The purpose of this study was to block the posterior branch of lumbar spinal nerve during PKP operation and compare it with the patients without spinal nerve block, so as to verify the effect of posterior branch block of spinal nerve in relieving short-term and long-term residual low back pain after operation.

Patients older than 60 years old who underwent Percutaneous kyphosis(PKP) surgery for osteoporotic fractures were randomly divided into two groups. The lumbar spinal nerve branch was blocked with betamethasone and ropivacaine in the experimental group during PKP operation, while the lumbar spinal nerve branch block was not performed in the control group during PKP operation. The low back pain was evaluated at 1 week, 2 weeks, 1 month, 3 months and 6 months after operation using Visual analogue pain score(VAS)scale.So as to compare the effect of lumbar spinal nerve block on residual pain after PKP.

Inclusion Criteria:

• osteoporotic fracture
• acute vertebral compression fracture (within 2 weeks)
• fracture level lower thanT6

Exclusion Criteria:

• other types of fractures
• patients younger than 60 years of age,
• with other disease (metabolic bone disease, metastasis, uncor- rectable coagulopathy, spinal infection, severe cardiopulmonary comorbidity, cognitive disorders etc)