IMPLANT FOR BONE FIXATION WITH MULTI-AXIAL HEAD AND METHOD OF IMPLANT INSTALLATION Russian patent published in 2009 - IPC A61B17/70 

FIELD: medicine.

SUBSTANCE: invention relates to medicine. Implant for bone fixation contains body, head, fixing olive and holding ring. Body contains means for bone fixation with fixation axis. Body also contains stretched part, head containing passage with passage axis and side opening. Head also contains channel made with thread, whose axis is not parallel to passage axis. Passage is made with possibility to accept rod for osteosynthesis through side opening, and channel with thread is made with possibility to accept fixing screw for fixation of rod for osteosynthesis in passage. Fixing olive interacts with stretched part of body. Holding ring interacts with head and is made with possibility to accept fixing olive. Fixing screw contains ball and socket made with possibility to fix rod in passage providing definite spacing of rod in passage around, at least, one axis parallel to passage axis. Fixing olive and holding ring are made with possibility to fix head on body providing definite spacing of head relative to body around at least one axis, not parallel to fixation axis. Fixing olive and holding ring together with ball and socket provide definite spacing of head relative to body around fixation axis, even when rod is inserted into passage. Two versions of installing implant for bone fixation, containing body. Body contains means for bone fixation with thread with fixation axis, stretched part with cylindrical part with tread and conic part, head, fixing olive, interacting with stretched part of body, nut and holding ring. Head contains passage, side opening and channel with thread. Passage is made with possibility to accept rod for osteosynthesis, containing contact site. Channel with thread is made with possibility to accept fixing screw, containing ball and socket with base with facet. Nut contains drilled opening with thread, interacting with cylindrical part with thread of stretched part of body. Holding ring interacts with head and is made with possibility to accept fixing olive. Method in both versions includes the following stages: introduction of rod for osteosynthesis through side opening into passage, rotation of fixing screw for placing base with facet of ball and socket on contact site of rod for osteosynthesis for holding rod for osteosynthesis in passage, rotation of nut for contact with fixing olive and holding of head providing movement of head around fixation axis. Final technique for first version is screwing in of means for bone fixation with thread into vertebra for lifting body and vertebra and rotation of nut for blocking body head in specified position. Final technique for second version is tightening the nut for lifting body and vertebra and blocking head and body in specified position.

EFFECT: reduction of limitations imposed on spinal column during correction of the latter and controlling degree of spondilolisthesis reduction.

17 cl, 6 dwg