Thumb Base Osteoarthritis: Ultrasound-guided Platelet-rich Plasma Versus Placebo Injection (Thumbs-up)

Thumb Base Osteoarthritis: Ultrasound-guided Platelet-rich Plasma Versus Placebo Injection (Thumbs-up Study)

The goal of this clinical trial is to evaluate whether platelet-rich plasma (PRP) injections improve pain and function in adults with thumb base osteoarthritis (CMC-I OA).

The main questions it aims to answer are:

Does a PRP injection reduce pain compared to a placebo (saline) injection? Does PRP improve hand function, strength, and thumb mobility? What adverse events occur following PRP treatment?

Researchers will compare PRP injections to a placebo injection (saline solution) to determine whether PRP is an effective treatment for CMC-I osteoarthritis.

Participants will:

Receive a single ultrasound-guided injection of PRP or placebo (saline) in the CMC-I joint.

Attend follow-up visits at 3, 6, 9, and 12 months for clinical assessments. Complete questionnaires on pain (VAS) and hand function (MHQ-DLV) at multiple time points.

Undergo physical examinations (grip strength, pinch strength, thumb motion). Undergo ultrasound evaluations to assess joint characteristics.

Study Overview

• Status: Not yet recruiting
• Conditions: Thumb Osteoarthritis
• Intervention / Treatment: Biological: Platelet-Rich Plasma (PRP) Injections; Drug: Saline (0.9% NaCl)

• Study Type: Interventional
• Enrollment (Estimated): 88
• Phase: Phase 2

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age 18 or older
• Patients with an Eaton-littler score of I, II or III
• Patients with uni- or bilateral CMC-I osteoarthritis
• Non-responders to conservative therapy i.e., hand therapy and immobilisation after 3 months

Exclusion Criteria:

• Aged below 18
• Patients with an Eaton-littler score of IV (STT arthrosis)
• Surgical interventions of the CMC-I joint
• A known articular systemic disease (e.g. rheumatoid arthritis) or additional hand osteoarthritis/ tenosynovitis or metabolic disease like diabetes mellitus
• Patients with an infectious arthritis of CMC-I joint
• A known psychiatric condition
• Neuropathic chronic pain syndrome
• Intra articular injection 6 months prior to inclusion
• Smoking
• Active use of statins

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Platelet-rich plasma group A	Biological: Platelet-Rich Plasma (PRP) Injections; Autologous platelet-rich plasma (PRP) is prepared from 90 mL of the participant's venous blood using a standardized two-step centrifugation protocol (ACP® Max system, Arthrex Inc.). The first centrifugation is performed at 3200 rpm for 9 minutes, followed by a second centrifugation at 1500 rpm for 5 minutes, resulting in approximately 2 mL of PRP. A single injection of 2 mL PRP is administered under sterile conditions and ultrasound guidance into the CMC-I joint, consisting of 1 mL intra-articular and 1 mL peri-articular injection. No repeated injections are performed.
Placebo Comparator: Placebo group B; Saline	Drug: Saline (0.9% NaCl); Participants receive a placebo injection consisting of 2 mL sterile saline (0.9% NaCl), administered under sterile conditions and ultrasound guidance into the CMC-I joint. The injection protocol is identical to the PRP group, with 1 mL injected intra-articularly and 1 mL peri-articularly. To maintain blinding, participants in the placebo group undergo a venous blood draw mimicking the PRP preparation procedure; however, the collected blood is discarded. The duration and procedural steps are standardized to ensure comparable treatment conditions between groups. No repeated injections are performed.; Other Names: Placebo injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical pain improvement: Visual Analog Scale (VAS) for pain	Pain will be assessed using the Visual Analog Scale (VAS), a continuous scale ranging from 0 to 100, where 0 indicates no pain and 100 indicates worst imaginable pain. A decrease in VAS score reflects an improvement in pain.	3, 6, 9 and 12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Functional improvement: Michigan Hand Outcomes Questionnaire (MHQ-DLV)	Hand function will be assessed using the Michigan Hand Outcomes Questionnaire (MHQ), Dutch Language Version (MHQ-DLV). The MHQ is a patient-reported outcome measure consisting of multiple domains (including overall hand function, activities of daily living, pain, work performance, aesthetics, and patient satisfaction), each scored on a scale from 0 to 100. For all domains except pain, higher scores indicate better hand function and greater satisfaction. For the pain domain, higher scores indicate more severe pain.	3, 6, 9 and 12 months
Functional improvement: Grip and pinch test		3, 6, 9 and 12 months
Functional improvement: Opposition of the thumb (pollexograph)		3, 6, 9 and 12 months
Functional improvement: Kapandji Opposition Score	Thumb opposition will be assessed using the Kapandji Opposition Score, a clinical scale ranging from 0 to 10, where 0 indicates no opposition and 10 indicates maximal opposition of the thumb across the palm. Higher scores indicate better thumb function and greater range of opposition.	3, 6, 9 and 12 months

Collaborators and Investigators

• Sponsor: Goed Medisch Centrum
• Collaborators: Arthrex, Inc.

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: March 18, 2026
• First Submitted That Met QC Criteria: March 18, 2026
• First Posted (Actual): March 24, 2026

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Regenerative medicine; platelet-rich plasma; Ultrasound-guided injection; PRP injection; Orthobiologics; Placebo-controlled trial; CMC-I joint; carpometacarpal joint osteoarthritis; Thumb base osteoarthritis
• Additional Relevant MeSH Terms: Therapeutics; Drug Administration Routes; Drug Therapy; Inorganic Chemicals; Chlorine Compounds; Sodium Compounds; Chlorides; Hydrochloric Acid; Injections; Sodium Chloride
• Other Study ID Numbers: NL-010929

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No