A Fresh Cadaver Study on the Innervation of Brachioradialis and Extensor Carpi Radialis Longus Muscles

PURPOSE

Distal nerve transfers have revolutionized peripheral nerve surgery by allowing the transfer of healthy motor nerves to paralyzed ones without causing additional morbidity. Radial nerve branches to the brachialis (Ba), brachioradialis (Br), and extensor carpi radialis longus (ECRL) muscles have not been investigated in fresh cadavers.

METHODS

The radial nerve and its branches were dissected in 34 upper limbs from 17 fresh cadavers. Measurements were taken to determine the number, origin, length, and diameter of the branches. Myelinated fiber counts were obtained through histological analysis.

RESULTS

The first branch of the radial nerve at the elbow was to the Ba muscle, followed by the branches to the Br and ECRL muscles. The Ba and Br muscles consistently received single innervation. The ECRL muscle showed varying innervation patterns, with one, two, or three branches. The branches to the Br muscles originated from the anterior side of the radial nerve, whereas the branches to the Ba and ECRL muscles originated from the posterior side. The average myelinated fiber counts favored the nerve to Br muscle over that to the ECRL muscle, with counts of 542 versus 350 and 568 versus 302 observed in hematoxylin and eosin and neurofilament staining, respectively.

CONCLUSIONS

This study provides detailed anatomical insights into the motor branches of the radial nerve to the Ba, Br, and ECRL muscles.

CLINICAL RELEVANCE

Understanding the anatomy of the radial nerve branches at the elbow is of utmost importance when devising a reconstructive strategy for upper limb paralysis. These findings can guide surgeons in selecting appropriate donor or recipient nerves for nerve transfer in cases of high tetraplegia and lower-type brachial plexus injuries.

Anatomy of Profunda Brachial Artery in the Axilla and Its Relationship With the Radial Nerve: Fresh-Cadaver Anatomical Study and Clinical Observations

PURPOSE

Dissection of the radial nerve in the axilla and upper portion of and posterior aspect of arm may be necessary for brachial plexus reconstruction, in axillary nerve paralysis, and in radial nerve injuries. The radial nerve is in intimate contact with the profunda brachial artery (PBA). The authors sought to describe the relationship of the PBA with the radial nerve.

METHODS

We dissected the PBA and the radial nerve bilaterally in 20 upper limbs from 10 fresh cadavers after subclavian artery injection with green latex. We studied the relationship of the PBA with the radial nerve, its branching patterns, and its diameters. In addition, we performed surgery on 5 patients with brachial plexus, radial, or axillary nerve injury in whom we dissected the PBA.

RESULTS

The PBA was present in all dissections, originating from the brachial artery (n = 19 specimens) close to the latissimus dorsi tendon or from the subscapular artery (n = 1 specimen). In 15 dissections, the PBA bifurcated into an anterior (AB) and a posterior (PB) branch. In one dissection, the AB was absent. The AB traveled toward the triceps medial head. The PB flanked the radial nerve posteriorly and traveled around the humerus, with the radial nerve passing between the medial and the lateral head of the triceps. The AB and PB were longer than the PBA and measured on average 53 mm (SD ± 33 mm) and 39 mm (SD ± 26 mm), respectively. Intraoperatively, the radial nerve could be exposed in the upper arm by pulling the triceps medial head anteriorly together with the AB. The PB was lateral to the radial nerve in the posterior arm approach.

CONCLUSIONS

In the upper arm, the radial nerve was not flanked by a single branch as postulated in anatomical textbooks but by 2 branches resulting from the bifurcation of the PBA.

CLINICAL RELEVANCE

Awareness of PBA anatomy is essential during radial nerve dissection from the anterior or posterior arm approach.

Retrograde peripheral nerve regeneration from sensory to motor pathways in rats: a new experimental concept in nerve repair

BACKGROUND

The polarity of nerve grafts does not interfere with axon growth. Our goal was to investigate whether axons can regenerate in a retrograde fashion within sensory pathways and then extend into motor pathways, leading to muscle reinnervation.

METHODS

Fifty-four rats were randomized into four groups. In Group 1, the ulnar nerve was connected end-to-end to the superficial radial nerve after neurectomy of the radial nerve in the axilla. In Group 2, the ulnar nerve was connected end-to-end to the radial nerve distal to the humerus; the radial nerve then was divided in the axilla. In Group 3, the radial nerve was divided in the axilla, but no nerve reconstruction was performed. In Group 4, the radial nerve was crushed in the axilla. Over 6 months, we behaviorally assessed the recovery of toe spread in the right operated-upon forepaw by lifting the rat by its tail and lowering it onto a flat surface. Six months after surgery, rats underwent reoperation, nerve transfers were tested electrophysiologically, and the posterior interosseous nerve (PIN) was removed for histological evaluation.

RESULTS

Rats in the crush group recovered toe spread between 5 and 8 days after surgery. Rats with nerve transfers demonstrated electrophysiological and histological findings of nerve regeneration but no behavioral recovery.

CONCLUSIONS

Ulnar nerve axons regrew into the superficial radial nerve and then into the PIN to reinnervate the extensor digitorum communis. We were unable to demonstrate behavioral recovery because rats cannot readapt to cross-nerve transfer.

Anconeus Muscle Transfer to Correct or Prevent Wrist Radial Deviation in Radial and Posterior Interosseous Nerve Injuries

PURPOSE

Wrist radial deviation is a possible complication of tendon transfer for restoration of wrist extension in cases of radial nerve paralysis. In posterior interosseous nerve (PIN) injury, this is because of the imbalance caused by the intact extensor carpi radialis longus and paralysis of the extensor carpi ulnaris (ECU). This deformity may also occur following transfer of the pronator teres (PT) to the extensor carpi radialis brevis (ECRB) for radial nerve palsy. To address wrist radial deviation, we propose transferring the anconeus muscle, extended by the intermuscular septum between the ECU and the flexor carpi ulnaris (FCU), to the ECU tendon.

METHODS

Through an incision over the ulna, the intermuscular septum between the ECU and FCU is harvested at the level of the periosteum and left attached to the anconeus proximally. The anconeus muscle is then released from the ulna, and the intramuscular septum extension is sutured to the ECU tendon under maximal tension. Anconeus muscle transfer was performed on two patients to correct chronic wrist radial deviation following PT to ECRB tendon transfer for radial nerve injury, as well as on two patients with PIN paralysis. In four patients, transfer was performed in addition to standard tendon transfers for radial nerve paralysis to prevent radial wrist deviation deformity.

RESULTS

Wrist radial deviation was corrected or prevented in all but one patient at an average follow-up of 10 months. Patients with PIN lesions and those who had anconeus transfer concomitantly with radial nerve tendon transfers were capable of active ulnar deviation. No patient experienced elbow extension weakness, pain, or instability.

