand and upper extremity

In the management of traumatic peripheral nerve injuries, the severity or degree of injury dictates the decision making between surgical management versus conservative management and serial examination. This review explores some of the recent literature, specifically addressing recent basic science advances in end-to-side and reverse end-to-side recovery, Schwann cell migration, and neuropathic pain. The management of nerve gaps, including the use of nerve conduits and acellularized nerve allografts, is examined. Current commonly performed nerve transfers are detailed with focus on both motor and sensory nerve transfers, their indications, and a basic overview of selected surgical techniques.

Double fascicular nerve transfer to the biceps and brachialis muscles after brachial plexus injury: clinical outcomes in a series of 29 cases

Object

The clinical outcomes of patients with brachial plexus injuries who underwent double fascicular transfer (DFT) using fascicles from the median and ulnar nerves to reinnervate the biceps and brachialis muscles were evaluated.

Methods

The authors conducted a retrospective chart review of 29 patients with brachial plexus injuries that were treated with DFT for restoration of elbow flexion. All patients underwent pre- and postoperative clinical evaluation using the Medical Research Council grading system.

Results

The mean patient age was 37 years (range 17–68 years), and there was a mean follow-up of 19 ± 12 months (range 8–68 months). At the most recent follow-up, all but 1 patient (97%) had regained elbow flexion. Eight patients recovered Grade M5, 15 patients recovered Grade M4, and 4 patients recovered Grade M3 elbow flexion strength. There was no evidence of functional deficit in the donor nerve distributions.

Conclusions

Study results demonstrated the reliable restoration of M4–M5 elbow flexion following double fascicular transfer in patients with brachial plexus injuries.

Femoral branch to obturator nerve transfer for restoration of thigh adduction following iatrogenic injury

Obturator nerve injury is a rare complication of pelvic surgery. A variety of management strategies have been reported, with conservative measures being the preferred treatment in most cases. While nerve transfer has become more commonly used for restoring brachial plexus injuries, it has rarely been applied to the lower extremities. To the authors' knowledge, this is the first report of an obturator nerve neurotization. A patient presented 7 months after an iatrogenic right obturator nerve palsy due to pelvic surgery for gynecological malignancy. She underwent a femoral branch to obturator nerve transfer to restore right thigh adduction. Ten months after the neurotization procedure, there was electromyographic evidence of almost complete obturator nerve reinnervation. At 1 year postoperatively, the patient had regained full muscle strength on thigh adduction and a normal gait. Nerve transfer could therefore be a good option in patients with obturator nerve injury whose symptoms fail to respond to conservative medical therapy.

Nerve transfer to the triceps after brachial plexus injury: report of four cases

These case reports review the clinical outcomes of 4 patients who underwent nerve transfer to a triceps motor branch of the radial nerve. Mean follow-up was 26 ± 15 months. Two patients had a transfer using an ulnar nerve fascicle to the flexor carpi ulnaris muscle, yielding a motor recovery of grade M5 elbow extension strength in one case and M4+ in the other. In 1 patient, a thoracodorsal nerve branch was used as the donor; this patient recovered M4 strength. One patient had a transfer using a radial nerve fascicle to the extensor carpi radialis longus muscle and recovered M5 strength. These outcomes indicate that expendable fascicles of the ulnar, thoracodorsal, and radial nerves are viable donors in the surgical reconstruction of elbow extension.

Median to radial nerve transfer to restore wrist and finger extension: technical nuances

BACKGROUND

Traditional methods for restoring finger and wrist extension following radial nerve palsy include interposition nerve grafting or tendon transfers. We have described the utilization of distal nerve transfers for the restoration of radial nerve function in the forearm.

OBJECTIVE

We review the neuroanatomy of the forearm and outline the steps required for the implementation of this transfer.

METHODS AND RESULTS

We use a step-by-step procedural outline and detailed photographs, line drawings, and video to describe the procedure.

CONCLUSION

This approach is technically feasible and is a reconstructive option for patients with this nerve deficit.

DISTAL MEDIAN TO ULNAR NERVE TRANSFERS TO RESTORE ULNAR MOTOR AND SENSORY FUNCTION WITHIN THE HAND

ULNAR NERVE INJURIES can be severely debilitating and result in weakness of wrist flexion, loss of hand intrinsic function, and ulnar-sided hand anesthesia. When these injuries produce a Sunderland fourth- or fifth-degree injury, surgical intervention is necessary for functional recovery. Traditional methods for restoring hand intrinsic function after ulnar nerve palsy include interposition nerve grafting for timely presentations or tendon transfers for either complex injuries or late presentations. Distal median to ulnar nerve transfer to restore ulnar intrinsic nerve muscle function was first performed in 1991. We continue to find it advantageous for recovery of ulnar intrinsic function in patients with proximal ulnar nerve injuries by significantly reducing denervation time and directing motor fibers into this critical motor distribution. Several case reports have been published discussing the concept behind this approach, but none have outlined the specific steps involved in this operation. As such, this article discusses our operative methodology behind the distal median to ulnar neurotization, which includes a Guyon canal release, identification of donor median and recipient ulnar nerve fascicular anatomy within the forearm, and an operative tutorial on proper technique for neurotization to restore both ulnar motor and sensory function. We present the technical nuances of the following nerve transfers to restore ulnar nerve function within the hand: anterior interosseous nerve to deep motor branch of ulnar nerve, third webspace sensory contribution of median nerve to volar sensory component of ulnar nerve, and end-to-side reinnervation of ulnar dorsal cutaneous to the remaining median sensory trunk.

