At Least 5-Year Outcomes of Whiplash-Induced Chronic Neck Pain Following Response to Intra-Articular Facet Joint Corticosteroid Injection

OBJECTIVE: To investigate whether the response to intra-articular facet joint corticosteroid injection can determine the long-term prognosis (at least 5 years after injury) of whiplash injury-related neck pain sustained 3–12 months after injury. METHODS: Of 65 patients who visited a university hospital for persistent whiplash injury-induced axial neck pain sustained 3–12 months after injury (numeric rating scale score ≥3) and had received intra-articular facet joint corticosteroid injection, 40 completed the telephone interview. We divided the patients into “good response group” (≥50% pain reduction at 1 month after the injection) and “poor response group” (<50% pain reduction at 1 month after the injection). We asked participants regarding the presence and degree of neck pain, its impact on work, and the use of oral pain medication or injection treatment. RESULTS: A follow-up at least 5 years after the injury found that the number of patients with persistent whiplash injury-related neck pain was significantly lower in the good response group than in the poor response group. The number of patients taking oral pain medications prescribed by a medical doctor or receiving injection treatments in a pain clinic or hospital for neck pain was lower in the good response group than in the poor response group. The number of patients who answered that their work was affected by neck pain was lower in the good response group than in the poor response group. CONCLUSION: The response to intra-articular corticosteroid injection might be helpful in determining at least 5-year outcomes of chronic whiplash injury-induced pain.