Abstract
Background:
Corticosteroid injection is the mainstay of nonoperative treatment for trigger finger (stenosing tenosynovitis), but despite substantial experience with this treatment, there is minimal available evidence as to the optimal corticosteroid dosing. The purpose of this study is to compare the efficacy of 3 different injection dosages of triamcinolone acetonide for the treatment of trigger finger.
Methods:
Patients diagnosed with a trigger finger were prospectively enrolled and treated with an initial triamcinolone acetonide (Kenalog) injection of 5 mg, 10 mg, or 20 mg. Patients were followed longitudinally over a 6-month period. Patients were assessed for duration of clinical response, clinical failure, Visual Analog Scale (VAS) pain scores, and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores.
Results:
A total of 146 patients (163 trigger fingers) were enrolled over a 26-month period. At 6-month follow-up, injections were still effective (without recurrence, secondary injection, or surgery) in 52% of the 5-mg group, 62% of the 10-mg group, and 79% of the 20-mg group. Visual Analog Scale at final follow-up improved by 2.2 in the 5-mg group, 2.7 in the 10-mg group, and 4.5 in the 20-mg group. The QuickDASH scores at final follow-up improved by 11.8 in the 5-mg group, 21.5 in the 10-mg group, and 28.9 in the 20-mg group.
Conclusions:
Minimal evidence exists to guide the optimal dosing of steroid injection in trigger digits. When compared with 5-mg and 10-mg doses, a 20-mg dose was found to have a significantly higher rate of clinical effectiveness at 6-month follow-up. The VAS and QuickDASH scores were not significantly different between the 3 groups.
Keywords: tendon, diagnosis, treatment, research and health outcomes, surgery, specialty, hand, anatomy, pain, diagnosis
Introduction
Corticosteroid injection is a widely used treatment for stenosing flexor tenosynovitis, commonly known as trigger finger. Injections are the mainstay of nonoperative treatment due to the high success rate, straightforward technique, negligible complication rate, and low cost.1,2 Multiple corticosteroid formulations are used in practice, including triamcinolone, methylprednisolone, betamethasone, and dexamethasone.
Triamcinolone acetonide is a commonly used injectable steroid, with a wide variation in typical dosage used in practice. Despite substantial clinical experience with this treatment, there is minimal evidence available to guide surgeons as to the optimal corticosteroid dosing regimen.3 -5 The purpose of this study was to compare the efficacy among 3 different dosages of triamcinolone acetonide for the treatment of trigger finger focusing on efficacy, duration of improvement in symptoms, and assessment of results with Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and Visual Analog Scale (VAS) scores.
Methods
The study is a prospective cohort study, and all patients were enrolled at the time of initial injection. The study protocol was approved by our institutional review board. Patients with idiopathic trigger finger that presented to the office of 1 of 5 board-certified, fellowship-trained hand surgeons in our division between January 2019 and March 2021 were invited to participate in the study. Patients included in the study were 18 years or older and presented with idiopathic trigger finger. Patients with multiple digit involvement, patients with diabetes, and patients with rheumatoid arthritis were included. Patients were excluded if they had a prior corticosteroid injection to that digit, prior injury to that digit, or any documented allergy to corticosteroid or lidocaine.
Patients were injected according to the standard practice of the surgeon who treated them, and each surgeon administered a single dosage to all their patients during the study period in a nonrandomized fashion. Patients were followed in 1 of 3 dosage groups: 5 mg, 10 mg, and 20 mg. Triamcinolone acetonide (Kenalog; Bristol Myers Squibb, Princeton, New Jersey) was used for all injections. In all cases, the injections were administered using aseptic technique into and around the flexor sheath at the level of the A1 pulley using a 25-gauge needle. For all groups, the total anesthetic/corticosteroid injection volume was 1.5 mL.
The 5-mg triamcinolone acetonide injection dose was prepared by mixing 1 mL of 1% lidocaine with 0.5 mL of 10 mg/mL triamcinolone acetonide. The 10-mg injection dose was prepared by mixing 0.5 mL of 1% lidocaine with 1 mL of 10 mg/mL triamcinolone acetonide. The 20-mg injection dose was prepared by mixing 1 mL of 1% lidocaine with 0.5 mL of 40 mg/mL triamcinolone acetonide. The participants were blinded to the medication dosage, but the treating physicians and study team were not.
