Biomechanics Research Today is a free monthly online journal that collates and summarizes the latest research about Biomechanics, including details on mechanics of living organisms, movement, locomotion, prosthetic limbs.

Dynamic degenerative lumbar spondylolisthesis: diagnosis with axial loaded magnetic resonance imaging.

Jayakumar P, Nnadi C, Saifuddin A, Macsweeney E, Casey A

Department of Spinal Surgery, The Royal National Orthopaedic Hospital, Middlesex, United Kingdom. pjay007@doctors.org.uk

STUDY DESIGN: Retrospective review of case notes and imaging. OBJECTIVE: To show the advantage of axial loaded magnetic resonance imaging (MRI) for identification of dynamic degenerative spondylolisthesis as a suspected cause of spinal claudication. SUMMARY OF BACKGROUND DATA: Degenerative spondylolisthesis typically occurs at L4/L5 and is usually evident on plain radiography. However, dynamic degenerative spondylolisthesis may become evident on erect radiographs when not shown on supine radiographs or MRI. METHODS: The case notes and imaging (radiography, conventional MRI, and axial loaded MRI) in 2 patients with symptoms of spinal claudication were reviewed. RESULTS: A 44-year-old female presented with a 3-year history of intermittent low back pain and right leg numbness after a fall. A 52-year-old female presented with a 4-year history of low back pain, bilateral leg weakness, and right leg numbness. In both cases, conventional MRI studies showed mild-to-moderate degenerative disc disease only with no evidence of abnormal spinal alignment or nerve root compression. Axial loaded MRI clearly showed the development of a degenerative spondylolisthesis with central canal stenosis and facet ganglion formation in 1 case. CONCLUSIONS: Axial loaded MRI identified occult dynamic degenerative spondylolisthesis, which correlated with the clinical picture but was not shown on initial conventional MRI or plain radiography.

Published 1 May 2006 in Spine, 31(10): E298-301.
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