Answer: Kummell's disease

One should be looking for a recent history of trauma such as a low-distance fall, MVA, etc (perhaps not even remembered by the patient)

Kummell's disease (aka vetebral osteonecrosis) is delayed collapse of the vertebral body following mild trauma. While the initial "trauma" may have been minimal and initial imaging would likely have been normal, there is a microfracture present. Normal fracture healing does not occur and instead a zone of ischemia and nonunion (ie avascular necrosis = osteonecrosis) delevops. Over the next few weeks to months, this can lead to progressive collapse of the vertebral body. This commonly is associated with increasing back pain and even development of neurologic compressive symptoms.

Association:

• Osteoporosis (of course)
• Steroid use (which is associated with AVN in general)
• Hepatic Cirrhosis
• Radiation therapy (again associated with AVN)

Location: Classically within the lower thoracic or upper lumbar spine

Radiology

• X-rays show a vetebral compression fracture (collapse of the vertebral body)
• CT shows the same but often with a classic "vacuum cleft" (ie air density) within the vetebral body. If large this may be seen on X-ray, and sometimes can be exaggerated with extension views of the spine
• MRI can show the same or a developing low T1/high T2 signal fluid collection within the body

It is suggested that the presence/degree of air in the body may be associated with more advanced disease/collapse

Treatment:

• Kyphoplasty/vertebroplasty for pain relief and to stop progression of collapse
• If neurologic symptoms are present, neurosurgical evaluation and surgical management are recommended