Formation Variations of Musculocutaneous Nerve

Öz

Musculocutaneous nerve, which arises from the lateral cord of the brachial plexus, undergoes a number of changes during its development. The goal of our study was to identify and classify the variations that occur during the formation of the musculocutaneous nerve. Our study was carried out on 102 upper extremities of 51 human fetuses (25 males, 26 females) aged between 17-40 weeks of gestation, without external pathology and anomalies. Brachial plexus was revealed by the anatomical dissection method, and the formation variations of the musculocutaneous nerve were determined and these variations were typed. Type 1 refers to the normal anatomical structure in typing, whereas types 2A and type 2B have respectively one and two connecting branches between the musculocutaneous nerve and median nerve. In type 3, the musculocutaneous and median nerve formed as a common root by the junction of the lateral root of median nerve and medial root of median nerve are separated after a certain distance. In our study, 91.1% (n=93) of the samples were type 1, 6.9% (n=7) type 2A, 1% (n=1) type 2B and 1% (n=1) of the samples was found as type 3. Knowing the variations during the formation of the musculocutaneous nerve and revealing the population prevalence are important in terms of congenital brachial plexus paralysis, gunshot injuries, lacerations, use of the nerve for neurotization, and prevention of postoperative complications.

Anahtar Kelimeler

• Musculocutaneous nerve
• Variation
• Brachial plexus

Nervus Musculocutaneus’un Oluşum Varyasyonları

Öz

Plexus brachialis’in fasciculus lateralis’inden ayrılan bir dal olan n. musculocutaneus’un oluşumu çeşitli varyasyonlar göstermektedir. Çalışmamızda n. musculocutaneus’un kök varyasyonlarının tespit edilmesi ve sınıflandırılması amaçlanmıştır. Çalışmamız yaşları 17-40 gebelik haftası yaşı arasında değişen, eksternal patolojisi ve anomalisi olmayan, 51 adet insan fetusu (25 erkek, 26 dişi)’na ait 102 üst ekstremite üzerinde gerçekleştirildi. Plexus brachialis, anatomik diseksiyon yöntemi ile ortaya çıkarıldı. Daha sonra, n. musculocutaneus’un varyasyonları belirlenerek sınıflandırıldı. Yaptığımız sınıflandırmada Tip 1 normal anatomik yapıyı ifade ederken tip 2A ve tip 2B’de n. musculocutaneus ile n. medianus arasında sırasıyla bir ve iki adet bağlantı dalı vardır. Tip 3’te radix lateralis nervi mediani ve radix medialis nervi mediani’nin birleşmesiyle ortak kök şeklinde oluşan n. musculocutaneus ve n. medianus belli bir mesafeden sonra ayrılmaktadır. Örneklerin %91,1’i (n=93) tip 1, %6,9’u (n=7) tip2A, %1’i (n=1) tip 2B ve %1’i (n=1) tip 3 olarak bulundu. Nervus musculocutaneus’un varyasyonlarının bilinmesi ve toplumsal prevalansın ortaya çıkarılması doğumsal plexus brachialis paralizisi, ateşli silah yaralanmaları, laserasyonlar, sinirin nörotizasyon amaçlı kullanımları ve post operatif komplikasyonların önlenmesi açısından önemlidir.

Anahtar Kelimeler

• Nervus Musculocutaneus
• Oluşum Varyasyonları
• Plexus Brachialis

Kaynakça

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