Botox for thumb arthritis? new trial tests pain relief

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

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.)