Thermal Annuloplasty for the Treatment of Discogenic Low Back Pain With a High-Intensity Zone After Full Endoscopic Discectomy.

Discogenic low back pain (DLBP) is difficult to diagnose. We performed full endoscopic spinal surgery (FESS) with thermal annuloplasty for DLBP and achieved good results. Here, we report a case in which thermal annuloplasty resulted in good outcomes for refractory DLBP accompanied by a residual high-intensity zone (HIZ) after full endoscopic discectomy (FED). The patient was a 22-year-old female with low back pain (LBP) that worsened on bending forward. Magnetic resonance imaging (MRI) revealed bulging at the L4/L5 level and lumbar disc herniation (LDH) at the L5/S1 level. The condition worsened but then improved over time. However, since she began working as a nurse a year prior to presentation, her symptoms worsened again, and she has experienced severe LBP and left sciatica. Since MRI showed a slight increase in the L5/S1 LDH, FED (interlaminar approach at the left L5/S1 level) was performed, and her symptoms in the left lower limb quickly disappeared. The LBP also improved, but when she returned to work, the pain worsened. Oral medications had little effect; therefore, she underwent periodic block injections. MRI revealed that the LDH at the L5/S1 level had disappeared, but a small HIZ lesion remained. LBP worsened on discography and improved with a disc block. The condition was diagnosed as DLBP accompanied by HIZ. Thermal annuloplasty was performed, resulting in the immediate disappearance of the LBP. An HIZ indicates inflammation; cauterization can suppress this inflammation and improve discogenic pain. The histopathological findings included angiogenesis and inflammatory cell infiltration. DLBP accompanied by an HIZ may develop after FED (transforaminal approach), and thermal annuloplasty is as effective as the usual HIZ. To our knowledge, this is the first report of thermal annuloplasty for the treatment of postoperative HIZ.