Spondylolysis following trauma. A case report and review of the literature.

A 31-year-old woman who had an apparently normal lumbosacral spine, developed a unilateral spondylolysis of L4 following injury, and then one year later, roentgenographically showed a bilateral spondylolysis. The cause of spondylolysis was not established, but several theories have been proposed, the most attractive of which is that this condition represents a stress fracture through an area of bone predisposed to fracture. The classifications of spondylolysis and the etiologic theories demonstrate that this case cannot be convincingly classified according to the usual criteria. However, trauma was documented and may have been a significant etiologic factor of spondylolysis.

Congenital absence of lumbar articular facets. Report of two cases.

X-ray evidence of an absent lumbar facet is usually considered to be indicative of the presence of an osteolytic bone lesion but on rate occasions may be due to a congenital anomaly. Two cases of the congenital absence of a lumbar superior articular facet suggest that this anomaly is not symptom-producing, and in one case was discovered incidentally in a patient without back pain yet led to the performance of a major surgical diagnostic operation. While, rare, a greater awareness of this condition, as clearly defined in the literature on the subject, might occasionally eliminate the need for a similar surgical procedure.