Evaluation of the Elbow
(See also Evaluation of the Patient With Joint Symptoms.)
Synovial swelling and thickening caused by joint disease occur in the lateral aspect between the radial head and olecranon, causing a bulge. Full 180° extension of the joint should be attempted. Although full extension is possible with nonarthritic or extra-articular problems such as tendinitis, its loss is an early change in arthritis. The area around the joint is examined for swellings. Rheumatoid nodules are firm, occurring especially along the extensor surface of the forearm. Tophi are sometimes visible under the skin as cream-colored aggregates and indicate gout. Nodules in the olecranon bursa may be either rheumatoid nodules or tophi. Swelling of the olecranon bursa occurs over the tip of the olecranon, is cystic, and does not limit joint motion; infection, trauma, gout, and RA are possible causes. Epitrochlear nodes occur above the medial epicondyle; they can result from inflammation in the hand but can also suggest sarcoidosis or lymphoma.
The needle is inserted in the depression felt between the lateral humeral epicondyle, ulna, and radial head (the ulnohumeral joint—see Figure: Arthrocentesis of the elbow.). A 25-gauge needle is used to place a wheal of local anesthetic over the needle entry site. A 20- or 22-gauge needle is used to aspirate the joint. The needle is advanced aiming toward the medial epicondyle, with back pressure on the syringe plunger during the advance. Synovial fluid will enter the syringe when the joint is entered. All fluid is drained from the joint. The needle is redirected at a different angle if it hits bone.