The present disclosure relates generally to customized patient-specific orthopaedic surgical instruments and more particularly to customized patient-specific patella resectioning guides.
Joint arthroplasty is a well-known surgical procedure by which a diseased and/or damaged natural joint is replaced by a prosthetic joint. 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 some cases, the knee prosthesis may also include a prosthetic patella component, which is secured to a posterior side of the patient's surgically-prepared patella. To do so, an orthopaedic surgeon may resect the posterior side of the patient's natural patella to secure the prosthetic component thereto. In use, the patella component articulates with the patient's natural or prosthetic femur during extension and flexion of the patient's knee.
To facilitate the replacement of the natural joint with the knee 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 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.
According to one aspect, a customized patient-specific orthopaedic instrument may include a customized patient-specific patella resectioning guide. The customized patient-specific patella resectioning guide may have a body including a bone-facing surface having a customized patient-specific negative contour configured to receive a portion of a posterior side of a patient's patella that has a corresponding positive contour. The customized patient-specific patella resectioning guide may also include a cutting guide coupled to the body. The cutting guide may include a cutting slot defined therein and the cutting slot may define a resectioning plane. The cutting guide may be positioned such that the resectioning plane extends through the patient's patella when the patella is received in the customized patient-specific negative contour of the body.
In some embodiments, the cutting guide may be formed from a material different from the material forming the body. The cutting guide may be formed from a metallic material or a non-metallic material. In some embodiments, the body may be formed from a polymeric material. In such embodiments, the cutting guide may be overmolded with the body. Additionally, in some embodiments, the body may have an outer surface opposite the bone-facing surface.
The resectioning guide may further include a medial side corresponding to the medial side of the patient's patella when patella is received in the customized patient-specific negative contour of the body. Additionally, the resectioning guide may include a lateral side corresponding to the lateral side of the patient's patella when the patella is received in the customized patient-specific negative contour of the body. The cutting slot of the cutting guide may include a first opening on the medial side of the resectioning guide. The first opening may be sized to receive a cutting saw blade. In some embodiments, the cutting slot of the cutting guide may include a second opening on the lateral side of the resectioning guide. The second opening may also be sized to receive a cutting saw blade. Additionally, in some embodiments, the resectioning guide may include an indentation formed on the medial side of the resectioning guide. The indentation may extend from the outer surface of the body to the cutting slot of the cutting guide.
In some embodiments, the body of the resectioning guide may include a sidewall extending upwardly from the bone-facing surface and intersecting with the resectioning plane to prevent the cutting saw blade from extending beyond the body. The sidewall may be positioned on the lateral side of the resectioning guide in some embodiments. Additionally, the cutting guide may be positioned on the medial side of the resectioning guide such that the customized patient-specific negative contour of the body may be positioned between the cutting guide and the sidewall.
Additionally, in some embodiments, the outer surface may have an indentation shaped to receive a clamp operable to secure the patella to the body. Additionally (or alternatively), the indentation may be sized to receive a thumb of a surgeon such that the body and patella may be held between the thumb and forefinger of the orthopaedic surgeon. Further, in some embodiments, the resectioning guide may further include compressible foam material secured to the outer surface of the body.
According to another aspect, a customized patient-specific orthopaedic instrument may include a customized patient-specific resectioning guide. The customized patient-specific resectioning guide may include a body having a bone-facing surface including a customized patient-specific negative contour configured to receive a portion of a posterior side of a patient's patella that has a corresponding positive contour. The resectioning guide may also include a non-captured cutting guide. The non-captured cutting guide may include a cutting surface defining a resectioning plane. The cutting guide may be positioned such that the resectioning plane extends through the patient's patella when the patella is received in the customized patient-specific negative contour of the body.
