Canal clearance in burst fractures using the AO internal fixator.

The purpose of this study was to evaluate the ability of posterior distraction delivered by the AO internal fixator to effect a satisfactory reduction of the intraspinal fragments in burst fractures. The overall decompression achieved was from an initial compromise of 54% to a residual encroachment of 40%. Canal clearance proved most effective when carried out in the first 4 days, with an initial canal compromise of between 34 and 66%. The extent of improvement, even in this group, was not dramatic, with an average of 31% encroachment still remaining, with some cases as high as 50%. Therefore, we recommend that when canal clearance is essential, anterior decompression is the treatment of choice.