Failed back surgery syndrome. Part I: Analysis of the clinical presentation and results of testing procedures for instability of the lumbar spine in 171 patients.

The clinical presentation and diagnostic approach in 171 patients with a failed back surgery syndrome is presented and analyzed with respect to the mode of the primary discectomy-approach and type of resulting instability as well as results of internal fixation. The clinical picture and physical signs are quite distinct but the indication for internal fixation is only obvious in the presence of positive results of additional testing procedures such as the anaesthesia of articular nerves and trial immobilisation in a plaster jacket. Different types of instability of the lumbar spine occur in relation to the mode of the primary and/or secondary discectomy-approach(es). By application of this diagnostic protocol excellent, good, satisfactory, moderate and poor results were obtained in 87 (53%), 42 (26%), 23 (14%), 9 (6%), and 2 (1%) patients, respectively (final evaluation was possible in 163 patients).