Efficacy of Intradiscal Injection of Autologous BM-MSC in Worker Patients Affected by Chronic LBP Due to Multilevel IDD

Inclusion Criteria: * Workers (it means subject has worked at least 2 months, even if not continuously, in the last 6 months) * Age between 18 and 65 years. * Signed informed consent. * Symptomatic chronic LBP due to moderate/severe IDD \[modified Pfirrmann score 3-5 (Pfirrmann et al., 2001), Griffith score 4-8 (Griffith et al., 2007)\] at max. 4 levels of the lumbar spine unresponsive to conservative treatment, physical and medical for at least 6 months. Physical treatment includes physiotherapy. Medical treatments includes AINS, paracetamol, opioids and myorelaxant. * Annulus fibrosus intact, demonstrated by MRI. * Pain baseline \> 40 mm on VAS (0- 100). * NSAID washout of at least 2 days before screening. * Painkillers washout of at least 24 hours before screening. * For females of childbearing potential, a negative pregnancy test must be documented at Screening. * Men and women should use effective contraception during treatment and for at least 12 months after BM-MSC discontinuation. The complete list of contraceptive methods is described in the patient information sheet and in the paragraph 6.5. As a precautionary measure, breast-feeding should be discontinued during treatment with BM-MSC and should not be restarted after discontinuation of BM-MSC. Exclusion Criteria: * Non-workers (it means that the person has worked less than 2 months, although not continuously, in the last 6 months) * Congenital or acquired diseases leading to spine deformations that may upset cell application (scoliosis, isthmus lesion, sacralization and hemisacralization, degenerative spondilolisthesis). * Spinal segmental instability assessed by dynamic X-Ray. * Symptomatic facet joints syndrome on MRI (facet joints hyperintensity and hypertrophy evaluated at coronal T2 weighted MRI). * Prior to the screening visit, has received: * Oral corticosteroid therapy within the previous 3 months, OR * Intramuscular, intravenous or epidural corticosteroid therapy within the previous 3 months * Presence of a 5th level with symptomatic IDD (modified Pfirrmann score 3-5, Griffith score 4-8) in the lumbar spine. * Spinal canal stenosis (Schizas score \> B). * History of spinal infection. * Lumbar disc herniation and sciatica. * Endplate abnormality such as Schmorl's Nodes. * Previous discal puncture or previous spine surgery. * IDD with Modic III changes on MRI images. * Patients not eligible to the intravertebral disc surgery. * Patients who have the risk to undergo a surgery in the next 6…