PATIENT-SPECIFIC TOOLS AND IMPLANTS
A method for preparing a femoral neck for receiving a neck implant includes resecting a femoral head from a femoral neck of a patient according to a pre-operative patient-specific plan. The method also includes removing only cancellous bone from the femoral neck and proximal femoral bone of the patient using a patient-specific broach. The patient-specific broach has a three-dimensional cutting surface matching as a negative mold a cortical/cancellous bone interface surface of the femoral neck of the patient.
This application is a divisional of U.S. application Ser. No. 13/041,665 filed on Mar. 7, 2011.
The disclosure of the above application is incorporated herein by reference.
INTRODUCTIONThe present teachings provide a bone-preserving design for a hip prosthesis. More specifically, the present teachings are directed to patient-specific femoral neck implants and associated tools and methods
SUMMARYThe present teachings provide various methods, tools and implants for preparing a femoral neck to receive a neck implant.
The present teachings provide a method for preparing a femoral neck for receiving a neck implant. The method includes obtaining image data of a proximal femoral bone and femoral neck of a patient by a medical imaging method and constructing a three-dimensional image model of the proximal femoral bone and neck of the patient using the image data. The method further includes identifying a three-dimensional cortical boundary surface at an interface between cortical and cancellous bone of the patient using the image model. A patient-specific broach having a three-dimensional cutting surface closely matching and complementary to the cortical boundary surface of the patient using the image model is designed and manufactured.
Another method according to the present teachings includes resecting a femoral head from a femoral neck of a patient according to a pre-operative patient-specific plan. The method further includes removing only cancellous bone from the femoral neck and proximal femoral bone of the patient using a patient-specific broach having a three-dimensional cutting surface closely matching and complementary to a cortical/cancellous bone interface surface of the femoral neck of the patient.
The present teachings provide a femoral neck implant. The femoral neck implant includes a body for implantation into a femoral neck of a patient. The body has a patient-specific cross-section of variable size and shape along a longitudinal axis of the body and a patient-specific three-dimensional outer surface that closely nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of the femoral neck of the specific patient after removing only the cancellous bone from the femoral neck. The neck implant can include a neck portion extending from the body and configured for coupling with a femoral head implant.
The present teachings provide a femoral neck cutting tool, such as a broach for preparing a femoral neck for a femoral neck implant. The cutting tool includes a body having a patient-specific cross-section of variable size and shape along a longitudinal axis and a patient-specific three-dimensional outer cutting surface that closely nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of a femoral neck of the specific patient and configured for removing only the cancellous bone from the femoral neck of the patient. The cutting tool can include a non patient-specific coupling component for engaging a non patent-specific driver tool.
The present teachings also provide a patient-specific guide for preparing a femoral neck of a patient for receiving a femoral neck implant. The patient-specific guide includes a first wall having a first inner surface with a patient-specific inner bore therethrough, and a peripheral wall extending from the first wall. The first inner surface is configured to mate with a resected surface of the femoral neck. The peripheral wall includes a three-dimensional patient-specific peripheral inner surface configured to mate in only one position with an outer peripheral surface of the femoral neck after resection.
Further areas of applicability of the present teachings will become apparent from the description provided hereinafter. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present teachings.
The present teachings will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description is merely exemplary in nature and is in no way intended to limit the present teachings, applications, or uses.
The present teachings provide patient-specific tools and implants designed for a conservative hip procedure that conserves a portion of femoral neck of a specific patient.
As described in commonly assigned U.S. application Ser. No. 11/756,057, filed on May 31, 2007, during a preoperative planning, imaging data of the relevant anatomy of a patient can be obtained at a medical facility or doctor's office. The imaging data can include, for example, a detailed scan of a pelvis, hip, knee, ankle or other joint or relevant portion of the patient's anatomy. The imaging data can be obtained using MRI, CT, X-Ray, ultrasound or any other imaging system. The imaging data obtained can be used to construct a three-dimensional computer image of the joint and prepare an initial pre-operative plan that can include bone or joint preparation, including planning for resections, milling, reaming, broaching, implant selection and fitting, design of patient-specific guides, templates, tools and alignment protocol for the surgical procedure.
