Are There Differences in Pain Reduction and Functional Improvement Among Splint Alone, Steroid Alone, and Combination for the Treatment of Adults With Trigger Finger?
Authors: Atthakomol Pichitchai , Wangtrakunchai Vorathep , Chanthana Phongniwath , Phinyo Phichayut , Manosroi Worapaka 
Published: April 2023

Abstract

Background
Steroid injection and splinting, which are commonly recommended nonsurgical treatments in adults with trigger finger, have been demonstrated to effectively relieve pain and improve function. However, to our knowledge, there have been no direct comparisons of pain relief and function improvement with splinting alone, steroid injection alone, or a combination of splinting and steroid injection in patients with this diagnosis.

Question/purpose
Are there differences in pain reduction and functional improvement in adults with trigger finger treated with splinting alone, steroid injection alone, and a combination of splinting and steroid injection at 6, 12, and 52 weeks after the intervention?

Methods
Between May 2021 and December 2021, we treated 165 adult patients for trigger finger at an academic university hospital. Based on prespecified criteria, all patients we saw during that period were eligible, but 27% (45 of 165) were excluded because they had received a previous local corticosteroid injection (n = 10) or they had concomitant carpal tunnel syndrome (n = 14), first carpometacarpal joint arthritis (n = 3), osteoarthritis of the hand (n = 6), de Quervain disease (n = 3), multiple-digit trigger finger (n = 6), or pregnancy during the study period (n = 3). After screening, 120 patients were randomized to receive either splinting (n = 43), steroid injection (n = 40), or splinting plus steroid injection (n = 37). Patients were randomly assigned to the different treatments using computer-generated block randomization (block of six). Sequentially numbered, opaque, sealed envelopes were used in the allocation concealment process. Both the allocator and the outcome assessor were blinded. Splinting involved the patient wearing a fixed metacarpophalangeal joint orthosis in the neutral position at least 8 hours per day for 6 consecutive weeks. Steroid injection was performed using 1 mL of 1% lidocaine without epinephrine and 1 mL of triamcinolone acetonide (10 mg/mL) injected directly into the flexor tendon sheath. No patients were lost to follow-up or had treatment failure (that is, the patient had persistent pain or triggering with the trigger finger treatment and requested additional medical management including additional splinting, steroid injection, or surgery) at 6 or 12 weeks after the intervention, and at 52 weeks, there was no difference in loss to follow-up among the treatment groups. An intention-to-treat analysis was performed with all 120 patients, and a per-protocol analysis was conducted with 86 patients after excluding patients who were lost to follow-up or had treatment failure. Primary outcomes evaluated were VAS pain reduction and improvement in Michigan Hand Outcomes Questionnaire (MHQ) scores at 6, 12, and 52 weeks after the intervention. The minimum clinically important difference (MCID) values were 1 and 10.9 for the VAS and MHQ, respectively.

Results
There were no clinically important differences in VAS pain scores among the three treatment groups at any timepoint, in either the intention-to-treat or the per-protocol analyses. Likewise, there were no clinically important differences in MHQ scores at any timepoint in either the intention-to-treat or the per-protocol analyses.

Conclusion
Splinting alone is recommended as the initial treatment for adults with trigger finger because there were no clinically important differences between splinting alone and steroid injection alone in terms of pain reduction and symptom or functional improvement up to 1 year. The combination of steroid injection and splinting is disadvantageous because the benefits in terms of pain reduction and symptom or functional improvement are not different from those achieved with steroid injection or splinting alone.

Level of Evidence
Level I, therapeutic study.