Compression fracture

Compression fractures are the result of "crumbling or smashing of cancellous bone by forces acting parallel to the long axis of bone. It is applied particularly to vertebral body fractures."

Cause / etiology

Compression type fractures can occur to any bone when an applied force overwhelms the ability of the trabecular structure of that bone to resist the pressure. Compaction of the bone occurs and a loss of height or size of the particular structure, most commonly a vertebra, results. A single traumatic injury may precipitate the fracture or, in the case of chronic disease, multiple tiny compressions occur over time with a slow loss of height. Under normal circumstances, healthy bone requires a significant fall or impact to cause compression, but more commonly, diseases that weaken the trabecular matrix within cancellous bone lower the threshold required to cause the bone to collapse. Spontaneous compression fractures appear to occur for no reason at all when a cough or a sneeze triggers the collapse. Essentially, the bone has become so weak that normal weight bearing is no longer possible. Conditions that can result in spontaneous compression fractures include those that cause osteopenia, or calcium loss within the bone, such as osteoporosis, metabolic diseases, metastatic cancer and lymphoma among others.

Diagnosis

Compression fractures of the spine are generally identified by the patient history of back pain, tenderness in the area of the fracture, and spasm or contracture of the surrounding musculature. Xray is the most common means of detecting and confirming compression fractures, though Computed Tomography (CT scan) and bone scan can show early signs of disruption of the trabecular pattern especially in those resulting from underlying disease. A triple phase bone scan is particularly useful in determining the age of the compression when timing of the injury is critical for treatment purposes. MRI will show an increased signal if inflammation is part of the process.

External links

• Fractures. compression - Information for patients from MedlinePlus (United States National Library of Medicine).