Bony vibration stimulation: a new, non-invasive method for examining intradiscal pain.

Fifty-seven patients with low-back pain were evaluated immediately prior to a discography examination by means of an electrical tool which produced bony vibration to the lumbar spinal processes. The vibrator was composed of a standard electric toothbrush shaft (Braun) with a blunt head instead of the brush. The lumbar spinal processes were compressed one by one for a few seconds with this blunt, vibrating tool. The patient's pain experience provoked by vibration was compared with that from injections during discography. A good correlation was found between these two examinations when patients with previously operated backs and painful, prolapsed discs were excluded: sensitivity was 0.96 and specificity 0.72. Prolapsed, but discographically painful discs were always painless in the vibration examination. The local, non-invasive bony vibration stimulation test is an easy, quick, safe, inexpensive and reliable method for examining intradiscal pain.