US 6,730,089 B2 · Nested closure plug and set screw with break-off heads

Abstract

A nested closure plug and set screw arrangement with break-off heads for securing a spinal fixation rod within to a bone screw includes a closure plug advanceable into an open channel of a bone screw and having a central threaded bore to receive a threaded set screw. The set screw is provided with a centrally positioned set point and a V-ring for cutting engagement with the surface of a clamped rod. The closure plug may be provided with a V-ring for the same purpose. The set screw V-ring is positioned and adapted to deform into engagement with the closure plug by engagement with the rod surface. By this means, the set screw and closure plug may be removed simultaneously. The closure plug and set screw have break-off installations which separate from their fasteners when pre-selected installation torques are exceeded.

Claims32

Dependent claims

A nested closure plug and set screw combination for securing a structural element within a receiver of a medical implant having a plug receiving opening, said combination comprising:

(a) a closure plug adapted to be interferingly positioned within the plug receiving opening of the structural element receiver so as to close the opening when in an installed configuration, said plug having a threaded bore formed therein;
(b) a threaded set screw operably threadably received in said bore of said plug and having a setting configuration wherein said set screw is in engagement with the structural element;
(c) said plug having a break-off plug head which operably breaks from said plug at a first preselected torque;
and
(d) said set screw having a break-off screw head that breaks from said set screw at a second preselected torque when in said setting configuration.

2 more elements

A nested closure plug and set screw arrangement for operably securing a structural element of a medical implant within a receiver having a plug receiving opening, said arrangement comprising:

(a) a closure plug adapted to be interferingly positioned within the plug receiving opening of the structural element receiver when in an installed configuration, said plug having a threaded coaxial bore formed therein;
(b) a threaded set screw threaded into said bore of said plug and into engagement with the structural element when in a setting configuration;
(c) said plug having a break-off plug head;
(d) said set screw having a break-off screw head;
(e) said closure plug including an external guide and advancement structure which is adapted to cooperate with complementary structure within the structural element receiver to operably interferingly position said plug within the plug receiving opening within the receiver, said guide and advancement structure enabling advancement of said plug into said installed configuration in response to rotation of said plug;
(f) said closure plug including a plug end interference feature which is shaped and positioned to operably cut into a surface of the structural element when in the installed configuration;
(g) said set screw including a screw end interference feature which is shaped and positioned to operably cut into a surface of the structural element in said setting configuration;
and
(h) at least one said set screw or said plug has a joining feature which forms a non-slip juncture of said plug and said set screw when said set screw is threaded into said setting configuration with the structural member to provide for simultaneous removal of said plug when said set screw is removed from said setting configuration.

6 more elements

Dependencies are inferred from the claim text.

Nested closure plug and set screw with break-off heads

Life of this patent

Nested closure plug and set screw with break-off heads

Life of this patent

Abstract

Claims32