Efficacy of Two Ultrasound-guided Intra-articular Injections of Botox® Combined With Custom-made Rigid Splinting in Painful Base-of-thumb Osteoarthritis.

Who can take part

• • Individuals aged at least 18 years; Pain intensity of at least 30 on a self-administered 11-point pain numeric rating scale (0: no pain to 100: maximal pain); Pain involving the base of the thumb; X-ray evidence of trapezometacarpial osteoarthritis with at least two of the following items involving the trapezometacarpial joint: osteophytes, joint space narrowing, subchondral bone sclerosis, or subchondral cysts; 1990 ACR classification criteria for hand osteoarthritis adapted to trapezometacarpial osteoarthritis; Patient able to give written informed consent prior to participation in the study; Affiliation with a mode of social security (profit or being entitled); Negative pregnancy test in women of childbearing potential

Who cannot take part

• • Secondary osteoarthritis; History of thumb surgery, inflammatory or crystal-associated rheumatic disease, or epilepsy; Uncontrolled dysphagia, pneumonia, cardiovascular diseases, or clinical or subclinical signs of neuromuscular transmission disorders; Contra-indication to onabotulinumtoxinA; Neurological disorders involving the hands other than carpal tunnel syndrome; Collagen disorders involving the hands; Osteoarthritis predominating at the scaphotrapezial joint on x-ray; Bilateral trapezometacarpial osteoarthritis without a predominant painful side; Hand or wrist trauma for up to 2 months; Intra-articular treatments for up to 2 months; Use of IM, IV or oral corticosteroids for up to 2 months; Protected adults (including individual under guardianship by court order); Pregnant women and lactation; lack of contraception for women of childbearing potential; Patient participating in another investigational therapeutic study; Patient unable to speak and read french