Compression of the ulnar nerve at the elbow in association with synovial cysts.

Compression neuropathies around joints in association with synovial cyst formation are rare events. A case of a posttraumatic ulnar nerve palsy in a patient with osteoarthritis of the elbow is presented. At operative exploration of the cubital tunnel, the ulnar nerve was found to be compressed by a synovial cyst. Cyst formation should be considered in determining the etiology of compression neuropathies in patients with posttraumatic and degenerative processes occurring around the joints.