Computer modeling for obtaining three-dimensional computer images of the relevant patient's anatomy can be provided by various CAD programs and/or software available from various vendors or developers, such as, for example, from Materialise USA, Plymouth, Mich. The computer modeling program can be used to plan a preoperative surgical plan, including planning various bone preparation procedures, selecting or designing/modifying implants and designing patient-specific guides and tools including patient-specific prosthesis components, and patient-specific tools, including reaming, broaching, milling, drilling or cutting tools, alignment guides, templates and other patient-specific instruments.
The pre-operative plan can be stored in any computer storage medium, in a computer file form or any other computer or digital representation. The pre-operative plan, in a digital form associated with interactive software, can be made available via a hard medium, a web-based or mobile or cloud service, a cellular portable device to the surgeon or other medical practitioner, for review. Using the interactive software, the surgeon can review the plan, and manipulate the position of images of various implant components relative to an image of the anatomy. The surgeon can modify the plan and send it to the manufacturer with recommendations or changes. The interactive review process can be repeated until a final, approved plan, is sent to the manufacturer.
After the surgical plan is approved by the surgeon, patient-specific implants and associated tools, including, for example, alignment guides, cutting/milling/reaming/broaching or other tools for the surgical preparation of the joint or other anatomy portion of the specific patient can be designed using a CAD program or other three-dimensional modeling software, such as the software provided by Materialise, for example, according to the surgical plan. Computer instructions of tool paths for machining the patient-specific tools and/or implants can be generated and stored in a tool path data file. The tool path data can be provided as input to a CNC mill or other automated machining system, and the tools and implants can be machined from polymer, ceramic, metal or other suitable material depending on the use, and sterilized. The sterilized tools and implants can be shipped to the surgeon or medical facility for use during the surgical procedure.
Patient-specific components or tools or portions discussed below are generally constructed by a surgical plan approved by the surgeon using thee-dimensional images of the specific patient's anatomy and made to closely conform and mate substantially as a negative mold of corresponding portions of the patient's anatomy, including bone surfaces with or without associated soft tissue. MRI scans, for example, allow modeling of soft tissue, such as articular cartilage, and modeling of bone portions of different densities, such as inner surfaces matching cortical and cancellous bone, as discussed below.
The present teachings provide a bone-preserving design for a hip prosthesis and associated tools. The procedure can conserve as much of the natural femoral neck 82 of the patient as determined by the surgeon depending on the specific patient by providing a patient-specific femoral neck implant 100 for supporting a femoral head implant 150, as illustrated in
Referring to
Specifically, the neck implant 100 is designed during the pre-operative plan based on a three-dimensional computer model of the femoral neck 82 of the patient as reconstructed from MRI, CT, X-ray or other scans of the patient. Referring to
Referring to
Referring to
Referring to
The patient-specific neck implant 100, patient-specific broach 200 and other custom or non-custom tools are sterilized and shipped to the surgeon's site. Referring to
Referring to
The patient-specific broach 200, the patient-specific milling guide 600 and the patient-specific implant 100 can be manufactured from biocompatible materials using machining, rapid manufacturing by stereolithography, laser welding, computer-assisted manufacturing using numerical machining or robotic controllers. Patient-specific alignment and/or resection guides for resecting and removing the femoral head can also be designed from the image model and manufactured by the above methods according to the pre-operative plan for the patient.
The foregoing discussion discloses and describes merely exemplary arrangements of the present teachings. Furthermore, the mixing and matching of features, elements and/or functions between various embodiments is expressly contemplated herein, so that one of ordinary skill in the art would appreciate from this disclosure that features, elements and/or functions of one embodiment may be incorporated into another embodiment as appropriate, unless described otherwise above. Moreover, many modifications may be made to adapt a particular situation or material to the present teachings without departing from the essential scope thereof. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations can be made therein without departing from the spirit and scope of the present teachings as defined in the following claims.
