A bone plate includes a bone-contacting surface, an upper surface opposite the bone-contacting surface, and a hole having a circumference and extending from the upper surface to the bone-contacting surface. The hole includes a first portion having a plurality of substantially parallel lips, each lip extends around the circumference of the hole and defines a diameter of the hole. The diameters of the hole, as defined by the lips, decrease in a direction from the upper surface to a center of the hole and increase in a direction from the center of the hole toward the bone-contacting surface.

A fastener, for example a bone screw, is sized to pass into an aperture of an implant, for example, a bone plate, the fastener having an anchor portion engageable with body tissue, and a head portion formed by an assembly of an insert and an anchor extension. The insert and anchor extension cooperate to form a reduced dimension passable into the aperture, and an expanded dimension not passable out of the aperture. The size of the assembly may be configurable, for example, by tabs, ramped surfaces, or an expanding diameter of a threadable insert.

A bone plate system is provided that includes bone plates and bone anchor assemblies for being inserted into bone plate bores to secure the bone plates to one or more bones. In one aspect, the bone plate system includes a bone anchor assembly having a locking cap and a locking fastener connected to a head portion of a bone anchor. The bone anchor assembly is driven into a bone plate bore before the locking fastener is shifted to expand the locking cap and fix the bone anchor assembly within the bore. In another aspect, the bone plate system includes a bone anchor assembly having a locking cap that deflects radially inward due to contact with the bone plate at large bone anchor assembly insertion angles. In addition, a bone anchor assembly having a preassembled condition with a locking cap resisting back out of a locking fastener.

Bone plate systems are provided for surgical implants and bone repair. The bone plate is multi-tiered for receiving bone anchors screws for securing a plurality of bones or bone fragments in a desired relationship. The plate members include throughbores for receiving a pivot base therein, with head ends of the bone anchors being secured in the pivot bases. The throughbores may permit and define a translation path for the pivot base and the bone anchor secured therein relative to the plate. Pivot members extending between the pivot base and the plate member facilitate pivoting and optional translation of the pivot base relative to the plate. With the bone anchor seated within the pivot base, an apparatus for inhibiting screw back out is employed.

A driver-specific back-out prevention mechanism is disclosed that includes a screw and a body. A first driver can be used for coupling and decoupling the screw with the body, and a second driver can only be used for adjusting the position of the screw in the receiving body. The body includes a cavity for receiving a head of the screw, with the cavity having an inward flange. The screw includes upper and lower sockets, with a channel extending though the head from the lower socket and a lock body disposed in the channel. Engagement with the first driver allows the locking body to move such that the fastener can be inserted and removed from the body. Engagement with the second driver displaces the locking body such that the locking body interferes with the flange such that screw fastener cannot be removed from the body by the second driver.

The present invention provides a method for stabilizing a fractured bone. The method includes positioning an elongate rod in the medullary canal of the fractured bone and forming a passageway through the cortex of the bone. The passageway extends from the exterior surface of the bone to the medullary canal of the bone. The method also includes creating a bonding region on the elongate rod. The bonding region is generally aligned with the passageway of the cortex. Furthermore, the method includes positioning a fastener in the passageway of the cortex and on the bonding region of the elongate rod and thermally bonding the fastener to the bonding region of the elongate rod while the fastener is positioned in the passageway of the cortex.

A fastening device for surgical holding systems includes a holding element and a fastening element with a ball joint, which can be locked by way of rotating an eccentric ring in the holding element. The joint socket defines a joint inner surface of the ball joint and the joint head a joint outer surface of the ball joint. When the eccentric ring clamps the joint head with respect to the joint socket, the position of three contact locations of the ball joint which lock the ball joint are unambiguously defined due to the shape of at least one of the three elements: joint socket, joint head and eccentric ring.

A fastener, for example a bone screw, is sized to pass into an aperture of an implant, for example, a bone plate, the fastener having an anchor portion engageable with body tissue, and a head portion formed by an assembly of an insert and an anchor extension. The insert and anchor extension cooperate to form a reduced dimension passable into the aperture, and an expanded dimension not passable out of the aperture. The size of the assembly may be configurable, for example, by tabs, ramped surfaces, or an expanding diameter of a threadable insert.

A bolster system having a first bolster device, a second bolster device, and an adjustable tether that includes a one-way pre-tied slideable adjustment knot. The adjustment knot is at a first position prior to insertion of the first bolster device into a passageway in one or more bones. The second bolster device includes a body portion having an outer portion that is sized to be received in the passageway and/or in an aperture of a bone plate. The body portion also includes a channel that is sized to accommodate recessed and/or embedded placement of the pre-tied slideable adjustment knot. The second bolster device can also include an oversized plate portion that abuts against a cortex of a bone or a wall of a bone plate. The second bolster device can also include a threaded member or retention tab that lockingly secures the second bolster device to a bone plate.

The invention encompasses a bone screw for use in the human body including a shaft having a threaded region along at least a portion of its length and a screw head including a locking mechanism to secure the screw, for example to a bone plate. In certain embodiments, the thread has an outer diameter dimensioned to pass through the screw hole in the implant. The screw head is configured to cooperatively engage at least a portion of the screw hole of the implant so as to prevent the screw from coming out of the implant and avoided soft tissue damage and other complications associated with unintended screw removal.