Search results
Results from the WOW.Com Content Network
In this movement the ulna, which is connected to the humerus by a simple hinge-joint, remains stationary, while the radius rotates, carrying the wrist and hand with it. To allow this rotation, the proximal (elbow) end of the radius is held in proximity to the ulna by a ligament known as the annular ligament.
The annular ligament (orbicular ligament) is a strong band of fibers that encircles the head of the radius, and retains it in contact with the radial notch of the ulna. [ 1 ] Per Terminologia Anatomica 1998 , the spelling is "anular", [ 2 ] but the spelling "annular" is frequently encountered.
The head of the radius has a cylindrical form, and on its upper surface is a shallow cup or fovea for articulation with the capitulum of the humerus.The circumference of the head is smooth; it is broad medially where it articulates with the radial notch of the ulna, narrow in the rest of its extent, which is embraced by the annular ligament.
It occurs between the circumference of the head of the radius and the ring formed by the radial notch of the ulna and the annular ligament. [2] The interosseous membrane of the forearm and the annular ligament stabilise the joint. [2] A number of nerves run close to the proximal radioulnar joint, including: median nerve; musculocutaneous nerve ...
The radial notch of the ulna (lesser sigmoid cavity) is a narrow, oblong, articular depression on the lateral side of the coronoid process; it receives the circumferential articular surface of the head of the radius. It is concave from before backward, and its prominent extremities serve for the attachment of the annular ligament.
the annular ligament (AL), from the posterior to the anterior margins of radial notch on the ulna, encircles the head of radius and holds it against the radial notch of ulna. [5] the accessory lateral collateral ligament (ALCL), from the inferior margin of the annular ligament to the supinator crest.
The repetitive stress placed on the ulna causes microtears in the ligament resulting in the loss of structural integrity over time. [15] The acute rupture is less common compared to the slow deterioration injury. The acute rupture occurs in collisions when the elbow is in flexion such as that in a wrestling match or a tackle in football. The ...
In radial head subluxation, there is little complaint of pain, and the person generally reports pain in the proximal forearm. The mechanism is slippage of the head of the radius under the annular ligament. The distal attachment of the annular ligament covering the radial head is weaker in children than in adults, allowing it to be more easily torn.