Results of nerve grafting in radial nerve injuries occurring proximal to the humerus, including those within the posterior cord

OBJECTIVE Results of radial nerve grafting are largely unknown for lesions of the radial nerve that occur proximal to the humerus, including those within the posterior cord. METHODS The authors describe 13 patients with proximal radial nerve injuries who were surgically treated and then followed for at least 24 months. The patients' average age was 26 years and the average time between accident and surgery was 6 months. Sural nerve graft length averaged 12 cm. Recovery was scored according to the British Medical Research Council (BMRC) scale, which ranges from M0 to M5 (normal muscle strength). RESULTS After grafting, all 7 patients with an elbow extension palsy recovered elbow extension, scoring M4. Six of the 13 recovered M4 wrist extension, 6 had M3, and 1 had M2. Thumb and finger extension was scored M4 in 3 patients, M3 in 2, M2 in 2, and M0 in 6. CONCLUSIONS The authors consider levels of strength of M4 for elbow and wrist extension and M3 for thumb and finger extension to be good results. Based on these criteria, overall good results were obtained in only 5 of the 13 patients. In proximal radial nerve lesions, the authors now advocate combining nerve grafts with nerve or tendon transfers to reconstruct wrist, thumb, and finger extension.

Outcomes of Transferring a Healthy Motor Fascicle From the Radial Nerve to a Branch for the Triceps to Recover Elbow Extension in Partial Brachial Plexus Palsy

BACKGROUND: Triceps reinnervation is an important objective to pursue when repairing the brachial plexus for cases with upper roots injuries, and a number of different techniques have been developed in order to restore elbow extension in such cases.

OBJECTIVE: To demonstrate the surgical outcomes associated with the technique of transferring a single healthy motor fascicle from the radial nerve of the affected arm to a branch innervating 1 of the 3 heads of the triceps.

METHODS: A retrospective study of 13 adult patients sustaining an upper trunk syndrome associated with total elbow extension palsy who underwent the proposed technique as part of the surgical planning for reconstruction of the brachial plexus.

RESULTS: Outcomes scored as M4 for elbow extension were noted in 9 cases (70%), M3 in 3 (23%), and M1 in 1 subject (7%). No patient considered the postoperative strength for carpal or finger extension as impaired. There were no differences in outcomes by using a fascicle activating carpal or finger extension as donor, as well as regarding the use of the branch to the medial or lateral head of the triceps as the recipient.

CONCLUSION: The technique of transferring a healthy motor fascicle from the radial nerve of the affected side to one of its nonfunctional motor branches to the triceps is an effective and safe procedure for recovering elbow extension function in patients sustaining partial injuries of the brachial plexus.

Contralateral Trapezius Transfer to Restore Shoulder External Rotation Following Adult Brachial Plexus Injury

PURPOSE

To evaluate the outcome of contralateral lower trapezius origin transfer (CLTOT) to restore shoulder external rotation in patients with shoulder paralysis after brachial plexus injury (BPI).

METHODS

We evaluated 12 patients with a history of BPI with persistent shoulder paralysis. All patients had compromised ipsilateral lower trapezius muscle function. All patients underwent CLTOT prolonged with lumbar fascia to the affected infraspinatus tendon either isolated (7 patients) or as part of multiple tendon transfer (5 patients). Standardized patient outcomes measures were obtained.

RESULTS

At 23 months' follow-up, 10 patients had improved shoulder external rotation from no motion preoperatively to an average external rotation 110° from the abdomen. Five patients had marked improvement of pain, including 2 with isolated CLTOT and 3 with additional tendon transfers. Two patients experienced no change in pain. There were noted improvements in the Constant shoulder scores, simple shoulder value, and Disabilities of the Arm, Shoulder, and Hand scores. One patient sustained a fall resulting in stretch injury to the transfer, underwent successful revision surgery, and regained 100° active shoulder external rotation away from the abdomen more than a year after revision surgery. Another patient's transfer failed during rehabilitation but the patient elected not to pursue treatment. No patients had changes in contralateral shoulder motion or strength or any pain from the contralateral shoulder.