CONCLUSIONS

Anconeus muscle transfer extended by intermuscular septum presents a viable alternative for addressing radial deviation of the wrist in cases of PIN nerve lesions or following PT to ECRB tendon transfer in radial nerve paralysis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Complete tibial nerve lesion secondary to postoperative popliteal pseudoaneurysm following anterior cruciate ligament arthroscopic reconstruction: A series of two patients

Background

Complications following arthroscopic anterior cruciate ligament reconstruction (ACLR) are rare, but injuries to the popliteal artery can occur. Popliteal pseudoaneurysms are a potential complication and can cause significant morbidity if not diagnosed and treated promptly.

Cases Description

We describe the cases of two patients who developed nerve injuries following arthroscopic ACLR, with subsequent diagnosis of a popliteal pseudoaneurysm. The peroneal nerve recovered spontaneously in both cases, while the tibial nerve was reconstructed using autologous nerve grafting. Satisfying, functional recoveries were observed 24 months postoperatively.

Conclusion

Prompt diagnosis and effective treatment of popliteal pseudoaneurysms are crucial to prevent further complications. However, timely diagnosis can be challenging due to inconsistent clinical presentations and a low index of suspicion. This case report highlights the need for increased awareness of this uncommon complication and provides insights into its pathophysiological mechanisms.

Base of the Third Metacarpal as a Palpable and Reliable Landmark for Identifying the Median Nerve's Thenar Branch

PURPOSE

The objective of this study was to investigate whether the base of the third metacarpal can predict the location of the thenar branch (TB) of the median nerve and the accuracy of palpating the base of the third metacarpal.

METHODS

In 15 patients with ulnar nerve lesions around the elbow, we transferred the opponens motor branch to repair the deep terminal division of the ulnar nerve (DTDUN). Before surgery, we located the TB by palpating the base of the third metacarpal volarly. During surgery, we placed three needles at the following places: one at the entrance of the TB into the abductor pollicis brevis, another at the point where the TB contacted the thenar muscles, and third at the DTDUN's trajectory over the third metacarpal. We obtained fluoroscopic images and measured distances between the needles and structures with image software. We also examined the relationship between the TB, DTDUN, and the volar tubercle of the base of the third metacarpal in cadaver hands. Finally, we invited 22 surgeons to palpate the base of the third metacarpal on volunteer hands and verified their accuracy using fluoroscopy.

RESULTS

During surgery, after dissection and palpation of the TB, under fluoroscopy, we confirmed that the palpable bone prominence was the base of the third metacarpal. In cadaver dissections, we observed the TB crossing the volar tubercle of the base of the third metacarpal superficially from proximal to distal and from ulnar to radial. The DTDUN was, on average, 14 mm distal to the base of the third metacarpal distal limit. In total, 19 of the 22 surgeons correctly identified the base of the third metacarpal and consequently the trajectory of the TB.

CONCLUSIONS

The palpable base of the third metacarpal can be used to determine the trajectory of both the TB and DTDUN.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Long-Term Donor-Site Morbidity Following Entire Sural Nerve Harvest for Grafting

PURPOSE

The sural nerve is the autologous nerve used most commonly for grafting. However, recent studies indicate a high rate of complications and complaints after sural nerve removal. In this prospective study, we evaluated donor-site morbidity following full-length sural nerve harvesting on long-term follow-up.

METHODS

Fifty-one legs from 43 patients who underwent complete sural nerve harvesting for brachial plexus reconstruction were included in the study. After an average of 5 years, with a minimum postoperative follow-up of 12 months, sensory deficits in the leg and foot were analyzed using 2.0-g monofilaments. Regions of sensory deficit were marked with a skin marker and photographed. Over these regions of decreased sensation, we tested nociception using an eyebrow tweezer. Patients were also asked about pain, cold intolerance, pruritis, difficulties walking, and foot swelling.

RESULTS

Regions most affected (84% of patients) were over the calcaneus and cuboid. However, in these regions, nociception was preserved. Regions of decreased sensation extended to the calf region in 11 of 51 legs. In 13 patients, we also observed regions of decreased sensation on the proximal leg. In five feet, the sensation was entirely preserved. No patient had any complaints about pain, cold intolerance, itchiness, difficulties walking, or foot swelling.

CONCLUSION

Decreased sensation with nociception preserved was most common along the lateral side of the foot over the calcaneus and cuboid. Removing the entire sural nerve produced no long-term complaints of pain. Sural nerve use appears safe.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

The Cutaneous Branches of the Median and Ulnar Nerves in the Palm

PURPOSE

The dermatomal distributions of the ulnar and median nerves on the palmar skin of the hand have been studied thoroughly. However, the anatomic course of the median and ulnar cutaneous nerve branches and how they supply the skin of the palm is not well understood.

METHODS

The cutaneous branches of the median and ulnar nerves were dissected bilaterally in 9 fresh cadavers injected arterially with green latex.

RESULTS

We observed 3 groups of cutaneous nerve branches in the palm of the hand: a proximal row group consisting of long branches that originated proximal to the superficial palmar arch and reached the distal palm, first web space, or hypothenar region; a distal row group consisting of branches originating between the superficial palmar arch and the transverse fibers of the palmar aponeurosis (these nerves had a longitudinal trajectory and were shorter than the branches originating proximal to the palmar arch); and a metacarpophalangeal group, composed of short perpendicular branches originating on the palmar surface of the proper palmar digital nerves at the web space. The radial and ulnar borders of the hand distal to the palmar arch were innervated by short transverse branches arising from the proper digital nerves of the index and little finger. Nerve branches did not perforate the palmar aponeurosis in 16 of 18 cases.

CONCLUSIONS

The palm of the hand was consistently innervated by 20-35 mm long cutaneous branches originating proximal to the palmar arch and shorter branches originating distal to the palmar arch. These distal branches were either perpendicular or parallel to the proper palmar digital nerves.

CLINICAL RELEVANCE

Transfer of long proximal row branches may present an opportunity to restore sensibility in nerve injuries.

Pulp-to-Pulp Pinch Reconstruction in a Tetraplegic Patient Utilizing Nerve and Tendon Transfers: A Case Report

In tetraplegia, hand reconstruction is of high priority. Key pinch reconstruction has been advocated for tetraplegia hand reconstruction because of the lack of donors for nerve and tendon transfers. We report a patient with mid-cervical tetraplegia who underwent nerve and tendon transfers in the right and left upper limbs seven months post-injury to reconstruct hand function. The particularity of our case resides in the left-hand thumb and index pulp-to-pulp reconstruction. For this, we transferred the nerve to the supinator to the posterior interosseous nerve and the nerve to the extensor carpi radialis brevis to the anterior interosseous nerve. During a second surgery, we relieved clawing by transferring the split flexor digitorum superficialis of the middle and ring fingers, motored by the brachioradialis, to the extensor apparatus of all fingers. Finally, to achieve better thumb palmar abduction, we osteotomized the scaphoid tubercle and fixed it to the distal radius while maintaining thenar muscle attachments. Five years after surgery, the patient was able to grasp and release small objects placed on a table after becoming left-handed. Here, we demonstrated that pinch-to-pinch reconstruction is possible, which increased hand use in daily activities, especially during eating and grabbing small objects over the table.

