Study the Pattern of Unusual Attachments of Pronator Teres in Flexor Muscles Group of the Forearm

• Published in: Bihdād Vol. 2; no. 2; pp. 108 - 112
• Main Authors: A.R. Shams, N. Abedpour, A.R. Darabi, M. Abbasi
• Format: Journal Article
• Language: Persian
• Published: Alborz University of Medical Sciencs 01.05.2013
• Subjects: Cadaver; Median nerve; Pronator teres; Anatomical Variation
• ISSN: 1735-6679

Background and Objectives: Study of the variations in the muscles, nerves and arteries formation and course is useful for the clinicians during surgery and for differential diagnosis of uncommon clinical conditions. As the arm and forearm are the point of formation of many body structures, variations are not uncommon but variations of Pronator teres (PT) are rare in literature. The role of PT is critical as one of the main flexors and pronators of the elbow joint. We present an unusual case of PT formation found during routine cadaveric dissection. PT is the most lateral muscle of the superficial group muscles of forearm. In pronation, it acts as a medial rotator of radius on ulna. PT has two origins, the humeral head, arises from the medial supracondylar ridge, and from the common flexor tendon which arises from the medial epicondyle of the humerus and the ulnar head which arises from the medial side of the coronoid process of the ulna. Median nerve crosses between these ends. The muscle passes obliquely across the forearm, and ends in a flat tendon, which is inserted at the middle of the lateral surface of the body of the radius. Material and Methods: During routine dissection of a 60 year-old male preserved corpse, whom we had no information from previous diseases, variations were found in PT. Results: There was an abnormal origin of PT and absence of its coronoid attachment. Due to its important relation with median nerve and brachial artery this variation may be important after probable trauma injuries. Furthermore there was a neural variance in this region as too early branching of anterior interosseus branch of median was seen. Conclusion: It is concluded that PT variations may affect the function of upper limb. Knowledge of such variations is important to anatomists, radiologists, anesthesiologists and surgeons in evaluation of unexplained sensory and motor loss after trauma and surgical interventions to the upper limb. The presence of anatomical variations is often used to explain unexpected clinical signs and symptoms and for differential diagnosis of uncommon clinical conditions. In this study Clinical consideration of the present variations has been discussed. The present variation should be considered in the etiology of PT syndrome.