Contralateral C7 transfer via both ulnar nerve and medial antebrachial cutaneous nerve to repair total brachial plexus avulsion: a preliminary report.

Aim: After brachial plexus injuries, sacrifice of the contralateral C7 (cC7) root from the non-injured side is well tolerated and various schemes to innervate the injured side from the cC7 root have been used. Objective: To demonstrate the surgical outcomes from transferring the cC7 to the affected side via both the ulnar nerve and medial antebrachial cutaneous nerve (MACN).Methods: A retrospective study of 16 adult patients sustaining total brachial plexus avulsion who underwent this procedure. The British Medical Research Council (MRC) grading system and the disabilities of the arm, shoulder, and hand (DASH) questionnaire scoring were used to evaluate the recovery.Results: About 68.75% of the patients achieved functional recovery of elbow flexion to M3 or better and 43.75% achieved motor recovery of wrist and finger flexion to M3 or better. Sensation in the median nerve territory recovered to S2 or better in 68.75%. The DASH scores after surgery were significantly lower than those before surgery.Conclusions: cC7 transfer via both ulnar and MACNs is an effective and safe procedure in patients sustaining total injuries of brachial plexus.

Possible anastomoses between the long branches of the brachial plexus and their clinical significance.

The brachial plexus consists of nerves that supply the upper limb and some nerves of the back, torso, and neck. It is formed by the ventral rami of C5 to T1 (in some cases, C4 or T2 also contribute). The anterior rami of the spinal nerves unite to the roots, trunks, divisions, cords, and terminal branches that innervate muscles and skin. An example is associated with terminal branches of the long nerves. Knowledge of this variation is necessary for enabling surgeons, orthopedists, and neurologists to avoid injury during surgical exploration in the arm or axilla region, and for achieving correct diagnoses, because such variability can evoke nonspecific responses. Awareness of this anastomosis is also mandatory for anesthetists performing anesthesia in the upper limb region. The aim of this article is to describe anastomoses between long nerves from the brachial plexus and to consider their clinical significance.

Isolated medial antebrachial cutaneous nerve injury after blunt trauma: a case report.

BACKGROUND: The medial antebrachial cutaneous nerve is a branch of the brachial plexus that contains C8-T1 segments. Injury of this nerve by various mechanisms has been reported in the literature; however, currently, there is no reported case of medial antebrachial cutaneous nerve injury in the setting of acute blunt trauma. CASE PRESENTATION: This case report presents the case of a 34-year-old Persian female with dysesthesia and pain in the medial side of the forearm immediately following a blunt trauma by mechanism of elbow external rotation. On electrodiagnostic evaluation, the medial antebrachial cutaneous nerve sensory nerve action potential of the symptomatic side had a significant amplitude drop (more than 50%), compared with the other side. On follow-up electrodiagnosis, after several sessions of physical therapy, the medial antebrachial cutaneous nerve sensory nerve action potential still had a significant amplitude difference. CONCLUSION: Blunt trauma can be one of the causes of medial antebrachial cutaneous nerve involvement. An electrodiagnostic study can be helpful in the diagnosis of this nerve injury after blunt trauma.

Ultrasonographic Identification of the High-Risk Zone for Medial Antebrachial Cutaneous Nerve Injury in the Elbow.

OBJECTIVE: To demonstrate the sonoanatomy of the medial antebrachial cutaneous nerve (MACN) in the elbow region using high-resolution ultrasonography (HRUS) to identify areas at a high risk of MACN injury. METHODS: A total of 44 arms were included in the study. In the supine position, the participants' arms were abducted 45° with the elbow fully extended. The MACN was visualized in the transverse view. The anterior branch of the MACN (ABMACN), posterior branch of the MACN (PBMACN), and location of the branching sites were determined. The distance between the ABMACN and superficial veins, including the basilic vein (BV) and median cubital veins (MCV) was measured. For the PBMACN, the distance to the ulnar nerve (UN) and to BV were measured. RESULTS: The MACN was subdivided into 2.18±1.00 branches, including ABMACN and PBMACN. The ABMACN and PBMACN were subdivided into 1.60±0.78 and 1.07±0.25 branches, respectively. The branching point of the MACN was 8.40±2.42 cm proximal to the interepicondylar line (IEL). We demonstrated that the ABMACN is located close to the BV and MCV in the elbow region, and the PBMACN was located approximately 1 cm and 0.8 cm anterior to the UN and posterior to the BV at the IEL level, respectively. CONCLUSION: Considering the location of the MACN, including ABMACN and PBMACN, clinicians can perform invasive procedures around the elbow region more carefully to lower the risk of MACN injury.

