Posterior Antebrachial Cutaneous Nerve Research Articles

Portal placement in elbow arthroscopy by novice surgeons: cadaver study.

In this anatomical cadaver study, the distance between major nerves and ligaments at risk for injury and portal sites created by trainees was measured. Trainees, inexperienced in elbow arthroscopy, have received a didactic lecture and cadaver instruction prior to portal placement. The incidence of iatrogenic injury from novice portal placement was also determined. Anterolateral, direct lateral, and anteromedial arthroscopic portals were created in ten cadavers by ten inexperienced trainees in elbow arthroscopy. After creating each portal, the trajectory of the portal was marked with a guide pin. Subsequently, the cadavers were dissected and the distances between the guide pin in the anterolateral, direct lateral, and anteromedial portals and important ligaments and nerves were measured. The difference between the distance of the direct lateral portal and the posterior antebrachial cutaneous nerve (PABCN) (22mm, p<0.001), the lateral antebrachial cutaneous nerve (4.0mm, p<0.001), and the radial nerve (25mm, p<0.001) was different from the average reported distances in the literature. A difference was found between the distance of the anterolateral portal and the PABCN (32mm, p<0.001) compared to previous studies. Three major iatrogenic complications were observed, including: laceration of the posterior bundle of the medial ulnar collateral ligament, lateral ulnar collateral ligament midsubstance laceration, and median nerve partial laceration. Surgeons increasingly consider arthroscopic treatment as an option for elbow pathology. In the present study a surgical complication rate of 30% was found with novice portal placement during elbow arthroscopy. Furthermore, as the results from this study have indicated, accurate, precise, and safe portal placement in elbow arthroscopy is not easily achieved by didactic lecture and cadaver instruction session alone. Level of evidence V.

Minimally invasive approach to the radial nerve – A new technique

To describe a minimally invasive approach to find the radial nerve (RN) simply and safely by tracing the posterior antebrachial cutaneous nerve (PACN) without damaging muscles, using only the surgeon's hand to define a window for the skin incision. Although it is absolutely necessary to locate the radial nerve during osteosynthesis of the humerus, the literature lacks guidelines on how to do so. We have dissected the upper extremities of 54 adult human cadavers, embalmed using Thiel's method. After the PACN was identified in a defined space, its course was traced proximally by incising the lateral intermuscular septum (LIS) of the upper arm and thereby reaching the radial nerve (RN). Subsequently, using the lateral epicondyle (LE) of the humerus as a reference point, the distances to the points where the PACN perforated the LIS, and where the RN was identified, were measured. These individual data were related to the total length of the humerus. The results indicate that with this approach and without harming musculature, the RN can be reached by tracing the PACN at a height of 11.1-13.0 cm (females) and 11.9-14.0 cm (males) starting from the LE. Our examination shows the PACN to be a convenient guide to the RN.

Normal values of posterior antebrachial cutaneous nerve conduction study related to age, gender, height, and body mass index.

Recent studies have proposed posterior antebrachial cutaneous (PABC) nerve could help in interpretation of some conditions in upper limb electrodiagnostic study. This study aimed to establish these normal values and to assess the effect of sex, age, height, and body mass index on these normal values. Eligible participants were 84 healthy adult people aged between 22 and 75 years who underwent PABC nerve conduction studies. The mean ± SD values of the base-to-peak amplitude, peak latency, and nerve conduction velocity of all participants were 10.95 ± 2.90 μV, 2.08 ± 0.20 milliseconds, and 57.85 ± 7.83 m/second, respectively. There was a significant positive correlation between the subjects' age and the PABC onset latency, peak latency, and nerve conduction velocity (r = 0.64, P < 0.001; r = 0.6, P < 0.001; and r = 0.44, P < 0.001, respectively). A significant negative correlation was observed between age and base-to-peak amplitude and peak-to-peak amplitude of participants, as well (r = -0.38, r = -0.41, P < 0.001, respectively). The correlation of body mass index with base-to-peak amplitude and peak-to-peak amplitude were r = -0.36, P < 0.001 and r = -0.40, P < 0.001, respectively. This study has established normal values for PABC nerve conduction studies. Furthermore, age and body mass index must be taken into account for making diagnostic conclusion in PABC nerve conduction studies.

Use of Free Modified Innervated Posterior Interosseous Artery Perforator Flap to Repair Digital Skin and Soft Tissue Defects.

