ABSTRACT
Background: Though rare but variations of brachialis muscle insertion have been reported. Material and Methods: The study was conducted on 115 upper limbs over a period of 4 years. The dissection of arm and forearm was done carefully to preserve all minute details ,observing the morphology of insertion pattern and nerve supply. Observation: Out of 115 specimens, 2 specimens showed insertion of brachialis into bicipital aponeuroses. Accessory slips were seen in 4 specimens which are mixed with main fibers at insertion point. Rarest of all was insertion of an accessory brachialis muscle on radial tuberosity in 2 specimens. The muscle originated from lateral border of shaft of humerus and shared a few fibers with main Brachialis muscle. The muscle was inserted into radius just below the radial tuberosity. Conclusion: The identification of an inter-nervous plane may allow for improvement in the current anterior and anterolateral surgical approaches to the humerus. This could be one of a possible etiology of Radial tunnel syndrome.
ABSTRACT
A thorough knowledge of the variations in the patterns of muscle insertion and the consequent neurovascular entrapment due to them is important for orthopedic and plastic surgeons. During routine dissection, we encountered a unique occurrence of an accessory brachialis muscle (acBr) blending with the medial aspect of bicipital aponeurosis in the cubital fossa. It also entrapped the median nerve and brachial artery due to its superficial position. The abnormality reported here might result in neurovascular compression symptoms in the upper limb and possible mechanical advantages or disadvantage in the flexion of elbow joint. To the best of our knowledge, the brachialis variant insertion we present here is rare in the list of its anomalies. We also discuss in this report the embryological background and the clinical application of the variation that can abet clinicians in evaluating symptoms involving the upper limb.
Es importante para los cirujanos ortopédicos y plásticos, el conocimiento integral de las variaciones en los patrones de inserción de los músculos y el consiguiente atrapamiento neurovascular. Durante una disección de rutina, encontramos un caso único de un músculo accesorio braquial con aponeurosis bicipital en el lado medial de la fosa cubital. También cubre la arteria braquial y nervio mediano debido a su posición superficial. La anomalía informada aquí podría resultar en síntomas de compresión neurovascular en el miembro superior y las posibles ventajas o desventajas mecánicas de flexión de la articulación del codo. De acuerdo a lo estudiado, la inserción variante braquial que presentamos aquí es un caso raro dentro de la lista de sus variaciones. También se discuten en este informe la base embriológica y la aplicación clínica de la variación que puede ser útil para los clínicos en la evaluación de los síntomas relacionados con el miembro superior.