Pre-operative planning and manufacturing method for orthopedic procedure

A pre-operative planning and manufacturing method for orthopedic surgery includes obtaining pre-operative medical image data representing a joint portion of a patient. The method also includes constructing a three-dimensional digital model of the joint portion and manufacturing a patient-specific alignment guide for the joint portion from the three-dimensional digital model of the joint portion when the image data is sufficient to construct the three-dimensional digital model of the joint portion. The patient-specific alignment guide has a three-dimensional patient-specific surface pre-operatively configured to nest and closely conform to a corresponding surface of the joint portion of the patient in only one position relative to the joint portion. The method further includes determining, from the image data, a size of a non-custom implant to be implanted in the patient and manufacturing the non-custom implant when there is insufficient image data to construct the patient-specific alignment guide therefrom.

INTRODUCTION

The present teachings provide various methods of pre-operative planning and manufacturing for orthopedic procedures.

SUMMARY

The present teachings provide a pre-operative planning and manufacturing method for orthopedic surgery. The method includes obtaining pre-operative medical image data representing a joint portion of a patient. The method also includes constructing a three-dimensional digital model of the joint portion and manufacturing a patient-specific alignment guide for the joint portion from the three-dimensional digital model of the joint portion when the image data is sufficient to construct the three-dimensional digital model of the joint portion. The patient-specific alignment guide has a three-dimensional patient-specific surface pre-operatively configured to nest and closely conform to a corresponding surface of the joint portion of the patient in only one position relative to the joint portion. The method further includes determining, from the image data, a size of a non-custom implant to be implanted in the patient and manufacturing the non-custom implant when there is insufficient image data to construct the patient-specific alignment guide therefrom.

A pre-operative planning and manufacturing method for orthopedic surgery is also disclosed. The method includes pre-operatively obtaining medical image data that is readable on a computer. The medical image data contains a plurality of two-dimensional medical images of a joint portion of a patient. The method also includes pre-operatively constructing a three-dimensional digital model of the joint portion from the plurality of two-dimensional medical images and displaying the three-dimensional digital model on a display of the computer when the plurality of two-dimensional medical images are sufficient to construct the three-dimensional digital model of the joint portion. Furthermore, the method includes selecting, based on the image data, a non-custom implant to be implanted in the patient and providing the non-custom implant when the plurality of two-dimensional medical images are insufficient for use in constructing a patient-specific alignment guide having a three-dimensional patient-specific surface configured to nest and closely conform to a corresponding surface of the joint portion of the patient in only one position relative to the joint portion. The non-custom implant is chosen from a group of non-custom implants of different sizes.

Moreover, a computerized pre-operative planning tool for planning an orthopedic surgical procedure is disclosed. The tool includes a receiver device that receives medical image data containing a plurality of two-dimensional medical images of a joint portion of a patient. The tool also includes a processor that determines whether the medical image data is sufficient for constructing a three-dimensional digital model of the joint portion from the plurality of two-dimensional medical images. The processor is additionally configured to construct the three-dimensional digital model when the medical image data is sufficient to construct the three-dimensional digital model. The processor is further configured to construct a patient-specific digital model of a patient-specific alignment guide when the medical image data is sufficient to construct the three-dimensional digital model. The patient-specific alignment guide has a three-dimensional surface that nests against a corresponding surface of the three-dimensional digital model of the joint portion. Additionally, the tool includes a display that displays the three-dimensional digital model of the joint portion and the patient specific digital model of the patient-specific alignment guide when the processor determines that the medical image data is sufficient for constructing the three-dimensional digital model of the joint portion. The display also displays at least one of the two-dimensional medical images of the joint portion for selection of a non-custom implant when the processor determines that the medical image data is insufficient for constructing the patient-specific alignment guide therefrom.

