Analyse biomécanique de stratégies d'instrumentation chirurgicale du rachis scoliotique

Scoliosis is a three-dimensional deformation of the spine which severe cases are usually treated by spinal instrumentation and fusion. Since the introduction of recent advanced instrumentation systems, the surgeon has a wide range of possibilities to achieve the surgery, such as various implants, diverse rod shape possibilities as well as intraoperative reduction maneuvers. Hence, the complexity of their surgical decision-making process has considerably increased.

The purpose of this study is twofold: the first part aims to document, analyze and classify the preoperative planning strategies for the posterior instrumentation of scoliotic spines. Afterward, the second part is to use a computer assisted surgery simulator to evaluate the effects of different instrumentation constructs and fusion levels for the same scoliotic cases.

In the first part of the project, 32 experienced fellows of the Scoliosis Research Society and members of the Spinal Deformities Study Group provided the detailed preoperative planning for five AIS patients with various scoliotic curves. Instrumentation planning of each surgeon was done using a graphical worksheet.

There exists a large variability of pre-operative instrumentation strategy in AIS within experienced orthopedic spine surgeons. It may be attributed to different objectives for correction, to personal surgeon's preferences and to the current lack of clearly defined strategies with modern instrumentation systems. Based on our results, this variability of instrumentation strategies within experienced surgeons produced rather different results. This study compares for the first time the effect of instrumentation strategies on the same patients, which is possible only with such a spine surgery simulator. This questions the criteria for optimal configuration and standards to objectively design the best surgical construct. A spine surgery simulator represents a powerful analytical tool to rationalize the surgical operations and thus provide optimal surgery results for a specific patient. (Abstract shortened by UMI.)