Jnl Wrist Surg
DOI: 10.1055/s-0039-1688693
Scientific Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Analysis of Radiographic Relationship between Distal Radius, Ulna, and Lunate

Tendai Mwaturura
1  Department of Orthopaedic Surgery, University of British Columbia, St Paul's Hospital, Vancouver, British Columbia, Canada
,
Frédéric-Charles Cloutier
1  Department of Orthopaedic Surgery, University of British Columbia, St Paul's Hospital, Vancouver, British Columbia, Canada
,
Parham Daneshvar
1  Department of Orthopaedic Surgery, University of British Columbia, St Paul's Hospital, Vancouver, British Columbia, Canada
› Author Affiliations
Further Information

Publication History

08 May 2018

25 March 2019

Publication Date:
09 May 2019 (eFirst)

Abstract

Background Wrist anatomy variability is associated with differing susceptibility to pathology. For example, a flat radial inclination is associated with Kienbock's disease. Lunate facet inclination (LFI) also exhibits variability. Its relationship with other wrist features is poorly documented.

Purposes We tested the hypothesis that high LFI is associated with increased uncovering of the lunate, negative ulnar variance (UV), and type 2 lunates to balance forces across wrists.

Methods In total, 50 bilateral and 100 unilateral wrist posteroanterior radiographs were reviewed. Lunate type, lunate uncovering index (LUI), lunate tilting angle (LTA), UV, and sigmoid notch angle (SNA) were measured, and correlation with LFI was assessed on 150 right wrist radiographs followed by an assessment of differences based on lunate morphology. Symmetry of 50 bilateral wrists was assessed.

Results There was no correlation of LFI with lunate morphology, LUI, and LTA. There was a low correlation of LFI with SNA and UV. There was an inverse relationship between UV and SNA. Wrists with type 2 lunates had more oblique sigmoid notches and higher LTA in comparison to wrists with type 1 lunates. Side-to-side comparison revealed strong correlation except for LUI, which exhibited moderate correlation.

Conclusions There is no correlation between LFI, LUI, and lunate morphology. Type 2 lunates are associated with higher LTA and more oblique SNA. Wrists were symmetrical.

Clinical Relevance Factors other than lunate morphology are essential in balancing forces across wrists. A better understanding of soft tissue and other factors will improve the understanding of wrist biomechanics and pathology. Contralateral wrist radiographs can guide reconstructive surgery.

Ethical Review Committee Statement

Approval for this work was provided by the University of British Columbia Providence Health Care Research Ethics Board.