Pectoralis Major Reinnervation by Retrograde Nerve Regeneration after Complete Paralysis of the Brachial Plexus

Spontaneous neuronal recovery is an expected phenomenon in brachial plexus palsy patients. However, the spontaneous recovery owing to retrograde regeneration is an evolving phenomenon with dearth of adequate research on it. Pectoralis major contraction on stimulation of median nerve (in the arm) is an unexpected phenomenon, in the absence of any anomalous communication and with distal coaptation site of intraplexal nerve repair. We presumably attribute it to the retrograde regrowth of axons. The case described supports our hypothesis. Level of Evidence: Level V (Therapeutic).

Bilateral Ulnar Nerve Injury in the Wrist: Comparison of First Webspace Muscle Reconstruction by Opponens Nerve Transfer in the Right Hand Versus Direct Ulnar Nerve Repair in the Left Hand

We report a case of a bilateral glass injury to the wrist with transection of flexor tendons and the ulnar nerve and artery in a 60-year-old male patient. Two days after his accident, we repaired all divided structures, and on the right hand, we added the transfer of the opponens motor branch to the deep terminal division of the ulnar nerve aimed at first dorsal interosseous and adductor pollicis muscle reinnervation. After surgery, the patient was followed over 24 months. Postoperative dynamometry of the hand, which included grasping, key-pinch, subterminal-key-pinch, pinch-to-zoom, and first dorsal interosseous muscle strength, indicated recovery only in the nerve transfer side.

Transdeltoid Approach to Axillary Nerve Repair: Anatomical Study and Case Series

PURPOSE

In cases of isolated paralysis of the axillary nerve, dissection of the distal stump at the posterior deltoid border can be difficult because of scarring from an injury or previous surgery. To overcome this, we propose dissecting the anterior division of the axillary nerve (ADAN) using a deltoid-splitting approach. We investigated the anatomy of the ADAN as it pertains to the transdeltoid approach and report the clinical application of this approach in 9 patients with isolated axillary nerve injury.

METHODS

The axillary nerve and its branches were dissected in 9 fresh cadaver specimens. In the clinical series, 1 patient with a lesion confined to the ADAN underwent nerve grafting. In the remaining 8 patients, the ADAN was repaired by transferring the triceps lower medial head and anconeus (TLMA) motor branch via a single-incision or double-incision posterior arm approach.

RESULTS

The posterior division of the axillary nerve does not travel around the humerus. It innervated the posterior deltoid and teres minor muscles. At the posterior margin of the humerus, the ADAN ran adjacent to the teres minor tendon. The ADAN's trajectory on the lateral side of the humerus was 65 mm (SD ± 8 mm) from the midpoint of the acromion. One centimeter from the origin, the ADAN offered a prominent branch to the middle deltoid and wound around the humerus anteriorly at the surgical neck just distal to the infraspinatus tendon. A transdeltoid approach was feasible in all our patients. The TLMA was reached without any tension in the ADAN. Middle deltoid strength in 1 patient who had received a graft scored M3, while anterior and middle deltoid strength in the remaining patients who underwent nerve transfers scored M4.

CONCLUSIONS

With axillary nerve lesions, reinnervation of the ADAN is a priority. The transdeltoid approach between the posterior and middle deltoid offers a direct and feasible approach to the ADAN.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Reverse Neurocutaneous Flap Based on the Dorsal Branch of the Ulnar Artery for Palm Coverage in Children: Long-Term Results

PURPOSE

Although the palm is spared mostly in severe burn injuries, it often is affected in children and requires radical excision of contracting scar tissue to allow normal hand development. Since alternatives are limited for palmar coverage, we primarily use a reverse-perfused, neurocutaneous dorsal ulnar artery flap. We report here our long-term follow-up results.

METHODS

We reviewed the long-term results of 10 postburn palmar contracture release and flap coverage procedures in 10 children. The applied flap was based distally on the dorsal branch of the ulnar artery and harvested along the ulnar aspect of the hand and wrist. The pivot point of the flap was located dorsally, close to the 4th and 5th metacarpal base. Patients were followed for a median period of 6 years (range, 4-20 years).

RESULTS

Flap size ranged from 60-130 mm in length and 20-35 mm in width. This variation in flap dimensions resulted from different hand sizes, because of the various patient ages at surgery. All flaps survived, donor site healing was uneventful, and marginal flap necrosis occurred only once. Satisfactory restoration of range of motion without secondary contractures was observed. Moreover, we detected adequate progressive growth, adaptability and sensory recovery in all flaps. Over time, the flaps mostly become hairless and progressively flattened without debulking.

CONCLUSIONS

The importance of this flap lies in the potential for considerable tissue mobilization to cover palmar defects without sacrificing any major vascular axis. The adequate progressive growth of the flap facilitates functional hand development in children. The predictable vascular anatomy, wide range, and durable, thin, and pliable skin make the reverse neurocutaneous dorsal ulnar artery flap an appealing option for soft tissue reconstruction of the palm in children.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Reconstruction of C5-C8 (T1 Hand) Brachial Plexus Paralysis in a Series of 52 Patients

PURPOSE

A C5-C8 brachial plexus root injury, also known as a T1 hand, is associated with paralysis of shoulder abduction or external rotation and elbow flexion, accompanied by variable elbow, wrist, thumb, or finger extension deficits. We report the results of reconstruction for C5-C8 brachial plexus paralysis in 52 patients operated upon within 12 months of injury and having at least 24 months of follow-up.

METHODS

We considered surgery to be indicated if, by the fifth month after trauma, shoulder abduction and external rotation and elbow flexion remained paralyzed. Root grafting was possible in 35% of the patients and was performed concomitantly with nerve transfers. Shoulder motion was reconstructed by transferring the spinal accessory to the suprascapular nerve. Elbow flexion was restored by transferring fascicles from either the median or ulnar nerve to the biceps motor branch. When needed, elbow extension was reconstructed by transferring 1 motor branch of the flexor carpi ulnaris to the triceps lower medial head motor branch. Wrist extension was restored by transferring the distal anterior interosseous nerve to the extensor carpi radialis brevis motor branch.

RESULTS

Within 12 months of injury, we observed preserved or spontaneous recovery of elbow, wrist, finger, and thumb extension in 25%, 12%, 50%, and 68% of patients, respectively. After surgical reconstruction, improved range of motion for shoulder, elbow flexion, and wrist extension scoring at least M3 was present in 90% of our patients. All 10 patients in whom a motor branch of the flexor carpi ulnaris was used for triceps reconstruction recovered elbow extension, while flexor carpi ulnaris function was preserved.

