Local corticosteroid injections are routinely used as first-line treatment for trigger finger. The accurate delivery of steroids into the tendon sheath is important for the effectiveness of the treatment and the prevention of complications. This study aimed to introduce our steroid injection technique for trigger finger, which uses tendon excursion of the flexor tendon, and evaluate the clinical outcomes in patients who were treated with this technique.
A total of 171 patients with trigger finger who were treated with steroid injections were retrospectively reviewed. The efficacy of injection and complications were investigated. The efficacy was evaluated as“good,” “fair,” or “poor.” The results were analyzed according to the type of finger and the Quinnell grading system.
The total efficacy was 83.6% (good/fair, 143 digits; poor, 28 digits). The treatment success rate for Quinnell grade IV was 43.8% (7 of 16). This rate was significantly lower than those of Quinnell grades II and III, which were 88.9% (88 of 99) and 87.5% (49 of 56), respectively (II vs. IV, p=0.004; III vs. IV, p=0.010). The success rate for the four fingers excluding the thumb was significantly higher than that of the thumb (88.2% vs. 75.4%, p=0.048).
The steroid injection technique using tendon excursion showed excellent results and low complication rates. In particular, the second to fourth fingers and cases of low-grade trigger finger showed more effective results.
Trigger finger, which is also known as stenosing tenosynovitis, is caused by the thickening of the first annular (A1) pulley surrounding the flexor tendon of the finger. It is the most common hand disease that causes pain and dysfunction of the hand [
Local steroid injection in the trigger finger, which was first reported in 1953 by Howard et al. [
This study aimed to introduce our steroid injection technique for trigger finger, which uses tendon excursion of the flexor tendon, and to evaluate the clinical outcomes in patients who received this technique as the primary treatment. Our hypothesis was that the technique simultaneously provided satisfactory finger function restoration and low complication rates.
Ethics statements: This study was performed in accordance with the Declaration of Helsinki. The design and protocol of this study were reviewed and approved by the Institutional Review Board (IRB) of Inha University Hospital (No. INHAUH 2019-09-008). Verbal informed consent was obtained from all participants prior to the study. Written informed consent was waived by the IRB because of its retrospective nature via medical records.
From January 2014 to June 2019, 478 patients with trigger finger who were treated with local steroid injections at our institution were retrospectively reviewed. The study subjects included patients with idiopathic trigger finger who were followed up for at least three months after steroid injection treatment. The diagnosis of idiopathic trigger finger was made on the basis of clinical assessments by an orthopedic hand surgeon at the first outpatient visit. The exclusion criteria included congenital trigger finger, diseases that involve the joints as rheumatoid arthritis or other connective tissue diseases, concomitant diseases that affect prognosis such as diabetes mellitus and/or chronic kidney disease, and coexisting symptomatic carpal tunnel syndrome or de Quervain’s disease. Patients who had a history of steroid injections at other hospitals or had undergone surgical treatment, those who were followed up for <3 months, or those with multiple digit involvement were also excluded from this study.
All patients were injected by an experienced orthopedic hand surgeon (T.J.L.) on an outpatient basis by using the following method (
The Quinnell grading system [
The data are presented as mean±standard deviation or as numbers and percentages. The treatment results of the thumb and other fingers were compared using Pearson chi-square test.
Among the 478 patients, 171 digits (171 patients) were enrolled in this study after applying the inclusion and exclusion criteria (
The total efficacy was 83.6% (good/fair, 143 digits; poor, 28 digits) (
The treatment success rate for Quinnell grade IV was 43.8% (7 of 16), which was significantly lower than those of Quinnell grades II and III, which were 88.9% (88 of 99) and 87.5% (49 of 56), respectively (II vs. IV, p=0.004; III vs. IV, p=0.010) (
In the case of the thumb, 53 out of 69 cases (76.8%) showed improvements in symptoms, and the other four fingers (excluding the thumb) showed improvements in symptoms in 90 out of 102 cases (88.2%). For the other fingers (excluding the thumb), the success rate was significantly higher than that of the thumb (p=0.048) (
During the follow-up period, one digit (0.6%) with subcutaneous tissue atrophy and two digits (1.2%) with skin depigmentation were observed (
Trigger finger, which was first described by Notta [
To increase the therapeutic effect of topical steroid injection, it is important to accurately inject the steroid into the flexor tendon sheath [
During injection, if the finger is well flexed and extended, the needle can come out of the flexor tendon well. In other words, with proper tendon excursion during injection, the tip of the needle can be positioned into the flexor tendon sheath (
In the trigger finger, as the A1 pulley surrounding the flexor tendon thickens, the tunnel for tendon excursion narrows, and the tendon excursion of the flexor tendon becomes limited [
Although local steroid injections are effective for treating various musculoskeletal disorders, complications may arise. The potential complications of local steroid injection include infection, skin depigmentation, tendon rupture, and fat atrophy [
Ultrasound-guided injection is a widely used technique for intrasheath injection and has been reported to have excellent treatment rates of 91.4% to 93.4% [
This study had several limitations. First, this was a retrospective study, and there was no control group that did not use our technique. Therefore, it was difficult to analyze the therapeutic effect of injections using our technique. Randomized controlled trials may be needed to provide a higher level of evidence. Second, our technique is to inject into the tendon sheath, which first requires intratendon needling. Although steroids are not injected directly into the tendon, it has the potential to cause microtrauma to the tendon. Finally, the confirmation of whether steroids were accurately delivered into the flexor tendon sheath was limited. Intrasheath injection was judged via the naked eye and by palpation of thrills. It may be necessary to accurately check whether the steroid is injected into the intrasheath by using ultrasound. Despite these limitations, our findings are meaningful because they provide evidence of the clinical effects of our technique and are valuable as a report that introduces our injection technique for trigger finger.
