Magnetic resonance imaging assessment of the alar ligaments in whiplash injuries: a case-control study.

STUDY DESIGN

Case-control study.

OBJECTIVE

To use high-resolution magnetic resonance imaging (MRI) in assessing signal intensity areas in the alar ligaments.

SUMMARY OF BACKGROUND DATA

Conflicting evidence exists whether areas of high signal intensity in the alar ligament on MRI are more frequent in whiplash patients than in noninjured control subjects.

METHODS

A case-control designed study of 173 subjects included one group with persistent whiplash associated disorder Grade I-II after a car accident (n = 59), one with chronic nontraumatic neck pain (n = 57) and one group without neck pain or previous neck trauma (n = 57). High-resolution proton-weighted MRI in 3 planes was used. The images were independently evaluated by two experienced neuroradiologists who were blinded to patient history and group allocation. The alar ligaments were evaluated according to a 4-point grading scale; 0 = low signal intensity throughout the entire cross section area, 1 = high signal intensity in one third or less, 2 = high signal intensity in one-third to two thirds, and 3 = high signal intensity in two thirds or more of the cross section area.

RESULTS

Alar ligament changes Grade 0 to 3 were seen in all 3 diagnostic groups. Areas of high signal intensity (Grade 2-3) were found in at least one alar ligament in 49% of the patients in the whiplash associated disorder Grade I-II group, in 33% of the chronic neck pain group and in 40% of the control group (chi, P = 0.22). CONCLUSION.: The previously reported assumption that these changes are due to a trauma itself is not supported by this study. The diagnostic value and the clinical relevance of magnetic resonance detectable areas of high intensity in the alar ligaments are questionable.