Failed back surgery syndrome. Part II: Surgical techniques, implant choice, and operative results in 171 patients with instability of the lumbar spine.

171 patients with an instability-related failed back surgery syndrome underwent internal fixation. The operative indication was based on specific diagnostic procedures such as anaesthesia of articular nerves and the trial external immobilization in a plaster jacket. Taking account of the different types of hypermobility/instability of the lumbar spine, different spinal implants were used leading to excellent, good, satisfactory, moderate and poor results in 87 (53%), 42 (26%), 23 (14%), 9 (6%) and 2 (1%) patients, respectively.