At the time of enrollment, data were collected on the duration of symptoms, the presence of diabetes or rheumatoid arthritis, laterality, involved digit, Quinnell grade of the digit, QuickDASH score, and VAS pain score. 6 Subjects were reevaluated with in-person or telephone follow-up visits at 6 weeks, 3 months, and 6 months after injection. At each follow-up evaluation, the patient completed a QuickDASH score and a VAS pain score, was assessed for any need for repeat injection or surgical release, and was asked whether they believed their initial symptoms had resolved. The injection was defined as effective if the patient reported their symptoms were resolved without secondary injection or surgical treatment during the study period.
Statistical analysis using χ2 testing for effectiveness and analysis of variance to assess changes in QuickDASH and VAS scores was carried out. Using clinical effectiveness as a primary end point, sample size was calculated at 40 patients per group. The changes in VAS and QuickDASH scores were compared between groups at each time point. P values <.05 were defined as statistically significant.
Results
A total of 146 patients with 163 trigger digits were analyzed in the final study data. A total of 189 patients with 212 trigger digits were initially enrolled, but 43 patients were excluded due to insufficient follow-up, for a final follow-up rate of 77%. Baseline demographic characteristics of each dosage group are summarized in Table 1. There were no statistically significant differences among the groups according to duration of symptoms, comorbidities, laterality, digit affected, Quinnell grade, or baseline QuickDASH/VAS.
Table 1.
Baseline Demographics.
| 5 mg | 10 mg | 20 mg | Total | |
|---|---|---|---|---|
| Patients | 44 | 57 | 45 | 146 |
| Digits | 52 | 59 | 52 | 163 |
| Duration of symptoms, mo | 5.7 | 4.1 | 4.5 | 4.5 |
| Comorbidities | ||||
| Diabetes | 11 | 4 | 4 | 19 |
| Rheumatoid arthritis | 3 | 1 | 0 | 4 |
| Laterality | ||||
| Right | 34 | 30 | 28 | 92 |
| Left | 18 | 29 | 24 | 71 |
| Digit | ||||
| Thumb | 9 | 22 | 19 | 50 |
| Index | 3 | 3 | 2 | 8 |
| Middle | 23 | 11 | 17 | 51 |
| Ring | 15 | 19 | 12 | 46 |
| Small | 2 | 4 | 2 | 8 |
| Grade | ||||
| I | 8 | 3 | 4 | 15 |
| II | 25 | 25 | 14 | 64 |
| III | 18 | 29 | 27 | 74 |
| IV | 1 | 2 | 7 | 10 |
| Initial QuickDASH | 28.7 | 33.2 | 36.1 | 32.6 |
| Initial VAS | 4.8 | 5.1 | 6.4 | 5.4 |
Note. QuickDASH = Quick Disabilities of the Arm, Shoulder, and Hand; VAS = Visual Analog Scale.
The average duration of symptoms was 4.5 months at the time of enrollment. In all, 11.7% of the patients had diabetes and 2.5% had rheumatoid arthritis. The thumb (30.6%), middle (31.3%), and ring (28.2%) fingers were most commonly affected. Most digits were rated as Quinnell grade II (39.3%) or grade III (45.4%). The initial QuickDASH score was 32.7, and the initial VAS score was 5.4. Results at each timepoint are detailed in Table 2.
Table 2.
Outcomes Data.