The steroid injection technique using tendon excursion of the trigger finger showed excellent results and low rate of complications. In particular, second to fourth fingers with longer tendon excursions showed more effective results than the thumb. Fingers of Quinnell grade IV with poor tendon excursion showed lower treatment results.
Supplementary Video 1 can be found via
The video showing the injection technique using tendon excursion in trigger finger.
The authors have nothing to disclose.
None.
Photograph demonstrating the injection technique using tendon excursion in trigger finger. (A) Palpitate the metacarpal neck. (B) With the affected finger in a flexed position, insert a 26-gauge needle aiming at 45°. (C) Ask the patient to flex and extend the finger to ascertain that the needle tip is not in the tendon. (D) Inject and feel the fluid thrill.
Flowchart of patient selection for this study.
Comparison of the efficacy of steroid injections by Quinnell grading.
A 56-year-old female patient with right trigger thumb developed complications after the second steroid injection. The photograph shows skin depigmentation and fat atrophy of the right thumb.
Diagram showing the needle tip position during tendon excursion. (A) Insertion of the needle tip up to the tendon in the bevel-up state. (B) Rotation of the needle tip 180° to bevel down. (C) View of the needle entering into the flexor sheath after tendon excursion but not passing through the tendon substance.
Cross-sectional view showing three possible positions of the needle tip in the A1 pulley. (A) Intratendinous injection, (B) intrasheath injection, and (C) extrasheath injection.
Quinnell grading of trigger finger [
Grade | Clinical finding | No. of patients (n=171) |
---|---|---|
0 | Normal movement | 0 (0) |
I | Uneven movement | 0 (0) |
II | Intermittent locking, actively correctable | 99 (57.9) |
III | Intermittent locking, passively correctable | 56 (32.7) |
IV | Locked digit | 16 (9.4) |
Values are presented as number (%).
Modified from Amiri Aref et al. [
Patients' demographics
Characteristic | Data (n = 171) |
---|---|
Age at the first visit (yr) | 56.1 ± 12.0 (17–83) |
Sex, female:male | 120 (70.2):51 (29.8) |
Symptom duration (mo) | 5.5 ± 9.4 |
Follow-up period (mo) | 17.6 ± 14.9 |
Affected digit | |
Thumb | 69 (40.4) |
Index finger | 28 (16.4) |
Middle finger | 58 (33.9) |
Ring finger | 26 (15.2) |
Little finger | 4 (2.3) |
Values are presented as mean±standard deviation (range) or number (%).
Comparison of clinical outcomes between the thumb and other fingers
Variable | Affected digit |
p-value |
||||||
---|---|---|---|---|---|---|---|---|
All (n=171) | Thumb (n=69) | Index finger (n=14) | Middle finger (n=58) | Ring finger (n=26) | Little finger (n=4) | Other fingers (n=102) | ||
No. of injections | 0.409 | |||||||
1 | 120 (70.2) | 46 (66.7) | 10 (71.4) | 44 (75.9) | 17 (65.4) | 3 (75.0) | 74 (72.5) | |
2 | 51 (29.8) | 23 (33.3) | 4 (28.6) | 14 (24.1) | 9 (34.6) | 1 (25.0) | 28 (27.5) | |
Response | 0.048 | |||||||
Good/fair | 143 | 53 | 12 | 51 | 22 | 3 | 90 | |
Poor | 28 | 16 | 2 | 7 | 4 | 1 | 12 | |
Efficacy | 143 (83.6) | 53 (76.8) | 12 (85.7) | 51 (87.9) | 22 (84.6) | 3 (75.0) | 90 (88.2) | |
Quinnell grade | 0.647 | |||||||
II | 99 (57.9) | 37 (53.6) | 9 (64.3) | 36 (62.1) | 14 (53.8) | 3 (75.0) | 62 (60.8) | |
III | 56 (32.7) | 25 (36.2) | 2 (14.3) | 21 (36.2) | 8 (30.8) | 0 (0) | 31 (30.4) | |
IV | 16 (9.4) | 7 (10.1) | 1 (7.1) | 5 (8.6) | 2 (7.7) | 1 (25.0) | 9 (8.8) |
Values are presented as number (%) or number only.
Comparisons of thumb vs. other fingers performed using the Pearson’s chi-square test.