CONCLUSIONS

In approximatively 90% of our patients, distal nerve transfers resulted in functional recovery of shoulder abduction, elbow flexion or extension, and wrist extension.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Triceps and cutaneous radial nerve branches investigated via an axillary anterior arm approach: new findings in a fresh-cadaver anatomical study

OBJECTIVE

The authors sought to describe the anatomy of the radial nerve and its branches when exposed through an axillary anterior arm approach.

METHODS

Bilateral upper limbs of 10 fresh cadavers were dissected after dyed latex was injected into the axillary artery.

RESULTS

Via the anterior arm approach, all triceps muscle heads could be dissected and individualized. The radial nerve overlaid the latissimus dorsi tendon, bounded by the axillar artery on its superior surface, then passed around the humerus, together with the lower lateral arm and posterior antebrachial cutaneous nerve, between the lateral and medial heads of the triceps. No triceps motor branch accompanied the radial nerve's trajectory. Over the latissimus dorsi tendon, an antero-inferior bundle, containing all radial nerve branches to the triceps, was consistently observed. In the majority of the dissections, a single branch to the long head and dual innervations for the lateral and medial heads were observed. The triceps long and proximal lateral head branches entered the triceps muscle close to the latissimus dorsi tendon. The second branch to the lateral head stemmed from the triceps lower head motor branch. The triceps medial head was innervated by the upper medial head motor branch, which followed the ulnar nerve to enter the medial head on its anterior surface. The distal branch to the triceps medial head also originated near the distal border of the latissimus dorsi tendon. After a short trajectory, a branch went out that penetrated the medial head on its posterior surface. The triceps lower medial head motor branch ended in the anconeus muscle, after traveling inside the triceps medial head. The lower lateral arm and posterior antebrachial cutaneous nerve followed the radial nerve within the torsion canal. The lower lateral brachial cutaneous nerve innervated the skin over the biceps, while the posterior antebrachial cutaneous nerve innervated the skin over the lateral epicondyle and posterior surface of the forearm. The average numbers of myelinated fibers were 926 in the long and 439 in the upper lateral head and 658 in the upper and 1137 in the lower medial head motor branches.

CONCLUSIONS

The new understanding of radial nerve anatomy delineated in this study should aid surgeons during reconstructive surgery to treat upper-limb paralysis.

Patterns of median nerve branching in the cubital fossa: implications for nerve transfers to restore motor function in a paralyzed upper limb

OBJECTIVE

The purpose of this study was to describe the anatomy of donor and recipient median nerve motor branches for nerve transfer surgery within the cubital fossa.

METHODS

Bilateral upper limbs of 10 fresh cadavers were dissected after dyed latex was injected into the axillary artery.

RESULTS

In the cubital fossa, the first branch was always the proximal branch of the pronator teres (PPT), whereas the last one was the anterior interosseous nerve (AIN) and the distal motor branch of the flexor digitorum superficialis (DFDS) on a consistent basis. The PT muscle was also innervated by a distal branch (DPT), which emerged from the anterior side of the median nerve and provided innervation to its deep head. The palmaris longus (PL) motor branch was always the second branch after the PPT, emerging as a single branch together with the flexor carpi radialis (FCR) or the proximal branch of the flexor digitorum superficialis. The FCR motor branch was prone to variations. It originated proximally with the PL branch (35%) or distally with the AIN (35%), and less frequently from the DPT. In 40% of dissections, the FDS was innervated by a single branch (i.e., the DFDS) originating close to the AIN. In 60% of cases, a proximal branch originated together with the PL or FCR. The AIN emerged from the posterior side of the median nerve and had a diameter of 2.3 mm, twice that of other branches. When dissections were performed between the PT and FCR muscles at the FDS arcade, we observed the AIN lying lateral and the DFDS medial to the median nerve. After crossing the FDS arcade, the AIN divided into: 1) a lateral branch to the flexor pollicis longus (FPL), which bifurcated to reach the anterior and posterior surfaces of the FPL; 2) a medial branch, which bifurcated to reach the flexor digitorum profundus (FDP); and 3) a long middle branch to the pronator quadratus. The average numbers of myelinated fibers within each median nerve branch were as follows (values expressed as the mean ± SD): PPT 646 ± 249; DPT 599 ± 150; PL 259 ± 105; FCR 541 ± 199; proximal FDS 435 ± 158; DFDS 376 ± 150; FPL 480 ± 309; first branch to the FDP 397 ± 12; and second branch to the FDP 369 ± 33.

CONCLUSIONS

The median nerve's branching pattern in the cubital fossa is predictable. The most important variation involves the FCR motor branch. These anatomical findings aid during nerve transfer surgery to restore function when paralysis results from injury to the radial or median nerves, brachial plexus, or spinal cord.

Elbow flexion reconstruction with nerve transfer or grafting in patients with brachial plexus injuries: A systematic review and comparison study

INTRODUCTION

Posttraumatic brachial plexus (BP) palsy was used to be treated by reconstruction with nerve grafts. For the last two decades, nerve transfers have gained popularity and believed to be more effective than nerve grafting. The aim of this systematic review was to compare elbow flexion restoration with nerve transfers or nerve grafting after traumatic BP injury.

METHODS

PRISMA-IPD structure was used for 52 studies included. Patients were allocated as C5-C6 (n = 285), C5-C6-C7 (n = 150), and total BP injury (n = 245) groups. In each group, two treatment modalities were compared, and effects of age and preoperative interval were analyzed.

RESULTS

In C5-C6 injuries, 93.1% of nerve transfer patients achieved elbow flexion force ≥M3, which was significantly better when compared to 69.2% of nerve graft patients (p < 0.001). For improved outcomes of nerve transfer patients, shorter preoperative interval was a significant factor in all injury patterns (p < 0.001 for C5-C6 injuries and total BP injuries, p = 0.018 for C5-C6-C7 injuries), and young age was a significant factor in total BP injury pattern (p = 0.022).

CONCLUSIONS

Our analyses showed that nerve transfers appear superior to nerve graftings especially in patients with a C5-C6 injury. Unnecessary delays in surgery must be prevented, and younger patients may have more chance for better recovery.

LEVEL OF EVIDENCE

Level II.

