Anschlussdegeneration Langzeitkomplikation nach lumbaler Fusion

Abstract

BackgroundThe development of pathology at the adjacent segment after a lumbar or lumbosacral spinal fusion has been termed “Adjacent Segment Disease” (ASD). It is considered a potential late consequence of spinal fusion that can necessitate further surgical intervention and adversely affect outcomes. However, segmental fusion is commonly used as the gold standard in the treatment of progressed or high-grade degenerative lumbar instability despite the frequent degeneration. Another problem in the surgical treatment is that there are many different kinds of degenerative pathologies in the adjacent segment, e.g. spinal stenosis and spondylarthrosis, making it difficult for the surgeon to decide between decompression of the adjacent segment or extension of the spinal fusion. The aim of this review is to present the problem of ASD and to discuss it with the results of a recently completed retrospective epidemiological case-control study, long-term follow-up of mono- and bisegmental spinal fusion with an interlaminar implant used as a “Topping-off”, as well as with data from the literature. Materials and MethodsSelective literature review and summary of the results of the case-control study with mono- and bisegmental spinal fusion and a dynamic implant as a “Topping-off”. ResultsThere are many reasons for degeneration in the adjacent segment after lumbar spinal fusion. Frequently it occurs in association with a chronic instability due to a degenerative disc disease with herniation, spondylolisthesis, instability, arthrosis of the facet joints or spinal stenosis. Even the instrumentation, the length of the fusion, the sagittal malalignement, a lesion of the facet joints by setting the pedicle screws, the patient's age and preexisting degeneration or the “normal” process of degeneration of the adjacent segment are listed as potential risk factors. The retrospective study showed 43 months postoperatively partially significant clinical and radiological differences from the comparison group. The results showed a graded Range of motion (harmonic transition) of the fusion segments over the decompressed and with an interlaminar implant provided segment towards to the adjacent segment. An objective, radiological confirmation by randomized, prospective studies with larger patient groups is desirable. ConclusionThe ASD as a long-term consequence after lumbar fusion is frequent. If there is already a pathology in the adjacent segment with an indication for a decompression, it seems useful to provide this segment with a hybrid construction (fusion and dynamic stabilization following the fusion) to be able to do a greater decompression with simultaneous stabilization of the segment long-term.