Inclusion Criteria:  Persons with back pain for at least 3 months (presumed to be due to degenerative disc disease or spondylolisthesis).  Persons who have received full information about the organisation of the research and have signed the informed consent and :  Age ≥ 18 years, having read and understood the information document. Affiliated to a social security scheme. Lumbar arthrodesis involving a maximum of 2 floors. Standardized lumbar arthrodesis surgery performed by one of the three senior neurosurgeons of the neurosurgery department of the Nancy CHRU, using similar surgical techniques.  Exclusion Criteria:  Low back pain of neuropathic origin. The Neuropathic Pain Scale 4 questionnaire is used to diagnose neuropathic pain (score is ≥ 4/10) History of lumbar spine surgery Presence of other pathologies responsible for lumbar pain (multistage discopathies, ankylosing spondylitis, spondylodiscitis, rheumatoid arthritis, vertebral compression, vertebral metastasis, narrow lumbar canal, scoliosis, spondylolisthesis by isthmic lysis) Pregnant women or women of childbearing age without suitable contraception or nursing mothers. Unstable medical condition and/or inability to remain immobile in supine position during recordings. Known allergy to any component of the radiopharmaceutical (TECHNESCAN HDP). Person referred to in Articles L. 1121-5, L. 1121-7 and L1121-8 of the Public Health Code. Persons deprived of their liberty by a judicial or administrative decision, persons under psychiatric care by virtue of Articles L. 3212-1 and L. 3213-1. Persons of full age who are unable to express their opposition.