Formae, Inc.

Other

Mansmann, Kevin A.

Kevin A Mansmann

Edward J Cheal

Peter Popper

A prosthetic implant replaces hyaline cartilage in a synovial joint with a flexible polymer sliding surface, preferably of hydrogel, on a segmented support with an array of adjacent segments to which the hydrogel is molded. Adjacent segments are laterally and angularly displaceable permitting the implant to conform to rounded or irregular surfaces or to be rolled or folded for arthroscopic placement. Tension cables threaded through segments along a circuit can cinch segments together for stiffening the supporting layer and/or the cable can pull the implant against a bone surface. Adjacent segments can have inter-engaged structures. In some embodiments the segments are carried on a flexible foil or fibrous sheet.

Rigid segmented flexible anchors

An prosthetic implant replaces hyaline cartilage in a synovial joint with a flexible polymer sliding surface, preferably of hydrogel, on a segmented support with an array of adjacent segments to which the hydrogel is molded. Adjacent segments are laterally and angularly displaceable permitting the implant to conform to rounded or irregular surfaces or to be rolled or folded for arthroscopic placement. Tension cables threaded through segments along a circuit can cinch segments together for stiffening the supporting layer and/or the cable can pull the implant against a bone surface. Adjacent segments can have inter-engaged structures. In some embodiments the segments are carried on a flexible foil or fibrous sheet.

A permanent non-resorbable implant allows surgical replacement of cartilage in articulating joints, using a hydrogel material (such as a synthetic polyacrylonitrile polymer) reinforced by a flexible fibrous matrix. Articulating hydrogel surface(s) are chemically treated to provide a negative electrical charge that emulates the negative charge of natural cartilage, and also can be treated with halogenating, cross-linking, or other chemical agents for greater strength. For meniscal-type implants, the reinforcing matrix can extend out from the peripheral rim of the hydrogel, to allow secure anchoring to soft tissue such as a joint capsule. For bone-anchored implants, a porous anchoring layer enables tissue ingrowth, and a non-planer perforated layer can provide a supportive interface between the hard anchoring material and the softer hydrogel material.

Implants for replacing cartilage, with negatively-charged hydrogel surfaces and flexible matrix reinforcement

Flexible cartilage-replacing implants are disclosed that use either or both of (1) enlarged peripheral rim components, and/or (2) elongated flexible reinforcing members that are embedded around the peripheral edge of an implant device. These types of anchoring devices, especially when used in combination, can provide flexible implants that can be implanted arthroscopically into synovial joints, for complete replacement of damaged cartilage segments.

Rim anchoring systems for flexible surgical implants for replacing cartilage

A surgical implant for replacing hyaline cartilage in a knee or other articulating synovial joint has an anchoring side on one side of the implant adapted for fixing the implant to one of the bones in the joint, and a bearing surface on the opposite side of the implant for lubricious rubbing and sliding contact with another bone in the joint. The anchoring side can be configured with an irregular surface for tissue ingrowth. The bearing side can include hydrogel. The implant can be rolled up from an original shape and surgically inserted by arthroscopic means, and opens into its original shape when released inside the joint.

Cartilage repair implant with soft bearing surface and flexible anchoring device

Implants with hydrogel layers reinforced by three-dimensional fiber arrays can replace hyaline cartilage. Such implants should replace an entire cartilage segment, rather than creating a crevice around a plug, so these implants must be thin and flat, they must cover large areas, the tips of any tufts or stitches must not reach the hydrogel surface, and they must be flexible, for arthroscopic insertion. The use of computerized stitching machines to create such arrays enables a redesigned and modified test sample to be made with no delays, and no overhead or startup costs. This provides researchers with improved tools for making and testing implants that will need to go through extensive in vitro, animal, and human testing before they can be approved for sale and use. Fiber-reinforced hydrogels also can be secured to strong shape-memory rims, for securing anchoring to bones.

Implants for replacing hyaline cartilage, with hydrogel reinforced by three-dimensional fiber arrays

Surgical tools are disclosed for minimally-invasive planing of bone surfaces that will support prosthetic implants, such as cartilage-repair implants. Such planing tools must create smooth surfaces that will closely fit the anchoring surface of an implant. Such tools can use a rotating cylindrical burr, partially covered by a cowl having adjustable components to control grinding depth and bone curvature. Burrs can be mounted on the ends of rotating shafts, or they can be angled, using drive-coupling interfaces. In other embodiments, shaver or burr tools can be supplemented by accessory-type devices (such as suction tubes, cautery tips, and pinchers) that can be extended beyond the normal working tip of a tool, to enable additional functions that will be useful during surgery.

Surgical tools with extendible and rotatable accessory components

Knotless suture anchors are disclosed for surgical use, which contain one or more types of ratcheting mechanisms that will allow a surgeon to pull a suture strand through an anchor device in one direction, without allowing the suture strand to travel or creep backward, in the other direction. This will allow a surgeon to emplace a number of such anchors in hard bone(s) or soft tissue(s), during installation of an implant device, while the various suture strands remain loose and do not interfere with proper positioning of the implant. When the implant device is roughly in position, the surgeon can gently 'snug' all of the suture strands (which preferably should be braided, to provide a non-smooth surface that will enable a stronger and more secure grip by the ratcheting mechanism), so that they will all reach a moderate plateau of gentle yet firm tension. After the surgeon has ensured that the implant is in proper position, with all of the anchoring sutures in a 'snug' status, a series of final tightening and tensioning steps can be carried out on all of the suture strands.

