[Isthmus lysis and spondylolisthesis. A traumatic pathology].

Fourty-five children presenting with an isthmic lysis, complicated or not with spondylolisthesis were studied. The authors suggest that the isthmic lysis could be a stress-induced lesion, a "fatigue fracture" which may heal if treated early, before spondylolisthesis occurs. The main point is therefore an early diagnosis.