Still further, a pre-operative planning and manufacturing method for orthopedic surgery of a knee joint of a patient is disclosed. The method includes obtaining pre-operative medical image data representing the knee joint, wherein the medical image data includes a plurality of two-dimensional images of the knee joint. The method also includes constructing a three-dimensional digital model of the knee joint and manufacturing a patient-specific alignment guide for the knee joint from the three-dimensional digital model of the knee joint when the plurality of two-dimensional images of the knee joint is sufficient to construct the three-dimensional digital model of the knee joint. The patient-specific alignment guide has a three-dimensional patient-specific surface pre-operatively configured to nest and closely conform to a corresponding surface of the knee joint of the patient in only one position relative to the knee joint. The method also includes determining, based on at least one of the two-dimensional images of the knee joint, a size of a non-custom implant to be implanted in the knee joint of the patient when there is insufficient image data to construct the patient-specific alignment guide therefrom. Additionally, the method includes determining a dimension for a non-custom surgical instrument configured for implanting the non-custom implant when there is insufficient image data to construct the patient-specific alignment guide therefrom. Moreover, the method includes manufacturing at least one of the non-custom implant and the non-custom surgical instrument when there is insufficient image data to construct the patient-specific alignment guide therefrom. Furthermore, the method includes assembling a kit containing the non-custom implant and the non-custom surgical instrument when there is insufficient image data to construct the patient-specific alignment guide therefrom.

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.

DESCRIPTION OF VARIOUS ASPECTS

The following description is merely exemplary in nature and is in no way intended to limit the present teachings, applications, or uses. For example, although some of the present teachings are presented in relation to surgical planning for implanting a knee joint prosthesis, the present teachings can be employed for planning surgical implantation of any prosthetic device.

The present teachings provide various pre-operative planning methods for orthopedic procedures. For instance, the present teachings can be employed for planning partial or total knee joint replacement surgery. Specifically, image data from medical scans of the patient can be provided, and if there is sufficient two-dimensional image data, an accurate three-dimensional digital model of the knee joint can be generated as well as a three-dimensional digital model of a patient-specific alignment guide. If there is insufficient two-dimensional image data to generate the three-dimensional digital model and a patient-specific alignment guide therefrom, the image data can still be used to determine a size of a non-custom prosthesis to be implanted. The image data can also be used to determine sizes and dimensions for instruments (e.g., resection guides, etc.) that will be used during surgery. Moreover, a kit can be pre-operatively assembled containing the selected alignment guide(s), prosthetic device(s), trial prosthetic device(s), instruments, etc. that will be used during surgery for a particular patient. These methods can, therefore, make pre-operative planning more efficient. Also, the surgical procedure can be more efficient since the prosthetic device and the related surgical implements can be tailored for the particular patient.

Referring initially toFIG. 1, a pre-operative planning tool10is illustrated. The tool10can be computer-based and can generally include a receiving device12, a processor14, a memory device16, and a display18.

The receiving device12can receive medical image data20of a joint portion24(e.g., a knee joint) of a patient. Representative image data20of a knee joint portion24(including a femur F and a tibia T) of a patient is illustrated inFIG. 3. It will be appreciated that the image data20can include any number of images of the joint portion24, taken from any viewing perspective.

Specifically, the receiving device12can receive medical scans prepared by a Magnetic Resonance Imaging (MRI) device, a Computed Tomography (CT) scanner, a radiography or X-ray machine, an ultrasound machine, a camera or any other imaging device22. The imaging device22can be used to generate electronic (e.g., digital) image data20. The image data20can be stored on a physical medium, such as a CD, DVD, flash memory device (e.g. memory stick, compact flash, secure digital card), or other storage device, and this data20can be uploaded to the tool10via a corresponding drive or other port of the receiving device12. The image data20may alternatively, or in addition, be transmitted electronically to the receiving device12via the Internet or worldwide web using appropriate transfer protocols. Also, electronic transmissions can include e-mail or other digital transmission to any appropriate type of computer device, smart phone, PDA or other devices in which electronic information can be transmitted.

The memory device16can be of any suitable type (RAM and/or ROM), and the medical image data20can be inputted and stored in the memory device16. The memory device16can also store any suitable software and programmed logic thereon for completing the pre-operative planning discussed herein. For instance, the memory device16can include commercially-available software, such as software from Materialise USA of Plymouth, Mich.

