Jnl Wrist Surg 2018; 07(03): 247-252
DOI: 10.1055/s-0038-1627458
Scientific Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The Effect of Axial Loading on Ulnar Variance

Kagan Ozer
Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
,
Andy F. Zhu
Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
,
Breana Siljander
University of Michigan, School of Medicine, Ann Arbor, Michigan
,
Jeffrey N. Lawton
Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan
,
Jennifer F. Waljee
Division of Plastic Surgery, Department of Surgery, University of Michigan, Ann Arbor, Michigan
› Author Affiliations
Funding None.
Further Information

Publication History

05 June 2017

08 January 2018

Publication Date:
12 February 2018 (eFirst)

Abstract

Background Forearm rotation results in change in ulnar variance. Axial loading of the wrist is required to maintain daily activities. Change in ulnar variance during axial loading has not been investigated previously.

Purpose To measure the change in ulnar variance on axially loaded wrists.

Patients and Methods We examined 21 asymptomatic individuals and 24 patients with unilateral ulnar-sided wrist pain. All patients underwent standard neutral posteroanterior wrist radiographs without load and under axial loading on bilateral wrists. Axial loading was standardized at 18.1 kgf using an analog weight scale. A magnetic resonance (MR) arthrogram was obtained only in patients with ulnar-sided wrist pain. Beighton flexibility score was recorded on healthy volunteers. Change in ulnar variance between 0 and 18.1 kgf was compared for each wrist among all subjects. A correlation was sought between the change in ulnar variance, MR arthrogram findings, and physical examination.

Results In individuals without wrist pain, on average, 0.4 mm increase in ulnar variance was measured between 0 and 18.1 kgf. There was no difference between the dominant and nondominant side. No correlation was found with increasing age. In contrast, patients with ulnar-sided wrist pain displayed an average increase of 0.8 mm in ulnar variance. Compared with the contralateral wrist, more than 1 mm increase in ulnar variance was correlated with intra-articular pathologies including dorsoulnar ligament disruption, central triangular fibrocartilage complex (TFCC) perforation, and foveal detachment.

Conclusion Compared with contralateral side, more than 1 mm increase in ulnar variance is suggestive of longitudinal instability or TFCC pathology.

Level of Evidence Level II, diagnostic.

Note

Institutional review board approved this study.