Stress distribution pattern in the distal radioulnar joint before and after ulnar shortening osteotomy in patients with ulnar impaction syndrome

Ulnar shortening osteotomy (USO) for ulnar impaction syndrome potentially leads to degenerative changes of the distal radioulnar joint (DRUJ). This study was performed to evaluate the effect of the sigmoid notch morphology on the stress distribution pattern of the DRUJ using computed tomography (CT) osteoabsorptiometry (CT-OAM). We reviewed the pre- and postoperative transverse CT images of 15 wrists that had undergone USO. The examined wrists were classified into two groups based on the sigmoid notch morphology: the linear-type notch (type L) and the curved-type notch (type C). We calculated and statistically compared the percentage of the high-density area (%HDA) in each divided region of the sigmoid notch. In type L, %HDA was significantly larger in the distal-dorsal region of the sigmoid notch before USO. Postoperatively, in type L, no specific regions showed a significantly different %HDA. In type C, %HDA was significantly larger in the distal-volar region of the sigmoid notch before USO. Postoperatively, %HDA of type C was significantly larger in the proximal-volar region. Our results suggest that in patients with ulnar impaction syndrome, morphological evaluation of the sigmoid notch can serve as a predictor of osteoarthritis in the DRUJ with or without USO.

Pronated Grip View With Wrist Deviation: A Pilot Study on the Effect on Ulnocarpal Relationships

Background We hypothesize that different positions of the wrist in the coronal plane makes the carpus susceptible to ulnar impaction. Methods We prospectively enrolled 10 adult volunteers and obtained fluoroscopic images of each wrist in 12 different positions using a standardized protocol. Distances from the ulna to the lunate (UL) and ulna to the triquetrum (UT) were digitally measured as was the portion of the lunate surface area that was uncovered (LUR) with wrist deviation. Results A wrist position of Pronation, Neutral Deviation, and Grip (P-ND-G) significantly shortened the ulnocarpal distance when compared to a position of Neutral Rotation, Neutral Deviation, and No Grip (NR-ND-NG). Radial deviation during pronation and gripping (Pronated, Radial Deviation, Gripping [P-RD-G]) resulted in the lowest mean UL distance (1.2 mm). UT distance was minimized by a position of ulnar deviation during a pronated grip (Pronated, Ulnar Deviation, Gripping [P-UD-G]) (3.1 mm). The lunate becomes more uncovered with radial deviation. Conclusion Radial deviation minimizes the UL distance while ulnar deviation minimizes the UT distance during a wrist position of pronation and gripping. Further, there is more proximal lunate surface area uncoverage during all positions of radial deviation compared to ulnar deviation.

Evaluating Immediate and Short-Term Postoperative Clinical Outcomes of Patients Undergoing Ulnar Shortening for Ulnar Impaction Syndrome Using PROMIS

Background The early recovery trajectory of patients undergoing ulnar shortening for ulnar impaction syndrome using the Patient-Reported Outcomes Measurement Information System (PROMIS) is unknown. Questions/Purposes Using PROMIS Upper Extremity (UE), Physical Function (PF), Pain Interference (PI), and Depression, we asked (1) do patients undergoing operative management for ulnar impaction syndrome present at their preoperative visit with notable impairment?; (2) At immediate follow-up, do patients present with a clinically appreciable change in symptom severity?; and (3) At short-term follow-up, do patients present with a clinically appreciable change in symptom severity? Patients and Methods We identified patients from 01/2017 to 12/2019 at our institution undergoing ulnar shortening for ulnar impaction syndrome who completed all PROMIS domains at a preoperative visit and at least one postoperative time point (i.e., less than 4 weeks and/or greater than 12 weeks). Distribution- and anchor-based minimal clinically important difference estimates were used to evaluate clinically appreciable changes in symptoms over time. Results A total of 38 patients met our inclusion criteria. The average change in PROMIS UE, PF, PI, and Depression scores from preoperative to immediate postoperative follow-up were –3.8, –4.3, 3.2, and 0.5, respectively. However, by short-term follow-up, the average change in PROMIS UE, PF, PI, and Depression scores were 3.7, 3.2, –4.7, and –3.9, respectively. Conclusions Patients have worsening function at the immediate postoperative follow-up. By short-term postoperative follow-up, functional status and PI levels improve. Our findings can help hand surgeons provide evidence-based guidance on expected initial recovery following operative management for ulnar impaction syndrome. Level of Evidence This is a level II, prognostic study.

Stress distribution pattern in the distal radioulnar joint before and after ulnar shortening osteotomy in patients with ulnar impaction syndrome

Ulnar shortening osteotomy (USO) for ulnar impaction syndrome potentially leads to degenerative changes of the distal radioulnar joint (DRUJ). The aim of this study was to evaluate the effect of the sigmoid notch morphology on the stress distribution pattern of the DRUJ using computed tomography (CT) osteoabsorptiometry (CT-OAM). We reviewed the pre- and postoperative transverse CT images of 15 wrists that had undergone USO. The examined wrists were classified into two groups based on the sigmoid notch morphology: the linear-type notch (type L) and the curved-type notch (type C). We calculated and statistically compared the percentage of the high-density area (%HDA) in each divided region of the sigmoid notch. In type L, %HDA was significantly larger in the distal-dorsal region of the sigmoid notch before USO. Postoperatively, in type L, no specific regions showed significantly different %HDA. In type C, %HDA was significantly larger in the distal-volar region of the sigmoid notch before USO. Postoperatively, %HDA of type C was significantly larger in the proximal-volar region. Our results suggest that in patients with USO, morphological evaluation of the sigmoid notch can serve as a predictor of osteoarthritis in the DRUJ with or without USO.