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Published in Clare E. Milner, Functional Anatomy for Sport and Exercise, 2019
The elbow consists of three joints all within the same joint capsule. The major articulation of the elbow is the hinge joint between the humerus of the upper arm and the ulna of the forearm. This ulnohumeral joint is responsible for flexion-extension of the elbow joint. Mediolateral movement at the joint is prevented by its bony structure (see planes and axes of movement). The distal end of the humerus, the trochlea, sits in the trochlear notch at the proximal end of the ulna. The second joint at the elbow is between the radius of the forearm and the humerus. This radiohumeral joint is not constrained by its bony structure. It is the articulation between the capitulum and the head of the radius. The radiohumeral joint would be susceptible to dislocation if the thick annular ligament, which forms a ring around the proximal end of the radius, was not present to stabilize it. The third joint at the elbow, the proximal radioulnar joint, between the radial head and the ulnar notch, enables pronation-supination of the forearm and, therefore, repositions the hand about the long axis of the upper limb.
Upper limb
Published in David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings, McMinn’s Concise Human Anatomy, 2017
David Heylings, Stephen Carmichael, Samuel Leinster, Janak Saada, Bari M. Logan, Ralph T. Hutchings
Distal radioulnar joint - between the head of the ulna and the ulnar notch of the radius (Fig. 4.15), the bones are held together by the triangular fibrocartilaginous disc, which normally separates this joint from the wrist joint.
The Articulations of the Upper Member
Published in Gene L. Colborn, David B. Lause, Musculoskeletal Anatomy, 2009
Gene L. Colborn, David B. Lause
The Distal Radio-ulnar Joint. The distal radio-ulnar joint is of the trochoid or pivot-type, the head of the ulna articulating with the ulnar notch of the distal end of the radius. The rotation of the distal end of the radius about the head of the ulna results in pronation and supination of the forearm. The two bones are held together distally by a number of ligamentous structures, the most important of which is the the fibrocartilaginous articular disk which joins the two bones together and which serves to separate the distal end of the ulna from direct contact with the carpal bones. Distally, the fibrocartilaginous disk is in contact with the triquetral bone and the medial part of the lunate bone.
IONM Troubleshooting in Spinal Procedures
Published in The Neurodiagnostic Journal, 2021
Procedures of the anterior cervical spine always involve a patient positioned supine with the arms tucked at the side (with the thumbs pointed up), and ideally wrapped in protective foam to minimize risk of compression injuries of the ulnar notch. Orthopedic surgeons typically stand on the left side of the patient (to avoid injuring the recurrent laryngeal nerve), and neurosurgeons on the right side of the patient (believed anecdotally to offer protection from injuring or occluding the carotid artery that supplies the left hemisphere of the brain), but variances exist in these preferences. With the arms tucked at the patients’ sides, stimulating pods for SSEP and recording pods for TcMEP can usually be hung safely out of the way of c-arm fluoroscopes near the patient’s knees. The recording pod for head electrodes, and the stimulation pod for TcMEP can be kept on the rail at the head of the OR table.