Prevalence of Concomitant Distal Suprascapular Nerve Injury in Patients with Root-level Brachial Plexus Palsy: A Clinical Anatomic Study of Injury Pattern.

BACKGROUND: Root-level suprascapular nerve palsy is commonly reconstructed via spinal accessory nerve transfer in brachial plexus injury, yet some patients fail to recover. We hypothesize that this relates to concomitant undetected lesions distal to the nerve transfer coaptation. METHODS: 67 patients with plexus injury and C5/6 root involvement were included in this prospective study between March 2021 and October 2022. During spinal accessory to suprascapular nerve transfer the entire suprascapular nerve was explored, via cresenteric clavicular osteotomy, and anatomic variations and injury patterns categorized. RESULTS: Proximal root involvement was C5-C6 (n=8), C5-C7 (n=13), C5-C8 (n=17), C5-T1(29). Mean time from injury to surgery was 5.6 months. The suprascapular nerve was found to be injured in 16/67 cases (24%). In 9 cases (13%) the lesion was proximal to the suprascapular fossa. In 3 cases (4%) the suprascapular nerve was injured both proximally and within the fossa, and in 4 cases (6%) in the fossa or distal to it. Therefore, in 7 cases (10%), a traditional suprascapular nerve transfer would not successfully bypass the zone of injury of the suprascapular nerve in the fossa. Of the 16 cases of concomitant suprascapular nerve injury, 1/8 in occurred in C5-C6 root injury, 4/13 of C5-C7 root injury, 5/17 of C5-C8 root injury and 6/39 in total paralysis. CONCLUSIONS: Concomitant distal suprascapular nerve injury in brachial plexus stretch palsy occurred in 24% of the cases. This warrants attention from the surgeon to identify distal lesions and to perform the nerve transfer beyond any secondary lesions.

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.

Distal nerve transfers for peripheral nerve injuries: indications and outcomes.

Distal nerve transfer is a refined surgical technique involving the redirection of healthy sacrificable nerves from one part of the body to reinstate function in another area afflicted by paralysis or injury. This approach is particularly valuable when the original nerves are extensively damaged and standard repair methods, such as direct suturing or grafting, may be insufficient. As the nerve coaptation is close to the recipient muscles or skin, distal nerve transfers reduce the time to reinnervation. The harvesting of nerves for transfer should usually result in minimal or no donor morbidity, as any anticipated loss of function is compensated for by adjacent muscles or overlapping cutaneous territory. Recent years have witnessed notable progress in nerve transfer procedures, markedly enhancing the outcomes of upper limb reconstruction for conditions encompassing peripheral nerve, brachial plexus and spinal cord injuries.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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. MATERIALS AND 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.

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.