THE LINEAR INTRAVERTEBRAL VACUUM - A SIGN OF BENIGN VERTEBRAL COLLAPSE

OBJECTIVE. We describe 11 patients with radiographically visible linea r intravertebral vacuums to increase awareness of this benign finding that is diagnostic of ischemic necrosis of the vertebral body (Kummell 's disease). MATERIALS AND METHODS. We retrospectively reviewed the ra diologic and clinical histories of 11 patients seen at our institution between 1991 and 1997 in whom the linear intravertebral vacuum phenom enon had been diagnosed. Imaging included plain radiographs in all pat ients, CT scans in three, bone scintigrams in three, and MR images in three. RESULTS. Twelve linear intravertebral vacuums associated with v ertebral compression deformities were visible in 11 patients from T8 t o L2, four at T12, and four at L1. Of the 12 linear intravertebral vac uums, seven (58%) were seen by the initial interpreting radiologist. T he mean age of these patients was 76.6 years. The female:male ratio wa s 10:1. During the period of analysis, two patients were known to have malignancy, one with metastasis to the spine but not to the affected vertebral body. One patient, who underwent equivocal MR imaging for ma lignancy, later underwent bone biopsy, which showed no neoplasm within the collapsed vertebra. Of the remaining nine patients, one was under going chronic corticosteroid therapy and another had a history of radi ation therapy to the spine. Seven of the 11 patients had histories of falling, prompting radiographs of the spine. All 11 patients were radi ographically osteopenic. Ultimately, none of the patients had clinical evidence of neoplasm or infection involving the affected vertebral bo dy. CONCLUSION. Recognition of the near-certain benign significance of a linear intravertebral gas collection revealed by radiography may pr event unnecessary imaging or biopsy in a patient with a suggestive ver tebral compression deformity.