To evaluate the effectiveness of magnetic resonance imaging (MRI) for the diagnosis and usefulness of vertebroplasty in osteoporotic occult vertebral fractures.

Of 472 osteoporotic vertebral fractures treated from May 2003 to July 2009, 45 patients were diagnosed with occult osteoporotic vertebral fracture. Their medical charts and radiographs were reviewed. The degree of vertebral body collapse was graded by a semiquantitative method. In order to increase the reliability, interpretation was based on radiographic diagnoses from 3 orthopedic surgeons. Vertebroplasty was performed at 31 of the 45 patients, for whom conservative treatment failed. Pre-operatively and post-operatively, pain was evaluated using a visual analog scale (VAS).

We observed 55 occult fractures in 45 patients. Forty vertebrae (72.7%) among the 55 vertebrae were just adjacent to an old vertebral fracture with deformation of the vertebral body. The rediagnosis rate of occult fracture attempted without MRI was only 21.8%. The average pre-operative VAS score of 8.07 (6~9) was improved to 2.43 after surgery and showed no delayed vertebral body collapse.

Gadolinium enhancement of MRI is critical to the diagnosis of occult vertebral fractures, which are 9% of whole osteoporotic vertebral fractures. Seventy-two point seven percent of occult vertebral fractures were just adjacent to an old vertebral fracture with collapse of the vertebral body. This means that if vertebroplasty is performed without thorough MRI examination, it may fail.