Current techniques to reconstruct soft tissue of the fingers result in scarring and functional deficits. Perforator flaps raised on the posterior interosseous artery are thin and well vascularised, and cause minimal donor site scarring. Using a flap with sensory nerves was hoped to contribute to the desired postoperative sensory recovery of fingers. We used modified innervated posterior interosseous perforator flaps to repair digital defects in 18 patients. Injuries included digit amputations and palmar soft tissue defects. The posterior antebrachial cutaneous nerve was carried in the flap and bridged with the defect section of the proper digital nerve. The flaps used measured 10cm × 6cm to 5cm × 3cm. All 18 flaps survived; one necrotic edge eventually healed. During the 10-28months of follow-up (average, 14months), two-point discrimination in flaps and injured fingers was 6-15mm. Good functional and sensory outcomes were obtained in primary operation, and patients were generally satisfied with the aesthetic results. Further work will be needed to assess the branches of the posterior interosseous artery preoperatively to improve surgical planning.

Normal conduction values for the posterior antebrachial cutaneous nerve

Objective To determine normal reference values for conduction in the posterior antebrachial cutaneous nerve.Methods Antidromic sensory conduction examinations of the bilateral posterior antebrachial cutaneous nerve were conducted with fifty-eight healthy subjects.The onset latency,peak latency,peak-to-peak amplitude and conduction velocity of the sensory nerve action potentials (SNAPs) were recorded and the inter-side ratios of the peak-to-peak amplitudes were calculated.Results The observed means (and standard deviations) of the onset time,the peak latency,the amplitude and the conduction velocity were 1.96 (0.12) ms,2.48 (0.14) ms,7.39 (2.36) μV and 61.39 (3.69) m/s,respectively.The side-to-side amplitude ratio (smaller/larger) was 0.88 ± 0.09,and no significant difference was observed between the left and right side.The average peak latency and amplitude were significantly different for different age groups.There was no statistically significant difference among the age groups with regard to onset latency or conduction velocity.Conclusion Conduction in the posterior antebrachial cutaneous nerve is easy to study.The peak latency is prolonged and the amplitude decreases with age,suggesting that different normal reference values should be established for different age groups. Key words: Posterior antebrachial cutaneous nerve; Radial nerve; Sensory conduction; Norms; Aging

The Future of Minimally Invasive Spine Surgery

OBJECTIVE: Recent advancements in neurotization and nerve grafting procedures have led to an increasing need for knowledge of the detailed anatomy of communicating branches between peripheral nerves. Although the surgical anatomy of the axilla has been well described, little is known regarding the degree or frequency of potential contributions to or communications with the brachial plexus. The aim of our study, therefore, was to explore extrathoracic, as well as potential intrathoracic, contributions to the brachial plexus from T2. METHODS: The anatomy of the ventral primary ramus of T2 and the second intercostal nerve, including its lateral cutaneous contribution as the intercostobrachial nerve, was examined in 75 adult human cadavers (150 axillae), with particular emphasis on the communications with the brachial plexus. RESULTS: Extrathoracically, communications were observed to occur in 86% of specimens. These contributions arose variably from either the intercostobrachial nerve or one of its branches and communicated with the medial cord (35.6%), medial antebrachial cutaneous nerve (25.5%), or posterior antebrachial cutaneous nerve (24%). Whereas the majority of specimens (68.2%) were observed to have only one extrathoracic communication, 31.7% of specimens exhibited two. Intrathoracically, communications were observed to occur in 17.3% of specimens. These communications always arose from the ventral primary ramus of T2. When combining and comparing data within individual specimens, it was observed that those axillae without an extrathoracic contribution from the intercostobrachial nerve always contained an intrathoracic communication. CONCLUSION: Based on our findings, we conclude that 100% of specimens contained a communication branch between T2 and the brachial plexus. Considering the possible implications of this data, with regards to sensory innervation of the arm and axilla, further studies in this area of research could prove extremely beneficial.

Absence of musculocutanous nerve and its distribution taken over by the lateral cord of brachial plexus, median nerve and radial nerve

Variations in the musculocutaneous nerve are very common. But, the absence of the nerve is rare. One such case of absence of musculocutaneous nerve which was observed in a male cadaver during routine dissection is reported here. In the present case there was total absence of a normal musculocutaneous nerve. The coracobrachialis which is normally supplied by the musculocutaneous nerve was innervated by a direct branch of lateral cord of brachial plexus, whereas biceps brachii and brachialis are supplied by branches from the lateral aspect of median nerve. Lateral cutaneous nerve of forearm was arising from the lateral aspect of median nerve in common with nerve to brachialis and was partly supplying the area of innervation of a normal lateral cutaneous nerve of forearm. The remaining of its area was supplied by the posterior cutaneous nerve of forearm, a branch of radial nerve. Further , a detailed literature review about the case was done and the surgical and clinical importance of the case was discussed.

