Spondylolisthesis
Spondylolisthesis is anterior displacement of a vertebral body, usually L5 on S1, through a bilateral pars interarticularis defect in children and adolescent athletes or through degenerative facet disease in older adults, graded by percentage slip on a lateral radiograph and managed with activity modification and NSAIDs for low-grade disease, escalating to fusion for a high-grade or progressive slip with neurologic compromise.
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What this article covers
- Overview
Spondylolisthesis is anterior displacement of a vertebral body relative to the one immediately below it, most commonly L5 sliding forward on S1.
- Epidemiology
The most common vertebral level and direction is L5 anteriorly displaced on S1, reflecting the concentration of shear force at the lumbosacral junction.
- Risk factors
A bilateral pars interarticularis defect (spondylolysis), the structural prerequisite for isthmic slippage; see spondylolysis.
- Pathophysiology
A bilateral pars interarticularis defect eliminates the posterior bony restraint that normally opposes forward shear on the vertebral body, allowing progressive anterior translation under axial and…
- Clinical features
Chronic low back pain worsened by lumbar extension and improved by flexion, the hallmark presentation, often insidious rather than related to a single traumatic event.
- Differential diagnosis
Cauda equina syndrome: bowel or bladder dysfunction, saddle anesthesia, and decreased anal sphincter tone distinguish compression of multiple lumbosacral roots from an uncomplicated slip; a surgical emergency; see cauda equina syndrome.
- Diagnosis
Spondylolisthesis is confirmed by a standing lateral lumbar radiograph showing anterior translation of one vertebral body relative to the one below, graded by the Meyerding classification according…
- Management
First, grade the slip and determine whether neurologic deficit or instability is present, since this determines whether conservative management or surgical referral is appropriate.
- Complications
Slip progression: a low-grade slip, particularly isthmic disease in a growing adolescent, can progress to a higher Meyerding grade across serial radiographs obtained every 6-12 months if unmonitored.
- Prognosis
Low-grade, stable spondylolisthesis generally has a favorable prognosis with activity modification, NSAIDs, and physical therapy, and most patients avoid surgery.
- Prevention
Limit cumulative extension-rotation training load in high-risk adolescent sports (gymnastics, weightlifting, diving, football) to reduce the risk of the underlying pars defect that leads to isthmic slippage; see spondylolysis.
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Related articles
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