A meta-analysis on the anatomical variability of the brachial plexus: Part III - Branching of the infraclavicular part.

INTRODUCTION: The anatomy of the brachial plexus has been a subject of interest to many researchers over time resulting in an inconsistent amount of data. Previously, our team had published two evidence-based studies on the anatomical variations involving the brachial plexus, therefore the aim of this study was to analyze the findings regarding the infraclavicular part of the brachial plexus with the use of meta-analytic techniques to complete the comprehensive series. MATERIAL AND METHODS: Major scientific databases were extensively searched to compile anatomical studies investigating the morphology of the infraclavicular part of the brachial plexus. Extracted data were classified based on our proposed classification system and subsequently analyzed with the use of random effects meta-analysis to state the pooled prevalence estimates of the distinct variation patterns. RESULTS: A total of 75 studies (4772 upper limbs) were selected for the meta-analysis. The branches of the lateral cord, including the lateral pectoral nerve and musculocutaneous nerve, resembled their usual origin in 76.8% (95% CI 50-96%) and 98.8% (95% CI 98-100%), respectively. The medial pectoral nerve, medial brachial cutaneous nerves, medial antebrachial cutaneous nerve and ulnar nerve emerging from the medial cord were observed originating from their usual origins in 90.9% (95% CI 68-100%), 90.7% (95% CI 73-100%), 87.9% (95% CI 67-99%) and 97.7% (95% CI 94-100%), respectively. Lastly, nerves branching from the posterior cord, including the superior and inferior subscapular nerves, thoracodorsal nerve, axillary nerve and radial nerve, originated as per textbook description in 90.7% (95% CI 80-98%), 76.1% (95% CI 61-89%), 90.1% (95% CI 84-95%), 79.8% (95% CI 68-90%) and 99.0% (95% CI 96-100%), respectively. Moreover, the usual origin of the median nerve from the lateral and medial cord via the corresponding roots was encountered in 89.7% (95% CI 84-95%) of cases. CONCLUSIONS: The nerves originating from the infraclavicular part of the brachial plexus exhibit a wide spectrum of possible origins. However, the usual patterns were significantly the most common types present in more than three quarters of cases. Especially clinicians might profit from the enhanced understanding of the brachial plexus anatomy presented herein, since we offer a strong guide for handling the anatomically challenging pathologies in this specific area.

A novel dual nerve transfer for restoration of shoulder function and sensory recovery of the hand, in patients with C567 traumatic root avulsion of the brachial plexus.

OBJECTIVE: The objective of our study is to determine the anatomical viability in cadavers of a novel doble nerve transfer technique for simultaneous reanimation of shoulder abduction and sensory recovery of the hand, in patients with brachial plexus injuries sustaining a C5-C6-C7 roots avulsion. These new transfers should be complemented in the clinical setting with other classic nerve transfers, i.e.: (1) a spinal accessory to suprascapular for shoulder abduction and stability, (2) ulnar nerve fascicles to the biceps branches of the musculocutaneous for elbow flexion, and (3) intercostal to triceps branches for elbow extension. METHODS: The proposed surgical technique includes (1) transferring motor fascicles of the median nerve (MNF), as donors to the axillary nerve (AN), and (2) the whole medial antebrachial cutaneous nerve (MACN) to the lateral contribution (sensory) of the median nerve (LCMN), both without the use of interposed nerve grafts. These techniques were performed in eight cadaveric upper extremities. Analyzed variables were: donor and receptor nerves diameter, length and distance of donor and receptors nerves, and axonal count. RESULTS: The mean distance between the MNF and its point of coaptation to the AN was 19 mm. The average length of each one of the MNF, after distal dissection, was 46.5 mm. The average diameter of each fascicle of the median nerve at its coaptation point with the axillary nerve was 0.8 mm, while the average diameter of the latter was 3.9 mm. The average distance between the MACN and its point of coaptation to the LCMN, was 16.5 mm. The average diameter of the MACN and the LCMN at their point of coaptation, were 2.7 mm and 3.5 mm, respectively. CONCLUSION: These nerve transfers are anatomically viable and could be a complement for other currently used techniques that can be employed in severely injured C567 brachial plexus patients.

