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

Phase 2

Not yet recruiting

• Conditions: Base-of-thumb Osteoarthritis; Osteoarthritis
• Interventions: Drug: OnabotulinumtoxinA; Drug: Normal saline (placebo)

• Registration Number: NCT06902805
• Lead Sponsor: Assistance Publique - Hôpitaux de Paris

Brief Summary

The main objective of this study will be to compare the effects of 2 intra-articular injections of onabotulinumtoxinA with those of 1 intra-articular injection of onabotulinumtoxinA and 1 of normal saline and those of 2 intra-articular injections of normal saline on base-of-thumb pain at 6 months after the first injection.

Detailed Description

The base of the thumb is a frequent location of osteoarthritis. Base-of-thumb osteoarthritis affects middle-aged and older individuals and results in base-of-thumb pain and limitations in hand-specific activities. For the medium and long term, evidence suggests that splinting could reduce pain and improve hand function. For the short term, a combination of conservative treatments is recommended, with small-to-moderate treatment effect. However, use of intra-articular treatments (e.g., glucocorticoids and hyaluronan) for the short and medium term is currently debated. Use of intra-articular botulinum toxin A injection as a pain modulator in joint diseases has recently raised interest. Botulinum toxin A is a neurotoxin produced by Clostridium botulinum that inhibits acetylcholine release into the synaptic cleft in cholinergic nerve terminals. Additionally, treatment with botulinum toxin A showed intrinsic antinociceptive effects in various animal models of joint diseases.

In a pilot single-centred randomized controlled trial of 60 participants with painful base-of-thumb osteoarthritis, the investigators compared the effects of a single intra-articular injection of onabotulinumtoxinA (Botox® ) with those of a single intra-articular injection of normal saline on base-of-thumb pain, and found a significant reduction in pain.

Several perspectives raised from this pilot study. Like in the treatment of spasticity, repeated courses of intra-articular injections onabotulinumtoxinA may be necessary to obtain sustained analgesic effects over time. A replication of these findings in a multicentred setting, analysis of cost-effectiveness and description of safety at longer term are also needed before the official recommendation of this treatment. In RHIBOT II, the investigators hypothesize that 2 ultrasound-guided intra-articular injections of onabotulinumtoxinA, as an add-on therapy to custom-made rigid splinting, could reduce base-of-thumb pain at 6 months after the first injection.

Study Timeline

• Study First Submitted: 2025-03-24
• Study First Submitted QC: 2025-03-28
• Study First Posted: 2025-03-30
• Status Verified: 2025-04
• Last Update Submitted: 2025-04-15
• Last Update Posted: 2025-04-18
• Study Start: 2025-05
• Primary Completion: 2025-10
• Study Completion: 2028-05

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 120

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
2 intra-articular injections of onabotulinumtoxinA	OnabotulinumtoxinA	-
1 intra-articular injection of onabotulinumtoxinA and 1 of normal saline	OnabotulinumtoxinA	-
1 intra-articular injection of onabotulinumtoxinA and 1 of normal saline	Normal saline (placebo)	-
2 intra-articular injections of normal saline	Normal saline (placebo)	-

Primary Outcome Measures

Name	Time	Method
Base-of-thumb pain on a self-administered 11-point numeric rating scale	6 months	French version of the self-administered base-of-thumb pain numeric rating scale (0: no pain to 100: maximal pain)

Secondary Outcome Measures

Name	Time	Method
Base-of-thumb pain on a self-administered 11-point numeric rating scale	1 and 12 months	French version of the self-administered base-of-thumb pain numeric rating scale (0: no pain to 100: maximal pain)
Hand-specific activity limitations on the self-administered Cochin Hand Function Scale	6 and 12 months	mean change from baseline in hand-specific activity limitations in the previous 2 weeks on the self-administered Cochin Hand Function Scale (0: no limitations to 90: maximal limitations) at 6 and 12 months
patient global assessment on a self-administered 11-point numeric rating scale	6 and 12 months	mean change from baseline in patient global assessment on a self-administered 11-point numeric rating scale (0: worst possible condition to 100: best possible condition) at 6 and 12 months
health-related quality of life on the self-administered EQ-5D-5L questionnaire	6 and 12 months	mean change from baseline in health-related quality of life on the self-administered EQ-5D-5L questionnaire (0: death, 1: best quality of life) at 6 and 12 months
Osteoarthritis Research Society International-Outcome Measures in Rheumatology response	6 and 12 months	Osteoarthritis Research Society International-Outcome Measures in Rheumatology response (Response / No response)
estimated total costs and incremental cost-utility ratio	12 months

Trial Locations

Locations (1)

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, France