The present study documents a phenomenon, which has received little attention despite its potential clinical importance. An 87-year-old woman presented with barely reported extravertebral gas and fluid collections probably originating from the contents of the adjacent cleft within the T10 collapsed osteoporotic vertebra. Her chief complaint was intractable pain radiating over the left thorax suggestive of intercostal neuralgia. The pain intensified when sitting up from a lateral decubitus position, correlating with a posture-related radiologic change of the intravertebral cleft, which appeared with a decubitus position and disappeared with a sitting position. Because these extravertebral collections were located where the 10th thoracic nerve root just exits the intervertebral foramina, her chest pain of a posture-dependent nature most likely resulted from nerve root compression by extravertebral gas and fluid forced out of the vertebral cleft. Posterior spinal fusion with pedicle screw instrumentation resulted in a complete resolution of the chest pain with disappearance of the extravertebral gas and fluid accumulations. An awareness of the possibility that the intravertebral cleft could communicate with the extravertebral space close to the nerve root will help avoid neurologic complications caused by bone cement leakage during vertebroplasty.