PREVENTION OF VERTEBRAL IMPLANT COMPRESSION Russian patent published in 2020 - IPC A61F2/46 A61F2/44 

FIELD: medicine.

SUBSTANCE: group of inventions relates to medicine. Disclosed is an implant for attachment between vertebrae, which includes an external part and an internal part. Outer part accommodates inner part. Outer part and inner part can move relative to each other, thus preventing rotation of inner part during extraction due to interaction of guide pins with guide groove. On the inner side of the expansion ring there is a thread, by means of which it mates with the thread on the outer side of the inner part. Expansion ring is installed coaxially relative to outer part and it also includes gear rim on its upper or lower side to provide drive of expansion ring. Safety element is a flat spring, located between the above external and internal parts and is conjugated with the appropriate ring gear of the expansion ring, which is used to provide the drive of the expansion ring. Cavity for disengagement between external part and inner part of implant is made with possibility of radial movement of safety element to provide possibility of expansion ring rotation. Also disclosed is an implant system for complete replacement of the intervertebral disc comprising the above expandable implant and an extension instrument comprising a profile of the holder for mating with an external recess of the external portion of the expandable implant. Expansion tool includes a central shaft inside the holder profile for radial movement of the safety element into the cavity between the outer and inner parts of the implant. On outer surface of shaft there is a toothed rim engaging with ring gear of expansion ring, so that expansion ring can turn when shaft is turned inside expansion tool.

EFFECT: inventions enable easy adaptation of the height of the prosthesis, while preventing compression or any unintentional change in height.

13 cl, 7 dwg