An implant intended to be at least partially implanted into a bone by means of an implant part having an endosseous surface, wherein said endosseous surface comprises at least one zone having a surface topography exhibiting: an arithmetic mean peak curvature parameter (Spc) less than or equal to 1 μm.sup.1, a density of peaks parameter (Spd) greater than or equal to 0.020 μm.sup.−2.

Assemblies of one or more implant structures make possible the achievement of diverse interventions involving the fusion and/or stabilization of the SI-joint and/or lumbar and sacral vertebra in a non-invasive manner, with minimal incision, and without the necessitating the removing the intervertebral disc. The representative lumbar spine interventions, which can be performed on adults or children, include, but are not limited to, SI-joint fusion or fixation; lumbar interbody fusion; translaminar lumbar fusion; lumbar facet fusion; trans-iliac lumbar fusion; and the stabilization of a spondylolisthesis.

Methods and apparatus for immobilizing a synovial joint, such as a sacroiliac (SI) joint are disclosed. In one form, a multipiece fixation device, such as a dowel, includes multiple expandable fasteners that are configured to fix adjacent bones of a synovial joint with respect to one another. The expandable fasteners include expansion portions that are expanded radially via insertion of another expandable fastener or an expansion device to fix the expandable fasteners to the bone. The fixation device may be configured to provide for compression or distraction of the bones of the synovial joint while at the same time stabilizing the joint.

A receiver assembly includes a receiver having a first channel, a through-space with internal recesses beneath a guide and advancement structure, and internal ridges projecting inwardly below the internal recesses. The assembly also includes an insert having a second channel, side structures protruding laterally outward below top surfaces, and opposed lower extensions extending downwardly below the second channel, with the insert being loadable into the through-space with the second channel in non-alignment with the first channel. The insert is the non-threadably rotatable within the through-space to align the second channel with the first channel and to move the side structures into the internal recesses above the internal ridges, with subsequent downward displacement of the insert within the through-space causing the opposed lower extensions to engage the capture head of a bone anchor with a frictional engagement that inhibits the bone anchor from moving upward within the through-space.

The present invention provides, in one aspect, a bone fixation device, the bone fixation device having a shaft, the shaft including a drive end and a tip end, at least a portion of the shaft configured to anchor into bone. The shaft further includes a first non-resorbable section extending from the tip end of the shaft, a second non-resorbable section extending from the drive end of the shaft, and a resorbable section. The resorbable section includes a tip side and a drive side, the resorbable section is between the first non-resorbable section and the second non-resorbable section, with the tip side of the resorbable section coupling to the first non-resorbable section and the drive side coupling to the second non-resorbable section.

A receiver of a bone anchor includes a base and a pair of upright arms extending upward from the base to define an open channel for receiving an elongate rod, with the upright arms having opposed interior surfaces with a discontinuous guide and advancement structure formed therein and side outer faces opposite the opposed interior surfaces extending downward across the base to a bottom of the receiver. A horizontally-elongated upper tool engaging groove is formed into the side outer face of each upright arm that extends to at least a front face or back face of the upright arm and that includes a downwardly-facing upper surface, an upwardly-facing lower surface, and an outwardly-facing inner surface. A vertical tool-engaging groove is also formed into the side outer face of each upright arm that extends downward from a top surface of the upright arm through to a level below the lower surface of the upper tool engaging groove.

A bone anchoring device for anchoring and fixing vertebrae and for insertion into a pedicle canal is disclosed. A fork head having a U-shaped cut-out in a side view for a correction element, a connecting rod with two legs which terminate proximally and form a threaded section which engages with an adjusting means, wherein the legs have a radially outer circumferential area in which at least one retaining groove or other instrument attachment point is formed for gripping the fork head by a handling instrument, and a bone anchoring element with a proximal end facing away therefrom in the axial direction such that a distal direction and a proximal direction are also defined. The bone anchoring element has a spherical head at the proximal area, and the bone anchoring element is polyaxially pivotable with respect to the fork head, and has a pressure piece distally partially surrounds the bone anchoring element at the ball head, and proximally forms a seat for the connecting rod.

A medical implant system is described for inhibiting infection associated with a joint prosthesis implant. An inventive system includes an implant body made of a biocompatible material which has a metal component disposed on an external surface of the implant body. A current is allowed to flow to the metal component, stimulating release of metal ions toxic to microbes, such as bacteria, protozoa, fungi, and viruses. One detailed system is completely surgically implantable in the patient such that no part of the system is external to the patient while the system is in use. In addition, externally controlled devices are provided which allow for modulation of implanted components.

Implant assemblies, systems, and methods for stabilizing a joint between a superior vertebra and an inferior vertebra may include a plate member coupled to an interbody spacer with at least one fastener that extends superiorly or inferiorly from the implant assembly to anchor within a vertebral body and stabilize the joint. Inserters and methods of insertion may also be included to facilitate fixation of various implant assemblies within the intervertebral space of the joint between the superior vertebra and the inferior vertebra.

The invention is a half pin for use in conjunction with external fixators, in which the half pin has a thin hydroxyapatite coating over a substantial portion thereof, a not-sharp hole-finding tip, and a variable pitch pattern in the threaded portion of the half pin. The hydroxyapatite coating must be thin—40-70 microns, deposited by plasma spray—and with limited porosity and pore size, and must extend not only over all the threads of the half pin but also a substantial portion of the unthreaded shaft proximal to the threaded end. The invention also includes a pin cube for use in association with the coated half pins. Wires may also be coated with the hydroxyapatite coating.