Transfer of the musculocutaneous nerve branch to the brachialis muscle to the triceps for elbow extension: anatomical study and report of five cases

We report the study of the anatomical feasibility of transferring the nerve to the brachialis muscle to the upper medial head motor branch that innervate the triceps, and outcomes of such transfers in restoring elbow extension in five patients with posterior cord lesion of the brachial plexus. The length of the branches to the brachialis muscle measured 7.6 cm and the triceps upper medial head motor branch was 5 cm in 10 adult cadavers. Five male patients were treated with this transfer 5 months after the injury (range 4 to 6 months) after posterior cord injury of the brachial plexus with a mean follow-up of 31 months (range 28 to 36 months). Elbow extension scored M4 in all cases. No complications occurred. These preliminary results suggest that transferring the nerve to the brachialis muscle is an effective technique for the reconstruction of elbow extension after posterior cord brachial plexus injuries.

LEVEL OF EVIDENCE

IV.

Patterns of Brachial Plexus Stretch Palsy in a Prospective Series of 565 Surgically Treated Patients

PURPOSE

To report the distribution of the different patterns of stretch brachial plexus injuries (BPIs) in a retrospective cohort of patients operated at our institution during an 11-year period.

METHODS

From September 2002 to June 2012, we evaluated and operated on 565 patients with traction injuries of the brachial plexus. Average age was 26.8 years (SD ±9.3 years); the interval between the injury and surgery was 5.4 months (SD ±2.8 months). The pattern of injury was defined based on data obtained from a standardized clinical examination, preoperative helical computed tomography myelography after intradural contrast injection, surgical findings, and intraoperative electric stimulation.

RESULTS

Supraclavicular injuries accounted for 91% of all cases (N = 512) whereas 9% of injuries were infraclavicular. Within the supraclavicular injuries, 50% of cases involved the entire plexus and in 12% there was avulsion of all 5 roots. Among them, 94% involved the upper plexus (C5 to C6 ± C7 ± C8), and 6% the lower plexus (C8 to T1 ± C7). C5 to C6 injuries accounted for 23% of partial BPI, C5 to C7 19%, C5 to C8 52%, C7 to T1 4%, and C8 to T1 2%.

CONCLUSIONS

The most relevant findings of this study were that most panplexal BPIs showed at least one graftable root, there was a high prevalence of C5 to C8 BPI, C7 to T1 root injury was the most common pattern of lower type of injury, and infraclavicular BPI was uncommon.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

The Towel Test: A Useful Technique for the Clinical and Electromyographic Evaluation of Obstetric Brachial Plexus Palsy

The towel test consists of covering an infant’s face with a towel and seeing if he/she can remove it with either arm. In this study it has been used to aid the clinical and electromyographic assessment of 21 infants with obstetric brachial plexus palsy. At 2 to 3 months, none of the 21 infants succeeded in removing the towel, either with their normal or affected arm. At 6 months, all the infants succeeded in removing the towel with their normal arm, but 11 could not with their affected arm, and the same was observed at a further assessment at 9 months. The towel test is a reliable technique for evaluating children with obstetric brachial plexus injuries.

Brachialis Muscle Transfer to the Forearm Muscles in Obstetric Brachial Plexus Palsy

Tendon transfers are frequently needed to improve hand function in obstetric brachial plexus injuries. The reconstruction cannot always be achieved using local donor transfers in the forearm as these are not always available. In such cases, we propose the use of the brachialis muscle as a useful donor for transfer. Five adolescents with obstetric brachial plexus palsy were operated on to reconstruct wrist extension and/or pronation using the brachialis muscle transfer to the pronator teres ( n = 1) extensor carpi radialis brevis ( n = 1) and extensor carpi radialis longus ( n = 3). Twelve months after surgery, average active motion recovery was 20° for wrist extension and 14° for pronation. Active and passive range of motion was similar.

Nerve transfer for sensory reconstruction of C8-T1 dermatomes in tetraplegia

OBJECTIVES

Absence of sensation in C8-T1 dermatome is a common finding in midcervical spinal cord injury. The goal was to restore sensation on the C8-T1 dermatomes by transferring sensory nerves with afferents on C5-C6 roots.

METHODS

A mean 10 months post spinal cord injury, we operated on 10 upper limbs from 5 tetraplegics averaging 23 years old. Cutaneous branches of the median nerve were transferred to the palm to the ulnar proper digital nerve of the little finger. In two patients, the lateral antebrachial cutaneous nerve was also transferred to the medial antebrachial cutaneous nerve.

RESULTS

At a mean 20 months after surgery, on the ulnar side of the hand and little finger, all patients were able to perceive 19.3 g Semmes-Weinstein monofilament pressure. Nociception was restored on the medial side of the elbow, forearm, and hand. Faulty location was a common finding, but not as a major complaint.

CONCLUSIONS

Sensory nerve transfers should be incorporated into the reconstruction of the upper limb in tetraplegics. © 2015 Wiley Periodicals, Inc. Microsurgery 36:637-641, 2016.

Nerve transfers for restoration of finger flexion in patients with tetraplegia

OBJECTIVE The purpose of this paper was to report the authors' results with finger flexion restoration by nerve transfer in patients with tetraplegia. METHODS Surgery was performed for restoration of finger flexion in 17 upper limbs of 9 patients (8 male and 1 female) at a mean of 7.6 months (SD 4 months) after cervical spinal cord injury. The patients' mean age at the time of surgery was 28 years (SD 15 years). The motor level according to the ASIA (American Spinal Injury Association) classification was C-5 in 4 upper limbs, C-6 in 10, and C-7 in 3. In 3 upper limbs, the nerve to the brachialis was transferred to the anterior interosseous nerve (AIN), which was separated from the median nerve from the antecubital fossa to the midarm. In 5 upper limbs, the nerve to the brachialis was transferred to median nerve motor fascicles innervating finger flexion muscles in the midarm. In 4 upper limbs, the nerve to the brachioradialis was transferred to the AIN. In the remaining 5 upper limbs, the nerve to the extensor carpi radialis brevis (ECRB) was transferred to the AIN. Patients were followed for an average of 16 months (SD 6 months). At the final evaluation the range of finger flexion and strength were estimated by manual muscle testing according to the British Medical Research Council scale. RESULTS Restoration of finger flexion was observed in 4 of 8 upper limbs in which the nerve to the brachialis was used as a donor. The range of motion was incomplete in all 5 of these limbs, and the strength was M3 in 3 limbs and M4 in 1 limb. Proximal retrograde dissection of the AIN was associated with better outcomes than transfer of the nerve to the brachialis to median nerve motor fascicles in the arm. After the nerve to the brachioradialis was transferred to the AIN, incomplete finger flexion with M4 strength was restored in 1 limb; the remaining 3 limbs did not show any recovery. Full finger flexion with M4 strength was demonstrated in all 5 upper limbs in which the nerve to the ECRB was transferred to the AIN. No functional downgrading of elbow flexion or wrist extension strength was observed. CONCLUSIONS In patients with tetraplegia, finger flexion can be restored by nerve transfer. Nerve transfer using the nerve to the ECRB as the donor nerve produced better recovery of finger flexion in comparison with nerve transfer using the nerve to the brachialis or brachioradialis.

