Biedermann, Motech Gmbh

Other

J&uuml;rgen Harms

Lutz Biedermann

An anchoring element with a screw ( ) comprising a threaded section ( ) and a head ( ) designed as a spherical segment-shaped section, and with a receiving portion ( ) for connecting the screw ( ) to a rod ( ), is provided. The receiving portion ( ) comprises a first end ( ) and a second end ( ) opposite the latter and a longitudinal axis ( ) passing through the two ends ( ). The receiving portion further comprises a bore ( ) coaxial with the longitudinal axis ( ), a first region adjoining the first end ( ) with an essentially U-shaped cross-section ( ) with two free arms ( ) comprising a thread for receiving the rod ( ) to be inserted, a region adjoining the other end ( ) for receiving the head ( ), and an element which exerts pressure on the rod ( ) or on the head ( ). In order that the screws can be used in situ for very different lengths, the threaded section ( ) and the head ( ) are designed as separate parts.

Anchoring element

A bone screw having a screw member ( ) possessing a threaded section ( ) and a head ( ) and a receiving part ( ) at the head end for receiving a rod to be connected to the bone screw is provided. The receiving part ( ) has on open first bore ( ) and a substantially U-shaped cross-section having two free legs provided with a thread. Furthermore, the receiving part has a second bore ( ) on the end opposite to the first bore ( ) whose diameter is greater than that of the threaded section ( ) and smaller than that of the head ( ). On the bottom of the first bore a seat for the head ( ) is provided. In order that the screw member can be pivoted to at least one side by an enlarged angle, the edge bounding the free end of the second bore ( ) viewed relative to the axis of the first bore ( ) is of asymmetric construction.

Bone screw

The invention relates to a bone screw and a tool for fixing same. A bone screw has a screw element ( ), comprising a screw shank ( ) and a screw head ( ), a cylindrical receiver part ( ) with a bore coaxial to the cylindrical axis coming from one end ( ) of the cylinder, an opening ( ) extending cross-wise to the cylindrical axis for receiving a rod ( ) to be connected to the bone screw, an inner thread ( ) at one end ( ) and a screw ( ) cooperating with it and also an outer thread ( ) at one end ( ) and a nut ( ) cooperating with it. Both threads ( ) are constructed as running in opposite directions. A fastening tool ( &prime;) acts as tool for fixing a bone screw, with a central shank ( ), which is constructed at one end for engagement with a screw or nut and at its other end has a first handle ( ), a sleeve-shaped shank ( ), surrounding the central shank ( ), which is constructed at one end for engagement with a screw or nut and at its other end has a second handle ( ), both shanks ( ) being rotatable with respect to one another.

Bone screw and fastening tool for same

A bone screw, known per se, with a thread section ( ) and a receiving part ( ) for receiving a rod ( ) to be connected to the bone screw is created. The connection and locking of the connection between bone screw and rod takes place via an outer nut ( ). So that the connection has the necessary strength and durability, the outer nut ( ) has on the inside a sleeve-shaped element ( ), having a predetermined inner measurement, the outer diameter of which is almost identical to or slightly smaller than the diameter of the bore ( ), and a pressure element ( ) arranged therein. The pressure element ( ) (sic) has at its end facing the floor of the bore ( ) a first section ( ), the outer measurement of which is larger than the predetermined inner measurement and which effects a widening of the element ( ) when pressure is exerted on the rod ( ) to be received.

Fixing element

There is provided a bone screw known per se, having a threaded portion ( ) and a reception part ( ) for receiving a rod ( ) to be connected to the bone screw. The securing and locking action of the connection between the bone screw and the rod is provided by an exterior nut ( ). To provide for the required strength and durability of the connection, the exterior nut ( ) comprises an inside sleeve-shaped element ( ) having a predetermined inner dimension and an outer diameter which is almost equal to or slightly less than the diameter of the bore ( ), and a pressure element ( ) arranged therein. The pressure element ( ) comprises a first section ( ) at its end facing the bottom of the bore hole ( ). The outer dimension of the first section is greater than the predetermined inner dimension and the first section causes the element ( ) to be expanded when pressure is exerted on the rod ( ) to be received.

A spacer for insertion between two vertebrae has a variable axial length. The spacer comprises a first sleeve-shaped shape member,and a second member,which is slidably guided within the first member in axial direction relative thereto for adjusting the overall length. The second member,comprises, on its outer portion facing the first member,, an axially extending portion having ratchet notch means,, and the first member,has an engagement member,cooperating with the ratchet notch means,for displacement to a desired overall length.

Growing community of inventors

Karlsruhe, Germany

Jürgen Harms

Growing community of inventors

Karlsruhe, Germany

J&uuml;rgen Harms

Jürgen Harms