Can Alar Ligament Injury Be Dectected By MRI?

[Guest guest]

The excellent diagnostic skills of Dr. Wei notwithstanding, the imaging of

ligament injuries in the upper cervical spine is controversial. The weight of

the evidence indicates that injured tissue often cannot be distinguished from

normal, thus calling into question the reasonableness and medical necessity of

this procedure.

The Bone and Joint Decade Task Force (Spine Volume 33, Number 4S, pp S101–S122)

stated:

The possible presence of demonstrable ligamentous injury to the upper cervical

spine after whiplash exposure has been investigated with special sequence MRI. A

phase I study (n = 30) showed that bright signals in the alar, transverse

ligaments, and other structures have been observed more frequently in subjects

with whiplash trauma exposure after 6 years (range, 2–9 years) than control

subjects. However, the reliability of different observers in classifying the

presence or degree of ligamentous injury, as shown by the MRI signal change,

showed high variability. Validation of this finding as diagnosing bona fide, and

clinically relevant ligamentous injury has not been demonstrated in these

patients with WAD (grades I–III).

They cited three articles by Krakenes, Kaale et al. Curiously, these researchers

are about the only ones to purport validity for these imaging studies. The

majority of studies indicate otherwise.

Muhle et al (Rofo. 2002 Apr;174(4):416-22) discussed radiological aspects of the

diagnosis of whiplash injuries. Although asymmetric dens position and widening

of the atlantodental distance to > 12 mm are indirect signs of alar ligament

rupture, best visualized on MRI, they state, " … changes of the alar ligaments on

MRI must be differentiated from normal variants in healthy individuals. "

Bitterling et al (Rofo. 2007 Nov;179(11):1127-36), reviewed studies on

biomechanics, anatomical and clinical MR imaging. They found that " biomechanical

experiments can not induce according injuries of alar ligaments. Although MRI

provides excellent visualization of alar ligaments, the range of normal variants

is high. " Furthermore, " … signal alterations of alar ligaments can hardly be

differentiated from common normal variants, " and " functional MRI provides no

diagnostic yield. "

Myran et al (Spine. 2008 Aug 15;33(18):2012-6) performed a case-control study

using MRI to assess signal intensity areas in the alar ligaments. 59 patients

with persistent whiplash associated disorder Grade I-II after a car accident, 57

with chronic nontraumatic neck pain, and 57 without neck pain or previous neck

trauma were compared. The alar ligaments were evaluated according to a 4-point

grading scale. Alar ligament grades 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 patients in the WAD Grade I-II group, in 33% of the chronic

neck pain group, and in 40% of the controls. They concluded, " 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. "

Respectfully,

J. Burke, D.C.