Case Report: Neurogenic Thoracic Outlet Syndrome Without Electrophysiologic Abnormality.

Neurogenic thoracic outlet syndrome (N-TOS) is a chronic compressive brachial plexopathy that involves the C8, T1 roots, and/or lower trunk. Medial antebrachial cutaneous (MABC) nerve conduction study (NCS) abnormality is reportedly one of the most sensitive findings among the features of N-TOS. The aim of the present study was to report clinical features, imaging findings, treatment, and prognoses of two N-TOS patients with no abnormalities in electrophysiological studies. Both patients presented with paresthesia of unilateral arm, and examination revealed no neurologic deficits. Electrophysiologic studies including MABC NCS were normal. Computed tomography (CT) angiography and brachial plexus magnetic resonance imaging (MRI) of the patients showed compression and displacement of the neurovascular bundle in the thoracic outlet by causative structures. Due to their sensory symptoms and CT angiography and brachial plexus MRI findings, after excluding other diseases, we diagnosed them with N-TOS. With the development of imaging techniques, more patients presenting with clinical features of lower trunk brachial plexopathy and anomalous structures compressing the neurovascular bundle on imaging studies can be diagnosed with N-TOS, even if electrophysiologic studies including MABC NCS do not show abnormalities.

Vascularization of the lateral and medial antebrachial cutaneous nerves by cutaneous perforator arteries: An anatomical study.

The forearm is an interesting donor site for non-vascularized nerve grafts, especially hand surgeons. Very few studies have described the use of the lateral and medial antebrachial cutaneous nerves (LABCN and MABCN, respectively) as vascularized nerve grafts (VNGs). The aim of this anatomical study was to analyze the characteristics and vascularization of these nerves to describe new potential donor sites for VNGs. Twelve forearms were dissected from fresh cadavers injected with red latex. The number of terminal branches, lengths, and proximal and distal diameters of both the LABCN and MABCN were studied. An anatomical description of the cutaneous perforator arteries from the radial and ulnar arteries that vascularized the nerve was also recorded: number of perforators, length, type of perforator (septo- or musculocutaneous), and location within the forearm (proximal, middle, and distal third). In over 80% of the specimens, the cutaneous perforator arteries from the radial and ulnar artery vascularized the LABCN and the MABCN, respectively. These arteries, found mostly in the proximal third of the forearm, had diameters >0.5mm. Most of them came from the radial and ulnar arteries (for LABCN and MABCN vascularization, respectively). In over 75% of the specimens, the nutrient arteries of both nerves also vascularized the superficial veins and the skin. We found that these nerves are vascularized by perforators arteries, which also participate in vein and skin vascularization. Altogether, this anatomical study shows that reconstructive surgeons could use new VNGs based on the perforator artery of the forearm.

Anatomy of the posterior branch of the medial antebrachial cutaneous nerve: A cadaveric study.

PURPOSE: The posterior branch of the medial antebrachial cutaneous nerve (MACN) is at risk to be damaged during cubital tunnel surgery. The purpose of this study was to identify the location of the posterior branch of the MACN (PBMACN) in relation to surgical landmarks pertinent in cubital tunnel surgery. METHODS: We performed an anatomical study on 20 limbs from 13 fresh cadavers. The nerve was dissected from 10cm proximal to 10cm distal of the medial epicondyle. We measured the distance between the nerve and the medial epicondyle, and also the distance separating the PBMACN from the ulnar nerve passage between the two heads of the flexor carpi ulnaris. Measurements were performed with the elbow at 45° and 90° of flexion, as well as in full pronation and supination. RESULTS: After its emergence from the main trunk of the MACN, the posterior branch ran anteriorly to the medial epicondyle, taking an oblique direction toward the ulnar shaft. The PBMACN was in average 2.53cm under the medial epicondyle when the elbow was flexed at 45°, and 2.96cm when the elbow was flexed at 90°. Average distance between the PBMACN and the penetrating point of the ulnar nerve within the flexor carpi ulnaris was 1.54cm when the elbow was flexed at 45°, and 1.62cm when the elbow was flexed at 90°. Pronation and supination positions of the forearm did not significantly modify our measurements. CONCLUSIONS: Understanding the position of MACN posterior branch during ulnar nerve release surgery at the elbow may help in preventing iatrogenic injury. According to our measurements, incision and superficial dissection anterior to the medial epicondyle or distal to the ulnar nerve penetrating point between the two heads of the flexor carpi ulnaris should be avoided or done with an elbow flexed at 90°.

