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

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

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.

Study Overview

• Status: Recruiting
• Conditions: Osteoarthritis; Base-of-thumb Osteoarthritis
• Intervention / Treatment: Drug: OnabotulinumtoxinA; Drug: Normal saline (placebo)

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 Type: Interventional
• Enrollment (Estimated): 120
• Phase: Phase 2; Phase 3

Contacts and Locations

• Study Contact: Name: Christelle Nguyen, MD, PhD; Phone Number: +33 01 58 41 29 45; Email: christelle.nguyen2@aphp.fr
• Study Contact Backup: Name: Laetitia PEAUDECERF, PhD; Phone Number: +33 01 58 41 12 13; Email: laetitia.peaudecerf@aphp.fr

Study Locations

• France
  • Île-de-France Region
    • Paris, Île-de-France Region, France, 75014
      • Recruiting
      • 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
      • Contact: Christelle Nguyen, MD, PhD; Phone Number: +33 01 58 41 29 45; Email: christelle.nguyen2@aphp.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 2 intra-articular injections of onabotulinumtoxinA	Drug: OnabotulinumtoxinA; intra-articular injection
Experimental: 1 intra-articular injection of onabotulinumtoxinA and 1 of normal saline	Drug: OnabotulinumtoxinA; intra-articular injection; Drug: Normal saline (placebo); intra-articular injection
Placebo Comparator: 2 intra-articular injections of normal saline	Drug: Normal saline (placebo); intra-articular injection

What is the study measuring?

Primary Outcome Measures

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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Hand-specific activity limitations on the self-administered Cochin Hand Function Scale	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	6 and 12 months
patient global assessment on a self-administered 11-point numeric rating scale	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	6 and 12 months
health-related quality of life on the self-administered EQ-5D-5L questionnaire	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	6 and 12 months
estimated total costs and incremental cost-utility ratio		12 months
Base-of-thumb pain on a self-administered 11-point numeric rating scale	French version of the self-administered base-of-thumb pain numeric rating scale (0: no pain to 100: maximal pain)	1 and 12 months
Osteoarthritis Research Society International-Outcome Measures in Rheumatology response	Osteoarthritis Research Society International-Outcome Measures in Rheumatology response (Response / No response)	6 and 12 months

Collaborators and Investigators

• Sponsor: Assistance Publique - Hôpitaux de Paris
• Collaborators: URC-CIC Paris Descartes Necker Cochin
• Investigators: Principal Investigator: Christelle NGUYEN, MD,PhD, Organizational Affiliation: Université Paris Cité, Faculté de Santé | UFR de Médecine

Study record dates

Study Major Dates

• Study Start (Actual): December 3, 2025
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): November 1, 2028

Study Registration Dates

• First Submitted: March 24, 2025
• First Submitted That Met QC Criteria: March 28, 2025
• First Posted (Actual): March 30, 2025

Study Record Updates

• Last Update Posted (Actual): April 3, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: base-of-thumb osteoarthritis
• Additional Relevant MeSH Terms: Musculoskeletal Diseases; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Amino Acids, Peptides, and Proteins; Proteins; Pharmaceutical Preparations; Biological Factors; Hydrolases; Enzymes; Enzymes and Coenzymes; Crystalloid Solutions; Isotonic Solutions; Solutions; Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Metalloproteases; Bacterial Proteins; Bacterial Toxins; Toxins, Biological; Botulinum Toxins, Type A; Saline Solution
• Other Study ID Numbers: APHP230823

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No