High Median Nerve Injury: Motor and Sensory Nerve Transfers to Restore Function

This article describes the clinically significant motor and sensory deficits that follow high median nerve injuries and addresses the indications, limitations, and outcomes of nerve transfers, when striving to overcome the deficits these patients' experiences. Preferred surgical reconstructive strategy using motor and sensory nerve transfers, and surgical techniques used to perform these transfers, are described.

Variation in nerve autograft length increases fibre misdirection and decreases pruning effectiveness. An experimental study in the rat median nerve

OBJECTIVES

In the clinical set, autologus nerve grafts are the current option for reconstruction of nerve tissue losses. The length of the nerve graft has been suggested to affect outcomes. Experiments were performed in the rat in order to test this assumption and to detect a possible mechanism to explain differences in recovery.

METHODS

The rat median nerve was repaired by ulnar nerve grafts of different lengths. Rats were evaluated for 12 months by behavioural assessment and histological studies, including ATPase myofibrillary histochemistry and retrograde neuronal labelling.

RESULTS

It was demonstrated that graft length interferes in behavioural functional recovery that here correlates to muscle weight recovery. Short nerve grafts recovered faster and better. Reinnervation was not specific either at the trunk level or in the muscle itself. The normal mosaic pattern of Type I muscle fibres was never restored and their number remained largely augmented. An increment in the number of motor fibres was observed after the nerve grafting in a predominantly sensory branch in all groups. This increment was more pronounced in the long graft group. In the postoperative period, about a 20% reduction in the number of misdirected motor fibres occurred in the short nerve graft group only.

CONCLUSION

Variation in the length of nerve grafts interferes in behavioural recovery and increases motor fibres misdirection. Early recovery onset was related to a better outcome, which occurs in the short graft group.

Clinical findings in C5-C6 and C5-C7 root palsies with brachial plexus traction lesions

Stretch injuries of the C5-C7 roots of the brachial plexus traditionally have been associated with palsies of shoulder abduction/external rotation, elbow flexion/extension, and wrist, thumb, and finger extension. Based on current myotome maps we hypothesized that, as far as motion is concerned, palsies involving C5-C6 and C5-C7 root injuries should be similar. In 38 patients with upper-type palsies of the brachial plexus, we examined for correlations between clinical findings and root injury level, as documented by CT tomomyeloscan. Contrary to commonly held beliefs, C5-C7 root injuries were not associated with loss of extension of the elbow, wrist, thumb, or fingers, but residual hand strength was much lower with C5-C7 vs C5-C6 lesions.

Muscle fiber type reorganization and behavioral functional recovery of rat median nerve repair with vascularized or conventional nerve grafts

In 1921, Ney introduced the concept of nerve grafts with preservation of the vascular blood supply. Today, over 70 years later, the use of vascularized nerve grafts in clinical practice is still controversial. Although the results of experiments with vascularized and conventional nerve grafts have been compared on the basis of electrophysiological and histological observations, the literature includes no vaJid comparison of the clinical and behavioral significance of these results. Therefore, in the experiments reported here, the rat median nerve was repaired using either a vascularized or a conventional ulnar nerve graft. The rates behavior between 0 and 360 days after surgery was assessed by the grasping test. Nienty-five, 120, 150, 210 and 360 days after surgery rats were submitted to retrograde labeling studies and muscle samples were removed and studied using routine hematoxilin-eosin and ATPase histochemistry. The present study provides evidence that autografting is a reliable procedure for nerve repair. Motor axons were able to reinnervate and largely respecify muscle properties. Reinnervation was not selective either at the nerve trunk level or at the muscle fiber. A mechanism of collateral pruning might have been present in the early phases of reinnervation. This mechanism was, however, self limiting and unable to correct all wrong projections. A mechanism of terminal sprouting was in part responsible for time-related improvement in muscle force recovery. While the present study does provide evidence that recovery was 20% faster in rats with vascularized grafts than in those with conventional grafts (P < 0.0001), it does not, however, provide evidence for better functional recovery in long-term assessment.

Distal sensory nerve transfers in lower-type injuries of the brachial plexus

PURPOSE

To report the results of sensory nerve transfers to reconstruct sensation on the ulnar side of the hand in lower-type palsies of the brachial plexus.

METHODS

From 2007 to 2009, we operated on 6 men and 2 women with a lower-type injury of the brachial plexus and observed them for a minimum of 24 months. The mean interval between the injury and surgery was 8 months (SD ± 8.6 mo). Before surgery, we documented anesthesia on the ulnar side of the hand in all patients. Donor nerves included cutaneous branches of the median nerve to the palm (n = 5) or the palmar cutaneous branch of the median nerve (n = 3). The ulnar proper digital nerve of the little finger was the recipient nerve. We evaluated sensory recovery by assessing static 2-point discrimination and sensation to Semmes-Weinstein monofilaments.

RESULTS

According to the British Medical Council system of evaluation, 5 patients scored S3 and 3 scored S3+.

CONCLUSIONS

In lower-type injuries of the brachial plexus, transfer of median nerve branches that innervate the palm of the hand to the ulnar proper digital nerve of the little finger predictably restored protective sensation on the ulnar side of the hand.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Results and current approach for Brachial Plexus reconstruction

We review our experience treating 335 adult patients with supraclavicular brachial plexus injuries over a 7-year period at the University of Southern Santa Catarina, in Brazil. Patients were categorized into 8 groups, according to functional deficits and roots injured: C5-C6, C5-C7, C5-C8 (T1 Hand), C5-T1 (T2 Hand), C8-T1, C7-T1, C6-T1, and total palsy. To restore function, nerve grafts, nerve transfers, and tendon and muscle transfers were employed. Patients with either upper- or lower-type partial injuries experienced considerable functional return. In total palsies, if a root was available for grafting, 90% of patients had elbow flexion restored, whereas this rate dropped to 50% if no roots were grafted and only nerve transfers performed. Pain resolution should be the first priority, and root exploration and grafting helped to decrease or eliminate pain complaints within a short time of surgery.

Transfer of supinator motor branches to the posterior interosseous nerve to reconstruct thumb and finger extension in tetraplegia: case report

We treated a patient with tetraplegia who had paralysis of thumb and finger extension by transferring supinator motor branches to the posterior interosseous nerve. Surgery was performed bilaterally, 7 months after a spinal cord injury. Six months after surgery, with the wrist in neutral, extension of the thumb and finger were almost full, bilaterally. In tetraplegic patients with strong wrist extensors, supinator motor branch transfer is a promising new alternative for the reconstruction of thumb and finger extension.

