gms | German Medical Science

Objectives/Interrogation: Ulnocarpal stress test is an essential physical examination for differential diagnosis of ulnar-sided wrist pain. However, there were some debates on the interpretation of the results of ulnocarpal stress test according to different forearm rotation position. Aim of this study was to analyze the correlation of positive results of ulnocarpal stress test in different forearm rotation with specific tender point of the wrist joint.

Methods: From March 2015 to February 2017, 54 patients who were diagnosed as ulnar impaction syndrome or ulnar styloid impingement syndrome by MRI or arthoscopy were included. We performed ulnocarpal stress test in forearm supination and pronation position and checked tenderness on dorsal lunate and ulnar head area (point A) and ulnar aspect of triquetrum and ulnar styloid area (point B). We analyzed odds ratio and statistical significance between positive physical examination and sites of tenderness using Fisher's exact test.

Results and Conclusions: 46 patients had tenderness on the point A and finally diagnosed as ulnar impaction syndrome through consistent radiologic findings; Subchondral sclerosis, subchondral cysts, and "kissing" lesions of the lunate, triquetrum, and ulnar head. Among them, 40 of 46 patients had positive ulnocarpal stress test in forearm supination position. Odds ratio of positive ulnocarpal stress test in forearm supination and tenderness of point A was 8.25 and it was statistically significant. 8 patients had tenderness at point B and were diagnosed as ulnar styloid impingement syndrome with radiographic chondromalacia between proximal triquetrum and the ulnar styloid. 6 of 8 ulnar styloid impaction syndrome patients had positive ulnocarpal stress test in forearm pronation position. There were 12 patients who were diagnosed as ulnar impaction syndrome had positive ulnocarpal stress test in both supination and pronation position. In conclusion, patients who had positive ulnocarpal stress test in forearm supination tend to have a tenderness on the luno-triquetral joint area and be diagnosed as ulnar impaction syndrome, and who had positive ulnocarpal stress test in forearm pronation tend to have a tenderness on the ulnar aspect of the triquetrum and ulnar styloid area and be diagnosed as ulnar styloid impingement syndrome.