Dynamic Degenerative Lumbar Spondylolisthesis: Diagnosis With Axial Loaded Magnetic Resonance Imaging

Abstract

Retrospective review of case notes and imaging. To show the advantage of axial loaded magnetic resonance imaging (MRI) for identification of dynamic degenerative spondylolisthesis as a suspected cause of spinal claudication. 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. The case notes and imaging (radiography, conventional MRI, and axial loaded MRI) in 2 patients with symptoms of spinal claudication were reviewed. 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. 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.