Postsurgical recurrent stress fracture in the spine affected by ankylosing spondylitis.

Stress fracture in the dorsolumbar region is a well-known complication of the rigid spine usually occurring at the end stages of ankylosing spondylitis. When indicated, surgical treatment by anterior spinal fusion is prescribed. Three cases illustrating the appearance of new stress fractures in different parts of the spine after the successful anterior surgical fusion of a previous lesion indicate the possibility of recurrence. This explains the persistence of back pain postoperatively. These stress fractures seem unrelated to spinal deformities. External bracing is useful, but additional surgical fusions may become necessary.