Two Botox injections plus custom rigid splinting for painful base-of-thumb osteoarthritis

Medium-and Long-term Efficacy of Two Ultrasound-guided Intra-articular Injections of onabotulinumtoxinA (Botox®) Combined With Custom-made Rigid Splinting in Painful Base-of-thumb Osteoarthritis : a Randomized Double-blind Controlled Trial in Three-parallel Arms

This trial tests whether two ultrasound-guided Botox injections together with a custom rigid splint reduce thumb-base pain in adults with base-of-thumb osteoarthritis.

Quick facts

• Phase: Phase2; Phase3
• Study type: Interventional
• Enrollment: 120 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: Assistance Publique - Hôpitaux de Paris (Academic / other)
• Locations: 1 site (Paris, Île-de-France Region)
• Trial ID: NCT06902805 on ClinicalTrials.gov

What this trial studies

This Phase 2/3 interventional trial compares three regimens combining ultrasound-guided intra-articular onabotulinumtoxinA (Botox®) injections and normal saline injections, all paired with custom-made rigid splinting, for symptomatic trapezometacarpal osteoarthritis. Participants receive two injections over the study period (either two Botox injections, one Botox plus one saline, or two saline injections) and are followed with the primary pain outcome measured six months after the first injection. Eligible participants must have radiographic evidence of trapezometacarpal osteoarthritis and a baseline pain score of at least 30/100. The procedures are delivered under ultrasound guidance at Assistance Publique - Hôpitaux de Paris (Hôpital Cochin).

Who should consider this trial

Good fit: Adults with symptomatic, radiographically confirmed trapezometacarpal (base-of-thumb) osteoarthritis who report at least moderate pain (≥30/100), can use a rigid splint, and can give written informed consent.

Not a fit: People with secondary osteoarthritis, prior thumb surgery, inflammatory or crystal arthritis, epilepsy, or certain uncontrolled comorbidities are excluded and unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, this approach could offer improved and longer-lasting relief of base-of-thumb pain with a localized treatment that may avoid some systemic therapies.

How similar studies have performed: A prior single-center randomized pilot found a single intra-articular Botox injection reduced base-of-thumb pain, but repeated injections combined with splinting remain relatively novel and not yet widely confirmed.

Eligibility criteria

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

Where this trial is running

Paris, Île-de-France Region

• Assistance Publique - Hôpitaux de Paris, Service de Rééducation et de Réadaptation de l'Appareil Locomoteur et des Pathologies du Rachis du Pr François Rannou, Hôpital Cochin — Paris, Île-de-France Region, France (Recruiting)

Study contacts

• Principal investigator: Christelle NGUYEN, MD,PhD — Organizational Affiliation: Université Paris Cité, Faculté de Santé | UFR de Médecine
• Study coordinator: Christelle NGUYEN, MD, PhD

Conditions Base-of-thumb Osteoarthritis; Osteoarthritis; base-of-thumb osteoarthritis