Changes in the length of the sacrospinous and sacrotuberous ligaments induced by Salter osteotomy: A computer simulation

Abstract

Severe developmental dysplasia of the hip may be treated by a Salter osteotomy. This osteotomy separates the origins of the sacrotuberous and sacrospinous ligaments from their insertions, thus changing the length of these ligaments. This study uses a multibody computer model in order to quantify this effect in relation to three different surgical parameters: lateral wedge height, wedge insertion angle and osteotomy height. The model, created in MSC.Adams, was based on medical images of an 8-year-old girl with severe dysplasia of both hips. Further data analysis was performed in the MATLAB matrix calculation environment. Every combination of surgical parameters that was tested, resulted in both ligaments getting shortened with the lateral wedge height having the strongest influence on these length changes. Thus, a Salter osteotomy may remove the stabilizing effects of these ligaments, but ligament strain does not appear to occur. © 2009 Springer Berlin Heidelberg.