Just to be clear on what this problem is, ulnar styloid impaction refers to a condition causing ulnar-sided wrist pain because there is a short ulna (one of the two bones of the forearm) and a long styloid.
The styloid is a piece of bone at the end of the ulna that makes the ulna look longer on one side compared to the other. The styloid is a normal feature of the ulnar bone but when it is too long, it presses against the bones of the wrist. In particular, the triquetrum bone in the wrist gets compressed.
The contact point between the too-long tip of the ulnar styloid and the triquetrum (wrist) bone starts to get inflamed and swell up. There can be bone bruising and bone edema as well. Pain along the ulnar side of the wrist is a hallmark finding. But the diagnosis can be difficult to make. Imaging studies such as MRIs and CT arthrography may be needed to see if there is any soft tissue damage that could cause the same or similar symptoms.
The natural history of ulnar styloid impaction (i.e., what happens without treatment) is as follows. At first, the impingement just causes pain. But after a while, pressure builds up from the styloid process (tip) pressing against the triangular fibrocartilage complex or TFCC ligament. The TFCC ligament holds several bony structures of the wrist together including the ulna and the triquetrum.
With continued chronic pressure, the TFCC starts to tear and the contact surfaces of the two bones start to wear unevenly. Bone-on-bone friction can lead to painful synovitis (inflammation of the synovial fluid inside the joint).
If the impaction is allowed to continue without treatment, the wrist can lose its stability. Ligaments holding the bones together in perfect alignment start to break down. Bones start to shift and sublux (partially dislocate) or fully dislocate. Pain, decreased wrist motion, and loss of wrist and hand function can create significant disability.
What can be done about this problem? Treatment ranges from conservative (nonoperative) care with antiinflammatories and hand therapy to surgery. There are several different types of surgical procedures that can be used. If you don’t want to have surgery, you can try the conservative care route for a few months. If with your best efforts to follow the hand therapist’s guidelines you don’t get significant improvement, then it may be time to review again with the surgeon just what the surgical options are.
Many patients who are treated surgically experience good-to-excellent results. But there can be some mild persistent wrist pain that comes and goes. For the most part, patients get back to their former level of activity (including sports). Their satisfaction level is high enough they say they would have the same surgery over again if faced with the same decision again.