The processor14can be of a known type for performing various calculations, analyzing the data, and other processes discussed hereinbelow. Also, the display18can be a display of a computer terminal or portable device, such as an electronic tablet, or any other type of display. As will be discussed, the display18can be used for displaying the medical image data20and/or displaying digital anatomical models generated from the image data20and/or displaying other images, text, graphics, or objects.

It will also be appreciated that the pre-operative planning tool10can include other components that are not illustrated. For instance, the planning tool10can include an input device, such as a physical or electronic keyboard, a joystick, a touch-sensitive pad, or any other device for inputting user controls.

As will be discussed, the image data20can be analyzed and reviewed (manually or automatically) using the tool10to determine whether the image data20is sufficient enough to generate and construct a three-dimensional (3-d) digital model26a,26bof the joint24. (A representative 3-d digital model26aof the patient's femur F is illustrated inFIG. 4A, and a representative 3-d digital model26bof the patient's tibia T is illustrated inFIG. 4B.)

For instance, if the image data20was collected by MRI or other higher-resolution imaging device, there are likely to be a relatively large number of two-dimensional images of the joint24taken at different anatomical depths, and these images can be virtually assembled (“stacked”) by the processor14to generate the three-dimensional electronic digital model26a,26bof the patient's anatomy. Using these digital models26a,26b, a first surgical plan30(FIG. 1) can be generated, and a corresponding kit33can be manufactured and assembled. As will be discussed, the kit33can include the physical components necessary for surgery, including patient-specific alignment guide(s), selected prosthetic devices, trial prosthetic devices, surgical instruments, and more. The kit33can be sterilized and shipped to be available for surgery for that particular patient.

However, if the image data20was collected by X-ray or other lower-resolution imaging device, there is unlikely to be sufficient data about the joint24to generate accurate three-dimensional digital models26a,26b. Regardless, the two-dimensional image data20can still be used to generate a second surgical plan32as shown inFIG. 1, and a corresponding kit34can be assembled. The kit34can include a selected non-patient-specific (non-custom) implant, trial implant, surgical instruments, and more. However, the items within the kit34can be size-specific (i.e., the size of the items in the kit34can be pre-operatively selected for the particular patient).

It will be appreciated that the same tool10can be used for planning purposes, regardless of whether the image data20is sufficient to generate three-dimensional digital models of the joint24or not. Thus, for instance, if the patient is able and willing to undergo MRI to obtain highly detailed images as recommended by the surgeon, the tool10can be used to generate a surgical plan30and to manufacture implements that are highly customized for that patient. Otherwise, if the patient is unable or unwilling to undergo MRI (e.g., because the patient has a pacemaker, because the patient has claustrophobia, because MRI is not recommended by the surgeon, etc.), the tool10can still be used to generate the surgical plan32, albeit with implements that are selected from inventory or manufactured on a non-custom basis. In either case, the surgery can be planned and carried out efficiently.

Referring now toFIG. 2, a method40of using the tool10will be discussed. The method40can begin in block42, in which the image data20is obtained. As mentioned above, the image data20can be obtained from an MRI device, an X-ray device, or the like. In the case of data20obtained by X-ray, one or more radio-opaque (e.g., magnetic) markers or scaling devices43can be used as shown inFIG. 3. These devices43can be of a known size and shape. For instance, the devices43can be discs that measure ten centimeters in diameter, or the devices43can be elongate strips or other shapes with known dimensions. The devices43can be placed over the patient's knee joint24before the X-ray is taken. The devices43will be very visible in the X-ray image. Since the actual size of the devices43are known, the size of the device43can be compared against the anatomical measurements taken from the image, and the scale of anatomy in the image can be thereby detected.

Next, as shown inFIG. 2, the method40can continue in block44, in which the image data20can be evaluated, and in block46, it can be determined whether there is enough data to generate accurate 3-d digital model(s)26a,26bof the joint24. “Accurate” in this context means that the image data20is sufficient and detailed enough to generate precise representations of the anatomical joint24. More specifically, “accurate 3-d models” are those that are detailed and precise enough to construct a patient-specific alignment guide therefrom. (Patient-specific alignment guides will be discussed in greater detail below.) It is noted that three 3-d models can still be generated from a lesser or insufficient number of medical scans, although such 3-d models will not be accurate enough to generate patient-specific alignment guides that mirror the corresponding joint surfaces of the specific patients.

