Fig. 2
From: Severity and location of lumbar spine stenosis affects the outcome of total knee arthroplasty
Morphological grade of stenosis [17, 20]. Axial T2-weighted MRI images shown. A Grade 0, normal thecal sac without cerebral spinal fluid (CSF) effacement. B Grade 1, mild CSF effacement without significant nerve root crowding/compression. C Grade 2, moderate CSF effacement with nerve root crowding/compression. D Grade 3, severe CSF effacement with indistinguishable individual nerve roots due to significant crowding/compression