Betamethasone vs Dextrose Injections in Trigger Finger

Trigger finger, also known as stenosing tenosynovitis, is a common hand disorder characterized by pain, catching, and locking of the affected digit due to impaired gliding of the flexor tendon at the A1 pulley. It can significantly impair hand function and quality of life.

Corticosteroid injections are widely accepted as an effective first-line treatment for trigger finger. However, potential adverse effects such as skin atrophy, tendon rupture, and systemic effects, particularly in patients with metabolic disorders, have led to increasing interest in alternative treatment options.

Dextrose injection has emerged as a potential alternative treatment modality in musculoskeletal disorders. However, there is limited high-quality evidence evaluating its effectiveness in trigger finger.

The aim of this prospective, randomized controlled trial is to compare the clinical effectiveness of ultrasound-guided betamethasone injection and dextrose injection in patients with trigger finger.

Eligible participants aged 18 to 75 years with clinically diagnosed trigger finger of at least 4 weeks' duration will be enrolled. Patients will be randomly assigned to one of two groups. One group will receive an ultrasound-guided injection of 1 ml lidocaine and 1 ml betamethasone, while the other group will receive an ultrasound-guided injection of 1 ml lidocaine and 1 ml 30% dextrose solution (resulting in a final concentration of 15% dextrose). All injections will be performed under sterile conditions at the A1 pulley level.

The study is designed as a randomized, participant-, injector-, and assessor-blinded trial. The injector will be blinded to the injectate using opaque-covered syringes. Randomization will be performed by an independent researcher who will not be involved in outcome assessment.

The primary outcome of the study is the change in pain intensity, assessed using the Numeric Rating Scale (NRS).

Secondary outcomes include triggering severity assessed using the Modified Quinnell classification, functional status assessed using the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire, grip and pinch strength, and fine motor skills evaluated with the Purdue Pegboard test.

Outcome assessments will be conducted at baseline, 1 hour, 2 weeks, 4 weeks, and 12 weeks after injection, according to the predefined schedule of each outcome measure.

This study is expected to provide high-quality evidence regarding the effectiveness of dextrose injection as a potential alternative to corticosteroid treatment in trigger finger.

Inclusion criteria

• Age between 18 and 75 years
• Clinical diagnosis of trigger finger
• Presence of symptoms for at least 4 weeks

Exclusion criteria

• Previous surgery on the affected finger
• Injection treatment to the affected finger within the previous 3 months
• Active local or systemic infection
• Active malignancy
• Active inflammatory rheumatic disease (e.g., rheumatoid arthritis, ankylosing spondylitis, polymyalgia rheumatica, vasculitis)
• Uncontrolled diabetes mellitus and/or uncontrolled hypertension
• Autoimmune connective tissue diseases (e.g., systemic lupus erythematosus, antiphospholipid syndrome, systemic sclerosis, Sjögren syndrome, polymyositis, dermatomyositis, adult-onset Still's disease)
• Coagulopathy that increases the risk of injection procedures
• Pregnancy
• Known allergy or hypersensitivity to lidocaine, betamethasone, or dextrose
• Mental impairment or severe psychiatric disorder that may interfere with study participation or informed consent