RESUMEN
Background: Brachialis is a muscle of anterior compartment of arm. It has two heads. Superficial head insertinginto ulnar tuberosity innervated by musculocutaneous nerve, the deep head inserts into coronoid process ofulna and supplied by radial nerve. Neuromuscular compression due to presence of additional slip of brachialisforms the basis of this study.Materials and methods: Study was done in 60 adult human cadaveric upper limbs of both the sides irrespectiveof sex in the Department of Anatomy, Kempegowda institute of medical sciences (KIMS), Bangalore and othermedical colleges nearby. Presence of additional slips of brachialis with important and interesting relations wasfound which were comparable with previous studies. As qualitative method was done, Descriptive statisticswere utilized.Results: Additional slips were present in 21.6%. It was found mainly in the left upper limbs in 69.2% and rest30.7% are present in right side limbs. Among 13 specimens, additional slips originated mainly from theanteromedial aspect in 84.6% and in 15.3% it originated from the anterolateral aspect of main brachialis.Additional slips were innervated mostly by the musculocutaneous nerve in 69.2%, median nerve in 15.3% andradial nerve in 7.6%. No innervation was observed in one specimen.Conclusion: Knowledge of additional slips and its origin and course is very important for identifying the causefor neurovascular symptoms due to compression of neurovascular structures
RESUMEN
Concurrent morphological variations of abductor pollicis longus (APL) and extensor pollicis brevis (EPB) are seldom reported in literature. Extra slips of APL and EPB are clinically significant as they are used to reconstruct the ruptured tendons in the hand. Herein, we report bilateral morphological variations of APB and EPB in a male cadaver. On each side of forearm, APL was divided into two tendinous slips within the first compartment of extensor retinaculum. One of these slips inserted on to the radial side of base of first metacarpal bone close to the insertion of EPB, and the other slip inserted on to both abductor pollicis brevis and opponens pollicis. EPB divided into two tendons slips deep to the extensor retinaculum. These slips were found to be inserted on to the dorsal surface of the base of proximal phalanx while the other inserted on to the radial aspect of the base of first metacarpal bone, close to the insertion of APL tendon. These additional slips are frequently associated with first carpo-metacarpal subluxation and de Quervain’s syndrome and may be responsible for the clinical manifestations of these diseases. In addition, knowledge of the morphological variations of APL and EPB can aid orthopaedic and plastic surgeons in performing successful tendon transplants.