Modified contralateral C7 nerve transfer: the possibility of permitting ulnar nerve recovery is confirmed by 10 cases of autopsy.

Contralateral C7 nerve transfer surgery is one of the most important surgical techniques for treating total brachial plexus nerve injury. In the traditional contralateral C7 nerve transfer surgery, the whole ulnar nerve on the paralyzed side is harvested for transfer, which completely sacrifices its potential of recovery. In the present, novel study, we report on the anatomical feasibility of a modified contralateral C7 nerve transfer surgery. Ten fresh cadavers (4 males and 6 females) provided by the Department of Anatomy, Histology, and Embryology at the Medical College of Fudan University, China were used in modified contralateral C7 nerve transfer surgery. In this surgical model, only the dorsal and superficial branches of the ulnar nerve and the medial antebrachial cutaneous nerve on the paralyzed side (left) were harvested for grafting the contralateral (right) C7 nerve and the recipient nerves. Both the median nerve and deep branch of the ulnar nerve on the paralyzed (left) side were recipient nerves. To verify the feasibility of this surgery, the distances between each pair of coaptating nerve ends were measured by a vernier caliper. The results validated that starting point of the deep branch of ulnar nerve and the starting point of the medial antebrachial cutaneous nerve at the elbow were close to each other and could be readily anastomosed. We investigated whether the fiber number of donor and recipient nerves matched one another. The axons were counted in sections of nerve segments distal and proximal to the coaptation sites after silver impregnation. Averaged axon number of the ulnar nerve at the upper arm level was approximately equal to the sum of the median nerve and proximal end of medial antebrachial cutaneous nerve (left: 0.94:1; right: 0.93:1). In conclusion, the contralateral C7 nerve could be transferred to the median nerve but also to the deep branch of the ulnar nerve via grafts of the ulnar nerve without deep branch and the medial antebrachial cutaneous nerve. The advantage over traditional surgery was that the recovery potential of the deep branch of ulnar nerve was preserved. The study was approved by the Ethics Committee of Fudan University (approval number: 2015-064) in July, 2015.

Surgical outcomes of neurogenic thoracic outlet syndrome based on electrodiagnostic tests and QuickDASH scores.

In total, 665 of 680 (97%) patients with neurogenic thoracic outlet syndrome (NTOS) improved with conservative treatment. The remaining (3%) patients (15 of 680 patients) did not benefit after 3 months of conservative treatment and were referred for transaxillary first rib resection. We retrospectively compared the preoperative and postoperative (3 months) electromyelography and Quick Disability of Arm, Shoulder and Hands results of operated NTOS patients. Three of the 15 (20%) patients in the surgical cohort were male, with a median age of 25.3 ±â€¯4.16 years, and the other 12 patients (80%) were female with a median age of 31.9 ±â€¯9.48 years. Two of the 15 patients had a cervical rib, 4 of the 15 patients had an extension of the C7 transverse process, and 14 of the 15 patients had a cervical band. These bone and tissue abnormalities were removed in addition to the first rib resection and division of the subclavius muscle and the anterior scalenus and middle scalenus muscles. QuickDASH scores were 1062 preoperatively and 549 postoperatively. The latency of the median F-wave was significantly prolonged on the affected side compared to the unaffected side preoperatively (p = 0.015). There was no remarkable difference in the latency of ulnar F-waves between sides (p = 0.246). The medial antebrachial cutaneous nerve response values increased significantly postoperatively (p < 0.0001). Significant increases in ulnar sensory nerve action potential values amplitude ratio (p < 0.003) and median nerve motor amplitudes (p < 0.0001) were also found postoperatively.