CONCLUSIONS

This study demonstrated that CLTOT to the infraspinatus tendon was effective in improving shoulder external rotation in patients with BPI.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Results of nerve grafting in radial nerve injuries occurring proximal to the humerus, including those within the posterior cord

OBJECT

Results of radial nerve grafting are largely unknown for lesions of the radial nerve that occur proximal to the humerus, including those within the posterior cord.

METHODS

The authors describe 13 patients with proximal radial nerve injuries who were surgically treated and then followed for at least 24 months. The patients’ average age was 26 years and the average time between accident and surgery was 6 months. Sural nerve graft length averaged 12 cm. Recovery was scored according to the British Medical Research Council (BMRC) scale, which ranges from M0 to M5 (normal muscle strength).

RESULTS

After grafting, all 7 patients with an elbow extension palsy recovered elbow extension, scoring M4. Six of the 13 recovered M4 wrist extension, 6 had M3, and 1 had M2. Thumb and finger extension was scored M4 in 3 patients, M3 in 2, M2 in 2, and M0 in 6.

CONCLUSIONS

The authors consider levels of strength of M4 for elbow and wrist extension and M3 for thumb and finger extension to be good results. Based on these criteria, overall good results were obtained in only 5 of the 13 patients. In proximal radial nerve lesions, the authors now advocate combining nerve grafts with nerve or tendon transfers to reconstruct wrist, thumb, and finger extension.

Transfer of a Terminal Motor Branch Nerve to the Flexor Carpi Ulnaris for Triceps Reinnervation: Anatomical Study and Clinical Cases

PURPOSE

To analyze the anatomical feasibility of transferring a motor branch nerve to the flexor carpi ulnaris (FCU) to the triceps upper medial head motor branch (UMHM) and to report the resultant outcome of the restoration of elbow extension in 5 patients with extensive brachial plexus injury.

METHODS

The ulnar and radial nerves were dissected in 10 cadavers. We measured the length and diameter of the branches to the FCU and the UMHM branch and counted the axons. Then, 5 male patients, mean age 30 years, underwent FCU nerve branch transfer for reconstruction of elbow extension. Elbow flexion was restored via a median nerve branch to biceps transfer.

RESULTS

Mean UMHM nerve length and diameter were 86 and 1.5 mm, respectively. Mean number of branches to the FCU muscle was 2.9. Mean FCU nerve length and diameter were 50 and 1.0 mm, respectively. Mean number of myelinated fibers was 818 and 743 for the UMHM and the longest branch to the FCU, respectively. Coaptation between nerves was possible without tension. All patients recovered functional active elbow extension at a mean follow-up of 19 months with a British Medical Research Council score of M4. After surgery, all patients retained a functional FCU with a British Medical Research Council score of M4.

CONCLUSIONS

Nonselective ulnar nerve fascicles at the root of the limb might not be adequate to restore elbow extension when combined with a median nerve branch transfer for elbow flexion. A selective distal ulnar motor fascicle such as a FCU motor branch could be harvested and connected to a triceps branch to restore elbow extension. Such a nerve transfer would also allow for later transfer of the still functional FCU tendon to the digital extensors.

CLINICAL RELEVANCE

For patients with extensive brachial plexus injury and a preserved medial cord, transferring a motor branch nerve to the FCU is an effective technique for the reconstruction of elbow extension.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Targeted Muscle Reinnervation of the Brachium: An Anatomic Study of Musculocutaneous and Radial Nerve Motor Points Relative to Proximal Landmarks

PURPOSE

Targeted muscle reinnervation (TMR) offers enhanced prosthetic use by harnessing additional neural control from unused nerves in the amputated limb. The purpose of this study was to document the location and number of motor end plates to each muscle commonly used in TMR in the brachium relative to proximally based bony landmarks.

METHODS

We dissected 18 matched upper limbs (9 fresh-frozen cadavers). The locations of each of the nerves' muscular insertions into the medial biceps and brachialis were measured relative to the anterolateral tip of the acromion. The terminal branches to the lateral triceps were measured relative to the posterolateral tip of the acromion. Both the number of branches and the location of the muscular insertions were documented. Common descriptive statistics were used to describe the data.

