Postoperative fractures of lumbar articular facets: occult cause of radiculopathy.

Fracture of the inferior lumbar articular facets after laminectomy with facetectomy is a relatively common but unrecognized cause of radiculopathy. Although not all patients may be symptomatic from the fractures, some may have radiculopathy or back pain caused by displacement of the fracture fragment. In a series of 400 postoperative spinal computed tomographic (CT) scans, 25 patients were found who had fractures through the base of the inferior facets. Axial scans revealed no abnormality other than slight widening of the joint on the affected side. Sagittal views demonstrated a lucent defect similar to a pars interarticularis fracture, whereas coronal views showed the fracture at a different location in the base of the facet. Typically patients become symptomatic after a period of postsurgical well-being. A new pain pattern, local tenderness, pain on unusual movements, and relief with recumbency help suggest facet fracture versus recurrent disk herniation.