Back spasms

Hi all. Chronic back, buttock, hip and thigh pain on L side due to scar tissue after spinal surgery for herniated disc since 2008. The worst part is the back spasms. Has anyone had any success in lessening the severity, frequency, or length of back spasms? My spasms happen anywhere from 1 to 8 times a week, last for anywhere from 1 hour to 9 days, and range from 5/10 pain and moderate mobility limitation (can walk bent over, slowly, for short distances) to 9/10 pain, complete mobility limitation.

Thanks!