RESULTS

There was a median of 2 branches to the medial biceps located 19.6 cm from the anterolateral tip of the acromion (range, 15-25 cm). There was a median of 3.5 branches to the brachialis located 24.2 cm from the anterolateral tip of the acromion (range, 19-27.5 cm). There was a median of 2.5 branches to the lateral triceps located 21.6 cm from the posterolateral tip of the acromion (range, 11-29 cm). The mean distances to the primary branch muscle and the number of smaller branches were not significantly different when compared by sex or side.

CONCLUSIONS

Motor points for the medial biceps, brachialis, and lateral triceps can be identified reliably using proximal landmarks in targeted muscle reinnervation.

CLINICAL RELEVANCE

The data obtained from this study may assist the surgeon in localizing the nerve branches and muscular insertions for the commonly used muscles for TMR of the brachium.

Targeted Muscle Reinnervation in the Upper Extremity Amputee: A Technical Roadmap

Targeted muscle reinnervation (TMR) offers the potential for improved prosthetic function by reclaiming the neural control information that is lost as a result of upper extremity amputation. In addition to the prosthetic control benefits, TMR is a potential treatment for postamputation neuroma pain. Here, we present our surgical technique for TMR nerve transfers in transhumeral and shoulder disarticulation patients.

Nerve transfer from triceps medial head and anconeus to deltoid for axillary nerve palsy

PURPOSE

To report our results with reconstruction of the axillary nerve by transferring the branch to the triceps lower medial head and anconeus to the anterior division of the axillary nerve.

METHODS

This study included 9 patients with isolated injury of the axillary nerve. Their average age ± SD was 35 ± 9 years, and the mean interval ± SD between injury and surgery was 6.6 ± 2.6 months. Through a posterior arm approach, the radial nerve branch to the lower triceps medial head and anconeus was transferred to the anterior division of the axillary nerve. We observed patients for a mean of 34 ± 7 months. At final evaluation, we measured range of shoulder motion, shoulder abduction and elbow extension strength, and abduction endurance. Patients were assessed via the deltoid extension lag test and abduction-in-internal-rotation test.

RESULTS

All patients recovered deltoid function and maintained full active elbow extension. Seven of 9 patients recovered from lagging abduction in internal rotation. Abduction strength improved from approximately 40% that of the normal side at 90° of abduction preoperatively to 60% of normal strength postoperatively. There was improved endurance in abduction from approximately 25% to 65% that of the normal side, which was sufficient to eliminate all reports of shoulder pain or fatigability.

CONCLUSIONS

Transfer of the radial nerve branch for the lower triceps medial head and anconeus to the anterior division of the axillary nerve proved to be an effective method of deltoid reinnervation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Reanimation of elbow extension with medial pectoral nerve transfer in partial injuries to the brachial plexus

Object

Recent advancements in operative treatment of the brachial plexus authorized more extensive repairs and, currently, elbow extension can be included in the rank of desirable functions to be restored. This study aims to describe the author's experience in using the medial pectoral nerve for reinnervation of the triceps brachii in patients sustaining C5–7 palsies of the brachial plexus.

Methods

This is a retrospective study of the outcomes regarding recovery of elbow extension in 12 patients who underwent transfer of the medial pectoral nerve to the radial nerve or to the branch of the long head of the triceps.

Results

The radial nerve was targeted in 3 patients, and the branch to the long head of the triceps was targeted in 9. Grafts were used in 6 patients. Outcomes assessed as Medical Research Council Grades M4 and M3 for elbow extension were noted in 7 (58%) and 5 (42%) patients, respectively.

Conclusions

The medial pectoral nerve is a reliable donor for elbow extension recovery in patients who have sustained C5–7 nerve root injuries.

Feasibility of contralateral trapezius transfer to restore shoulder external rotation: part I

PURPOSE

We evaluated the feasibility of contralateral trapezius transfer to restore shoulder external rotation.

MATERIALS AND METHODS

The length of the lower trapezius and distance necessary for contralateral trapezius transfer were measured in 20 volunteers and directly in 12 cadavers. The average distances between the medial spine of the scapula and T12 (length of lower trapezius) and the spine to the greater tuberosity (distance for transfer) were measured with the scapula neutral, maximally protracted, and maximally retracted. In cadavers, the origin of the lower trapezius was detached, transferred to the contralateral greater tuberosity, and retracted to determine its effectiveness in external rotation and tension on the vascular pedicle.