In some embodiments, the resectioning guide may further include a medial side corresponding to the medial side of the patient's patella when the portion of the posterior side of the patient's patella is received in the customized patient-specific negative contour of the body. Additionally, the resectioning guide may include a lateral side corresponding to the lateral side of the patient's patella when the portion of the posterior side of the patient's patella is received in the customized patient-specific negative contour of the body. The body may also include a sidewall extending upwardly from the bone-facing surface and intersecting with the resectioning plane to prevent the cutting saw blade from extending beyond the body. In some embodiments, the sidewall may be positioned on the lateral side of the resectioning guide. In such embodiments, the cutting guide may be positioned on the medial side of the resectioning guide such that the customized patient-specific negative contour of the body is positioned between the cutting guide and the sidewall.
According to a further aspect, a customized patient-specific orthopaedic instrument may include a customized patient-specific patella resectioning guide. The customized patient-specific patella resectioning guide may have a body including a first bone-facing surface having a customized patient-specific negative contour configured to receive a portion of a posterior side of a patient's patella that has a corresponding positive contour and a second bone-facing surface opposite the first bone-facing surface. The second bone-facing surface may include a customized patient-specific negative contour configured to receive a portion of a distal end of the patient's femur that has a corresponding positive contour. The resectioning guide may also include a cutting guide coupled to the body. The cutting guide may also include a cutting slot defined therein. The cutting slot may define a resectioning plane. The cutting guide may be positioned such that the resectioning plane extends through the patient's patella when the patella is received in the customized patient-specific contour of the first bone-facing surface of the body.
In some embodiments, the resectioning guide may further include a medial side corresponding to the medial side of the patient's patella when the portion of the posterior side of the patient's patella is received in the customized patient-specific negative contour of the body. Additionally, the resectioning guide may include a lateral side corresponding to the lateral side of the patient's patella when the portion of the posterior side of the patient's patella is received in the customized patient-specific negative contour of the body. The cutting slot of the cutting guide may include an opening on the lateral side of the resectioning guide. The opening may be sized to receive a cutting saw blade.
Additionally, in some embodiments, the resectioning guide may further include an enclosed housing extending upwardly from the bone-facing surface of the body. The enclosed housing may be spaced apart from the cutting guide. The enclosed housing may have an aperture co-planar with the resectioning plane defined by the cutting slot. Additionally, the enclosed housing may be positioned on the medial side of the resectioning guide, and the cutting guide may be positioned on the lateral side of the resectioning guide such that the customized patient-specific negative contour is formed between the cutting guide and the enclosed housing.
The detailed description particularly refers to the following figures, in which:
While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
Terms representing anatomical references, such as anterior, posterior, medial, lateral, superior, inferior, etcetera, may be used throughout the specification in reference to the orthopaedic implants and surgical instruments described herein as well as in reference to the patient's natural anatomy. Such terms have well-understood meanings in both the study of anatomy and the field of orthopaedics. Use of such anatomical reference terms in the written description and claims is intended to be consistent with their well-understood meanings unless noted otherwise.
Referring to
In some embodiments, the customized patient-specific orthopaedic surgical instrument may be customized to the particular patient based on the location at which the instrument is to be coupled to one or more bones of the patient. For example, in some embodiments, the customized patient-specific orthopaedic instrument may be a customized patient-specific patella resectioning guide including one or more bone-contacting or facing surfaces having a negative contour that matches the contour of a portion of the patient's patella, which is discussed in more detail below in regard to
As shown in
In process step 14, the orthopaedic surgeon may determine any additional pre-operative constraint data. The constraint data may be based on the orthopaedic surgeon's preferences, preferences of the patient, anatomical aspects of the patient, guidelines established by the healthcare facility, or the like. For example, the constraint data may include the orthopaedic surgeon's preference for a particular prosthesis type, the thickness of the bone to resect, the size range of the orthopaedic implant, and/or the like. In some embodiments, the orthopaedic surgeon's preferences are saved as a surgeon's profile, which may be used as a default constraint values for further surgical plans.
In process step 16, the medical images and the constraint data, if any, are transmitted or otherwise provided to an orthopaedic surgical instrument vendor or manufacturer. The medical images and the constraint data may be transmitted to the vendor via electronic means such as a network or the like. After the vendor has received the medical images and the constraint data, the vendor processes the images in step 18. The orthopaedic surgical instrument vendor or manufacturer process the medical images to facilitate the determination of the proper positioning of the prosthetic component, implant sizing, and fabrication of the customized patient-specific patella resectioning guide as discussed in more detail below.