In some embodiments, the processor14can analyze the data20to automatically determine if it is sufficient to model the complex, three-dimensionally curved surfaces of the distal end of the femur F and the proximate end of the tibia T. In other embodiments, the tool10can automatically detect whether the data20is MRI data (higher-resolution data) or X-ray data (lower-resolution data). If the data20is MRI data, then the digital models26a,26bcan be generated and block46is answered affirmatively. If the data20is X-ray data, then the digital models26a,26bcannot be generated and block46is answered negatively.

If decision block is answered in the affirmative, then block48follows, and the digital models26a,26bare generated as represented inFIGS. 4A and 4B. These digital models26a,26bcan be displayed on the display18. Subsequently in block49, the first surgical plan30is generated. Specifically, various dimensions of the femur F and tibia T can be automatically detected from the digital models26a,26b, the mechanical axis of the joint24can be detected from the digital models26a,26b, resection plane(s) for the femur F and tibia T can be planned according to the digital models26a,26b, soft tissue can be analyzed in the digital models, etc. A prosthetic implant assembly60(FIG. 6) can then be selected and/or designed according to this analysis.

More specifically, as shown inFIG. 6various inventories70,72of differently sized prosthetic implant assemblies60can be provided. The inventory70can include components for a full knee replacement, and the inventory72can include components for a partial knee replacement. From the digital models26a,26b, the surgeon can decide to do a full knee replacement, as represented inFIG. 6. From the digital models26a,26b, the surgeon can also determine the size of the prosthetic implant assembly60that is appropriate for the patient. Thus, the surgeon can determine the size and other appropriate features for a femoral component62, a tibial component64(tibial tray), a bearing66, and one or more fasteners68for the patient. Each of these components62,64,66,68can be individually selected from the inventory70.

In some embodiments, the prosthetic implant assembly60can be selected from non-custom, inventoried components of the commercially-available VANGUARD™ complete knee system of Biomet, Inc. of Warsaw, Ind. The surgeon also has the option of selecting components from the other inventory72, such as partial knee prosthetic implants of the OXFORD™ partial knee system of Biomet, Inc. of Warsaw, Ind. In still other cases, the surgeon can design a patient-specific prosthetic implant (i.e., one that is customized, non-inventoried, and intended for a single patient). In any case, the surgeon can rely on the digital models26a,26bfor selecting and/or designing the most appropriate implant assembly60for restoring function of the joint24. It will be appreciated that the prosthetic implant assembly60can be selected from any one of various types, such as bilateral or unilateral implants, constrained, semi-constrained, mobile types, etc. It will also be appreciated that the components62,64,66,68may not be stocked in inventory, and the components62,64,66,68can be manufactured on-demand.

A resection guide80can also be selected from an inventory82of different resection guides of different sizes and dimensions. The resection guide80can include one or more guide surfaces (e.g., grooves, or slots) used for guiding a resection tool while resecting the bones F, T. The resection guide80can be selected such that the resection plane(s) will be located as determined in block49. The resection guide80can be of any suitable type, such as a 4-in-1 femoral cut block, which is commercially available from Biomet, Inc. of Warsaw, Ind. Resection guides can also be selected for resecting the tibia T as well.

Once the surgical plan has been generated in block49, block50follows as shown inFIG. 2. In block50, patient-specific alignment guides36a,36b(FIGS. 4A and 4B) can be designed according to the anatomical digital models26a,26band according to the prosthetic implant assembly60selected in block49. Patient-specific alignment guides36a,36band their method of manufacture are disclosed and described in detail in the commonly-owned, co-pending U.S. patent application Ser. No. 11/756,057, filed on May 31, 2007, and published as U.S. Patent Publication No. 2007/0288030, which is hereby incorporated herein by reference in its entirety. The femoral alignment guide36acan be configured to include a three-dimensional patient-specific surface52athat nests and closely conforms to a corresponding surface51aof the distal femur F in only one position (with or without articular cartilage). Likewise, the tibial alignment guide36bcan be configured to include a three-dimensional patient-specific surface52bthat nests and closely conforms to a corresponding surface51bof the proximal tibia T in only one position (with or without articular cartilage). Furthermore, the alignment guides36a,36bcan each be designed to include respective alignment holes54a,54bat predetermined locations relative to the bones F, T. The alignment holes54a,54bcan be positioned relative to the bones F, T for aligning surgical instruments (drill guides, resection guides, etc.).

