SPONDYLOLISTHESIS AND PRESPONDYLOLISTHESIS

Spondylolisthesis was first described about seventy-five years ago. For a long time thereafter very few cases were recorded. Gradually, as the symptomatology became better known, more instances of this lesion were discovered. In the last two decades the subject has been studied in many quarters, and numerous reports, some of large series of cases, have appeared in the literature. At present many articles in English and foreign languages detailing the clinical aspects and the pathology are available. The exact etiology, however, has been a moot question. But increasing experience tends to confirm the opinion of recent observers that spondylolisthesis, whether coming on suddenly or appearing insidiously, is primarily the result of a congenital cleft in the laminae of the neural arch. As most of the cases are seen in adults, and none have ever been found in very young children (i. e., in the preadolescent age), one wonders about the