ABSTRACT
@#Isolated musculocutaneous nerve (MCN) lesion is rare and usually associated with direct trauma. Along with the rarity of this condition, other muscles involved in elbow flexion, such as brachioradialis and pronator teres, can mask the weakness induced by the MCN injury and make it difficult to identify it. Here, we report a 17-year-old patient with isolated MCN palsy following a single episode of anterior shoulder contusion. A lack of suspicion for this rare condition delayed diagnosis until 7 months post injury, when atrophy of muscles in the left upper arm became prominent and weakness of the elbow flexors persisted. After 6 months of rehabilitation therapy rather than undergoing surgical exploration, elbow flexor strength was nearly fully recovered but sensory symptoms remained. The mechanism of injury is speculated to be a sudden overloading of the anterior shoulder with extension and external rotation, which overstretched and compressed the MCN within the coracobrachialis muscle where the nerve is relatively fixed. Although isolated peripheral nerve injury is rare, it can be caused by a single episode of vigorous impact. Therefore, even in patients without any external wounds, careful physical examination with suspicion of peripheral nerve injury as one of the differential diagnoses is needed.
ABSTRACT
OBJECTIVE: To define the anatomy of the lateral antebrachial cutaneous nerve (LABCN) and the cephalic vein (CV) in the anterior forearm region of living humans using ultrasonography for preventing LABCN injury during cephalic venipuncture. METHODS: Thirty forearms of 15 healthy volunteers were evaluated using ultrasonography to identify the point where the LABCN begins to contact with the CV, and the point where the LABCN separates from the CV. The LABCN pathway in the forearm in relation to a nerve conduction study was also evaluated. RESULTS: The LABCNs came in contact with the CV at a mean of 0.6±1.6 cm distal to the elbow crease, and separated from the CV at a mean of 7.0±3.4 cm distal to the elbow crease. The mean distance between the conventionally used recording points (point R) for the LABCN conduction study and the actual sonographic measured LABCN was 2.4±2.4 mm. LABCN usually presented laterally at the point R (83.3%). CONCLUSION: The LABCN had close proximity to the CV in the proximal first quarter of the forearm. Cephalic venipuncture in this area should be avoided, and performed with caution if needed.
Subject(s)
Humans , Elbow , Forearm , Healthy Volunteers , Neural Conduction , Phlebotomy , Ultrasonography , VeinsABSTRACT
Objective To provide anatomical basis for lateral antebrachial neurocutaneous flap pedi-cled with inferior cubital artery perforator in repairing tissue defects around elbow joint. Methods Thirty embalmed upper limbs of adult cadavers perfused with red latex were used for this study, and followings were observed:①The course and distribution of lateral antebrachial cutaneous nerve; ②Anastomoses between inferior cubital artery and nutrient vessels of lateral antebrachial cutaneous nerve. Mimic operation was performed on other side of fresh specimen. Results ①The main trunk of lateral antebrachial cutaneous nerve (LACN) lined in the radial forearm and distributed in the 1/3 region of lateral forearm. ①The nutritional vessels of the flap were plurisegmental and polyphyletic. The inferior cubital artery which was relatively constant reached to skin through "V"-shaped peak formed by communicating branches of cephalic vein and deep venous system. They also gave off large number of small veins, which closely aligned with perineural branches and neural stem vascular chain of lateral antebrachial cutaneous nerve. Conclusion The lateral antebrachial neurocutaneos flap pedicled with inferior cubital artery perforator can be formed to repaire tissue defects around elbow joint.
ABSTRACT
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.