| 5 mg | 10 mg | 20 mg | P value | |
|---|---|---|---|---|
| Baseline | ||||
| Patients | 44 | 57 | 45 | |
| Fingers | 52 | 59 | 52 | |
| Duration of symptoms | 5.7 | 4.1 | 4.5 | |
| Initial VAS | 4.8 | 5.1 | 6.4 | |
| Initial QuickDASH | 28.7 | 33.2 | 36.1 | |
| 6 wk | ||||
| VAS | 1.4 | 0.6 | 1.0 | |
| Δ VAS | −3.5 | −4.5 | −5.4 | .03* |
| QuickDASH | 6.8 | 5.1 | 6.1 | |
| Δ QuickDASH | −21.9 | −28.1 | −30 | .27 |
| Still effective | 83.0% | 90.0% | 94.0% | .21 |
| 3 mo | ||||
| VAS | 1.6 | 1.0 | 0.6 | |
| Δ VAS | −3.2 | −4.0 | −5.8 | .01* |
| QuickDASH | 5.6 | 8.5 | 2.9 | |
| Δ QuickDASH | −23.1 | −24.7 | −33.3 | .01* |
| Still effective | 78.3% | 84.7% | 89.4% | .35 |
| 6 mo | ||||
| VAS | 2.7 | 2.4 | 1.9 | |
| Δ VAS | −2.2 | −2.7 | −4.5 | .35 |
| QuickDASH | 16.9 | 11.8 | 7.3 | |
| Δ QuickDASH | −11.8 | −21.5 | −28.9 | .19 |
| Still effective | 51.7% | 62.1% | 79.5% | .04* |
Note. QuickDASH = Quick Disabilities of the Arm, Shoulder, and Hand; VAS = Visual Analog Scale.
p<.05.
At 6 weeks after injection, there was no significant difference in effectiveness between the study groups (83.0% in the 5-mg group, 90.0% in the 10-mg group, 94.0% in the 20-mg group; P = .21). There was a significant between-group difference in the change in VAS scores from baseline (−3.5 in the 5-mg group, −4.5 in the 10-mg group, −5.4 in the 20-mg group; P < .05). There was no significant between-group difference in the change in QuickDASH scores from baseline (−21.9 in the 5-mg group, −28.7 in the 10-mg group, −30.0 in the 20-mg group; P = .27).
At 3 months after injection, there was no significant difference in between-group effectiveness (78.3% in the 5-mg group, 84.7% in the 10-mg group, 89.4% in the 20-mg group; P = .35). There was a significant between-group difference in the change in VAS scores from baseline (−3.2 in the 5-mg group, −4.0 in the 10-mg group, −5.8 in the 20-mg group; P < .05). There was a significant between-group difference in the change in QuickDASH score from baseline (−23.1 in the 5-mg group, −24.7 in the 10-mg group, −33.3 in the 20-mg group; P < .05).
At 6 months after injection, there was a significant difference in between-group effectiveness (51.7% in the 5-mg group, 62.1% in the 10-mg group, 79.5% in the 20-mg group; P < .05). This is graphically depicted in Figure 1. There was no significant between-group difference in the change in VAS scores from baseline (−2.2 in the 5-mg group, −2.7 in the 10-mg group, −4.5 in the 20-mg group; P = .35). There was no significant between-group difference in the change in QuickDASH score from baseline (−11.8 in the 5-mg group, −21.5 in the 10-mg group, −28.9 in the 20-mg group; P = .19).
Figure 1.
Clinical effectiveness at each time point. The clinical effectiveness at each timepoint (6 weeks, 3 months, and 6 months) is demonstrated graphically.
Discussion
Injection of corticosteroids as a treatment for trigger finger has long been accepted as a very effective, first-line treatment option. Typically, efficacy is reported as 50% to 60% for a single injection. 1 Effectiveness has been well demonstrated with a 64% effectiveness rate of corticosteroid versus 20% in a placebo control group of lidocaine alone. 7 The technical points of trigger finger injection, namely, the ideal injectable medication and the optimal dose, have only been studied very minimally.
Ring et al 3 evaluated the role of insoluble (triamcinolone) versus soluble (dexamethasone) steroid and demonstrated that triamcinolone may have a modestly more rapid but ultimately less durable effect. Similarly, Roberts et al 4 assessed the question of the ideal injectable medication in 2021 and demonstrated a slightly higher rate of surgery in their methylprednisolone group compared with triamcinolone and dexamethasone.
In the most applicable study to this investigation, Kosiyatrakul et al 5 recently studied the question of dosage in 2018. They similarly found a dose-response effect for larger dosages of triamcinolone. They found a higher success rate with the 20-mg (100% at 3 months, 62.5% at 6 months) compared with their 10-mg group (90% at 3 months, 35% at 6 months) and 5-mg group (60% at 3 months, 20% at 6 months). This effect equalized at 9 and 12 months. However, the authors did not use a validated outcome instrument to assess the results of treatment.
