Anomalous ossicle in a lumbar facet joint.

A case of an anomalous ossicle in a lumbar facet joint is reported and the operative findings presented. The nature of the anomaly is not fully understood but is thought to be the result of non-fusion between a normal appearing ossification center and the adjacent articular process. The patient's symptoms--severe chronic low back pain--subsided completely after surgery. It is concluded that the presence of such ossicles in facet joints in some cases may lead to severe symptoms and that surgical treatment in such cases should be considered.