In process step 20, the vendor may convert or otherwise generate three-dimensional images from the medical images. For example, in embodiments wherein the medical images are embodied as a number of two-dimensional images, the vendor may use a suitable computer algorithm to generate one or more three-dimensional images from the number of two-dimensional images. Additionally, in some embodiments, the medical images may be generated based on an established standard such as the Digital Imaging and Communications in Medicine (DICOM) standard. In such embodiments, an edge-detection, thresholding, watershed, or shape-matching algorithm may be used to convert or reconstruct images to a format acceptable in a computer aided design application or other image processing application. Further, in some embodiments, an algorithm may be used to account for tissue such as cartilage not discernable in the generated medical images. In such embodiments, any three-dimensional model of the patient-specific instrument (see, e.g., process step 26 below) may be modified according to such algorithm to increase the fit and function of the instrument.
In process step 22, the vendor may process the medical images, and/or the converted/reconstructed images from process step 20, to determine a number of aspects related to the bony anatomy of the patient such as the anatomical axis of the patient's bones, the mechanical axis of the patient's bone, other axes and various landmarks, and/or other aspects of the patient's bony anatomy. To do so, the vendor may use any suitable algorithm to process the images.
In process step 24, the resectioning plane of the patient's patella is determined. The planned resectioning plane is determined based on the type, size, and position of the prosthetic patella component to be used during the orthopaedic procedure, on the process images such as specific landmarks identified in the images, and on the constraint data supplied by the orthopaedic surgeon in process steps 14 and 16. The type and/or size of the prosthetic patella component may be determined based on the patient's anatomy and the constraint data. For example, the constraint data may dictate the type, make, model, size, or other characteristic of the prosthetic patella component. The selection of the prosthetic patella component may also be modified based on the medical images such that a prosthetic component usable with the bony anatomy of the patient and matching the constraint data or preferences of the orthopaedic surgeon is selected.
In addition to the type and size of the prosthetic patella component, the planned location and position of the prosthetic patella component relative to the patient's bony anatomy is determined. To do so, a digital template of the prosthetic patella component may be overlaid onto one or more of the processed medical images. The vendor may use any suitable algorithm to determine a recommended location and orientation of the prosthetic patella component (i.e., the digital template) with respect to the patient's bone based on the processed medical images (e.g., landmarks of the patient's patella and/or femur defined in the images) and/or the constraint data. Additionally, any one or more other aspects of the patient's bony anatomy may be used to determine the proper positioning of the digital template. In some embodiments, the digital template along with surgical alignment parameters may be presented to the orthopaedic surgeon for approval.
The planned resectioning planes for the patient's patella may then be determined based on the determined size, location, and orientation of the prosthetic patella component. In addition, other aspects of the patient's bony anatomy, as determined in process step 22, may be used to determine or adjust the planned resectioning planes. For example, the determined mechanical axis, landmarks, and/or other determined aspects of the femur and/or patella of the patient may be used to determine the planned resectioning planes.
In process step 26, a model of the customized patient-specific patella resectioning guide is generated. In some embodiments, the model is embodied as a three-dimensional rendering of the customized patient-specific patella resectioning guide. In other embodiments, the model may be embodied as a mock-up or fast prototype of the customized patient-specific patella resectioning guide. The customized patient-specific patella resectioning guide to be modeled and fabricated may be determined based on the patella orthopaedic surgical procedure to be performed, the constraint data, and/or the type of prosthetic patella component to be implanted in the patient.
The particular shape of the customized patient-specific patella resectioning guide is determined based on the planned location of the patella resectioning guide relative to the patient's bony anatomy. The location of the customized patient-specific patella resectioning guide with respect to the patient's bony anatomy is determined based on the type and determined location of the prosthetic patella component to be used during the orthopaedic surgical procedure. That is, the planned location of the customized patient-specific patella resectioning guide relative to the patient's bony anatomy may be selected based on, in part, the planned resectioning planes of the patient's bone(s) as determined in step 24. For example, the location of the patella resectioning guide is selected such that the cutting guide of the patella resectioning guide matches one or more of the planned resectioning planes determined in process step 24. Additionally, the planned location of the patella resectioning guide may be based on the identified landmarks of the patient's patella and femur identified in process step 22.