RESULTS

In volunteers, the average difference between the length of the lower trapezius and the transfer distance was 19 mm in neutral. When the scapula was protracted and retracted, the difference was 79 and -49 mm. In the cadavers, the average transfer distance (in mm) was 290 ± 12, 365 ± 15, and 209 ± 25 in the neutral, protracted, and retracted positions, respectively. The average length of the lower trapezius (in mm) was 270 ± 10, 285 ± 12, and 258 ± 10 in the neutral, protracted, and retracted positions. The transfer was universally feasible when the scapula was partially retracted. Prolongation of the lower trapezius with lumbar fascia made the transfer possible in all scapular positions. Pulling on the transferred muscle resulted in contralateral shoulder external rotation without tension or impingement on the neurovascular pedicle.

CONCLUSION

Contralateral trapezius transfer to the infraspinatus insertion appears feasible and potentially effective in restoration of shoulder external rotation.

Topographical anatomy of the radial nerve and its muscular branches related to surface landmarks

Understanding of the anatomy of the radial nerve and its branches is vital to the treatment of humeral fracture or the restoration of upper extremity function. In this study, we dissected 40 upper extremities from adult cadavers to locate the course of the radial nerve and the origins and insertions of the branches of the radial nerve using surface landmarks. The radial nerve reached and left the radial groove and pierced the lateral intermuscular septum, at the levels of 46.7, 60.5, and 66.8% from the acromion to the transepicondylar line, respectively. Branches to the long head of the triceps brachii originated in the axilla, and branches to the medial and lateral heads originated in the axilla or in the arm. The muscular attachments to the long, medial, and lateral heads were on average 34.0 mm proximal, 16.4 mm distal, and 19.3 mm proximal to the level of inferior end of the deltoid muscle, respectively. The radial nerve innervated 65.0% of the brachialis muscles. Branches to the brachioradialis and those to the extensor carpi radialis longus arose from the radial nerve above the transepicondylar line. Branches to the extensor carpi radialis brevis usually arose from the deep branch of radial nerve (67.5%); however, in some cases, branches to the extensor carpi radialis brevis arose from either the radial nerve (20.0%) or the superficial branch of the radial nerve (12.5%). Using these data, the course of the radial nerve can be estimated by observing the surface of the arm.

Triceps brachii reinnervation in primary reconstruction of the adult brachial plexus: experience in 25 cases

BACKGROUND

Elbow flexion and shoulder abduction are the primary goals in brachial plexus surgery; however, reinnervation of the triceps is also an objective to be considered, as restoration of elbow extension improves the stabilization of the elbow and can provide a more powerful grasp. This study aims to demonstrate the author's experience with restoration of elbow extension function in cases of brachial plexus surgery in adults.

METHODS

Records of 25 patients sustaining traumatic brachial plexus injuries who were treated surgically with reinnervation of the triceps were reviewed. Nine techniques were employed, including posterior cord reconstruction and nerve transfers using donors such as the ipsilateral C7 root, phrenic nerve, medial pectoral nerve, intercostal nerves, the spinal accessory nerve, and a motor fascicle of the ulnar nerve. The targeted structure was the radial nerve or the branch to the long head of the triceps.

FINDINGS

Twenty-one subjects (83%) obtained triceps reinnervation, and good results (M3 or better) were observed in 19 cases (76%). M4 grade was noted in 36% of the cases, M3 grade in 40%, M2 grade in 8%, M1 grade in 8%, and M0 grade in 8% of the patients. The best outcomes were observed in the cases presenting a C5 to C7 palsy and those in which the nerve to the triceps was chosen as the transfer target.

CONCLUSIONS

Reinnervation of the triceps can be achieved in most patients if adequate donor and recipient nerves are carefully selected based on an individual case-specific decision.

Transfer of the teres minor motor branch for triceps reinnervation in tetraplegia

In a case involving tetraplegia and paralysis of elbow extension, the authors transferred teres minor branches to the nerve of the triceps long head. Surgery was performed bilaterally 9 months after the patient sustained a spinal cord injury. Fourteen months postoperatively, elbow extension was complete (British Medical Research Council Score M4). Harvesting of the teres minor motor branch produced no deficits in shoulder function. In patients with tetraplegia, nerve transfer seems to be a promising new alternative for elbow extension reconstruction.

