title: Elastic resistance of the spine: Why does motion preservation surgery almost fail?
abstract: Single metamere motility should not be interpreted merely as a movement on the 3 planes but also, and above all, as elastic resistance to dynamic stress on these 3 planes. In the light of this consideration, the aim of motion preservation is to neutralize excessive movements while preserving the physiological biomechanical properties of the metamere involved to interrupt the progression of degenerative processes and to prevent adjacent segment disease. Despite the fact that a myriad of devices have been developed with the purpose of achieving dynamic neutralization of the spine, there are now some doubts regarding the true efficacy of these devices.
authors.affiliation: Alessandro Landi, Department of Neurology and Psychiatry, Division of Neurosurgery, University of Rome "Sapienza", 00181 Rome, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Landi
keywords: Biomechanics; Disc prosthesis; Dynamic implant; Elastic resistance; Interspinous device