This section is from the book "Anatomy Of The Arteries Of The Human Body", by John Hatch Power. Also available from Amazon: Anatomy of the Arteries of the Human Body, with the Descriptive Anatomy of the Heart.
The Posterior Ulnar Recurrent, much larger than the preceding, descends at first a little inwards, between the flexor profundus digitorum, which lies behind it, and the muscles arising from the internal condyle, which lie in front. It then ascends parallel to the ulnar nerve and between the heads of the flexor carpi ulnaris, to arrive at the interval between the internal condyle and olecranon process; here it terminates in communicating with the anastomotic and inferior profunda branch of the brachial, having previously supplied the above-mentioned muscles, besides the elbow-joint, ulnar nerve and integuments. The superior radio-ulnar articulation is supplied by a small artery, arteria articularis cubiti media, which, according to Meyer, arises from the brachial, ulnar, or interosseal artery; this small artery passes into the joint and supplies the synovial membrane; he says it is analogous to the posterior articular artery of the knee-joint.