Prosthetic Intervertebral Disk

摘要

An intervertebral disk prostheses for the total replacement of an intervertebral disk of the lumbar and cervical spine has an upper plate having upwardly projecting formations anchoring it to an upper vertebra on its upper face and a concavity on its inner face surrounded by an edge. A lower plate is provided with downwardly projecting formations anchoring it to a lower vertebra on its lower face and a flat inner face surrounding a groove extending front-to-back. A middle plate between the upper and lower plate has on its upper face a convexity that is identically or differently shaped to the concavity on the inner face of the upper plate and a ridge extending front-to-back surrounded by a flat lower face of the middle plate. The ridge has flanks and the groove houses the ridge of the middle plate and permits the ridge to slide front-to-back in the groove.

主权项

1. An intervertebral disk prosthesis for the total replacement of an intervertebral disk of the lumbar and cervical spine, the prosthesis comprising
an upper plate having an upper face formed with upwardly projecting formations for anchoring the upper plate to an upper vertebra and a lower face formed with a concavity surrounded by an edge; a lower plate having a lower face formed with downwardly projecting formations for anchoring the lower plate to a lower vertebra and a flat upper inner face forming and surrounding at least one guide groove that extends front-to-back; an intermediate sliding plate arranged between the upper and lower plate having an upper face formed with a convexity surrounded by an edge engaging the concavity on the lower face of the upper plate and a flat lower face formed with and surrounding at least one guide ridge having flanks, extending front-to-back, and engaging in the at least one guide groove of the lower plate in such a manner that the at least one guide ridge can slide in a straight line between front and back in the at least one guide groove, and the at least one guide ridge is made of a semi-elastic composition and is formed with at least one open slit so that the guide ridges can be elastically deformed and fitted into the respective at least one guide groove, and the convexity of the intermediate sliding plate, the concavity of the upper plate and the surrounding edges of convexity and concavity permit limited ranges of motion.