Lumbar listhesis (spondylolisthesis) refers to translational displacement of one lumbar vertebra over an adjacent vertebra, most often anterior (anterolisthesis); posterior translation (retrolisthesis) is less common. Wiltse-Newman-MacNab classification recognizes six types: type I dysplastic (congenital, often L5-S1, sacral dysplasia), type II isthmic (pars interarticularis defect from spondylolysis, most common in young patients and athletes such as gymnasts, divers, weightlifters), type III degenerative (adults >50, secondary to facet arthropathy and disc degeneration, most common at L4-L5), type IV traumatic (acute fracture), type V pathologic (tumor, infection, Paget disease), and type VI iatrogenic (postsurgical destabilization).
Clinical features include axial low back pain (often mechanical, worse with extension), radicular leg pain (L5 nerve root compression in degenerative L4-L5 listhesis is common), neurogenic claudication (worsens with walking, relieved by sitting/lumbar flexion), hamstring tightness, gait abnormalities, and rarely cauda equina syndrome with high-grade slip. Examination shows step-off palpable in spinous processes, paravertebral muscle spasm, and positive straight leg raise.
Imaging: standing lateral lumbar radiograph diagnoses listhesis with Meyerding grading (I ≤25%, II 25–50%, III 50–75%, IV 75–100%, V spondyloptosis >100%); flexion-extension lateral views detect dynamic instability. Oblique radiographs show pars defect (Scotty dog with collar in spondylolysis). MRI evaluates neural compression, disc disease, and facet pathology. CT confirms pars defect anatomy. Treatment: nonoperative management for low-grade asymptomatic cases (physical therapy with core strengthening, lumbar bracing, NSAIDs, epidural steroid injections). Surgery for refractory pain, progressive slip, neurologic deficit, cauda equina, or high-grade slip in pediatric patients: posterior lumbar decompression with instrumented fusion (PLF, PLIF, TLIF), reduction in selected high-grade slips, and consideration of L5-S1 fusion in pediatric isthmic. Activity modification and core stability are mainstays of conservative management.