An implant or endoprosthesis suitable to be implanted in human or animal tissue includes two (or more than two) parts to be joined in situ. Each one of the parts includes a joining location, the two joining locations facing each other when the device parts are positioned for being joined together, wherein one of the joining locations includes a material which is liquefiable by mechanical vibration and the other one of the joining locations includes a material which is not liquefiable by mechanical vibration and a structure (e.g. undercut cavities or protrusions) suitable for forming a positive fit connection with the liquefiable material. The joining process is effected by pressing the two device parts against each other and by applying ultrasonic vibration to one of the device parts when the two parts are positioned relative to each other such that the two joining locations are in contact with each other.

A geared cam expandable spinal implant. Rotational motion of a rotating portion is translated into linear motion of a yoke, which moves geared cams at the distal end of the implant to mate with, and walk along, teeth of corresponding racks. The walking of the gear cam teeth along the rack teeth creates a regular rate of implant expansion, reduces initial excessive expansion force applied to the implant, and provides fine adjustment of the expansion rate and force.

Deployable Euler Spiral Connectors (DESCs) are introduced as compliant deployable flexures that can span gaps between segments in a mechanism and then lay flat when under strain in a stowed position. This paper presents models of Euler spiral beams combined in series and parallel that can be used to design compact compliant mechanisms. Constraints on the flexure parameters of DESCs are also presented. Analytic models developed for the force-deflection behavior and stress were compared to finite element analysis and experimental data. A spinal implant and a linear ratcheting system are presented as illustrative applications of DESCs.

A placeholder for vertebrae or vertebral discs includes a tubular body, which along its jacket surface has a plurality of breakthroughs or openings for over-growth with adjacent tissue. The placeholder includes at least a second tubular body provided with a plurality of breakthroughs and openings at least partially inside the first tubular body. The first and second tubular bodies can have different cross-sectional shapes, can be are arranged inside one another by press fit or force fit or can be connected to each other via connecting pins and arranged side by side to one another in the first body.

A placeholder for vertebrae or vertebral discs includes a tubular body, which along its jacket surface has a plurality of breakthroughs or openings for over-growth with adjacent tissue. The placeholder includes at least a second tubular body provided with a plurality of breakthroughs and openings at least partially inside the first tubular body. The first and second tubular bodies can have different cross-sectional shapes, can be are arranged inside one another by press fit or force fit or can be connected to each other via connecting pins and arranged side by side to one another in the first body.

A geared cam expandable spinal implant. Rotational motion of a rotating portion is translated into linear motion of a yoke, which moves geared cams at the distal end of the implant to mate with, and walk along, teeth of corresponding racks. The walking of the gear cam teeth along the rack teeth creates a regular rate of implant expansion, reduces initial excessive expansion force applied to the implant, and provides fine adjustment of the expansion rate and force.

The present invention relates to a discal annular assistance device and the surgical instruments necessary for the insertion and removal thereof. This new device assists the annulus fibrosus following the exeresis of the nucleus pulposus of a lumbar intervertebral disc, to stop accelerated progression towards the discoligamentous instability of a vertebral unit operated on for a nucleus pulposus hernia.

A method of placing an implant for intervertebral fusion between adjacent vertebral bodies in a patient includes inserting the implant in a space between the adjacent vertebral bodies such that both a first intervertebral spacer body and a second intervertebral spacer body contact each of the adjacent vertebral bodies. The first intervertebral spacer body is spaced apart from the second intervertebral spacer body. An expandable container portion of the implant disposed between the first intervertebral spacer body and the second intervertebral spacer body is filled with fill material such that the expandable container expands to contact each of the adjacent vertebral bodies.

A method of placing an implant for intervertebral fusion between adjacent vertebral bodies in a patient includes inserting the implant in a space between the adjacent vertebral bodies such that both a first intervertebral spacer body and a second intervertebral spacer body contact each of the adjacent vertebral bodies. The first intervertebral spacer body is spaced apart from the second intervertebral spacer body. An expandable container portion of the implant disposed between the first intervertebral spacer body and the second intervertebral spacer body is filled with fill material such that the expandable container expands to contact each of the adjacent vertebral bodies.

A method and apparatus can include: a delivery tool having an insertion mandrel; an implant having a distal segment coupled to a proximal segment, the proximal segment having a proximal segment upper and a proximal segment lower, the distal segment having a distal segment upper and a distal segment lower, the implant including: a straight configuration based on the insertion mandrel being extended through the proximal segment and the distal segment, and a curved configuration based on the insertion mandrel being retracted from the distal segment; and an expansion mandrel configured for insertion into the implant, the implant including an expanded configuration based on the expansion mandrel being inserted between the proximal segment upper and the proximal segment lower, and being inserted between the distal segment upper and the distal segment lower.