Surgery – Instruments – Orthopedic instrumentation
Patent
1988-12-01
1990-09-18
Hafer, Robert A.
Surgery
Instruments
Orthopedic instrumentation
606 57, 606 59, 606 61, 128 69, A61B 1760
Patent
active
049574957
DESCRIPTION:
BRIEF SUMMARY
The invention concerns a device for setting a spinal column with damaged vertebrae, said device consisting of an adjustable arm on a guide shaft and another fixed arm, each of said arms bearing a hollow receiving piece adjustable in two planes for an extension rod which connects to a bone screw.
A device for setting a spinal column with damaged vertebrae is known in which the arms situated on the guide shaft are flexed, said arms bearing threaded pins attached at the end by a hinge, said pins bearing a receiving sheath that can be turned and fastened with a wing nut.
The specific manner in which setting is accomplished, and, in particular, the way the receiving sheath is mounted and fastened down, do not, however, correspond to the requirements which an operator must make on such an instrument, especially with a view toward easy handling.
The purpose of the invention, therefore, is to improve the device for setting a spinal column with damaged vertebrae in such a way as to permit easy handling.
This is achieved in the invention in that each arm has an articulated mid-piece with two hinges, wherein a bracket for the hollow receiving piece is hinged onto the articulated mid-piece, said bracket being in the form of a cylindrical piece with a tangential hole that can be fixed in place.
A setting screw to hold the extension rod in place is mounted at an acute angle to the tangential hole. The cylindrical piece is axially adjustable and can be fixed in an end position.
In an especially advantageous version, the bracket has a perpendicular threaded pin, said pin having a notch plate on one end and at some distance from it a nut which can be turned on the thread, whereby the hollow receiving piece is mounted between the nut and the notch plate in a way that it can be turned and adjusted axially.
The tangential hole 16 receives the extension rod 17. The extension rod 17 is fastened with the set screw 18 which is mounted at an acute angle to the tangential hole 16. The shape of the hollow receiving piece, i.e., as a settable cylindrical piece with a tangential hole makes the device easier to handle, because the parts to be mounted and the parts to be adjusted are readily accessible.
In addition, because of the articulated mid-piece 5 and 5a and the circumstance that the cylindrical piece can be adjusted on the threaded pin 10 the extension piece can be set in any position, so that the extension rods 17 and 17a mounted on the bone screw 19 can also be set accordingly, which effectuates a corresponding setting of the bone screws screwed into the healthy vertebrae.
The special shape of the extension rod and the attached bone screw also represent an improvement in the handling of the device by the operator.
This is achieved in that the extension rod has a recessed configuration 20 which is occupied by the bone screw 19. The bone screw accordingly has a correspondingly shaped profiled piece 21 on its head, with a grid or knurled surface 22 mounted on the top side of said profiled piece 21. The profiled piece 21 is fastened in the recessed configuration 20 by a screw 23 situated at an acute angle to the axis of the extension rod 17 (FIG. 1).
The recessed configuration 20 has a more than semi-circular shape, so that the bone screw 19 with its profiled piece 21 can be longitudinally inserted or withdrawn (FIG. 3).
If the vertebrae 24 are set with this device, this position must be made stationary. This is done with a setting rod 25 made up of the telescoping pieces 26 and 27. The two parts are set by virtue of the circumstance that the inserted part 26 has setting notches 28. The other sleeve-shaped telescoping piece 27 can be firmly fastened to the inserted part in that pressure is exerted with special tongs on the sleeve-shaped telescoping piece in the region of the setting notches, thereby pinching the pieces together. A perforated board, in the shape, for example, of a U-track piece, can serve as an accessory, said board having holes the same distance apart as the setting notches (FIGS. 4 and 5).
The setting rod has on
REFERENCES:
patent: 2238870 (1941-04-01), Haynes
patent: 2439995 (1948-04-01), Thrailkill
patent: 4548199 (1985-10-01), Agee
patent: 4572170 (1986-02-01), Cronk et al.
patent: 4573455 (1986-03-01), Hoy
patent: 4611586 (1986-09-01), Agee et al.
patent: 4733657 (1988-03-01), Kluger
Kluger, Gerner; Mechanik des Fixateur, 1986.
Hafer Robert A.
Rooney Kevin G.
LandOfFree
Device for setting the spinal column does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for setting the spinal column, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for setting the spinal column will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1569716