Stability of the lumbar spine after intradiscal electrothermal therapy

Objective: To assess the stability of the human lumbar cadaveric spinal mot ion segment before and after treatment with intradiscal electrothermal ther apy (IDET). Design: An in vitro biomechanic analysis of 5 human cadaveric spinal motion segments by using nondestructive biomechanic testing in flexion/extension, lateral bending, and axial rotation with loads of ON, 600N, and 1200N. Setting: University-based hospital research center. Cadavers: Spinal unit specimens (upper and middle lumbar) from 5 human cada vers (age range, 39-79 yr). Interventions: A spinal catheter consisting of a thermal-resistive heating coil was placed circumferentially into the outer annulus by using the stand ard extrapedicular discographic technique through a 17-gauge introducer nee dle. The disc was then heated in a saline bath (37 degreesC) from 65 degree sC up to 90 degreesC for a total of 17 minutes. Main Outcome Measure: The stability of the spinal segments was measured bef ore and shortly after IDET. Stability of the spine was measured as the comp liance of the spine (the angular deformation afforded by the spine under ap plied bending moments). Results: With increasing preloads, there is a decrease in motion of the spi nal segment in all planes of testing. However, there was no significant dif ference (p >.05) in the stability of the lumbar spine before and after trea tment with IDET. Conclusions: IDET does not destabilize the spinal motion segment in vitro.