Background: Chronic pain in the cervical zygapophyseal joints is a common problem after a whiplash injury. Treatment with intraarticular injections of corticosteroid preparations has been advocated, but the value of this approach has not been established. We compared the efficacy of a depot injection of a corticosteroid preparation with the efficacy of an injection of a local anesthetic agent in patients with painful cervical zygapophyseal joints.
Methods: Sixteen men and 25 women with pain in one or more cervical zygapophyseal joints after automobile accidents (mean age, 43 years; median duration of pain, 39 months) were randomly assigned to receive an intraarticular injection of either bupivacaine (0.5 percent) or betamethasone (5.7 mg) under double-blind conditions. The patients were followed by means of regular telephone contact and clinic visits until they reported a return to a level of pain equivalent to 50 percent of the preinjection level. The time from treatment to a 50 percent return of pain was compared in the two groups with the use of a survival analysis.
Results: Less than half the patients reported relief of pain for more than one week, and less than one in five patients reported relief for more than one month, irrespective of the treatment received. The median time to a return of 50 percent of the preinjection level of pain was 3 days in the 21 patients in the corticosteroid group and 3.5 days in the 20 patients in the local-anesthetic group (P = 0.42).
Conclusions: Intraarticular injection of betamethasone is not effective therapy for pain in the cervical zygapophyseal joints after a whiplash injury.