Next, in block53, the alignment guides36a,36bcan be manufactured. The digital models26a,26bcan be used to automatically generate computer instructions of tool paths for machining the patient-specific alignment guide(s)36a,36b. These instructions can be stored in a tool path data file and provided as input to a CNC mill or other automated maching system, and the alignment guides36a,36bcan be machined from polymer, ceramic, metal or other suitable material, and sterilized. The sterilized alignment guides36a,36bcan be shipped to the surgeon or medical facility for use during the surgical procedure. The alignment guides36a,36bcan also be manufactured out of a polymer or other material using known rapid-prototyping machines and techniques. Also, in block53, the components of the prosthetic implant assembly60selected in block49can be manufactured. These components can be made from a biologically compatible material (e.g., Titanium), and can be manufactured by casting and polishing manufacturing methods. In other embodiments, the method40can skip block53because the prosthetic implant assembly60has been previously manufactured and the assembly60is simply obtained from inventory. Trial prosthetics (e.g., prosthetic components that are temporarily implanted as a test during surgery) can also be manufactured in block53.

Finally, in block59, the kit33containing all of the previously-selected components is assembled for the particular patient. As mentioned above with respect toFIG. 1, the kit33can include the patient-specific alignment guides36b, the prosthetic implant assembly60selected in block49, trial prosthetics, resection guides and other instruments, etc. The kit33can be sterilized and shipped to the surgeon or surgical facility for surgery. Accordingly, the planning tool10and its method40of use can be highly effective for tailoring the surgery to the particular patient, and the proper components are very likely to be available during surgery.

Referring back to block46, if the image data20is insufficient for generating an accurate 3-d digital models (i.e., block46answered negatively), then block55follows, and the second surgical plan32is generated according to the available 2-d image data20. The image data20can be displayed on the display18. Next, in block56, the anatomy can be measured in order to select a non-custom implant that would be appropriate for the particular patient. For instance, as shown inFIG. 3, a condylar width W can be measured directly from the image data20, and as shown inFIG. 5, a femoral component62with a width W closest to the measured width W can be selected from inventory70(FIG. 6) for implantation. Other anatomical dimensions and features of the anatomy can be similarly measured to identify the appropriate femoral component62for implantation. The tibia T can be similarly measured to identify the appropriate tibial component64and bearing66. In some embodiments, 2-d templates can be generated and utilized according to the image data20, and these templates can be used for selecting the components of the prosthetic implant assembly60.

Subsequently, in block58, a resection guide80can be selected from an inventory82of different resection guides of different sizes and dimensions. The resection guide80can be selected such that the resection plane(s) will be located as determined in block55. The resection guide80can be of any suitable type, such as a 4-in-1 femoral cut block, which is commercially available from Biomet, Inc. of Warsaw, Ind. Resection guides can also be selected for resecting the tibia T as well. Other resection guides, including distal femoral cutting blocks, and/or other surgical instruments (drill guides, etc.) can be selected in a similar fashion in block58.

Next, the components of the non-custom prosthetic implant assembly60can be manufactured in block53. Alternatively, as discussed above, the components can be retrieved from inventory. Finally, the kit34containing the components of the implant assembly60, a trial implant, surgical instruments can be assembled in block59and stored until the day of surgery.

In summary, the methods described above can streamline pre-operative planning because the surgery can be planned based on either 2-d or 3-d medical image data20. The surgery, the prosthetic implant assembly60and surgical instruments can be tailored for the particular patient in an efficient and convenient fashion.

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 teachings of the invention 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.