Similarly, our study supports a modest dose-response effect, with higher doses of triamcinolone leading to greater clinical efficacy at the final 6-month time point. All dosage injections were quite effective up to 6 weeks and even 3 months, but then the curves began to diverge between the 3-month and 6-month time periods.
Overall, the primary strengths of this study are the generalizability to a common clinical problem that most hand surgeons face every day. A limitation inherent to our study design was the lack of follow-up greater than 6 months. It is worth noting that we did include patients with multiple digit involvement, patients with diabetes, and patients with rheumatoid arthritis to maintain the generalizability of the study to the typical trigger finger patient population. These variables are all likely to decrease the efficacy of a given injection.8,9 There were no reported complications in the study period. However, our study was not designed or powered to assess any adverse reactions, such as flare reaction, skin depigmentation, or possible changes in infection rates after eventual surgical release.
Conclusions
In summary, higher doses of injectable corticosteroid for idiopathic trigger finger than have typically been used in practice may provide a meaningful improvement in clinical effectiveness.
Footnotes
Ethical Approval: This study was approved by the NYU Langone institutional review board (s17-0102).
Statement of Human and Animal Rights: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2008.
Statement of Informed Consent: Informed consent was obtained from all individual participants included in the study.
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding: The author(s) received no financial support for the research, authorship, and/or publication of this article.
ORCID iDs: Jared Bookman 
https://orcid.org/0000-0002-4855-1480
Madeline Rocks
https://orcid.org/0000-0002-5766-2959
References
- 1. Fleisch SB, Spindler KP, Lee DH. Corticosteroid injections in the treatment of trigger finger: a level I and II systematic review. J Am Acad Orthop Surg. 2007;15(3):166-171. doi: 10.5435/00124635-200703000-00006. [DOI] [PubMed] [Google Scholar]
- 2. Peters-Veluthamaningal C, Van Der Windt DAWM, Winters JC, et al. Corticosteroid injection for trigger finger in adults. Cochrane Database Syst Rev. 2009;1:CD005617. doi: 10.1002/14651858.CD005617.pub2. [DOI] [PubMed] [Google Scholar]
- 3. Ring D, Lozano-Calderón S, Shin R, et al. A prospective randomized controlled trial of injection of dexamethasone versus triamcinolone for idiopathic trigger finger. J Hand Surg Am. 2008;33(4):516-523. doi: 10.1016/j.jhsa.2008.01.001. [DOI] [PubMed] [Google Scholar]
- 4. Roberts JM, Behar BJ, Siddique LM, et al. Choice of corticosteroid solution and outcome after injection for trigger finger. Hand. 2021;16(3):321-325. doi: 10.1177/1558944719855686. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5. Kosiyatrakul A, Loketkrawee W, Luenam S. Different dosages of triamcinolone acetonide injection for the treatment of trigger finger and thumb: a randomized controlled trial. J Hand Surg Asian Pac Vol. 2018;23(2):163-169. doi: 10.1142/S2424835518500157. [DOI] [PubMed] [Google Scholar]
- 6. Quinell R. Conservative management of trigger finger. Practitioner. 1980;224(1340):187-190. [PubMed] [Google Scholar]
- 7. Robinson JH. Steroid versus placebo injection for trigger finger. J Hand Surg Am. 1996;21(3):530. doi: 10.1016/S0363-5023(96)80392-3. [DOI] [PubMed] [Google Scholar]
- 8. Baumgarten KM, Gerlach D, Boyer MI. Corticosteroid injection in diabetic patients with trigger finger: a prospective, randomized, controlled double-blinded study. J Bone Joint Surg Am. 2007;89(12):2604-2611. doi: 10.2106/JBJS.G.00230. [DOI] [PubMed] [Google Scholar]
- 9. Rozental TD, Zurakowski D, Blazar PE. Trigger finger: prognostic indicators of recurrence following corticosteroid injection. J Bone Joint Surg Am. 2008;90(8):1665-1672. [DOI] [PubMed] [Google Scholar]