Anatomy of the medial antebrachial cutaneous nerve and its significance in ulnar nerve surgery: An anatomical study.

BACKGROUND: During cubital tunnel surgery, the medial antebrachial cutaneous nerve (MACN) may be injured, causing painful scars, neuromas, hypaesthesia or hyperalgesia. As the literature on the anatomy of crossing branches in this area is contradictory, this study aimed to re-examine the anatomy of the MACN in this region. METHODS: Forty upper limbs were dissected. We looked specifically from 5 cm proximal to 6 cm distal to the medial epicondyle (ME) and documented the number of crossing branches and the distances between the crossing points and the ME; we also measured the length of each limb. RESULTS: The most common location for crossing branches was 2 cm distal to the ME. Twenty-seven branches (∼23%) were found proximal to or at the level of the ME, and 91 branches (∼77%) were distal to it. The average distance between the proximal crossing points and the ME was 1.7 cm, the mean number of crossing branches was 0.7 and at least one crossing branch per limb was found in 16/40 cases. For the distal crossing points, the average distance to the ME was 2.9 cm, the mean number of crossing branches was 2.3 and at least one crossing branch per limb was found in all cases. There was no correlation between the limb lengths and the number of crossing branches. CONCLUSION: Because the incidence of posterior branches of the MACN crossing the course of the ulnar nerve is 100%, it is important to take the anatomy of the MACN into consideration when undertaking ulnar nerve surgery.

Brachial branches of the medial antebrachial cutaneous nerve: A case report with its clinical significance and a short review of the literature.

The medial antebrachial cutaneous nerve (MACN) is a branch of the brachial plexus with a great variation within its branches. Knowledge of these variations is critical to neurologists, hand surgeons, plastic surgeons, and vascular surgeons. The aim of this study was to search for variations of the MACN and to discuss their clinical significance. For this study, six arm cadavers from three fresh cadavers were dissected and examined to find and study possible anatomical variations of the MACN. The authors report a rare case of a variation of the MACN, in which there are four brachial cutaneous branches, before the separation to anterior (volar) and posterior (ulnar) branch, that provide sensory innervation to the medial, inferior half of the arm, in the area that is commonly innervated from the medial brachial cutaneous nerve. To our knowledge, this is the first documented case of this nerve variation. This variation should be taken into serious consideration for the differential diagnosis of patients with complaints of hypoesthesia, pain, and paresthesia and for the surgical operations in the medial part of the arm.

Determination of an ideal stimulation site of the medial antebrachial cutaneous nerve using ultrasound and investigation of the efficiency.

OBJECTIVE: To determine an ideal stimulation site of the medial antebrachial cutaneous nerve (MACN) using ultrasound measurement and to compare the efficiency of the new stimulation site with the conventional stimulation site on the nerve conduction study. METHODS: Both arms of 15 healthy participants were measured using ultrasound. The MACN was identified in the transverse view at each 0, 2, 4, 6, and 8 cm proximal sites from the medial epicondyle, and the distances to the median nerve and to the skin from the MACN were measured. The ideal stimulation site should be located at the level which can give the shortest distance from the skin and the longest distance from the median nerve in terms of volume conduction. To confirm the efficiency of the ideal site, we measured the amplitude of the MACN conduction study at the ideal site against one at the 4 cm proximal to the medial epicondyle (conventional site). RESULTS: The ultrasound showed the ideal stimulation site for the MACN could be the elbow crease line. However, the nerve conduction study revealed that the amplitudes of the MACN were significantly larger at the 4 cm proximal to the medial epicondyle compared with ones at the ideal site. CONCLUSION: The ideal stimulation site based on the ultrasound did not permit better stimulation site for the nerve conduction study of the MACN compared with the conventional site. Careful adjustment of the stimulation site on the basis of this study would contribute to an accurate conduction study of the MACN.

Neurogenic thoracic outlet and pectoralis minor syndromes in children.

