Study Design. Prospectively acquire magnetic resonance images of the neck in normal subjects and patients with radiculopathy to measure and compare measures of the facet joint space thickness and volume.
Objective. The goal was to determine whether there is any difference in facet joint architecture between the 2 populations with the head in each of neutral and pain-eliciting rotation.
Summary of Background Data. Degeneration and altered mechanics of the facet joint can result in pathological nerve root compression and pain. Although lumbar facet joint space thinning has been reported in the context of low back pain, few studies have quantified the cervical facet joint space, especially in the context of pain.
Methods. The cervical spine of 8 symptomatic and 10 asymptomatic subjects was imaged in the sagittal plane in a 3T magnetic resonance scanner, using a T2-pulse sequence optimized for bone imaging. The facet joint space was identified and segmented in the acquired images. The thickness and volume of the facet joint space, and their changes between positions, were computed from the 3-dimensional representation for all cervical levels on both sides.
Results. Generally, the facet joint space thickness and volume were smaller in the symptomatic subjects than in the asymptomatic subjects. The differences were more robust on the left, especially in neutral and left torsion. The changes in both volume and thickness from neutral to torsion were also different in sign and magnitude at isolated joint levels between the 2 populations.
Conclusion. Quantification of the facet joint space architecture in the cervical spine of patients with radiculopathy is feasible using standard magnetic resonance imaging sequences. Measurements of the facet space thickness and volume, and their changes, from both pain-free and painful positions, can provide context for localizing potential sources of painful tissue loading.
Level of Evidence: 3
Facet joint space thickness and volume were measured using magnetic resonance images of patients with cervical radiculopathy in pain-free (neutral) and painful positions and in corresponding positions for asymptomatic subjects. Both facet joint space volume and thickness are smaller in the symptomatic subjects in both the neutral and painful positions.
*Departments of Neurosurgery
‡Medical Image Processing Group, Department of Radiology, University of Pennsylvania, Philadelphia.
Address correspondence and reprint requests to Beth A. Winkelstein, PhD, Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, 210 S. 33rd St, Room 240 Skirkanich Hall, Philadelphia, PA 19104; E-mail: firstname.lastname@example.org or http://spinepain.seas.upenn.edu/
Acknowledgment date: July 24, 2013. First revision date: October 8, 2013. Second revision date: December 19, 2013. Acceptance date: January 2, 2014.
The manuscript submitted does not contain information about medical device(s)/drug(s).
Cervical Spine Research Society and the Catherine Sharpe Foundation funds were received to support this work.
Relevant financial activities outside the submitted work: grant, grants/grants pending, and expert testimony.