| Intervertebral prosthesis -> Monitor Keywords |
|
|
  Intervertebral prosthesisUSPTO Application #: 20080103597Title: Intervertebral prosthesis Abstract: Intervertebral prosthesis (1), in particular intervertebral disk prosthesis, with a central axis (6) and comprising A) a first prosthetic component (2) having a first apposition surface (4) and a first inner surface (7), both being disposed transversely to the central axis (6) and having a spherical recess (11); B) a second prosthetic component (3) having a second apposition surface (5) and a second inner surface (8) both being disposed transversely to the central axis (6) and having a calotte (9) congruent with said recess (11); C) the first and second prosthetic components (2;3) being connectable in an articulated manner by means of the calotte (9) which may be slidably received in the recess (11); whereby D) the first and second prosthetic components (2;3) have a width B and a length H each being transverse to the central axis (6), said first and second prosthetic components (2;3) further comprise a longitudinal axis L1, respectively L2 extending parallel to the respective length H; and whereby E) the length H is greater than the width B, such that the prosthetic components (2;3) may be put into a position in the intervertebral space in which the two longitudinal axes L1 and L2 intersect each other at an angle α>0° when being projected in a plane being orthogonal to the central axis (6). (end of abstract) Agent: Stroock & Stroock & Lavan LLP - New York, NY, US Inventors: Beat Lechmann, Robert Frigg, Andreas Appenzeller USPTO Applicaton #: 20080103597 - Class: 623 1716 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20080103597. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS REFERENCE TO RELATED APPLICATION [0001]This Application is a national stage application under 35 U.S.C. 371 based on International Application Serial No. PCT/CH2005/000774 filed on Dec. 27, 2005 for "INTERVERTEBRAL PROSTHESIS". FIELD OF INVENTION [0002]The invention relates to an intervertebral prosthesis, in particular to an intervertebral disk prosthesis. DESCRIPTION OF RELATED ART [0003]In recent years, intervertebral prostheses have gained wide acceptance in vertebral column surgery. These prostheses are inserted anteriorly or antero-laterally between the vertebral bodies in place of the intervertebral disk. This implantation technique represents a certain risk, as the access leads through the abdominal region. There is a risk that greater vessels in the region of the anterior lumbar column may be injured. From a biomechanical point of view, the anterior access has the disadvantage that the anterior longitudinal ligament of the vertebral column has to be partially or entirely dissected in order to enable the insertion of the prosthesis. This dissection will result in a certain instability of the vertebral column and may, in the worst case, facilitate a ventral migration of the prosthesis. In order to reduce the risk of a migration of the prosthesis, different anchoring means are used which fix the prosthesis on the cover plates of the adjacent vertebral bodies. [0004]An intervertebral prosthesis of this type is known from WO 01/01893 MARNAY. This known prosthesis comprises two plates having a ball-and-socket joint and two differently shaped projections for anchoring the prosthesis in two vertebrae. In said document it is also proposed to minimize the height of the prosthesis during insertion in that the two components are made to engage with each other. Despite the provided fixation means, there is a risk for the prosthesis to migrate back along the insertion channel. SUMMARY OF THE INVENTION [0005]The invention is intended to provide a remedy for this. The present invention is directed to an intervertebral prosthesis which for implantation purposes is decomposable into two parts and which is inserted into the intervertebral space via transforaminal and/or extraforaminal accesses. The articulation of the intervertebral prosthesis preferably consists of a spherical calotte and a corresponding spherical recess. During the implantation of the two prosthetic components, which are implanted separately into the intervertebral space via the two separate accesses, the two longitudinal axes of the prosthetic components cross each other in the intervertebral space. By freely selecting the angle .alpha. between the longitudinal axes of the two prosthetic components, the position of the point of intersection can be adjusted in a sagittal direction with the insertion points remaining unchanged. This adjustment may be planned preoperatively by means of CT or X-ray photographs or may be defined intraoperatively by means of guide wires and/or templates. [0006]The advantages achieved by the invention reside essentially in the fact that due to the intervertebral prosthesis of the invention: [0007]an individual adjustment of the intervertebral prosthesis for any pair of vertebral bodies is possible. Thus, an individual anatomy of the motion element can be taken into account; [0008]the individual segmental motion sequences may be preoperatively taken into account and defined by the surgeon; [0009]an uncomplicated and secure operation technique is made possible compared to implants which are inserted into the intervertebral space in a completely assembled state; [0010]the risk of an antero-posterior and/or lateral migration