Prosthesis (i.e. – artificial body members) – parts thereof – or ai – Implantable prosthesis
Reexamination Certificate
1996-11-14
2001-01-30
Mancene, Gene (Department: 3738)
Prosthesis (i.e., artificial body members), parts thereof, or ai
Implantable prosthesis
C128S898000, C424S484000
Reexamination Certificate
active
06179871
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the repair of joints of the human body, and is more particularly concerned with a method for repairing damaged cartilage and with means, especially the particular biodegradable scaffolding, utilized in carrying out the method.
PRIOR ART
The inability of adult articular cartilage for repair has been well recognized and has stimulated major interest in orthopaedic research. Even though considerable progress has been made in the field of articular reconstructive surgery, successful management of large chondral and osteochondral defects and degenerative lesions is still a challenge to the orthopaedic surgeon.
Current treatment is directed at replacement of articular surfaces with total joint reconstructions when sufficient destruction has occurred. A far more preferable approach would be to remedy or replace the articular cartilage defects before progressive and debilitating arthritis has occurred.
The number of individuals with symptomatic, identifiable, and potentially treatable cartilage defects is at least an order of magnitude greater than those who currently undergo some form of total joint arthroplasty.
For example, extrapolation of the published research findings for arthroscopic surgery of the knee in the United States would lead to an estimate of significant cartilage damage of the knee in over 250,000 patients. Numbers far greater than this are treated with nonsteroidal anti-inflammatory medication (NSAID) until their disease has progressed to the stage that a total joint arthroplasty is justifiable.
Multiple research centers in industry and academia are currently involved in pursuing a successful treatment for full thickness cartilage lesions. While some approaches are promising, there are currently no commercially viable treatment alternatives to date. The current approaches can be summarized into a few basic categories:
1. Abrasion arthroplasty
2. Chondroplasty
3. Drilling into the subchondral plate
4. Transplantation of autograft chondrocytes
5. Application of a variety of scaffolding materials including, collagen, polymers, polyglycolic acid, carbon fiber
6. Full thickness osteochondral allograft transplants
7. Continuous passive motion
8. Perichondrium transplants
Previous studies have shown that chondrocytes from an allogenic source cultured in a composite collagen gel/fibrillar matrix could be used successfully to repair cartilage surface defects in a rabbit knee joint model (Grande et al; 1987). However, it would be clinically superior to be able to repair these defects by mobilizing the intrinsic repair response to push stem cells toward a chondrogenic lineage by the use of growth factors known to be mitogenic to such cells. Recent studies have shown that both periosteum and bone marrow have cellular populations that can be isolated in tissue culture and can form cartilage both in vivo and in vitro (Nakahara et al; 1990). Miura et al. (1992) have shown that exposure of periosteal tissue to transforming growth factor beta (TGF
b
) in culture enhances chondrogenesis. Additional studies have shown the potent effect of fibroblast growth factor on connective tissue. The temporal sequence and bioavailability of growth factors in a wound repair model of articular cartilage are poorly understood.
In the publication,
TREATMENT OF DEEP CARTILAGE DEFECTS IN THE KNEE WITH AUTOLOGOUS CHONDROCYTE TRANSPLANTATION
, Brittberg et al. disclose the performance of autologous chondrocyte transplantation in 23 people with deep cartilage defects in the knee. Healthy chondrocytes obtained from an uninvolved area of the injured knee during arthroscopy were isolated and cultured in the laboratory for 14 to 21 days. The cultured chondrocytes were then injected into the area of the defect. The defect was covered with a sutured periosteal flap taken from the proximal medial tibia. Patients were followed for 16 to 66 months. Two years after transplantation 14 of the 16 patients studied with temporal condylar transplants had good to excellent results, with two of the patients requiring a second operation because of severe central wear in the transplants.
The idea that a magnetic field may have application to chondrogenesis or repair of a cartilage defect or treatment of arthritis is not new. However, to date, despite considerable research, no current approach is actually being used clinically for treatment of cartilage defects. The applications of magnetically related patents may be grouped into the following categories:
(1) The use of opposing magnets to act as an artificial joint.
(2) Application of a fluctuating magnetic field to induce chondrogenesis.
(3) Application of a magnetic field to influence the release of an active agent from a scaffolding.
(4) Creation of magnetic microspheres for intravascular delivery of a tagged agent, most commonly a chemotherapeutic agent for treatment of cancer.
(5) Contrast agents for NMR (nuclear magnetic resonance) imaging enhancement.
Magnetic means have previously been utilized in the laboratory technique of the prior art.
Senyei and Widder U.S. Pat. No. 4,230,685 (1980) describe a method for magnetic separation of cells utilizing magnetic microspheres. Claim is made for the preferential selection of a group of cells. A polymer mix is described.
Gordon U.S. Pat. No. 4,731,239 (1988) proposed a method for enhancing NMR imaging by use of ferromagnetic, paramagnetic, or diamagnetic particles composed of a number of constituents. This approach built on his previous patents U.S. Pat. No. 4,303,636 and U.S. Pat. No. 4,136,683 and U.S. Pat. No. 4,106,488. This series of patents deals with NMR image improvement and particles which are administered intravenously, the goal being to define metabolic diseases or malignant states. Gordon has an additional patent, 1988 U.S. Pat. No. 4,735,796 in which he proposes the use of ferromagnetic, diamagnetic or paramagnetic particles useful in the diagnosis and treatment of disease. In this use, he proposes to use the magnetic particles to enhance the destructive capability of an external field to treat inflammatory arthritis.
Similarly, Widder U.S. Pat. No. 4,675,173 (1987) proposed a method of magnetic resonance imaging of the liver and spleen using ferromagnetic microspheres given intravenously. Widder had a subsequent patent, 1989 U.S. Pat. No. 4,849,210 entitled “Magnetic resonance imaging of liver and spleen with superparamagnetic contract agents”.
Prior Art with Arthroscopically Applied Techniques
Shah U.S. Pat. No. 5,263,987 (1993) proposed applying a series of small plugs to the damaged cartilage surface, replacing a joint utilizing a plurality of joint surface members which are attached to a prepared surface arthroscopically. This approach seeks to create an artificial joint by a series of tack-like structures composed of artificial materials similar to an artificial knee replacement. This is not similar to my approach, but because the implants are inserted arthroscopically, it is mentioned.
Prior Art with Magnetically-tagged Microspheres
Yen et al. U.S. Pat. No. 4,157,323 (1979) proposed using metal containing polymeric functional microspheres for laboratory separation of labelled cells, but also concentration within the body for treatment of a malignant tumor by applying a magnetic field to the location.
Morris U.S. Pat. No. 4,331,654 (1982) proposed the use of magnetically localizable biodegradable lipid microspheres for delivery of drugs.
Molday U.S. Pat. No. 4,452,773 (1984) described colloidal sized particles composed of magnetic iron oxide which could be covalently bonded to antibodies, enzymes and other biological molecules for use in labelling and separating cells, cellular membranes and other biological particles. He describes a specific particle which I do not use and applies this to a different use.
Widder U.S. Pat. No. 4,345,588 (1982) described a method of delivering a therapeutic agent to a target capillary bed. In his case, the agent was administered intravascularly and given for the purpose of delivering an oncolytic agent to a mali
Mancene Gene
O'Hara Kelly
The Firm of Hueschen and Sage
LandOfFree
Means for cartilage repair does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Means for cartilage repair, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Means for cartilage repair will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2452185