The State-of-the-art knowledge on isthmic spondylolisthesis

Abstract

The widespread general belief is that isthmic spondylolisthesis is nothing more than a simple slip of the spine in the saggital plane and that the effect of the slip affects only lumbosacral area. That thinking stands in contrast with current knowledge on anatomy of the spino-sacro-pelvic region in individuals with isthmic spondylolisthesis. This knowledge changed our way of thinking of isthmic slips. Isthmic spondylolisthesis is now recognized a more complex pathology which is not limited to a simple slip. Until recently we did not appreciate the role of sacro-pelvic abnormalities in the etiology and assessment of isthmic spondylolisthesis. Recent radiological studies of the sacro-pelvic anatomy in spondylolisthesis led to conclusion that a local pathology in the sacro-pelvic region affects the anatomical relationships between spine and pelvis and this in turn results in disturbances of the posture and saggital balance of the body. In other words: isthmic slip being a local pathology may result in more global effect distant to sacro-pelvic area. This „local pathology” may affect global body posture and imbalance in the saggital plane. Recent years observe the awareness that radiological studies of isthmic slips should take into consideration not only a grade of the slip measured according to Me yerding. In addition some quantitative parameters of sacro- and spino-pelvic anatomy should be analyzed and assesed. Isthmic slip being the local pathology may produce apparently global effect which is saggital imbalance and abnormalities of the posture. And this is the key issue of isthmic spondylolisthesis which changed our thinking of this pathology and surgical management. The latter is focused on rather surgical correction of local kyphosis than reduction of the slip. The results is correction of local spino-pelvic anatomy and therefore the whole body posture which is the final aim of spine surgery. Along with correction of posture such management results in improvement in pain an neurological symptoms. The authors present and discuss parameters of sacro-pelvic and spino-pelvic balance used in diagnosis and assesment of isthmic spondylolisthesis. They also present modern classifications of isthmic slips based on criteria of spino-pelvic parameters as well as the evolution of classification systems beginning with historical classification by Meyerding. The authors intend to draw attention of specialists dealing with spondylolistheis to the modern approach in isthmic slip. This approach is not yet widely used in clinical practice including the field of spinal surgery. The new approach in unde rstanding the isthmic spondylolisthesis made us to introduce studies on body posture and balance with the use of Zebris system in our Institution (Medical Faculty of Rzeszów University). Preliminary results of this study led to opening of doctoral thesis in our Department of Physiotherapy.