VARIATIONS IN THE ATTACHMENTS AND INNERVATION OF MUSCLES IN AXILLA

Dr Ranjana Verma; Dr Pooja Bhadoria

Volume : VI, Issue : II, February - 2016

VARIATIONS IN THE ATTACHMENTS AND INNERVATION OF MUSCLES IN AXILLA

Dr Ranjana Verma, Dr Pooja Bhadoria

Abstract :

Introduction: The axillary arch muscle is a rare muscle which usually extends between the latissimus dorsi and pectoralis major. The musculocutaneous nerve is a anch of lateral cord of achial plexus which pierces corachoachialis and supplies muscles of the flexor compartment of arm i.e. corachoachialis, biceps and achialis. Method: During a routine cadaveric dissection of right upper limb of a 50 year old male cadaver, we observed two major variations in the axilla. The left side of the axilla was also dissected but did not show any variation. Observation: A variant muscular slip arose as separate fies from the lateral aspect of latissimus dorsi and gained attachment as aponeurosis to the fascia covering the pectoralis major. This muscular slip coursed superficial to the axillary vessels and anches from the cords of achial plexus. In addition to this the musculocutaneous nerve did not pierce the corachoachialis and coursed immediately beneath the musculoaponeurotic arch. Moreover coracoachialis is supplied by a separate anch arising directly from lateral cord of the achial plexus. Discussion: Awareness of this variation is important for surgeons and orthopaedicians during surgery for axillary lymph node removal in east cancer, repair of achial plexus lesions, arthroscopy for shoulder joints and repair of fracture humerus. The musculoaponeurotic arch may also be the cause of various compression syndromes like entrapment neuropathy or lymphoedema of upper limb.