of the prosthesis due to flexion/extension or lateral bending of the spinal column is minimized; [0011]the natural intervertebral disk has to be only partially removed, i.e. in order to implant the two prosthetic components in the intervertebral space (intervertebral disk) it is only necessary to clear two paths of a width B and a length H, so that only the apposition surfaces of the two prosthetic components are in bone contact with the respective end plates. The rest of the intervertebral disk remains in situ and prevents the intervertebral prosthesis from migrating laterally and/or antero-posteriorly once the two prosthetic components have been implanted. [0012]In a preferred embodiment, the ratio of the length H of the prosthetic components to the width B thereof is between 3:1 and 5:1. The advantages of this design essentially are that in order to implant the two prosthetic components in the intervertebral space (intervertebral disk) it is only necessary to clear two narrow paths of a width B and a length H. [0013]In another embodiment, the intervertebral prosthesis is realized in two pieces, i.e. the calotte is made in one piece with one of the two prosthetic components. [0014]In a further embodiment, the intervertebral prosthesis is realized in three pieces, so that the calotte forming the third piece is connectable with one of the two prosthetic components. The advantage of this design is to be seen essentially in the fact that the plate and the calotte may be realized by using different materials, so that it is possible to achieve optimal sliding properties for the articular surfaces. Preferred materials for the plates are titanium or a titanium alloy as well as PEEK or coated variants, and for the calotte highly crosslinked polyethylene (X-UHMWPE), an alloy of cobalt and chrome, or a ceramic material. [0015]In again a further embodiment, the intervertebral prosthesis is realised in at least three pieces and comprises an articular shell including the recess, whereby said articular shell is attachable to one of said first and second prosthetic components as a third piece. The advantage of this design is to be seen essentially in the fact that the plate and the calotte may be realised using different materials, so that it is possible to achieve optimal sliding properties for the articular surfaces. [0016]In a further embodiment, the calotte and the articular shell consist of a material combination made of metal and plastic. The advantages of this embodiment are that it is possible to use proven combinations of joint replacement materials such as, for example, highly crosslinked polyethylene (X-UHMWPE) and an alloy of cobalt and chrome. Further advantages are to be seen in the fact that low frictional forces are achievable for the relative displacement of the articular surfaces and that a compensation of axial impact loads can be achieved. [0017]In yet another embodiment a ceramic-to-ceramic articulation is used. [0018]In a further embodiment the surfaces of the calotte and the recess are coated with titanium carbide or with amorphous carbon (ADLC) therewith permitting a substantial reduction of the coefficient of friction. [0019]In another embodiment, at least the calotte is made of a memory metal or of a material capable of swelling (e.g. hydrogels). [0020]In still another embodiment at least the calotte is made of a flowable, thermosetting material. The monomers, comonomers, homopolymers, oligomers, or mixtures which contain such thermosetting, flowable substances may suitably be selected from the group of: [0021]a) polyethylene glycols, preferably polyethylene glycol(di)-acrylates; [0022]b) n-vinylpyrrolidones; and [0023]c) vinyls, preferably vinyl alcohols; and [0024]d) styrenes. [0025]The polymers thus obtained may be widely varied as regards to their elasticity. The advantages of these designs are to be seen essentially in the fact that due to the reduced volume of the joint, the insertion of the intervertebral prosthesis becomes less invasive, the increased volume being best suited for achieving an optimal articular function. Continue reading... Full patent description for Intervertebral prosthesis Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Intervertebral prosthesis patent application. Patent Applications in related categories: 20080103596 - Artificial-intervertebral-disk insertion jigs, jig set, and artificial intervertebral disk - The artificial intervertebral disk has a constitution comprising: a core material comprising a structure which is either a multiaxis three-dimensional woven structure or knit structure made of organic fibers arranged along three or more axes or a structure comprising a combination of the woven structure and the knit structure; and ... ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Intervertebral prosthesis or other areas of interest. ### Previous Patent Application: Artificial-intervertebral-disk insertion jigs, jig set, and artificial intervertebral disk Next Patent Application: Ankle prosthesis with neutral position adjustment Industry Class: Prosthesis (i.e., artificial body members), parts thereof, or aids and accessories therefor ### FreshPatents.com Support Thank you for viewing the Intervertebral prosthesis patent info. IP-related news and info Results in 0.15562 seconds Other interesting Feshpatents.com categories: Novartis , Pfizer , Philips , Polaroid , Procter & Gamble , |
||
