Anteroposterior view showing degenerative spondylolisthesis at L4-L5.
Lateral view of the patient’s spine.
A 58-year-old woman presents with lower back pain for more than a year. She denies having radiating pain to the buttocks or legs and weakness in the lower extremities. She has no bowel or bladder changes. Sitting and standing aggravate her symptoms, and lying down seems to be the most tolerable position. During examination, she has tenderness and spasm to palpation over the paraspinous muscles bilaterally. Neurologically, her patella and Achilles reflexes are intact. Light touch sensation over the L3, L4, L5, and S1 distribution is intact. Motor strength of the quadriceps, tibialis anterior, extensor hallucis longus, and gastrocnemius muscles are 5 out of 5 and equal bilaterally. She has full range of motion of the hip, knee, and ankles. She has some flexible flat feet. Vascular examination shows dorsalis pedis and posterior tibial pulses of 2+. Skin examination is within normal limits. Anteroposterior and lateral X-rays above show degenerative spondylolisthesis at L4-L5.
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Degenerative spondylolisthesis is a condition in the spine where one vertebral body slips or slides forward over another. The condition generally occurs in patients older than 50 years of age, and women are more commonly affected than men. The condition is 8 times more likely to occur in women due to increased ligamentous laxity. The most common affected level is L4-L5. Presenting symptoms are similar to those of spinal stenosis. These may include chronic back pain with frequent lower extremity radiculopathy. Neurogenic claudication is also common, which includes symptoms of pain in the buttocks and thigh while standing or walking. Flexing the back forward often relieves symptoms, which is often referred to as the shopping cart sign.1
Two main types of spondylolisthesis occur in adults: degenerative and isthmic or spondylolysis. Instability with isthmic spondylolisthesis is caused by a defect in the pars interarticularis (spondylolysis). In the degenerative type, the cascade of instability involves disc degeneration and narrowing of the disc space, buckling of the ligamentum flavum, and facet degeneration. Laxity of supporting ligaments further increases instability. The Meyerding classification system is commonly used to describe the severity of the slip. Grade 1 is less than 25% slip, grade 2 is 25% to 50% slip, grade 3 is 50% to 75% slip, and grade 4 75% to 100% slip. Grade 1 may progress in as many as 30% of patients but rarely progresses past a grade 2 slip. Isthmic spondylolisthesis more commonly progresses past grade 2. 1,2
- Majid K, Fischgrund JS. Degenerative lumbar spondylolisthesis: trends in management. J Am Acad Orthop Sur. 2008;16(4):208-215.
- Moore D. Degenerative spondylolisthesis. Orthobullets web site. http://www.orthobullets.com/spine/2039/degenerative-spondylolisthesis. Updated June 25, 2016. Accessed July 19, 2016.