Reconstruction of complex tissue defects of the hand with humeral osteocutaneous lateral arm flap

Objective To investigate the clinical effect of the application of humeral osteocutaneous lateral arm flap in reconstruction of complex tissue defects of the hand. Methods Eight cases of complex tissue defects of the hand were treated. The location and size of the bone flap was designed first according to the defect of the metacarpal and phalangeal bones (the distal end of the bone flap was at the upper margin of the lateral epicondyle). Then the location and size of the cutaneous flap was designed according to the defects of the hand. The line between the insertion of deltoid muscle and the epicondylus lateralis humeri is the body projection of the posterior branch of radial collateral artery. It is the axis while designing the flap. The posterior antebrachial cutaneous nerve can be retained in the flap in order to restore sensation of the recipient site. The area of the skin flaps ranged from 4.0 cm× 8.0 cm to 6.0 cm× 8.0 cm, while the area of the bone flaps ranged from 4.0 cm× 1.5cm×1.0cm to 6.0cm×1.5cm×1.0cm. Results All 8 osteocutaneous flap survived uneventfully.The donor sites were closed directly in all 8 cases. Functions of the upper arm were not impaired. The patients were follow-up for 4 to 24 months. Flap sensation recovery was satisfactory. Bone healing was observed and hand appearance was satisfactory. Conclusion The humeral osteocutaneous lateral arm flap is ideal for reconstruction of complex tissue defects of the hand. Key words: Wounds and injuries; Arm; Humerus; Osteocutaneous flap

Musculocutaneous nerve substituting for the distal part of radial nerve: A case report and its embryological basis

In the present case, we have reported a unilateral variation of the radial and musculocutaneous nerves on the left side in a 64-year-old male cadaver. The radial nerve supplied all the heads of the triceps brachii muscle and gave cutaneous branches such as lower lateral cutaneous nerve of the arm and posterior cutaneous nerve of forearm. The radial nerve ended without continuing further. The musculocutaneous nerve supplied the brachioradialis, extensor carpi radialis longus and extensor carpi radialis brevis muscles. The musculocutaneous nerve divided terminally into two branches, superficial and deep. The deep branch of musculocutaneous nerve corresponded to usual deep branch of the radial nerve while the superficial branch of musculocutaneous nerve corresponded to usual superficial branch of the radial nerve. The dissection was continued to expose the entire brachial plexus from its origin and it was found to be normal. The structures on the right upper limb were found to be normal. Surgeons should keep such variations in mind while performing the surgeries of the upper limb.

Communication between radial nerve and medial cutaneous nerve of forearm

Radial nerve is usually a branch of the posterior cord of the brachial plexus. It innervates triceps, anconeous, brachialis, brachioradialis, extensor carpi radialis longus muscles and gives the posterior cutaneous nerve of the arm, lower lateral cutaneous nerve of arm, posterior cutaneous nerve of forearm; without exhibiting any communication with the medial cutaneous nerve of forearm or any other nerve. We report communication between the radial nerve and medial cutaneous nerve of forearm on the left side in a 58-year-old male cadaver. The right sided structures were found to be normal. Neurosurgeons should keep such variations in mind while performing the surgeries of axilla and upper arm.

Erratum

Other than very simple descriptions of the existence of the lateral intermuscular septum (LIS), the literature offers almost nothing about its detailed anatomy, relationships to the radial nerve, and proximal branches. To further elucidate its morphological characteristics, the present cadaveric study was performed. The lateral arm was bilaterally dissected from 25 adult fixed cadavers (50 sides). Specifically, a detailed evaluation of the LIS was made, and this structure's attachments and relationships to the radial nerve were analyzed and measured. In addition to the previously described muscles arising from the LIS, the authors identified the extensor carpi radialis brevis muscles as partially arising from this structure. The deep and posterior portion of the deltoid tendon was confluent with the superior aspect of the LIS. The mean thickness of the LIS was 1.0 mm. Distally, the LIS attached strongly to the lateral epicondyle of the humerus and became confluent with the annular ligament encircling the head of the radius. The distal attachment of the LIS was confluent with the capsule of the elbow joint. All radial nerves traveled through a defect (mean diameter 1 cm) in the LIS. With traction on the nerve from proximal and distal to this defect, there was free excursion. In 85% of the specimens, however, the posterior antebrachial cutaneous nerve traveled through a tunnel within the LIS and pierced the septum at a mean of 5 cm proximal to the lateral epicondyle. The lower lateral brachial cutaneous nerve proximally pierced the LIS near its origin, occurring a mean of 3.2 cm distal to the LIS's origin from the humerus. To the authors' knowledge, the details regarding the LIS and its relationships to the radial nerve have not been reported. Such information may be of use to surgeons who operate in this region, for example, during neural repair or entrapment procedures.

