A Slightly Dorsally Tilted Lunate on MRI can be Considered Normal

Document Type: RESEARCH PAPER

Authors

1 Orthopaedic Hand and Upper Extremity Service, Yawkey Center, Suite 2100, Massachusetts General Hospital, Boston, MA, USA

2 Chief Orthopaedic Hand Service, Yawkey Center, Suite 2100, Massachusetts General Hospital, Boston, MA, USA

Abstract

 
Background:
Abnormal angulation of the lunate can be an indication of intercarpal pathology. On magnetic resonance images (MRIs) the lunate often looks dorsally angulated, even in healthy wrists. The tilt on individual slices can also be different and might be misinterpreted as pathological, contributing to inaccurate diagnoses and unnecessary surgery. The primary aim of this study was to determine the average radiolunate angle on sagittal wrist MRI images as well as the radiolunate angle in the most radial, central and most ulnar part of the lunate; also the interobserver reliability was determined.
 
Methods:
140 MRIs from adult, non-pregnant patients presenting to the outpatient hand and upper extremity service between 2010 and 2013 with wrist pain were used for this retrospective study. One author measured the radiolunate and capitolunate angle (i.e., tangential and axial method) in all MRIs. Additionally, two authors measured the same angles independently in 46 MRIs to analyze interobserver reliability.
Results:
The average radiolunate angle was 8.7 degrees dorsal. There were no significant differences in the radiolunate angles between the different parts of the lunate. A very good interrater agreement was measured considering the radiolunate angle and capitolunate angle (tangential and axial method).
Conclusions:
Our study showed that the lunate appears slightly dorsally angulated on an MRI of a healthy wrist. Regarding the radiolunate angle, 10 to 15 degrees of dorsal tilt can be considered normal. This study provides reference information of normal anatomy for carpal axial alignment that may facilitate diagnoses of wrist pathology.

Keywords

References

1. Nakamura R, Hori M, Imamura T, Horii E, Miura
T. Method for measurement and evaluation of
carpal bone angles. J Hand Surg Am. 1989;14(2 Pt
2):412-6.
2. Smith DK, Gilula LA, Amadio PC. Dorsal lunate tilt
(DISI configuration): sign of scaphoid fracture
displacement. Radiology. 1990;176(2):497-9.
3. Timins ME, Jahnke JP, Krah SF, Erickson SJ, Carrera
GF. MR imaging of the major carpal stabilizing
ligaments: normal anatomy and clinical examples.
Radiographics. 1995;15(3):575-87.
4. Wolfe SW, Pederson WC, Hotchkiss RN, Kozin SH,
Cohen MS. Green’s Operative Hand Surgery. 6th ed.
Elsevier; 2011.
5. Rhee PC, Moran SL, Shin AY. Association between
lunate morphology and carpal collapse in cases
of scapholunate dissociation. J Hand Surg Am.
2009;34(9):1633-9.
6. Yang Z, Mann FA, Gilula LA, Haerr C, Larsen CF.
Scaphopisocapitate alignment: criterion to establish
a neutral lateral view of the wrist. Radiology.
1997;205(3):865-9.
7. Larsen CF, Mathiesen FK, Lindequist S.
Measurements of carpal bone angles on lateral wrist
radiographs. J Hand Surg Am. 1991;16(5):888-93.
8. Maizlin ZV, Vos PM. How to measure scapholunate
and Cobb’s angles on MRI and CT. J Digit
Imaging.25(4):558-61.
9. Larsen CF, Stigsby B, Lindequist S, Bellstrom T,
Mathiesen FK, Ipsen T. Observer variability in
measurements of carpal bone angles on lateral wrist
radiographs. J Hand Surg Am. 1991;16(5):893-8.

The Archives of Bone and Joint Surgery

Volume 4, Issue 4
October 2016
Pages 348-352

Files

History

  • Receive Date: 06 September 2014
  • Revise Date: 14 November 2015
  • Accept Date: 08 December 2015

Share

How to cite

Statistics