Intradiscal Microprobe With a Vibrational Optical Fiber for Diagnosis and Thermal Therapy of Discogenic Pain Due to an Annular Fissure

Major studies have shown that discogenic pain is the most common cause of chronic lower back pain, accounting for 40% of all the causes. Provocation discography—inducing pains by pressing nerve structures around the annular fissures—is recognized as the only method for diagnosing discogenic pain. However, the method is not available to the patient with full-thickness fissures because of a contrast media leakage through the fissure. In this paper, intradiscal microprobes (IDMPs) affecting direct mechanical stimulus on the nerve fiber are presented for diagnosis of the fissure. The plastic optical fiber (POF), located in the flexible polymer tube, can be navigated to fissure vicinities. Then, a linear or rotational motor placed inside the probe grip generates a minute axial or radial vibration of the fiber tip, which irritates the tiny pain nerve fiber around the fissure. The intensity of the pain can serve as a guideline to determine the level of discogenic disease. The frequency and amplitude of the axial (radial) vibration discography were 2.9–5.7 (4.0–7.0) Hz and 1.5–3.4 (0.06–3.25) mm, respectively. Furthermore, the optical experiments for evaluation of thermal therapy application were successfully confirmed.