TECHNICAL FIELD

The present disclosure relates generally to orthopaedic surgical instruments and, more particularly, to customized patient-specific orthopaedic surgical instruments.

BACKGROUND

Joint arthroplasty is a well-known surgical procedure by which a diseased and/or damaged natural joint is replaced by a prosthetic joint. For example, in a total knee arthroplasty surgical procedure, a patient's natural knee joint is partially or totally replaced by a prosthetic knee joint or knee prosthesis. A typical knee prosthesis includes a tibial tray, a femoral component, and a polymer insert or bearing positioned between the tibial tray and the femoral component. In a hip replacement surgical procedure, a patient's natural acetabulum is replaced by a prosthetic cup and a patient's natural femoral head is partially or totally replaced by a prosthetic stem and femoral ball.

To facilitate the replacement of the natural joint with a prosthesis, orthopaedic surgeons use a variety of orthopaedic surgical instruments such as, for example, cutting blocks, drill guides, milling guides, and other surgical instruments. Typically, the orthopaedic surgical instruments are reusable and generic with respect to the patient such that the same orthopaedic surgical instrument may be used on a number of different patients during similar orthopaedic surgical procedures.

The orthopaedic surgical instruments may also be customized to a specific patient. Such “customized patient-specific orthopaedic surgical instruments” are single-use surgical tools for use by a surgeon in performing an orthopaedic surgical procedure that is intended, and configured, for use on a particular patient. It should be appreciated that these instruments are distinct from standard, non-patient-specific orthopaedic surgical instruments that are intended for use on a variety of different patients. These customized patient-specific orthopaedic surgical instruments are distinct from orthopaedic prostheses, whether patient-specific or generic, which are surgically implanted in the body of the patient. Rather, customized patient-specific orthopaedic surgical instruments are used by an orthopaedic surgeon to assist in the implantation of orthopaedic prostheses.

SUMMARY

According to one aspect of the disclosure, a customized patient-specific surgical instrument includes a polymeric body including a bone-facing surface and an outer surface positioned opposite the bone-facing surface, a first bone-contacting segment coupled to the bone-facing surface and having a bone-contacting surface that is raised relative to the bone-facing surface, and a surgical guide defined by inner walls that extend from the outer surface to the bone-facing surface or to the bone-contacting surface of the bone-contacting segment. The bone-contacting surface defines a customized patient-specific first negative contour shaped to match and receive a corresponding first positive contour of the patient's bone. The first positive contour corresponds to a silhouette curve of a three-dimensional model of the patient's bone. The silhouette curve corresponds to a contour of the patient's bone captured in a first two-dimensional image that is used to generate the three-dimensional model. In an embodiment, the bone-facing surface is devoid of any negative contour shaped to match and receive a corresponding positive contour of the patient's bone.

In an embodiment, the surgical instrument further includes a second bone-contacting segment coupled to the bone-facing surface and having a bone-contacting surface that is raised relative to the bone-facing surface, wherein the bone-contacting surface of the second bone-contacting segment defines a customized patient-specific second negative contour shaped to match and receive a corresponding second positive contour of the patient's bone, wherein the second positive contour corresponds to a silhouette curve of the three-dimensional model that corresponds to a contour of the patient's bone captured in a second two-dimensional image that is used to generate the three-dimensional model. In an embodiment, the second bone-contacting segment is arranged generally perpendicular to the first bone-contacting segment. In an embodiment, the first two-dimensional image and the second two-dimensional image are captured in orthogonal imaging planes.

In an embodiment, the polymeric body includes a base and an elongated first arm coupled to the base, and the first bone-contacting segment extends from the base to a posterior end of the first arm. In an embodiment, the surgical instrument further includes a second bone-contacting segment coupled to the bone-facing surface and having a bone-contacting surface that is raised relative to the bone-facing surface, wherein the bone-contacting surface of the second bone-contacting segment defines a customized patient-specific second negative contour shaped to match and receive a corresponding second positive contour of the patient's bone, wherein the second positive contour corresponds to a silhouette curve of the three-dimensional model that corresponds to a contour of the patient's bone captured in a second two-dimensional image that is used to generate the three-dimensional model. The second bone-contacting segment extends generally perpendicular to the first bone-contacting segment from a lateral side of the first arm to a medial side of the first arm.

