In a study that was approved nine years ago (EK-22/2009) we could show (i) that spinal manipulative therapy (SMT) is a very effective and safe treatment for acute and chronic lumbar disc herniation (LDH); (ii) that SMT is as effective and less expensive than lumbar nerve root injections and (iii) that the recurrence rate up to one year was very low in acute and in chronic LDH patients. However, the long-term outcome of this conservatively treated LDH patients is unknown. Thus, the objective of this amendment is to investigate the proportion of long-term recurrences in these patients who were treated with SMT for their LDH and to compare these results with already existing data from other treatments, e.g. surgery. This is important information to know whether this conservative method is a sustainable approach for treating LDH.

All 148 patients with magnetic resonance imaging-confirmed disc herniation who were recruited for the study EK 22-2009 will be re-contacted to assess the course of their back problem during the past approx. nine years using a questionnaire.

Inclusion Criteria:

-The same patients who were recruited for the study EK-22/2009

Exclusion Criteria:

• The same as for study EK-22/2009:

Patients with specific pathologies of the lumbar spine that are contraindications to chiropractic manipulative treatment, such as tumors, infections, inflammatory spondylarthropathies, acute fractures, Paget's disease and severe osteoporosis, will be excluded. Also excluded will be patients with previous spinal surgery, signs of cauda equina syndrome (CES), sequestration of disc material, body mass index >30, spondylolisthesis, neurogenic claudication and pregnancy.

The same patients who were recruited for the study EK-22/2009: Patients with lumbar disc herniation that is treated with spinal manipulation