L2 spinal nerve-block effects on acute low back pain from osteoporotic vertebral fracture.

UNLABELLED: Elderly patients with osteoporosis sometimes experience lumbar vertebral fracture and may feel diffuse nonlocalized pain in the back, the lateral portion of the trunk, and the area surrounding the iliac crest. The pattern of sensory innervation of vertebral bodies remains unclear. Some sensory nerves from the L2 and L5 vertebral bodies may enter the paravertebral sympathetic trunks and reach the L2 dorsal root ganglion. Our randomized controlled study was to clarify the effect of L2 spinal nerve block on low back pain originating from acute osteoporotic lumbar vertebral fracture. Patients with low back pain originating from acute L3 or L4 osteoporotic vertebral fractures received a spinal nerve root block (L2 block group, n = 30) or subcutaneous injection (control, n = 30). Both groups received 1.5 mL of 1% lidocaine. The visual analog scale score, Roland Morris Disability Questionnaire, and Short Form questionnaire were examined before and after treatment. In both groups, spinal nerve blocks were significantly effective in alleviating low back pain (P < .05). One hour, 1 week, and 2 weeks after treatment, the visual analog scale score improved more in the L2 block group than in the control group (P < .05). From 1 month to 4 months after treatment, there were no significant differences in the pain scores between groups (P > .05). We conclude that L2 spinal nerve block for acute L3 or L4 osteoporotic vertebral body fracture was effective for 2 weeks, but it had no long-term effects on pain and social function.

PERSPECTIVE: L2 spinal nerve block treatment for L3 or L4 osteoporotic vertebral body fracture was effective. This results suggest that the L2 dorsal root ganglion may innervate the L3 and L4 vertebral bodies in humans. L2 spinal nerve block for lumbar osteoporotic vertebral fracture may be a useful strategy to treat acute low back pain.