Brachial plexus compression (BPC) occurs above the clavicle as neurogenic thoracic outlet syndrome (NTOS) and below as neurogenic pectoralis minor syndrome (NPMS). It was recently noted that 75% of the adults seen for NTOS also had NPMS and in some this was the only diagnosis. This is also true in children but has not yet been reported. Because surgical treatment of NPMS is a minimum risk operation for pectoralis minor tenotomy (PMT), recognition of NPMS and distinguishing it from NTOS becomes important. In this study, 40 operations, 20 PMT and 20 NTOS procedures, were performed. Success rate for PMT was 85% and for thoracic outlet decompression was 70%. It was concluded that in children, as in adults, BPC is more often due to combined NTOS and NPMS. Surgical PMT should be considered first as the treatment of choice for children with NPMS. Thoracic outlet decompression is available if PMT is unsuccessful.

Nerve transfer strategies for spinal cord injury.

BACKGROUND: Spinal cord injury (SCI) is a devastating condition, which beleaguers its victims with long-term health issues. Nerve transfer is a feasible option for restoration of critical limb function in patients with SCI that potentially improves independence and quality of life. METHODS: This article delineates the general principles of nerve transfer and its specific application pertinent to SCI. The available nerve transfer strategies are described based on the targeted limb function, mostly involving critical upper extremity function. The role of nerve transfer for paraplegia, diaphragm reanimation, and bladder reinnervation is also discussed. RESULTS: Nerve transfer offers several advantages over the traditionally used tendon transfer. CONCLUSIONS: Nerve transfer does not require prolonged immobilization and provides greater functional gain for a given transfer. Reconstruction of several facets of upper limb function potentially can be performed in a single stage. The merits of nerve transfer deserve further study to evaluate its value for spinal cord injury in humans.

Determination of an Ideal Stimulation Site of the Medial Antebrachial Cutaneous Nerve Using Ultrasound and Investigation of the Efficiency

OBJECTIVE: To determine an ideal stimulation site of the medial antebrachial cutaneous nerve (MACN) using ultrasound measurement and to compare the efficiency of the new stimulation site with the conventional stimulation site on the nerve conduction study. METHODS: Both arms of 15 healthy participants were measured using ultrasound. The MACN was identified in the transverse view at each 0, 2, 4, 6, and 8 cm proximal sites from the medial epicondyle, and the distances to the median nerve and to the skin from the MACN were measured. The ideal stimulation site should be located at the level which can give the shortest distance from the skin and the longest distance from the median nerve in terms of volume conduction. To confirm the efficiency of the ideal site, we measured the amplitude of the MACN conduction study at the ideal site against one at the 4 cm proximal to the medial epicondyle (conventional site). RESULTS: The ultrasound showed the ideal stimulation site for the MACN could be the elbow crease line. However, the nerve conduction study revealed that the amplitudes of the MACN were significantly larger at the 4 cm proximal to the medial epicondyle compared with ones at the ideal site. CONCLUSION: The ideal stimulation site based on the ultrasound did not permit better stimulation site for the nerve conduction study of the MACN compared with the conventional site. Careful adjustment of the stimulation site on the basis of this study would contribute to an accurate conduction study of the MACN.

Medial antebrachial cutaneous nerve: anatomical relationship with the medial epicondyle, basilic vein and brachial artery / Nervio cutáneo antebraquial medial: relación anatómica con el epicóndilo medial, vena basílica y arteria braquial

Medial antebrachial cutaneous nerve (MACN) courses in the medial arm to provide sensory innervation to the medial forearm. Its anatomy has been partly described since data regarding its branching pattern and distances to adjacent landmarks are still lacking. The purpose of this study was to provide morphometric anatomy of the MACN with comparisons between sides and sexes. Ninety-six upper extremities from 26 males and 22 females were dissected. We found that up to 5 branches of MACN pierced the deep fascia with the maximum of 4 reaching the interepicondylar line (IEL). Presence of 2 and 3 branches was found in the majority of cases (> 80%). The distances from these branches to the landmarks varied considerably. In case of no branch, the mean distances to the medial epicondyle (ME) and brachial artery (BA) were approximately 1.5 cm while those to the basilic vein (BV) were 0.7 cm in both sexes. Regardless of the branching pattern, the MACN could pass over or close (within 0.5 cm) to the ME, BV and BA. Asymmetry in the branching pattern was found in 50% of specimens. Sex but not side differences were observed in some measurement parameters. These data are crucial for not only localizing the MACN during nerve block and graft harvest but also avoiding the nerve injury during surgical procedures.