Transfer of the supinator muscle to the extensor pollicis brevis for thumb extension reconstruction in C7-T1 brachial plexus palsy

With C7-T1 brachial plexus injuries, finger motion is absent while shoulder, elbow and wrist function are largely preserved. Previously, we have reconstructed finger flexion by transferring the brachialis muscle to the flexor digitorum profundus and flexor pollicis longus; and we have restored extension of thumb and finger by transferring the motor nerve to the supinator to the posterior interosseous nerve, which is only feasible in fresh injuries. We describe the transfer of the supinator muscle to the extensor pollicis brevis to reanimate thumb extension in patients with long standing C7-T1 brachial plexus palsy.

Lengthening of subscapularis and transfer of the lower trapezius in the correction of recurrent internal rotation contracture following obstetric brachial plexus palsy

An internal rotation contracture is a common complication of obstetric brachial plexus palsy. We describe the operative treatment of seven children with a recurrent internal rotation contracture of the shoulder following earlier corrective surgery which included subscapularis slide and latissimus dorsi transfer. We performed z-lengthening of the tendon of the subscapularis muscle and transferred the lower trapezius muscle to the infraspinatus tendon. Two years postoperatively the mean gain in active external rotation was 47.1 degrees, which increased to 54.3 degrees at four years. Lengthening of the tendon of subcapularis and lower trapezius transfer to infraspinatus improved the range of active external rotation in patients who had previously had surgery for an internal rotation contracture.

Lower trapezius muscle transfer for reconstruction of elbow extension in brachial plexus injuries

Elbow extension is a prerequisite for adequate hand position. Muscle transfers are often employed in partial injuries of the brachial plexus, when neurological surgery is unlikely to achieve desired results. The posterior deltoid and latissimus dorsi are the two muscles most commonly used for transfer but there are few alternatives when these two muscles are paralysed. We now report on the successful transfer of the lower trapezius muscle to reconstruct triceps function in three patients with longstanding lesions of the brachial plexus that had not been previously treated surgically.

Pain after avulsion injuries and complete palsy of the brachial plexus: the possible role of nonavulsed roots in pain generation

OBJECTIVE

Pain after complete brachial palsy has been attributed to the deafferentation of the spinal cord subjected to root avulsion. However, the large majority of patients have at least one nonavulsed root. We postulated that pain, be it subacute or chronic, originates in the stump of the nonavulsed roots.

METHODS

Thirty-six patients underwent brachial plexus grafting within 8 months of their initial injury. Ten other patients with palsy that had lasted for more than 2 years underwent selective, computed tomography-guided anesthetic blocks of the nonavulsed root. Pain was evaluated at different intervals, using a numerical scale ranging from 0 (no pain) to 10 (severe pain).

RESULTS

In all groups, pain decreased substantially or disappeared after a local anesthetic block or grafting. In the patients who underwent grafting, pain reduction was noted the first day after surgery in 56% of the 36 patients. Three weeks after surgery, pain decreased dramatically, by 80% (P < 0.001). By 12 months after surgery, pain had decreased by 90%, and within 24 months, by 95%. Only the difference between 3 weeks and 24 months after surgery was significant (P < 0.001). At final evaluation, 80% of the patients receiving grafts reported either no or minimal pain.

CONCLUSION

Our data suggest that nonavulsed roots mediate pain in subacute and chronic complete brachial plexus palsy.

Flexor tendon grafting using a plantaris tendon with a fragment of attached bone for fixation to the distal phalanx: a preliminary cohort study

PURPOSE

Secure methods of graft attachment ensure safe early motion after flexor tendon grafting. This has been achieved at the proximal graft juncture using Pulvertaft's technique. For secure distal attachment, we investigate the results of flexor tendon grafting using the plantaris tendon with a fragment of attached bone fixed with a screw to the distal phalanx.

METHODS

Thirteen digits from 10 patients with longstanding flexor tendon injuries in zone II had surgical reconstruction. A plantaris tendon-bone graft was attached to the distal phalanx using a mini-screw. This was followed by immediate active motion. At 3 and 8 months after surgery, total active motion was calculated as the sum of the degrees of active flexion in the proximal and distal interphalangeal joints minus the sum of the degrees of extension deficits for each of these joints. The results of total active motion were compared to the normal contralateral digit.

RESULTS

Three months after surgery, the mean rate of recovery, relative to the normal contralateral finger, was 74%, whereas 8 months after surgery, this value was 70%. This difference was statistically significant. There were no failures or poor results (ie, less than 50% recovery).

CONCLUSIONS

The tendon-bone plantaris graft employed here ensured immediate active motion and early use of the involved hand in daily activities.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Triceps Motor Nerve Branches as a Donor or Receiver in Nerve Transfers

Objective:

The pattern of triceps innervation is complex and, as yet, has not been fully elucidated. The purposes of this study were 1) to clarify the anatomy of the triceps motor branches, and 2) to evaluate their possible uses as a donor or receiver for nerve transfer.

Methods:

The radial nerve and its motor and cutaneous branches were bilaterally dissected from the axilla and posterior arm regions of 10 embalmed cadavers.

Results:

A single branch innervates the triceps long head, whereas double innervation was identified for the lateral and medial heads. The upper branch to the lateral head originated from the radial nerve, whereas the lower branch to the lateral head stemmed from the lower medial head motor branch, which ultimately innervated the anconeus muscle. Both the long head and the upper medial head motor branches originated in the axillary region in the vicinity of the latissimus dorsi tendon.

Conclusion:

Each of the triceps’ motor branches might be used as a donor for transfer. The triceps long head motor branch should be used preferentially when the intention is to establish triceps reinnervation.

Treatment of scaphoid non-unions by a palmar approach with vascularised bone graft harvested from the thumb

Ten patients with scaphoid non-unions which had been present for longer than 2 years were treated using a vascularised bone graft harvested from the thumb and pedicled on the first dorsal metacarpal artery. Bone harvesting and grafting were performed by a single palmar approach. Concomitant cancellous bone graft was not used. Bone healing was confirmed by CT scans in nine of the ten patients. Persistence of the non-union was observed in one patient who was the oldest in this series, had the longest standing non-union and was a heavy smoker. Twelve months after surgery, nine of the ten patients had significant pain relief with an improved range of motion and grip strength.

The course of aberrant reinnervation following nerve repair with fresh or denatured muscle autografts

Denatured muscle grafts obtained by freeze thawing have been proposed to replace losses in the peripheral nerves. In the present report, we compare the performance of such grafts with fresh grafts in the rat median nerve. A long-term effect of muscle interposition on reinnervation was studied by behavioral assessment, muscle ATPase histochemistry, and retrograde labeling of motoneurons. There was no difference in grasping strength recovery between fresh and denatured 10-mm-long muscle grafts. Recovery was delayed and incomplete. Twelve months after surgery, only 50% of the normal grasping strength was attained. Grasping recovery was not observed in the 20-mm-long graft groups. Pathway reinnervation was non-specific with a huge amount of motor fiber misdirection. A decrease in the number of misdirected motor fibers occurred with time and activity recovery. Muscle reinnervation was not specific with disturbance of the mosaic pattern and type-grouping formation. Preference of type I axons for reinnervating deeper zones was observed. Type I aberrant reinnervation was demonstrated in the muscle periphery. The mosaic distribution of type I and II muscle fibers was not stable, and readjustments were observed with time, correlating with grasping improvement. During grasping strength recovery, there was a decrease in the number of type I fibers peripherally located and an increase of those deeply disposed. A time- and activity-related recovery was associated with readjustment in the pathways and muscle fiber rearrangement. We suggest that muscle activity generates specificity.

