The Menisci of the Lumbar Zygapophyseal Joints

The literature describing menisci in the lumbar zygapophyseal joints is reviewed. The only true menisci in these joints are rudimentary fibrous invaginations of the dorsal and ventral capsule. So-called menisci at the superior and inferior poles of the joint are basically fat-filled synovial reflections, some of which contain dense fibrous tissue, which probably arises as a result of mechanical stress. The theory of meniscus entrapment is appraised, but is considered to have been an overstated cause of those forms of "acute locked back" that responds to manipulation.