Nerve root pain secondary to posterior articular cysts: a report of 6 cases and review of the literature.

The authors report 6 cases of posterior articular cysts responsible for nerve root pain, generally in the form of sciatica. Cysts of the posterior intervertebral joints are a rare cause of nerve root compression. Plain x-rays demonstrate posterior inter-apophyseal osteoarthritis. Demonstration of the posterior articular cyst requires the use of computed tomography with contrast injection and/or MRI. Arthrography of the posterior inter-apophyseal joint allows the cyst to be opacified and treated by infiltration of a corticosteroid.