Ulnar Stump Stabilization Using the Flexor Carpi Ulnaris Tendon for the Rheumatoid Wrist

Background: The objective of this retrospective study was to evaluate the outcomes of ulnar stump stabilization after ulna head resection using the FCU tendon by investigating the rate of postoperative extensor tendon rupture and click on forearm rotation. Methods: Wrist synovectomy (distal radioulnar joint (DRUJ), radiocarpal and midcarpal joints) and ulnar head resection combined with ulnar stump stabilizing procedure were performed in 58 wrists of 53 patients with RA in our hospital. Before operation, the dorsal subluxation ratio (DSR) of the ulnar head was measured with a multi-slice computed tomography (CT) images. The stabilization of ulnar stump after head resection was performed by the value of the DSR or the instability before the operation. Results: There was neither extensor tendon rupture nor click on forearm rotation in all the patients. Smooth forearm rotation was achieved by ulnar head resection and stabilizing procedure for the ulnar stump. The active range of forearm supination and pronation increased significantly from 68° ± 23° (mean ± SD) to 80° ± 10°, and from 69° ± 17° to 74° ± 13°. The grip power increased from 117 ± 62 mmHg to 185 ± 55 mmHg. In the assessment using 3DCT, the preoperative DSR of 54% improved to 8% on the whole (n = 58). In the wrists with extensor tendon rupture (n = 36), the preoperative DSR of 58% improved to 12%. In the wrists without tendon rupture (n = 22), the preoperative DSR of 46% improved to 2%. Conclusions: The operative technique of ulnar stump stabilization using the FCU tendon was one of the suitable procedure to prevent complications after ulnar head resection.