Bone screw
First Claim
1. A bone screw comprising:
- a screw head, a threaded shaft portion having a longitudinal axis and a free end opposite to said screw head, a longitudinal bore extending along said longitudinal axis through said threaded shaft portion, said longitudinal bore comprising a flared portion at said free end, at least two slits formed in said threaded shaft portion in the region of said flared top portion, said slits extending parallel said longitudinal axis, an expanding member comprising a to portion forming a top of said bone screw and a shaft extending through said longitudinal bore, and locking means provided at said top portion and at said threaded shaft portion for locking said top portion in said threaded shaft portion.
3 Assignments
0 Petitions
Accused Products
Abstract
A bone screw (1) having a threaded shaft portion (2) and a head (3) is provided. In order to ensure a good fastening capability of the bone screw even in soft bone material the bone screw has a longitudinal bore (5) extending along the longitudinal axis of the threaded shaft portion (2) and having a portion (7) which flares towards the free end (6) opposite to the head (3). Slits (8) extending parallel to the longitudinal axis are provided in this portion of the threaded shaft portion. An expanding member (20) comprises a top portion (22) forming the top (22) of the bone screw (1) and a shaft (21) adjacent thereto extending into the longitudinal bore (5). The threaded shaft portion is provided with notches at its inner wall adjacent to the flared portion (7) of the longitudinal bore (5), the notches surrounding the longitudinal bore (5) in a defined region thereof. When expanding the bone screw within the bone, the top portion (22) is pulled into the longitudinal bore (5) in such a manner that a peripheral edge (25) at the top portion (22) engages the notches (9) of the threaded shaft portion (2). This expands the end of the bone screw (1) screwed into the bone.
212 Citations
9 Claims
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1. A bone screw comprising:
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a screw head, a threaded shaft portion having a longitudinal axis and a free end opposite to said screw head, a longitudinal bore extending along said longitudinal axis through said threaded shaft portion, said longitudinal bore comprising a flared portion at said free end, at least two slits formed in said threaded shaft portion in the region of said flared top portion, said slits extending parallel said longitudinal axis, an expanding member comprising a to portion forming a top of said bone screw and a shaft extending through said longitudinal bore, and locking means provided at said top portion and at said threaded shaft portion for locking said top portion in said threaded shaft portion. - View Dependent Claims (2, 3, 4, 6, 7, 8)
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5. A bone screw comprising:
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a screw head, a threaded shaft portion having a longitudinal axis and a free end opposite to said screw head, a longitudinal bore extending along said longitudinal axis through said threaded shaft portion, said longitudinal bore comprising a flared portion at said free end, at least two slits formed in said threaded shaft portion in the region of said flared portion, said slits extending parallel to said longitudinal axis, an expanding member comprising a top portion forming a top of said bone screw and a shaft extending through said longitudinal bore, and locking means provided at said top portion and at said threaded shaft portion for locking said top portion in said threaded shaft portion, where said top portion comprises a first, substantially conical portion which tapers towards said shaft, and a second portion adjacent to said first portion, said second portion tapering towards said top of said bone screw, said substantially conical first portion positively fitting into said flared portion.
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9. A bone screw comprising:
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a screw head, a threaded portion having a longitudinal axis and a free end opposite to said screw head, a longitudinal bore extending along said longitudinal axis through said threaded shaft portion, said longitudinal bore comprising an internal flared portion at said free end, at least two slits formed in said threaded shaft portion in the region of said flared portion, said slits extending parallel to said longitudinal axis, an expanding member comprising extending a top portion forming a top of said bone screw and a shaft extending through said longitudinal bore, and locking means provided at said top portion and at said threaded shaft portion for locking said top portion in said threaded shaft portion.
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Specification