Effectiveness of Cortisone Injection and Splinting for Trigger Finger

Trigger finger has a prevalence rate of up to 3%. There are many approaches available to manage this condition. While corticosteroid injection is widely accepted as the most common first-line treatment, its superiority over splint treatment has not been established. This study aims to test the effectiveness of cortisone injections, splint and cortisone+splint to resolve symptoms.

BACKGROUND:

Multiple approaches, such as nonsteroidal anti-inflammatory medication (NSAIDs), splinting, percutaneous surgery, and open surgery, are available for managing trigger finger, blind corticosteroid injection has been widely accepted as the most common first-line treatment (Castellanos 2015). Splinting is helpful in reducing symptoms, is relatively inexpensive and has a low risk of complications, however, no concrete evidence exists to support the role of splinting in patients presenting with trigger finger (Tarbhai 2012). Surgical intervention is the most effective treatment; however, it is associated with higher risks and loss of time from work (Nimigan 2006). Corticosteroid injection is considered the most effective treatment to resolve symptoms in nondiabetic patients, as the success rate is slightly lower in patients with diabetes (Nimigan 2006). Although there are few studies suggesting effectiveness of cortisone injections and splinting for patients with trigger finger. There is lack of consensus on whether cortisone injections and splinting are effective on their own or in combination to resolve patient symptoms in the long term.

OBJECTIVE:

The objective is to prospectively compare the effectiveness of cortisone injections, splint and cortisone+splint for complete resolution of symptoms for the entirety of the follow-up period.

STUDY DESIGN AND METHODOLOGY:

This is a randomized controlled trial. On receipt of consent, the subjects will be screened for eligibility criteria and informed about the study by their surgeon or their delegate, Katrina Munro who is a research assistant working on this project. They will be informed that if they choose to participate, they will be randomized to receive either a splint, corticosteroid injection or both. Side effects will be explained. In keeping with standard ethical procedures, patients will be informed about confidentiality, that their care will not be affected by their choice, and their rights to withdraw consent at any time. Upon receiving verbal consent, patients will sign the consent form approved by the institutional/ ethics review board. Once a patient has consented, block randomization will occur according to the following stratification variables: A.Severity Grade 1 (pain/history of catching) and Grade 2 (demonstrable catching, can actively extend) Grade 3 (demonstrable locking, requiring passive extension) B. Diabetes (y/n)

DATA ANALYSIS:

Statistical Package for Social Sciences for Windows software (SPSS version 23, IBM SPSS Inc., Chicago, Ill., USA) for Windows (Microsoft) will be used for statistical analyses. Variables will be expressed as mean and range or mean ± SD, as appropriate. Univariate analysis will be used to compare clinical, and demographic data between study groups, including independent t-test for continuous variables and chi square test for categorical variables. General linear models with repeated measures of ANOVA and mixed model ANOVA will be used to examine the change in outcomes within and between the participant groups respectively. Non-parametric tests will be employed when applicable. Logistic and linear multivariate regression analysis will be used to examine binary and continuous outcome variables respectively, controlling for confounding variables.

Eligibility Criteria:
Inclusion Criteria:

1. Skeletally mature adults
2. Symptom duration of at least 3 months
3. Diagnosis of trigger finger: based on history of triggering and physical examination (pain over the flexor tendon, tenderness or nodule over the A1 pulley, stiffness, and reproducible locking or triggering).
4. Green's Grade 1-3 (Green's Classification to Grade the Severity of Trigger Finger)

Exclusion Criteria:

1. Congenital trigger thumb
2. Green's Grade 4 (fixed flexion contracture)
3. Previous treatment for trigger finger (injection or surgery)
4. Allergy to cortisone
5. Multiple digits (\>2 digits)