SURGICAL-TREATMENT OF DEGENERATIVE SPONDYLOLISTHESIS IN THE LUMBAR SPINE - NO REPOSITION WITHOUT PRIOR DECOMPRESSION

In the present note, the cause of root compression in cases with degen erative lumbar spondylolisthesis is discussed in order to clarify the best method of surgery and to avoid iatrogenic damage of the cauda equ ina if a transpedicular fusion is going to be performed. The root comp ression is due to osteophytes growing out from the upper articular fac ets and from the upper ridge of the lamina of the lower vertebra. Ther efore, the repositioning of the anteriorly displaced vertebra by the i nstrumentation could lead to the squeezing of the cauda equina between the withdrawn vertebral body and the degeneratively enlarged and hype rtrophic facet joints of the lower vertebra. The reposition (even if i ncomplete) must always be preceded by decompression on both sides, eve n if radicular complaints are unilateral.