Diagnostic modalities and nonoperative treatment of lumbar spinal stenosis

Lumbar spinal stenosis is a common and disabling condition with increasing prevalence in the United States. It is seen in the setting of degenerative lumbar pathology such as degenerative disc disease, spondylolisthesis or degenerative scoliosis and typically results in symptoms of neurogenic claudication – pain in the buttocks or legs that occurs with walking or standing and resolves with sitting or lumbar flexion. While diagnosis can typically be made with a thorough history and physical exam, functional tests such as walking exercise treadmill protocols can be used to increase specificity. Plain radiography with flexion-extension views are the initial imaging modality and demonstrate alignment, instability, bone density, and overall degenerative findings. Magnetic resonance imaging (MRI) is the imaging test of choice since it provides excellent detail of the bony anatomy as well as neural elements without the use of ionizing radiation. Canal cross-sectional area less than 100 to 130 mm² is generally the threshold for central stenosis, whereas a lateral recess height ≤ 2 mm, lateral recess depth ≤ 3 mm, or a lateral recess angle < 30˚ are indicative of lateral recess stenosis. Computed tomography (CT) is obtained when MRI is contraindicated in patients and provides superior resolution of bony anatomy, but poorer resolution of the neural elements. Nonoperative treatment is the first line strategy, with the use of anti-inflammatories, analgesics, muscle relaxants, neuromodulators, opioids, as well as physical therapy, steroid injections, multidisciplinary rehabilitation and lifestyle modification. Other treatments that have been explored include calcitonin, methylcobalamin, and alternative medicine strategies. Given that rapid deterioration is rare and symptoms often wax and wane, nonoperative treatment can provide an effective initial management strategy.