The Role of Distraction in Improving the Space Available in the Lumbar Stenotic Canal and Foramen

Abstract

The terminal event in disc space narrowing and facet subluxation of the lumbar spine can produce clinical symptoms of spinal stenosis. Reversal of this process via distraction was performed on ten cadaveric motion segments with documented stenosis. Computerized tomography and caliperic methods for the measurement of canal and foraminal areas were calculated in each segment after 5 and 10 mm of symmetrical distraction. Measurements were done in a blinded manner verified with orthographic software and statistical analysis. Decompression of foraminal space was statistically significant in 7 of 10 cadaveric specimens after 5 mm of distraction and 9 of 10 specimens after 10 mm of distraction. Minimal yet insignificant improvement in stenotic canal area was evident with distraction. The presence of posterior vertebral osteophytes was associated uniformly with poor improvement of space available in both stenotic canal and foramen.