Research article

The accuracy of MRI in the detection of Lumbar Disc Containment

Bradley K Weiner^1,2 and Rikin Patel³

¹Weill Cornell Medical College, USA

²Department of Orthopaedic Surgery, The Methodist Hospital, Houston, Texas, USA

³Institute for Orthopaedic Research and Education, The Methodist Hospital Houston, Texas, USA

author email corresponding author email

Journal of Orthopaedic Surgery and Research 2008, 3:46doi:10.1186/1749-799X-3-46

Published:	2 October 2008

Abstract

Background

MRI has proven to be an extremely valuable tool in the assessment of normal and pathological spinal anatomy. Accordingly, it is commonly used to assess containment of discal material by the outer fibers of the anulus fibrosus and posterior longitudinal ligaments. Determination of such containment is important to determine candidacy for intradiscal techniques and has prognostic significance. The accuracy of MRI in detecting containment has been insufficiently documented.

Methods

The MRI's of fifty consecutive patients undergoing open lumbar microdiscectomy were prospectively evaluated for disc containment by a neuroradiologist and senior spinal surgeon using criteria available in the literature and the classification of Macnab/McCulloch. An independent surgeon then performed the surgery and documented the actual containment status using the same methods. Statistical evaluation of accuracy was undertaken.

Results

MRI was found to be 72% sensitive, 68% specific, and 70% accurate in detecting containment status of lumbar herniated discs.

Conclusion

MRI may be inaccurate in assessing containment status of lumbar disc herniations in 30% of cases. Given the importance of containment for patient selection for indirect discectomy techniques and intradiscal therapies, coupled with prognostic significance; other methods to assess containment should be employed to assess containment when such alternative interventions are being considered.