As a result of this study, hand surgeons from Duke University (North Carolina) are suggesting the use of both arthroscopic and open incision surgery for one kind of painful wrist fracture that doesn’t heal. Bone fractures that don’t heal are called nonunion fractures. The nonunion fracture in this study was of the ulnar styloid.
A little bit of wrist anatomy will help us understand what they found and why they make this recommendation. At the end of the forearm, two bones meet the first row of bones in the wrist. The two bones in the forearm are the radius (on the thumb side) and the ulna (on the little finger side).
The ulnar styloid is a small projection of bone at the bottom of the ulna. You can see and feel this as a bump on the back of your wrist on the little finger side. A fall on to the outstretched hand is the most common way this bone gets broken. Nonunion ulnar styloid fractures aren’t always painful. But when they are, there is usually a reason. It might be because there is abnormal motion at the nonunion site. Or there could be a tear of the triangular fibrocartilage complex (TFCC).
The triangular fibrocartilage complex (TFCC) describes a group of tough ligaments that hold the radius and ulnar together. The TFCC also connects the ulnar styloid to the bones in the wrist. The TFCC is a major stabilizer of the radioulnar and wrist joints.
Surgery to repair the broken styloid hasn’t been very successful. For patients who have a painful nonunion, the surgeon just removes the broken pieces and smoothes down any jagged edges that remain. But pain will persist if the TFCC is torn. The surgeon has to decide what approach to take: an open incision or an arthroscopic procedure? That’s where this study comes in.
The surgeons treated eight different patients with ulnar styloid nonunion fractures who also had a tear of the triangular fibrocartilage complex. They used an open incision approach to remove the bone fragments and an arthroscopic technique to repair the torn soft tissues. They report both their findings (what they saw during the procedure) and the results or outcomes patients experienced after surgery.
The authors also described the surgical technique used for both procedures. In the process of repairing the torn TFCC, they had to avoid injury to any of the sensory nerves in the area. Once the procedures were completed, the patients were put in a custom-molded orthosis (brace) for four weeks. Then they enrolled in a rehab program with a hand therapist. The therapist guided the patients through exercises to regain motion, strength, and function.
Although X-rays and MRIs were done on each patient, the triangular fibrocartilage complex (TFCC) tear was only observed before surgery in five of the eight patients. Arthroscopic exam remains the only way to be 100 per cent sure there is a TFCC tear. During the scoping procedure, the surgeon can find where the tear is located, how deep (partial thickness or full thickness) and long it is, and look for any other signs of damage. Several of the patients did have tears of other wrist ligaments.
Outcomes as measured by pain reduction and improved function were good-to-excellent for everyone. The radioulnar joint was stable. All of the patients said they would do it again if they had it to do over. The surgeons say they recommend combining these two surgical procedures.
In other words, when there is a fracture of the ulnar styloid process, the surgeon should take the time to insert a scope and look for damage to the soft tissues, ligaments, and cartilage around the radioulnar and wrist joints.
The results of this study confirm that tears of the triangular fibrocartilage complex (TFCC) are possible with ulnar styloid fractures. Although imaging studies done after the injury and before the surgery are helpful, they don’t always show damage to the TFCC. Left unrepaired, TFCC pathology is likely to leave patients with chronic wrist pain and possible joint instability.