Evaluating the effectiveness of interlaminar epidural steroid injections for cervical radiculopathy using PROMIS as an outcome measure

Background

Cervical interlaminar epidural steroid injections (CIESI) are frequently used to treat cervical radiculopathy due to cervical nerve root impingement.

Objective

The purpose of this study was to evaluate the therapeutic effect of CIESI for patients with cervical radiculopathy.

Methods

We conducted a retrospective review of consecutive adult patients with cervical radicular pain and corroborative cervical spondylotic foraminal stenosis on MRI that failed at least 6 weeks of conservative management consisting of medication and physical rehabilitation seen at a multidisciplinary, tertiary academic spine center. Patient Reported Outcome Measurement Information System (PROMIS) domains of Physical Function (PF) v1.2/v2.0 and Pain Interference (PI) v1.1 were collected at all patient visits. Scores were recorded at baseline, 3-months, 6-months and 12-months post-procedure. Statistical analysis comparing baseline scores with follow-up postprocedural PROMIS scores was performed. The percentage of patients reporting improvement greater than the minimal clinically important difference (MCID) was calculated for responders and for the worst case scenario.

Results

179 patients met inclusion criteria. PROMIS PI at 3-, 6-, and 12-month follow-up statistically improved by 1.5 (95 % confidence interval [CI] 1.4–1.6; p = 0.02), 1.5 (95 % CI 1.4–1.6; p = 0.03) and 1.7 (95 % CI 1.6–1.8; p = 0.4), respectively. Follow-up PROMIS PF at 3-month follow-up improved by 1.6 (95 % CI 1.5–1.7; p = 0.04) but did not significantly differ at 6- or 12-month follow-up. The percentage of patients that exceeded MCID thresholds of clinical significance was 44 % (95 % CI 36%–53 %) at 3-months, 49 % (95 % CI 39%–59 %) at 6-months, and 54 % (95 % CI 41%–66 %) at 12-months. Worst case scenario analysis demonstrated that 32 % (95 % CI 36%–53 %) of patients exceeded the MCID thresholds at 3-months, 31 % (95 % CI 24%–37 %) at 6-months, and 21 % (95 % CI 15%–27 %) at 12-months.

Discussion/conclusions

Our study demonstrated that CIESI leads to an improvement in function and pain for patients with cervical radiculopathy. This study was limited by retrospective design, loss to follow-up, and variation in steroids used.