[Biomechanical consequences of variations in artificial disc positioning. A finite element study on the lumbar spine].

Artificial disc prostheses are becoming more and more attractive for the treatment of degenerative disc diseases using non-fusion techniques. However, the influence of disc position within the intersegmental space on lumbar biomechanics has scarcely been investigated. A validated finite element model of the lumbar spine was used to investigate the effects of non-ideal implant positioning and orientation, which are more likely to occur using ventrolateral approaches. The model predicts, especially for lateral eccentricities, strongly increased lumbar loads. Therefore, great care should be taken in placing the implant in an optimal position.