Is ulnar shortening osteotomy effective for the treatment of ulnar styloid impaction syndrome compared to ulnar impaction syndrome?

Abstract

Purpose: This study aimed at evaluating the outcomes of ulnar shortening osteotomy (USO) for the treatment of ulnar styloid impaction syndrome (USIS) and to compare them with those of USO for the treatment of ulnar impaction syndrome (UIS).

Methods: We enrolled 144 patients who underwent USO between March 2015 and October 2021. The patients were divided into a UIS group (group I, n = 93) and a USIS group (group II, n = 51). Clinical and radiological parameters, including Disabilities of the Arm, Shoulder, and Hand (DASH) score, ulnar variance, ulnar styloid length, and ulnar styloid process index (USPI), were collected pre-operatively and one year post-operatively, and a comparative analysis was performed.

Results: The DASH score showed significant improvement in both groups (p < .001 and p < .001), and there was no significant difference between the two groups one year after surgery (p = .143). The USPI was significantly different between the two groups (p < .001). The ulno-lunate and ulno-triquetrum distances showed significant increases in both groups, with significant differences between the two groups (p = .020, and p < .001, respectively). The incidence of post-operative arthritic changes in the distal radioulnar joint was significantly greater in the UIS group than that in the USIS group (21 vs 3, respectively; p = .017). No remarkable differences were observed in the post-operative evidence of chondromalacia at the last follow-up between the two groups.

Conclusion: The USO, which was performed as a treatment for USIS showed reliable outcomes compared to the USO for the treatment of UIS. Therefore, USO is a viable option for the treatment of USIS.

Keywords: Ulnar impaction syndrome; Ulnar shortening osteotomy; Ulnar styloid impaction syndrome; Ulnar styloid process index.