Differences between radial and ulnar deviation of the wrist in the study of the intrinsic intercarpal ligaments: magnetic resonance imaging and gross anatomic inspection in cadavers.

Objective: To demonstrate how radial and ulnar deviation of the wrist can affect the visualization of the intrinsic intercarpal ligaments using magnetic resonance (MR) imaging, MR arthrography and gross anatomic inspection in cadavers.

Materials And Methods: The detectability of the intrinsic intercarpal ligaments of ten fresh human wrists was analyzed in coronal, axial and sagittal images in the neutral position and in radial and ulnar deviation with MR imaging and MR arthrography. The findings were then correlated with gross anatomic inspection. Additionally, quantitative measurements including the radiocarpal distances and capitate angles were performed.

Results: Differences were noted in the visual conspicuity of only the intercarpal ligaments of the proximal carpal row with different techniques and wrist positions. The average width of the radiocarpal joint was 0.62 mm, 1.55 mm and 2.0 mm (radial side) and 3.78 mm, 2.25 mm and 1.16 mm (ulnar side) in radial deviation, neutral position, and ulnar deviation of the wrist, respectively. Statistically, these maneuvers produced significant opening in the ulnar side during radial deviation (Student's t-test; P = 0.0005) and in the radial side in ulnar deviation (P = 0.007).

Conclusion: Significant differences in the width of the radiocarpal joint were observed during radial and ulnar deviation of the wrist, influencing the visualization of the intrinsic ligaments, mainly the scapholunate and lunotriquetral ligaments. The use of MR arthrography with radial and/or ulnar deviation has the potential to improve diagnosis in clinical cases in which injury to one or both of these ligaments is suggested.