Abstract
Several studies have reported that remodelling of the spinal canal occurs in lumbar burst fractures following non-operative treatment. Various theories have been proposed for spinal canal remodelling, including the possible effect of the oscillatory pulsations of the subdural space, but no studies have been done to evaluate this effect.
In a prospective study between September 1999 and April 2002, we evaluated 17 men and seven women, with a mean age of 35.25 years (19 to 59), who had sustained a burst fracture in the upper lumbar region. The fractures were at the L1 and L2 regions in 14 and 10 patients respectively. The epidural pressure and radiological appearances were initially evaluated approximately two weeks after injury, and again 12 months after injury. All patients were neurologically intact and treated non-operatively.
CT evaluation of the initial injury showed a mean initial canal compromise of 49.81% (22.3% to 80%) as measured by mid-sagittal diameter and 13.9% (8.2% to 16.9%) as measured by volumetric assessment, with a mean epidural pressure of 14.56mmHg (2.5 to 30.38). At follow-up 12 months later, the mean epidural pressure was -4.67mmHg (−1.1 to −8.9) and the mean canal compromise as measured by the mid-sagittal diameter and volumetric measurements on CT scan were 24.56% and 8.9% respectively.
Our data show that the epidural pressure was raised in acute burst fractures and reverts to normal with remodelling. We can conclude that the raised epidural pressure may be one of the mechanisms that contribute to the remodelling process.
The abstracts were edited by Prof. M.B.E. Sweet. Correspondence should be addressed to him at the Department of Orthopaedic Surgery, Medical School, University of the Witwatersrand, 7 York Road, Parktown, 2193 South Africa