El recorrido del nervio cutáneo antebraquial medial (NCAM) proporciona la inervación sensorial medial del antebrazo. Su anatomía se ha descrito en parte, porque los datos relativos a su patrón de ramificación y distancias a puntos de referencia adyacentes son insuficientes. El propósito de este estudio fue proporcionar datos morfométricos sobre la anatomía del NCAM, comparando entre lados y sexos. Se disecaron 96 miembros superiores de 26 hombres y 22 mujeres. Se encontró que 5 ramos del NCAM traspasaron la fascia profunda y llegaron 4 hasta la línea interepicondilar (LIE). Presencia de 2 y 3 ramos se encontró en la mayoría de los casos (>80%). Las distancias de estos ramos a los puntos anatómicos variaron considerablemente. En caso de ausencia de ramos, la distancia medial al epicóndilo medial (EM) y arteria braquial (AB) fueron de aproximadamente 1,5 cm, mientras que a la vena basílica (VB) fueron 0,7 cm en ambos sexos. Independientemente del patrón de ramificación, el NCAM podría pasar sobre o cerca (a menos de 0,5 cm ) del EM, VB y AB. Asimetría en el patrón de ramificación se encontró en 50% de las muestras. Diferencias en algunos de los parámetros de medición se observaron según sexo, pero no por lado. Estos datos son relevantes para localizar el NCAM durante el bloqueo del nervio y la toma de injertos, sino también para evitar la lesión del nervio durante los procedimientos quirúrgicos.

Anatomical Distribution of Branches of the Medial Antebrachial Cutaneous Nerve during Cubital Tunnel Surgery

PURPOSE: The purpose of this prospective study is to examine the anatomical variations of the branches of the medial antebrachial cutaneous nerve in Koreans encountered during cubital tunnel surgery. METHODS: Ninety two patients with cubital tunnel syndrome were treated with a standard approach from December 2008 to July 2012. The position of the branches of medial antebrachial cutaneous nerve was evaluated based on the medial humeral epicondyle with the elbows fully extended. RESULTS: At least one medial antebrachial cutaneous nerve branch was found during the surgeries in all patients. The average number of crossing medial antebrachial cutaneous nerve branches per patient was 1.6. Thirty-eight percent of the cases showed that the medial cutaneous nerve branches cross proximal to the medial humeral epicondyle within 1 cm. Eighty-two percent showed that the medial antebrachial cutaneous nerve branches cross distal to the medial humeral epicondyle within 1.9 cm. CONCLUSION: When using standard approach during cubital tunnel surgery, more than one medial forearm cutaneous nerve is found. Therefore, understanding the general position of medial antebrachial cutaneous nerve branches helps avoid iatrogenic damage to this nerve during cubital tunnel surgery.

Anatomical Considerations of Lateral and Medial Antebrachial Cutaneous Nerves

OBJECTIVE: To evaluate the anatomic course of the lateral antebrachial cutaneous nerve (LABCN) and medial antebrachial cutaneous nerve (MABCN) in the forearm. METHOD: We dissected 29 upper extremities of 16 cadavers for LABCN and 20 upper extremities of 15 cadavers for the MABCN. We measured the distance (BT_L) between the biceps tendon (BT) and LABCN on the intercondylar line. The BT is the point at which biceps tendon crosses intercondylar line. The distance (L12) between LABCN and the point of 12 cm distal to BT on the line between BT and radial artery at wrist was measured. The distance (ME_M) between MABCN and medial epicondyle on the intercondylar line was measured. M8 and M10 are the distances between MABCN and the points 8 cm and 10 cm distal to BT on the line from BT to mid-point of flexor carpi radialis and palmaris longus at the wrist respectively. RESULTS: BT_L and L12 were 1.4+/-3.7 mm and 4.4+/-3.7 mm respectively. ME_M, M8 and M10 were 28.6+/-6.9 mm, 18.9+/-8.9 mm and 18.3+/-8.2 mm respectively. The thickness of LABCN and MABCN was 19.1+/-4.9 mm and 13.2+/-4.2 mm respectively. CONCLUSION: The LABCN was emerge just lateral to biceps tendon at the elbow and ran down to radial artery. The anatomic course of MABCN was variable at the elbow and forearm.