Nerve transfer for elbow flexion in radiation-induced brachial plexopathy: a case report

Radiation-induced brachial plexopathy is an uncommon but devastating late complication seen in patients receiving radiation therapy to the chest wall and axilla. Treatment options are unfortunately limited. We report a case of a 59-year-old woman treated with radiation therapy for breast cancer 12 years earlier, who presented with loss of elbow flexion and marked shoulder weakness. Electromyogram and intraoperative stimulation of the musculocutaneous nerve branches were consistent with a proximal motor nerve conduction block. Microsurgical transfer of median and ulnar nerve fascicles to the biceps and brachialis branches of the musculocutaneous nerve, respectively, were performed. The patient recovered MRC grade 4/5 elbow flexion after surgery. The characteristics of this disorder and surgical treatment options are reviewed.

Motor nerve transfers to restore extrinsic median nerve function: case report

Active pronation is important for many activities of daily living. Loss of median nerve function including pronation is a rare sequela of humerus fracture. Tendon transfers to restore pronation are reserved for the obstetrical brachial plexus palsy patient. Transfer of expendable motor nerves is a treatment modality that can be used to restore active pronation. Nerve transfers are advantageous in that they do not require prolonged immobilization postoperatively, avoid operating within the zone of injury, reinnervate muscles in their native location prior to degeneration of the motor end plates, and result in minimal donor deficit. We report a case of lost median nerve function after a humerus fracture. Pronation was restored with transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres branch of the median nerve. Anterior interosseous nerve function was restored with transfer of the supinator branch to the anterior interosseous nerve. Clinically evident motor function was seen at 4 months postoperatively and continued to improve for the following 18 months. The patient has 4+/5 pronator teres, 4+/5 flexor pollicis longus, and 4-/5 index finger flexor digitorum profundus function. The transfer of the extensor carpi radialis brevis branch of the radial nerve to the pronator teres and supinator branch of the radial nerve to the anterior interosseous nerve is a novel, previously unreported method to restore extrinsic median nerve function.

Nerve transfers in the forearm and hand

In the forearm, vital and expendable functions have been identified, and tendon transfers use these conventions to maximize function and minimize disability. Using similar concepts, distal nerve transfers offer a reconstruction that often is superior to reconstruction accomplished by traditional grafting. The authors present nerve transfer options for restoring motor and sensory deficits within each nerve distribution on the forearm and hand.

Median to radial nerve transfer for treatment of radial nerve palsy. Case report

The purpose of this study is to report a surgical technique of nerve transfer to restore radial nerve function after a complete palsy due to a proximal injury to the radial nerve. The authors report the case of a patient who underwent direct nerve transfer of redundant or expendable motor branches of the median nerve in the proximal forearm to the extensor carpi radialis brevis and the posterior interosseous branches of the radial nerve. Assessment included degree of recovery of wrist and finger extension, and median nerve function including pinch and grip strength. Clinical evidence of reinnervation was noted at 6 months postoperatively. The follow-up period was 18 months. Recovery of finger and wrist extension was almost complete with Grade 4/5 strength. Pinch and grip strength were improved postoperatively. No motor or sensory deficits related to the median nerve were noted, and the patient is very satisfied with her degree of functional restoration. Transfer of redundant synergistic motor branches of the median nerve can successfully reinnervate the finger and wrist extensor muscles to restore radial nerve function. This median to radial nerve transfer offers an alternative to nerve repair, graft, or tendon transfer for the treatment of radial nerve palsy.

Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion

PURPOSE

To report the results of a surgical technique of nerve transfer to reinnervate the brachialis muscle and the biceps muscle to restore elbow flexion after brachial plexus injury.

METHODS

Retrospective review was performed on 6 patients who had direct nerve transfer of a single expendable motor fascicle from both the ulnar and median nerves directly to the biceps and brachialis branches of the musculocutaneous nerve. Assessment included degree of recovery of elbow flexion and ulnar and median nerve function including pinch and grip strengths.

RESULTS

Clinical evidence of reinnervation was noted at a mean of 5.5 months (SD, 1 mo; range, 3.5-7 mo) after surgery and the mean follow-up period was 20.5 months (SD, 11.2 mo, range, 13-43 mo). Mean recovery of elbow flexion was Medical Research Council grade 4+. Postoperative pinch and grip strengths were unchanged or better in all patients. No motor or sensory deficits related to the ulnar or median nerves were noted and all patients maintained good hand function. No patients required additional procedures to further improve elbow flexion strength.

CONCLUSIONS

Transfer of expendable motor fascicles from the ulnar and median nerves successfully can reinnervate the biceps and brachialis muscles for strong elbow flexion. The reinnervation of the brachialis muscle, the primary elbow flexor, as well as the biceps muscle provides an additional biomechanical advantage that accounts for the excellent elbow flexion strength obtained using this technique. Direct coaptation of the nerve fascicles was performed without the need for nerve grafts and there was no functional or sensory donor morbidity.