Medial transposition of the radial nerve for anterolateral plate fixation of the humerus: Cadaveric study

In the operative treatment of humeral shaft fractures the radial nerve may be injured during the reduction of fracture fragments or the application of plate and screws. Also, secondary surgical explorations due to delayed or non-union carry a high risk of radial nerve injury because of the scarring of the neighboring tissue and proximity of the nerve to the implants. Consequently, the need for the transposition of the radial nerve to a safer position arises. A total of 22 (11 right, 11 left) cadaveric upper extremities were studied to evaluate the medial transposition of the radial nerve during the open reduction and anterolateral plate fixation of humeral fractures. The radial nerve was transposed medially in a distal plate fixated humeral fracture model. Distance measurements of the radial nerve and the division points of its branches were carried out in the transposed position and in the original course of the nerve. There was no statistically significant difference between the original course and medially transposed measurements. The distances from the reference point to the division points of other branches (posterior antebrachial cutaneous nerve, motor branch to brachioradialis, most distal motor branch to triceps) were not altered. The mean length of the radial nerve was 185.2 +/- 14.3 mm in its original course and 183.7 +/- 13.8 mm in the medially transposed course. In conclusion, the present study shows that medial transposition of the radial nerve through the fracture line does not increase the nerve's length and may be utilized in cases in which anterolateral plate fixation is indicated.

T2 CONTRIBUTIONS TO THE BRACHIAL PLEXUS

Recent advancements in neurotization and nerve grafting procedures have led to an increasing need for knowledge of the detailed anatomy of communicating branches between peripheral nerves. Although the surgical anatomy of the axilla has been well described, little is known regarding the degree or frequency of potential contributions to or communications with the brachial plexus. The aim of our study, therefore, was to explore extrathoracic, as well as potential intrathoracic, contributions to the brachial plexus from T2. The anatomy of the ventral primary ramus of T2 and the second intercostal nerve, including its lateral cutaneous contribution as the intercostobrachial nerve, was examined in 75 adult human cadavers (150 axillae), with particular emphasis on the communications with the brachial plexus. Extrathoracically, communications were observed to occur in 86% of specimens. These contributions arose variably from either the intercostobrachial nerve or one of its branches and communicated with the medial cord (35.6%), medial antebrachial cutaneous nerve (25.5%), or posterior antebrachial cutaneous nerve (24%). Whereas the majority of specimens (68.2%) were observed to have only one extrathoracic communication, 31.7% of specimens exhibited two. Intrathoracically, communications were observed to occur in 17.3% of specimens. These communications always arose from the ventral primary ramus of T2. When combining and comparing data within individual specimens, it was observed that those axillae without an extrathoracic contribution from the intercostobrachial nerve always contained an intrathoracic communication. Based on our findings, we conclude that 100% of specimens contained a communication branch between T2 and the brachial plexus. Considering the possible implications of this data, with regards to sensory innervation of the arm and axilla, further studies in this area of research could prove extremely beneficial.

Anatomy of the Posterior Antebrachial Cutaneous Nerve: Practical Information for the Surgeon Operating on the Lateral Aspect of the Elbow

Anatomy of the Posterior Antebrachial Cutaneous Nerve: Practical Information for the Surgeon Operating on the Lateral Aspect of the Elbow

Anatomy of the Posterior Antebrachial Cutaneous Nerve: Practical Information for the Surgeon Operating on the Lateral Aspect of the Elbow

To investigate the anatomic relationships of the posterior antebrachial cutaneous nerve (PABCN) to anatomic landmarks on the lateral side of the elbow. The PABCN was explored in 30 cadaveric upper extremities. Distances were noted from easily identifiable structures including the lateral epicondyle, the lateral intermuscular septum, and the radial nerve. The path of the PABCN follows the spiral groove initially, diverging as the radial nerve pierces the lateral intermuscular septum. The PABCN emerges from the posterior compartment through a hiatus in the deep fascia at a mean of 6.6 cm proximal to the lateral epicondyle and passes a mean of 2.1 cm anterior to the lateral epicondyle. The anatomic relationships determined in this study should enable the surgeon to avoid injuring the PABCN when performing surgery in the lateral elbow region.

