Inclusion Criteria:  Patient >18 years old Patient with rhizarthrosis objectified by interrogation, radiography with at least 2 of the following criteria: osteophyte, joint space narrowing, subchondral sclerosis or geode Patient who has had an X-ray of the wrist (face, profile and Kapandji incidence) to estimate the severity of the rhizarthrosis. Patient with signed informed consent. Visual analog scale (VAS) of pain > 4 Failure of well-conducted drug treatments with level 1 and 2 analgesics, anti-inflammatory drugs and orthotic devices Patients must have stopped all corticosteroid or non-steroidal anti-inflammatory drugs therapy within the last 48 hours. Patient affiliated with a Social Security plan Patient who can understand the study instructions Patient on effective contraception for more than one month according to the marketing authorization (Pill, intrauterine device, vaginal ring, contraceptive skin patch, hormonal subcutaneous implant) Infertile patients in connection with surgery (tubal ligation, oophorectomy, adnexectomy, hysterectomy)  Exclusion Criteria:  History of surgery of the thumb column Patient who has received an intra-articular trapezoidal metacarpal injection of corticoids, botulinum toxin or hyaluronic acid or other product within the last 6 months. Patient who has received a Botulinum toxin injection at any site within the last 3 months Myasthenia or Lambert-Eaton disease, neuromuscular dysfunction, hypersensitivity to incobotulinumtoxin A, severe respiratory disorder or severe swallowing disorder Patients with hypersensitivity to botulinum toxin or to any of the excipients (human albumin sucrose) Patient with an infection or inflammation at the injection site concerned Pregnant or breastfeeding women (a urine pregnancy test will be performed) Patients with chronic inflammatory joint disease or microcrystalline pathology Current participation or less than 30 days of participation in a clinical drug trial Any medical or psychiatric condition that could prevent the proper understanding and conduct of the treatment and study (adult under guardianship) Patient who wishes to discontinue contraception during the study Patients at high risk of bleeding complications from the intra-articular injection (hemophilia, anticoagulant treatment, etc.)