Depuy Synthes Products, Inc.

Synthes Usa, LLC

Hfsc Company

Synthes Gmbh

André Schlienger

Robert Frigg

Peter Senn

Markus Buettler

Patrick Streff

Markus Büttler

Rainer Ponzer

Bryan James Griffiths

Samuel Leuenberger

Robert J Schoutens

Marcello Memmolo

Kai Stephan

Daniela Pricope

Dankward Höntzsch

Christian Raehle

Senn Peter

Described herein is a surgical nail in the form of an intramedullary nail with a central axis made from a material M with a tensile strength F, compressive strength F, density &#x3c1;and modulus of elasticity E. The nail has a transverse bore extending transversely to the central axis and having a cross-sectional profile F and a transverse axis, the cross-sectional profile F having a maximum length a that runs in the direction of the central axis and a maximum width b that runs perpendicular to the length. An insert with the longitudinal axis, made from material m and having a modulus of elasticity e that is smaller than the modulus of elasticity E of material M, can be introduced into the transverse bore. The insert also has a length L that runs in the direction of its longitudinal axis and satisfies the condition L&#x3e;0.2 D.

Surgical nail

The surgical nail, here in the form of an intramedullary nail, has a central axis, a longitudinal borehole with a diameter D extending coaxially with the central axis, a casing with an inner surface and a transverse borehole, extending transversely to the central axis with the cross-sectional profile F and the borehole axis. A component, which narrows the cross-sectional profile F, is provided in the longitudinal borehole in the region of the transverse borehole. By these means, the clearance, which is usually present between the medullary nail and the locking screws that have been introduced therein, can be eliminated without risk and an improved holding force as well as an improved guiding effect between the locking screw and the medullary nail can be achieved.

A system and method are for bone fixation. A radially expandable sleeve is inserted over an elongated shaft of a bone screw. The bone screw and radially expandable sleeve are inserted into a transverse opening extending through a bone fixation device positioned in a bone until the radially expandable sleeve is fully housed within the transverse opening. The bone screw is further screwed into the bone relative to the radially expandable sleeve to cause expansion of the radially expandable sleeve within the bone fixation device, thereby locking the sleeve to the bone fixation device.

Bone screw

Expandable fixation assemblies, expandable cranial fixation assemblies, and expandable intervertebral implant assemblies are provided for securing structures to bone and for securing bones and/or bone segments with respect to each other. An expansion member can be moved through at least a portion of an expandable fixation body, thereby causing expansion of the expandable fixation body, such that bone engagement features of the expandable fixation body engage surrounding structure, such as bone.

Expandable fixation assemblies

A locking screw for an intramedullary nail having at least one transverse hole. The locking screw has a central longitudinal axis and includes a screw shank, which is at least partially provided with an external thread, and a screw head. The diameter of the screw head is greater than the outer diameter of the external thread, and the screw head includes a passage extending generally parallel to the longitudinal axis of the screw and the external thread. The passage is configured to receive a longitudinal wedge element. As a result, any gap between the locking screw and the intramedullary nail is eliminated and the screw is wedged in position in the transverse hole of the intramedullary nail.

Locking screw for an intramedullary nail

A surgical nail in the form of an intramedullary nail with a central axis, consisting of a material M with the tensile strength F, the compression strength F, the density &#x3c1;and the modulus of elasticity E. The nail has at least at least one transverse borehole extending transversely to the central axis with the cross-sectional profile F, where the cross-sectional profile F has a maximum length a in the direction of the central axis and a maximum width b perpendicularly thereto. The nail also includes a longitudinal bore, which extends coaxially with the central axis, and a wall, as well as an insert with a longitudinal axis, which can be introduced within the longitudinal bore of the nail into the region of the transverse borehole. The insert is formed of a material m, which has a lower modulus of elasticity e&#x3c;E than does the material M.

The invention concerns a bone screw having a distal end and a proximal end, which has the distinguishing features a shaft with a core diameter 'k' and having an external thread with an external diameter 'd'. The external diameter &#x201c;d&#x201d; of the thread or the core diameter &#x201c;k&#x201d; of the shaft tapers in a middle region of the shaft from a larger dimension &#x201c;d&#x201d; or &#x201c;k&#x201d; respectively towards the proximal end to a smaller dimension &#x201c;d&#x201d; or &#x201c;k&#x201d;, respectively, where &#x201c;d&#x201d; and &#x201c;k&#x201d; do not equal zero. Further, the shaft is provided with a concentrically disposed, radially expandable sleeve, and the sleeve being positioned on the part of the shaft which has the smaller external diameter &#x201c;d&#x201d;. The bone screw may be introduced into a transverse borehole of a medullary pin. The medullary pin is provided with a continuous cannulation, which extends coaxially with the longitudinal axis of the medullary pin and has an external diameter Dand a wall thickness W. The transverse borehole may have a diameter D, which is larger than das well as larger than d. In one embodiment, diameter Dmay be approximately 90% of the diameter dof the sleeve. The sleeve may be inserted completely into the transverse borehole and, with the flange, is in contact with the wall of a facet of the transverse borehole.

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Arlesheim, Switzerland

André Schlienger