Osteochondral implant procedure

[0001] This invention relates to an improved surgical procedure for implanting tissue from a cadaver/autograft bone into a recipient site at an anatomical area of a patient.

[0002] There are several surgical procedures in place in which host tissue is replaced with cadaver/autograft tissue. For example, in osteochondral replacement, hip and shoulder arthroscopies, ankle and TMJ procedures, a cadaver/autograft tissue is harvested for implanting in the host bone. In these procedures it is essential that the cadaver/autograft tissue match the anatomic surface of the host bone. More specifically, the tissues must be properly mapped to ensure congruent anatomic surfaces between the host and the cadaver/autograft tissues.

[0003] According to an embodiment of the invention, a process to map anatomic structures is provided to facilitate accurate harvesting of cadaver/autograft tissue using various imaging modalities, computer modeling and automated database selection of tissue.

[0006] The present invention will be described, for the purpose of example, in connection with an osteochondral replacement, it being understood that it is equally applicable to procedures involving other areas of the anatomy such as hip and shoulder arthroscopies, as well as ankle and TMJ procedures.

[0007] Referring to FIG. 1 of the drawing, the reference numeral 10 refers, in general, to a knee of a human including a femur 12 and a tibia 14 whose respective chondral areas are in close proximity. A cartilage 16 extends over a portion of the chondral area of the femur 12, and a meniscus 18 extends between the cartilage and the tibia 14. The patella, as well as the tendons, ligaments, and quadriceps that also form part of the knee 10, are not shown in the interest of clarity.

[0008] It will be assumed that a portion of the cartilage 16 extending over a chondral area of the femur 12, has been damaged and removed by the surgeon, or has worn away, leaving a defect, or recipient site, 12a. Thus, the procedure according to an embodiment of the invention will be described in connection with implanting a tissue from another area of the patient, from a donor, or from a cadaver in the recipient site.

[0009] To this end, one or more openings (not shown) are formed at the recipient site 12a and extend from the condyle of the recipient site 12a into the corresponding chondral area of the femur 12. Each opening is adapted to receive a tissue in a manner to be described. The tissue(s) is harvested from another area of the patient/recipient, such as an undamaged non-load bearing area of the femur or tibia, or from a corresponding area of a donor or cadaver in accordance with known techniques. The tissue(s) is sized so as to be implantable in the opening(s) at the recipient site in accordance with known techniques, and an embodiment of the invention involves mapping of the cadaver/autograft tissues and the recipient site to ensure congruent anatomic surfaces.

[0010] To this end, and referring to FIG. 2, a computer readable medium is provided that is encoded with a computer program including instructions for performing several steps that are described below.

[0011] According to step 10, the position of the recipient site is initially identified based on anatomical structures and the site is oriented to a common datum.

[0012] According to step 12, image data of the recipient site is obtained using magnetic resonance imaging and/or computed tomography (CT scan and CAT scan).

[0013] According to step 14, a three-dimensional model of the recipient site is constructed based on the image data.

[0014] According to step 16, the location and geometric boundaries of the cadaver/autograft tissue is determined.

[0015] According to step 18, image data of the tissue is obtained using magnetic resonance imaging and/or computed tomography (CT scan and CAT scan).

[0016] According to step 20, a three-dimensional model of the tissue is constructed based on the image data obtained in step 18.

[0017] According to step 22, the tissue is properly sized by driving computerized, numerically-controlled machine tools or robotics based on the image data obtained in step 18 and the model of step 20. According to step 24, a geometric analysis is made to determining an appropriate geometric match of the tissue with the recipient site based on the above models as well as data stored in a database.

[0018] According to step 26, the recipient site is prepared by image guidance based on the model of the site obtained in step 14 so that the site will accept the tissue.

[0019] After the above has been completed, the tissue is harvested based on the geometric match of step 24, above, and the harvested tissue is implanted in the recipient site.

[0020] As stated above, the replacement of tissue in the knee has been described above for the purposes of example only, it being understood that it is equally applicable to procedures involving other areas of the anatomy such as hip and shoulder arthroscopies, as well as ankle and TMJ procedures.

[0021] It is understood that a computer network can serve as the computer-readable medium described above. Such a network is shown, in general by the reference numeral 30 in FIG. 3, and includes a computer 32 associated with the computer readable medium identified in the drawing so as to implement the steps listed above. It is understood that the computer readable medium can be distributed across many different mechanisms, e.g., a first part stored in a first memory unit of a first computer, a second part stored in a second memory unit of a second computer, and so on.

[0022] Those skilled in the art will readily appreciate that many variations and modifications of the embodiment described above can be made without materially departing from the novel teachings and advantages of this invention. Accordingly, all such variations and modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts a nail and a screw are equivalent structures.