The gross anatomy of the extrathoracic course of the intercostobrachial nerve

Recent reports emphasize the importance of preserving the intercostobrachial nerve (ICBN) during surgical procedures (i.e., mastectomy, axillary clearance). However, a limited number of scientific reports explore the surgical anatomy of this nerve. We dissected 100 adult human formalin-fixed cadavers (200 axillae). In all the cadavers the ICBN was present with variant contributions from intercostal nerves T1, T2, T3, and T4. The arrangements of the ICBN were typed as I through VIII. The components of Type I (45% or 90 of our specimens) included a branch to the posterior antebrachial cutaneous nerve, a branch to the anterior and lateral parts of the axilla, a branch to the medial side of the arm, and a branch to the medial antebrachial cutaneous nerve. Type II (25%) describes the ICBN arising from T2 and giving off a branch to the brachial plexus. In Type III (10%), lateral cutaneous branches of T2 and T3 fuse as a common trunk and then split immediately after exiting the intercostal space to form an ICBN. In type IV (5%), T2 and T3 join distally to form an ICBN that ends as its terminal branches. Type V (5%): T3 joins T2 from the same intercostal space proximally, with Type VI (3%) showing a very proximal branching of the sensory terminal nerves. Type VII (5%) displayed a contribution from T3 and a branch to the brachial plexus with multiple terminating branches. A contribution from T3 and T4 and a branch to the brachial plexus with multiple branches of termination comprised Type VIII (2%).

Posterior antebrachial cutaneous nerve conduction study in radial neuropathy

Radial neuropathy most commonly occurs as a result of external compression at the spiral groove region. The posterior antebrachial cutaneous nerve (PACN) conduction study was performed in 15 consecutive patients with radial palsy. Unilateral PACN abnormalities were present in 11 patients. A normal PACN study was correlated with clinical improvement at 3 months. Conversely, PACN abnormality was correlated with radial motor axon loss and a poorer prognosis. The PACN study is a simple adjunct which provides additional information relating to the diagnosis and prognosis of radial lesions.

Posterior antebrachial cutaneous nerve conduction studies in normal subjects.

The posterior antebrachial cutaneous (PABC) nerve is a sensory nerve that branches out from the radial nerve at the level of the spiral groove. Thus it can be affected in a radial nerve lesion at or proximal to its origin in the spiral groove. However, there has been limited knowledge about the normal values of PABC nerve conduction studies. This study was done to determine these normal values. Sixty-three healthy adults (23 males) with a mean age of 41.5+/-10.6 (range, 20-90) years were recruited with informed consent. A total of 126 nerves were studied. The nerve conduction studies were performed using a Dantec Counterpoint EMG machine (Dantec, Skovlunde, Denmark). The mean+/-standard deviation values for the onset as well as peak latency, conduction velocity, amplitude and side-to-side amplitude ratio were 2.07+/-0.16 (range, 1.80-2.60) ms, 2.35+/-0.15 (range, 2.05-2.90) ms, 58.21+/-4.29 (range, 46.15-66.67) m/s, 6.10+/-2.11 (range, 2.90-13.00) microV and 0.83+/-0.12 (range, 0.60-0.99), respectively. There was a significant correlation between the subject age and the PABC onset and peak latencies as well as the amplitudes. The PABC nerve is assessable for nerve conduction studies and these normal values may be useful in evaluation of patients with suspected radial nerve lesions.

Arthroscopy of the elbow joint: A cadaveric study of portal placement

Sixteen fresh cadaver elbows were examined by arthroscopy and dissection to evaluate the usefulness and the anatomic relationships of seven previously described portals for elbow arthroscopy. Most of the examined portals were found to be relatively close to neurovascular structures. The nerves that were found to be located closest to the portals were the posterior antebrachial cutaneous nerve at the direct lateral and antero-lateral portals, the radial nerve at the antero-lateral portal, and the medial antebrachial cutaneous nerve at the high and low antero-medial portals. The degree of flexion and fluid distension of the joint were found to influence the position of nerves and vessels in relation to the arthroscopy portals. At least three different portals were found to be required for thorough examination of the elbow joint. The combination of the low postero-lateral, the direct lateral, and the high antero-medial portals provided the largest visualized area.