Abstract: Abstract: Objective: To study the relationship between the spinal instability and symptoms after lamina decompression. Method: Of 132 patients who accepted lamina decompression from 1990 through 2014, 76 were followed up for a minimum of 4 years. The patients were divided into instability group and non-instability group according to the X-ray result of the last following up. Compare with the VAS score, JOA score between the two group of the preoperation, 1 month after operation and the last follow up, and the JOA improvement rate index before and after the surgery, t test and chi square test method was used to analyze the outcome, with P < 0.05 a statistically significant difference. Results: Of the 76 patients, there were 27 patients in the instability group and 49 patients in the non-instability group which accounting for 35.5% and 64.5%. There were statistical significant in the VAS and JOA score between before and after surgery (P<0.05), but there were no statistical significant in the two groups(P >0.05). In the JOA improvement rate index, the non-instability group is higher than the instability group ,but no statistical significant(P>0.05). Conclusion: As a non-fusion method, there is no relationship between instability and symptoms improvement, which would be a better choice under the premise of surgical indications.

Key words: Key words: Lumbar spinal stenosis, lamina decompression, lumbar instability