In an embodiment, the surgical instrument further includes a second bone-contacting segment coupled to the bone-facing surface, spaced apart from the first bone-contacting segment, and having a bone-contacting surface that is raised relative to the bone-facing surface, wherein the bone-contacting surface of the second bone-contacting segment defines a customized patient-specific second negative contour shaped to match and receive a corresponding second positive contour of the patient's bone and wherein the second positive contour corresponds to a silhouette curve of the three-dimensional model that corresponds to a contour of the patient's bone captured in the first two-dimensional image. The polymeric body further includes an elongated second arm coupled to the base, and the second bone-contacting segment extends from the base to a posterior end the second arm. The first bone-contacting segment is positioned on a medial side of the polymeric body and the second bone-contacting segment is positioned on a lateral side of the polymeric body. In an embodiment, the bone-facing surface is positioned between the first bone-contacting segment and the second bone-contacting segment, and the bone-facing surface is devoid of any negative contour shaped to match and receive a corresponding positive contour of the patient's bone.

In an embodiment, the surgical instrument further includes a third bone-contacting segment coupled to the bone-facing surface, spaced apart from the first bone-contacting segment and the second bone-contacting segment, and having a bone-contacting surface that is raised relative to the bone-facing surface, wherein the bone-contacting surface of the third bone-contacting segment defines a customized patient-specific third negative contour shaped to match and receive a corresponding third positive contour of the patient's bone, wherein the third positive contour corresponds to a silhouette curve of the three-dimensional model that corresponds to a contour of the patient's bone captured in the first two-dimensional image. The third bone-contacting segment is positioned between the first bone-contacting segment and the second bone-contacting segment.

In an embodiment, the surgical instrument further includes a fourth bone-contacting segment coupled to the bone-facing surface and having a bone-contacting surface that is raised relative to the bone-facing surface, wherein the bone-contacting surface of the fourth bone-contacting segment defines a customized patient-specific fourth negative contour shaped to match and receive a corresponding fourth positive contour of the patient's bone, wherein the fourth positive contour corresponds to a silhouette curve of the three-dimensional model that corresponds to a contour of the patient's bone captured in a second two-dimensional image, and a fifth bone-contacting segment coupled to the bone-facing surface and having a bone-contacting surface that is raised relative to the bone-facing surface, wherein the bone-contacting surface of the fifth bone-contacting segment defines a customized patient-specific fifth negative contour shaped to match and receive a corresponding fifth positive contour of the patient's bone, wherein the fifth positive contour corresponds to a silhouette curve of the three-dimensional model that corresponds to a contour of the patient's bone captured in the second two-dimensional image. The fourth bone-contacting segment extends generally perpendicular to the first bone-contacting segment from a lateral side of the first arm to a medial side of the first arm. The fifth bone-contacting segment extends generally perpendicular to the second bone-contacting segment from a lateral side of the second arm to a medial side of the second arm.

In an embodiment, the surgical guide includes a cutting slot defined by the inner walls. In an embodiment, the surgical guide includes a cylindrical bone-pin guide slot defined by the inner walls.

According to another aspect, a method for creating a patient-specific resection guide includes generating a three-dimensional model of a patient's bone based on a plurality of images, wherein each image views the patient's bone in a different imaging plane of a plurality of imaging planes, mapping the three-dimensional model to a plurality of silhouette curves, wherein each silhouette curve corresponds to a contour of the patient's bone captured in an image of the plurality of images, and determining a plurality of customized patient-specific negative contours based on the plurality of silhouette curves, wherein each customized patient-specific negative contour is shaped to match and receive a corresponding positive contour of the patient's bone, and wherein each positive contour corresponds to a silhouette curve of the plurality of silhouette curves. In an embodiment, the method further includes imaging the patient's bone in the plurality of imaging planes to generate the plurality of images.

In an embodiment, the method further includes generating a guide having a polymeric body including a bone-facing surface and an outer surface positioned opposite the bone-facing surface and a plurality of bone-contacting surfaces coupled to the bone-facing surface and raised relative to the bone-facing surface, wherein each bone-contacting surface defines a customized patient-specific negative contour of the plurality of patient-specific negative contours. In an embodiment, the bone-facing surface is devoid of any negative contour shaped to match and receive a corresponding positive contour of the patient's bone. In an embodiment, generating the guide includes molding the polymeric body. In an embodiment, generating the guide includes additively manufacturing the polymeric body.

In an embodiment, the polymeric body further includes a cutting guide defined by inner walls that extend from the outer surface to the bone-facing surface and to a bone-contacting surface of the bone-contacting segment.

In an embodiment, the method further includes attaching the plurality of bone-contacting surfaces of the guide to the patient's bone, wherein the negative contour of each bone-contacting surface contacts the patient's bone at a position of the corresponding positive contour of the patient's bone; and performing a surgical operation using the cutting guide in response to attaching the plurality of bone-contacting surfaces of the guide to the patient's bone.

