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.