Changes in Intradiscal Pressure During Flexion-Distraction Type of Chiropractic Procedure: A Pilot Cadaveric Study

Objective: The study objective was to quantify the changes in intradiscal pressure (IDP) during the application of a chiropractic procedure known as the Cox flexion-distraction technique. Materials and Methods: Pressure sensors were inserted into lumbar intervertebral discs of eight unembalmed cadavers (five male and three female, age range 43?75 years). Five 4-second cycles of flexion distraction were performed for a 20-sec period. Pressure data were collected while the discs were in an unpressurized state as well as a pressurized state (with water). The pressure data were collected during three separate applications of the flexion-distraction procedure with transducers inserted into the L2-L3, L3-L4, and L4-L5 intervertebral discs. The mean pressure values were documented before, during (in the distracted position), and after the treatment procedure (calculated). Pressure differences were compared using the paired t-test for significance in pressure changes from initial prone position to distracted treatment position. Results: The IDPs significantly decreased in both pressurized and unpressurized discs at all studied disc levels. The average IDP decreases in unpressurized discs were as follows: 5.6?kPa at L2-L3, 20.6?kPa at L3-L4, and 22.0?kPa at L4-L5. The IDP decrease range in pressurized-in-the-initial-prone-position discs were as follows: 17.8?kPa at L2-L3, 35.2?kPa at L3-L4, and 122.0?kPa at L4-L5. Conclusions: IDP was found to decrease during the flexion-distraction procedure, which is consistent with the hypothesis that this procedure may be able to draw a protruded nucleus pulposus back toward the intervertebral disc's center and allow for the nutrients flow into the disc.