Pharmacological characterisation of the rat brachial plexus avulsion model of neuropathic pain

Recently, our laboratory has proposed the avulsion of rat brachial plexus as a new and reliable model for the study of neuropathic pain. In this model, the neuropathy can be detected even at distant sites from the injury, both in ipsilateral and contralateral hindpaws. The purpose of this study was to pharmacologically characterise this behavioural model of persistent peripheral neuropathic pain by assessing the effects of several analgesic drugs currently used in clinical practice. For this purpose, the effects of these drugs on the mechanical and cold allodynia were analysed 20-40 days after rat brachial plexus avulsion. Injection of saline, administered by the same route as the other drugs, did not significantly affect the nociceptive threshold either in sham-operated or in neuropathic rats. However, administration of the opioid analgesic morphine (5 mg/kg, s.c.), the alpha2 adrenoceptor agonist clonidine (300 microg/kg, i.p.), the NMDA receptor antagonist ketamine (25 mg/kg, i.p.) or the anticonvulsant drug gabapentin (70 mg/kg, p.o.) consistently reduced both mechanical and cold allodynia following avulsion of rat brachial plexus. The administration of the selective COX-2 inhibitor celecoxib (10 mg/kg, p.o.) blocked mechanical allodynia, but not cold allodynia, whereas the sodium channel blocker lidocaine (40 mg/kg, i.p.) attenuated only cold allodynia. The non-steroidal anti-inflammatory drug diclofenac (100 mg/kg, i.p.), the steroidal anti-inflammatory dexamethasone (1.5 mg/kg, i.p.) and the antidepressant imipramine (10 mg/kg, i.p.) all failed to significantly attenuate both mechanical and cold allodynia in the rats following avulsion of brachial plexus. These findings suggest that avulsion-associated mechanical and cold allodynia, two classic signs of persistent neuropathic pain, were consistently prevented by several analgesics currently available in clinical practice, namely morphine, clonidine, ketamine and gabapentin, and to a lesser extent by celecoxib and lidocaine. Therefore, this new proposed model of persistent nociception seems to be suitable for the study of the underlying mechanisms involved in neuropathic pain and for the identification of potential clinically relevant drugs to treat this aspect of peripheral neuropathy.

Avulsion injury of the rat brachial plexus triggers hyperalgesia and allodynia in the hindpaws: a new model for the study of neuropathic pain

In the present study, we sought to characterise a behavioural model of persistent peripheral neuropathic pain produced by avulsion of the right brachial plexus in rats. In addition, we compared the effects of avulsion with those of ligation or crush injury of the brachial plexus. Avulsion and, to a lesser extent, ligation and crushing of brachial plexus caused a long-lasting (up to 90 days) and highly reproducible mechanical hyperalgesia, in both ipsilateral and contralateral hindpaws. However, the same injury did not produce thermal hyperalgesia. The avulsion and, to a lesser extent, ligation and crushing of the brachial plexus elicited a significant and long-lasting (up to 90 days) ipsilateral and contralateral cold and mechanical allodynia. Furthermore, the brachial plexus injury caused a significant decrease in functional activity of the forepaws as assessed in the grasping strength test, but did not alter the locomotor activity of the rats in the open field test in comparison with control or sham groups. Taken together these results show that avulsion of the brachial plexus in rat produces persistent mechanical and cold allodynia and mechanical hyperalgesia, and might represent a valuable method for understanding the mechanisms underlying the aetiology of neuropathic pain.

Hemidigital resection with collateral ligament transplantation in the treatment of macrodactyly: a case report

Macrodactyly is a rare congenital anomaly of the hand that is difficult to treat. We describe a new technique consisting of hemidigital, longitudinal, and transverse en bloc resection with collateral ligament transplantation to the proximal interphalangeal joint that we used in a case of macrodactyly. Four years after the procedure the digit's appearance was largely improved with preservation of complete motion at the proximal interphalangeal joint. Transplantation of the collateral ligament ensured a stable joint. Fingertip sensibility was maintained.

Cross-chest radial nerve transfer in brachial plexus injuries. Experimental and anatomical basis

Brachial plexus avulsion injuries are devastating injuries to the upper limb, and nerve transfer remains the only option in reconstruction. Despite the encouraging results concerning recovery of shoulder and elbow function, no option is available for treatment of the paralytic hand. In rats, we sectioned the radial nerve in the elbow region and transferred it across the chest to reinnervate the lesioned contralateral medial cord of the brachial plexus. Rats were then evaluated for motor and sensory recovery, electrophysiologically, behaviorally and morphologically. Forepaw functional recovery was estimated to be 90%. In cadavers, the radial nerve and profunda brachii artery were dissected. It was observed that the radial nerve vascularized by the profunda brachii artery was able to reach the contralateral brachial plexus distal to the shoulder region without nerve grafts. After sectioning the radial nerve, sensory loss is minimal and motor palsy can be easily restored by tendon transfers. The results of tendon transfer for radial nerve palsy are better than for any other nerve. Cross-chest radial nerve transfer might be of clinical interest in the reconstruction of hand function in entire injury to the brachial plexus.

Brachial plexus dorsal rhizotomy in the treatment of upper-limb spasticity

OBJECT

This study was conducted to evaluate the effects of dorsal rhizotomy on upper-limb spasticity, functional improvement, coordination, and hand sensibility.

METHODS

Fifteen spastic upper limbs in 13 patients were selected and prospectively studied. Brachial plexus dorsal rhizotomy was performed in which two, three, or four dorsal roots were completely sectioned. Patients were followed up for at least 12 months after surgery; the mean follow-up period was 15.6 months and the maximum period was 30 months. A remarkable relief of spasticity was observed in all cases. Recurrence was observed in only one patient and was caused by insufficient dorsal root section. Functional improvement was observed in all cases, and functional improvement in the hand was found to be related to the presence of active finger extension in the preoperative period. Even when extended dorsal root section was performed, no hand anesthesia, either total or partial, was observed. No patient lost movement ability in the postoperative period, and no ataxic limbs were observed.

CONCLUSIONS

Brachial plexus dorsal rhizotomy is very effective as a treatment for upper-limb spasticity and results in functional improvement without loss of sensation in the hand.