Nerve root grafting and distal nerve transfers for C5-C6 brachial plexus injuries

PURPOSE

To investigate the results of distal nerve transfer, with and without nerve root grafting, in C5-C6 palsy of the brachial plexus.

METHODS

We prospectively studied 37 young adults with C5-C6 brachial plexus palsy who underwent surgical repair an average of 6.3 months after trauma. In 7 patients, no nerve roots were available for grafting, so reconstruction was achieved by transferring the accessory nerve to the suprascapular nerve, ulnar nerve fascicles to the biceps motor branch, and triceps branches to the axillary nerve (a triple nerve transfer). In 24 patients, C5 nerve root grafting to the anterior division of the upper trunk was combined with triple nerve transfer. In 6 patients, the C5+C6 nerve roots were grafted to the anterior and posterior divisions of the upper trunk, the accessory nerve was transferred to the suprascapular nerve, and ulnar nerve fascicles were connected to the biceps motor branch. The range of shoulder abduction/external rotation recovery and elbow flexion strength were evaluated between 24 and 26 months after surgery.

RESULTS

Both full abduction and full external rotation of the shoulder were restored in one of the 7 patients in the C5 and C6 nerve root avulsion group, in 14 of 21 patients who received C5 nerve root grafting, and in 2 of 6 patients in the C5+C6 nerve root graft group. The average percentages of elbow flexion strength recovery, relative to the normal, contralateral side, were 27%, 43%, and 59% for the C5-C6 nerve root avulsion, C5 nerve root graft, and C5+C6 nerve root graft groups, respectively.

CONCLUSIONS

We repaired C5-C6 brachial plexus palsies using a combination of strategies depending on the site of root injury (ie, intradural vs extradural). Patients with injuries that were able to be reconstructed with both root grafting and nerve transfers had the best function. These results suggest that the combined use of nerve transfers and root grafting may enhance outcomes in the reconstruction of C5-C6 injuries of the brachial plexus.

Results of grafting the anterior and posterior divisions of the upper trunk in complete palsies of the brachial plexus

PURPOSE

In most complete brachial plexus injuries, at least 1 root still is available for grafting. We report on the results obtained with reconstruction of the brachial plexus using short sural nerve grafts that connect nonavulsed roots to the anterior, posterior, or both divisions of the upper trunk.

METHODS

We prospectively studied 22 young adults with complete brachial plexus palsy who had surgical repair an average of 5 months after trauma. Sural nerve grafts connected the C5 root to the anterior division and the C6 root to the posterior division of the upper trunk. When the C6 root was not available, the posterior division of the upper trunk was repaired by means of a nerve transfer. In all cases except one, the suprascapular nerve was repaired via a nerve transfer. Outcomes were assessed an average of 35 months after surgery, focusing on recovery of muscle strength, categorized using the Medical Research Council scale. We compared the results obtained after a single root graft, either C5 (n = 11) or C6 (n = 1), with those observed after double root grafting (i.e., C5 + C6; n = 9). The single case of 3 roots available for grafting was excluded for this comparative study.

RESULTS

With grafting of the anterior division of the upper trunk, 17 of the 22 patients (n = 15) regained useful pectoralis major and biceps function of at least M3. Grafting the anterior and the posterior divisions of the upper trunk resulted in 18 of the 22 patients (n = 18) recovering shoulder abduction-adduction and either elbow flexion or extension. In only 5 cases (5 of 22 patients), however, was shoulder abduction-adduction achieved with concomitant recovery of both elbow flexion and extension. Grafting the posterior division of the upper trunk did not enhance the recovery of shoulder abduction, but it did restore elbow extension in approximately 6 of the 9 patients. In terms of muscle strength, an average of 2.3 muscles scored M3 or M4 in the single-root group, compared with 3.1 in the C5/C6 group (p < .05). The relative probability of recovering elbow flexion and shoulder adduction did not differ between patients with 1 versus 2 root grafts. The results of nerve transfers to the posterior division and of forearm muscle reinnervation were poor.

CONCLUSIONS

Grafting the divisions of the brachial plexus ensured multiple function reconstruction in 18 of the 22 patients (n = 18). However, only 5 of 22 patients (n = 4) experienced restoration of elbow flexion and extension.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.