Claims
1-20. (canceled)
21. A femoral neck implant comprising:
- a body for implantation into a femoral neck of a patient, the body having a patient-specific cross-section of variable size and shape along a longitudinal axis of the body and a patient-specific three-dimensional outer surface that nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of the femoral neck of the specific patient after removing only the cancellous bone from the femoral neck; and
- a neck portion extending from the body and configured for coupling with a femoral head implant.
22. The femoral neck implant of claim 21, wherein the neck portion is configured to be aligned along a patient-specific articulation axis.
23. The femoral neck implant of claim 21, further comprising a flange coupled to the body and configured for abutting a resected surface of the femoral neck of the specific patient.
24. The femoral neck implant of claim 21, wherein the body is sized to extend only into the femoral neck of the specific patient and has a patient-specific length.
25. The femoral neck implant of claim 21, wherein the femoral head implant is coupled to the neck portion and has a patient-specific shape.
26. The femoral neck implant of claim 21, in further combination with a femoral neck cutting tool comprising:
- a body having a patient-specific cross-section of variable size and shape along a longitudinal axis and a patient-specific three-dimensional outer cutting surface that nests and conforms complementarily to the cortical boundary surface corresponding to the cortical/cancellous bone interface surface of the femoral neck of the specific patient, wherein the body is configured for removing only the cancellous bone from the femoral neck of the specific patient to facilitate implantation of the femoral neck implant.
27. The femoral neck implant of claim 21, in further combination with a patient-specific guide for preparing the femoral neck of the specific patient for receiving the femoral neck implant, the guide comprising:
- a first wall having a first inner surface with a patient-specific inner bore therethrough, wherein the first inner surface is configured to mate with a resected surface of the femoral neck, wherein the patient-specific inner bore is configured for guiding a cutting tool to remove only the cancellous bone from the femoral neck to the cortical boundary surface corresponding to the cortical/cancellous bone interface surface of the femoral neck for receiving the femoral neck implant; and
- a peripheral wall extending from the first wall, wherein the peripheral wall includes a three-dimensional patient-specific peripheral inner surface configured to mate in only one position with an outer peripheral surface of the femoral neck after resection by the cutting tool.
28. A patient-specific guide for preparing a femoral neck of a patient for receiving a femoral neck implant comprising:
- a first wall having a first inner surface with a patient-specific inner bore therethrough, wherein the first inner surface is configured to mate with a resected surface of the femoral neck, wherein the patient-specific inner bore is configured for guiding a cutting tool to remove only a cancellous bone from the femoral neck to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of the femoral neck of a specific patient; and
- a peripheral wall extending from the first wall, wherein the peripheral wall includes a three-dimensional patient-specific peripheral inner surface configured to mate in only one position with an outer peripheral surface of the femoral neck after resection by the cutting tool.
29. The patient-specific guide of claim 28, in further combination with the cutting tool which includes a body having a patient-specific cross-section of variable size and shape along a longitudinal axis and a patient-specific three-dimensional outer cutting surface that nests and conforms complementarily to the cortical boundary surface corresponding to the cortical/cancellous bone interface surface of the femoral neck of the specific patient, wherein the body is configured for removing only the cancellous bone from the femoral neck of the specific patient.
30. The patient-specific guide of claim 28, in further combination with the patient-specific femoral neck implant, the femoral neck implant comprising:
- a body for implantation into a femoral neck of a patient, the body having a patient-specific cross-section of variable size and shape along a longitudinal axis of the body and a patient-specific three-dimensional outer surface that nests and conforms complementarily to the resected surface corresponding to the cortical boundary surface at the cortical/cancellous bone interface surface of the femoral neck of the specific patient; and
- a neck portion extending from the body and configured for coupling with a femoral head implant.