Adjustable racheting suture anchors

A semi-permeable membrane can be used to promote the surgical repair of cartilage in a damaged or diseased joint, such as a knee, hip, or shoulder. In one method, the semi-permeable membrane is secured to the 'articulating' surface (the exposed surface, as opposed to the 'anchoring' surface which rests on a condyle) of a resorbable fibrous matrix that has been seeded, before implantation, with chondrocyte or similar cells that generate cartilage. A membrane used in this manner can help protect the cells as they grow, reproduce, and secrete new cartilage inside the resorbable matrix. In another method, the semi-permeable membrane is secured to a slightly damaged surface of a cartilage segment that is suffering from a condition known as chondromalacia, without using an underlying implanted matrix or other device. In a slightly different use, a semi-permeable membrane as disclosed herein can be used in conjunction with a cell-growing scaffold that is being used to generate tissue to repair or supplement an internal organ, such as a liver, spleen, pancreas, or possibly a heart.

Semi-permeable membranes to assist in cartilage repair

A device for surgical implantation to replace damaged tissue in a joint (such as a meniscus in a knee) is created from a hydrogel that is reinforced by a three-dimensional flexible fibrous mesh. In a meniscal implant, the mesh is exposed at one or more locations around the periphery, to provide anchoring attachments that can be sutured, pinned, or otherwise securely affixed to tissue that surrounds the implant. The fibrous mesh should extend throughout most of the thickness of the hydrogel, to create an &ldquo;interpenetrating network&rdquo; (IPN) of fibers modelled after certain types of natural body tissues. Articulating surfaces which will rub and slide against cartilage should be coated with a hydrogel layer that is completely smooth and nonabrasive, and made of a material that remains constantly wet. This composite structure provides a meniscal implant with improved strength, performance, and wettability compared to implants of the prior art. This type of implant may also be useful in repairing other joints, such as shoulders, wrists, ankles, or elbows, and in repairing injured or diseased hands, fingers, feet, or toes.

Meniscus-type implant with hydrogel surface reinforced by three-dimensional mesh

A load-sharing resorbable scaffold is used to help transplanted chondrocytes or other cells generate new cartilage in a damaged joint such as a knee, hip, or shoulder. These scaffolds use two distinct matrix materials. One is a relatively stiff matrix material, designed to withstand and resist a compressive articulating load placed on the joint during the convalescent period, shortly after surgery. Due to the requirement for relatively high stiffness, this material must be denser and have less pore space than other matrices, so it will not be able to support highly rapid cell proliferation and cartilage secretion. The second material comprises a more open and porous matrix, designed to promote maximal rapid generation of new cartilage. In one preferred geometric arrangement, the stiffer matrix material is used to provide an outer rim and one or more internal runners, all of which can distribute a compressive load between them. The rim and runners create a cluster of internal cell-growing compartments, which are filled with the porous and open matrix material to encourage rapid cell reproduction and cartilage generation. These improved scaffolds can also have an articulating outer membrane with certain traits disclosed herein, bonded to and resting upon the upper edges of the runners and rim. The scaffold will support the membrane with a degree of stiffness and resiliency that allows the membrane to mimic a healthy cartilage surface. These scaffolds can be made of flexible materials, to allow them to be inserted into a damaged joint using arthroscopic methods and tools.

Resorbable scaffolds to promote cartilage regeneration

A flexible 'scaffold' envelope is disclosed which can be used to replace damaged cartilage in knees, shoulders, or other joints of a mammalian body. Designed for use in arthroscopic surgery, the envelope is sufficiently flexible to allow it to be rolled up or folded and inserted into a knee or other joint via a small skin incision. Before insertion, a segment of damaged cartilage is removed from a bone surface, and the bone surface is prepared, using various tools and alignment guides disclosed herein. After the envelope is inserted into the joint, it is unfolded, positioned properly, and anchored and cemented to a bone surface. After anchoring, the envelope is filled via an inlet tube with a polymeric substance that will set and solidify at body temperature. During filling and setting, the surgeon can manipulate the exterior shape of the scaffold envelope, to ensure that the implant will have a proper final shape after the polymer has cured into fully solidified form. Using these materials and methods, a synthetic replacement can be created for damaged or diseased cartilage, having a smooth surface and a non-rigid stiffness closely resembling natural cartilage. The entire procedure can use minimally invasive tools and methods, to avoid having to cut open and fully expose a joint that is being repaired. Various devices and methods are disclosed to facilitate this procedure, including tools and devices to help ensure proper arthroscopic preparation of large bone surfaces, and proper positioning, alignment, anchoring, and filling of a scaffold envelope.

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Paoli, PA, United States of America

Kevin A Mansmann