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

Inclusion criteria

• • 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

Exclusion criteria

• • 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