31. A femoral neck cutting tool comprising:
- a body having a patient-specific cross-section of variable size and shape along a longitudinal axis and a patient-specific three-dimensional outer cutting surface that closely nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of a femoral neck of the specific patient and configured for removing only the cancellous bone from the femoral neck of the patient; and
- a non patient-specific coupling component for engaging a non patent-specific driver tool.
32. The cutting tool of claim 31, wherein the coupling component includes a protrusion extending from a proximal surface of the cutting tool and a bore defined through the proximal surface of the cutting tool.
33. The cutting tool of claim 32, in combination with a driver tool having a distal surface with a driver tool bore for receiving the protrusion and a retractable rod having a distal portion insertable into the bore of the cutting tool for holding the cutting tool.
34. The cutting tool of claim 31, in further combination with a patient-specific guide for preparing the femoral neck of the specific patient, the guide comprising:
- a first wall having a first inner surface with a patient-specific inner bore therethrough, wherein the first inner surface is configured to mate with a resected surface of the femoral neck, wherein the patient-specific inner bore is configured for guiding the cutting tool to remove only the cancellous bone from the femoral neck to the cortical boundary surface corresponding to the cortical/cancellous bone interface surface of the femoral neck for receiving a femoral neck implant; and
- a peripheral wall extending from the first wall, wherein the peripheral wall includes a three-dimensional patient-specific peripheral inner surface configured to mate in only one position with an outer peripheral surface of the femoral neck after resection.
35. The cutting tool of claim 31, in further combination with a patient-specific neck implant having a body with a patient-specific cross-section of variable size and shape along a longitudinal axis of the body and a patient-specific three-dimensional outer surface that nests and conforms complementarily to the resected surface which corresponds to cortical boundary surface at the cortical/cancellous bone interface surface of the femoral neck of the specific patient after removal of only the cancellous bone from the femoral neck.
36. A system for preparing a femoral neck of a specific patient comprising:
- a cutting tool having a patient-specific cross-section of variable size and shape along a longitudinal axis and a patient-specific three-dimensional outer cutting surface that nests and conforms complementarily to a cortical boundary surface corresponding to a cortical/cancellous bone interface surface of the femoral neck of the specific patient, wherein the cutting tool is configured for removing only a cancellous bone from the femoral neck of the specific patient to create a resected surface; and
- a femoral neck implant for implantation into the femoral neck of a patient, the femoral neck implant having a body with a patient-specific cross-section of variable size and shape along a longitudinal axis of the body and a patient-specific three-dimensional outer surface that nests and conforms complementarily to the resected surface which corresponds to cortical boundary surface at the cortical/cancellous bone interface surface of the femoral neck of the specific patient after removal of only the cancellous bone from the femoral neck.
37. The system of claim 36, in further combination with a patient-specific guide comprising:
- a first wall having a first inner surface with a patient-specific inner bore therethrough, wherein the first inner surface is configured to mate with the resected surface; and
- a peripheral wall extending from the first wall, wherein the peripheral wall includes a three-dimensional patient-specific peripheral inner surface configured to mate in only one position with an outer peripheral surface of the femoral neck after resection.
38. The system of claim 36, wherein the femoral neck implant further includes a neck portion extending from the body, the neck portion is configured to be aligned along a patient-specific articulation axis.
39. The system of claim 36, wherein the femoral neck implant further includes a flange coupled to the body and configured for abutting the resected surface of the femoral neck of the specific patient.
40. The system of claim 36, wherein the body of the femoral neck is sized to extend only into the femoral neck of the specific patient and has a patient-specific length.
Type: Application
Filed: Aug 1, 2016
Publication Date: Nov 24, 2016
Inventors: Jason D. Meridew (Warsaw, IN), John R. White (Winona Lake, IN), Robert Metzger (Wakarusa, IN)
Application Number: 15/224,741