A 68-year-old woman has low back pain with bilateral leg heaviness worsened by walking and relieved by sitting. Lateral radiograph shows forward slip of L4 on L5 measuring 20 percent. Oblique views show an intact pars interarticularis. What is the most likely diagnosis?

• A Pathological spondylolisthesis
• B Isthmic spondylolisthesis
• C Dysplastic spondylolisthesis
• D Degenerative spondylolisthesis ✓

Explanation

Degenerative spondylolisthesis occurs typically in older women at the L4-L5 level, where facet joint arthrosis and ligamentous laxity allow slip with an intact neural arch, producing neurogenic claudication from canal stenosis. Isthmic spondylolisthesis requires a pars defect and favours L5-S1 in younger patients. Dysplastic slips occur at the sacralised lumbosacral junction with congenital facet anomalies, and pathological slips arise from tumour or infection destroying bone.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.