In some embodiments, the particular shape or configuration of the customized patient-specific patella resectioning guide may be determined based on the planned location of the guide relative to the patient's bony anatomy. That is, the customized patient-specific patella resectioning guide may include a bone-contacting surface having a negative contour that matches a corresponding positive contour of a portion of the patella of the patient. The positive contour of the portion of the patella of the patient may be received in the negative contour of the patella resectioning guide such that the patella is placed in a unique location. When the patella resectioning guide receives the patient's patella, one or more guides (e.g., cutting guide) of the patella resectioning guide may be aligned to the one or more of the resectioning plane(s), as discussed above.
After the model of the customized patient-specific patella resectioning guide has been generated in process step 26, the model is validated in process step 28. The model may be validated by, for example, analyzing the rendered model while the three-dimensional model of the patient's patella is received in the resectioning guide model to verify the correlation of the cutting guide and the resectioning plane. Additionally, the model may be validated by transmitting or otherwise providing the model generated in step 26 to the orthopaedic surgeon for review. For example, in embodiments wherein the model is a three-dimensional rendered model, the model along with the three-dimensional images of the patient's relevant bone(s) may be transmitted to the surgeon for review. In embodiments wherein the model is a physical prototype, the model may be shipped to the orthopaedic surgeon for validation.
After the model has been validated in process step 28, the customized patient-specific patella resectioning guide is fabricated in process step 30. The customized patient-specific patella resectioning guide may be fabricated using any suitable fabrication device and method. Additionally, the customized patient-specific patella resectioning guide may be formed from any suitable material such as a metallic material, a plastic material, or combination thereof depending on, as discussed in more detail below. The fabricated customized patient-specific patella resectioning guide is subsequently shipped or otherwise provided to the orthopaedic surgeon. The surgeon performs the orthopaedic surgical procedure in process step 32 using the customized patient-specific patella resectioning guide. As discussed above, because the orthopaedic surgeon does not need to determine the proper location of the patella resectioning guide intra-operatively, which typically requires some amount of estimation on part of the surgeon, the guesswork and/or intra-operative decision-making on part of the orthopaedic surgeon is reduced.
It should also be appreciated that variations in the bony anatomy of the patient may require more than one customized patient-specific patella resectioning guide to be fabricated according to the method described herein. For example, the patient may require the implantation of two prosthetic patella components to replace both natural knees. As such, the surgeon may follow the method 10 of
Referring now to
As shown in
In the illustrative embodiment of
As shown in
The cutting guide 52 includes a cutting slot 70 extending from the medial side 44 of the resectioning guide 40 to the lateral side 46 of the resectioning guide 40. The cutting slot 70 defines a resectioning plane 72 that extends through the patient's patella 42 when the patella 42 is received in the customized patient-specific contour 56 of the body 50. The cutting slot 70 extends from a medial opening 74 formed in the medial side 44 through an opening (not shown) into the negative contour 56 of the body 50. The cutting slot 70 also extends from a lateral opening 76 formed in the lateral side 46 through an opening 82 into the negative contour 56 of the body 50. The cutting slot 70 is sized to receive a cutting saw blade (not shown).
A viewing window 90 is formed on the medial side 44 of the resectioning guide 40. The viewing window 90 is formed as an indentation 92 extending from the outer surface 58 of the body 50 to the interior of the cutting slot 70 of the cutting guide 52. The viewing window 90 is positioned to allow the surgeon to view the cutting saw blade within the cutting slot 70. It should be appreciated that in other embodiments the body 50 and cutting guide 52 may include additional viewing windows of different sizes and shapes to facilitate the surgeon's view of the cutting saw blade. For example, in one embodiment, the resectioning guide 40 may include a viewing window on each of the medial and lateral sides 44, 46.
As shown in
In use, an orthopaedic surgeon may secure the patella 42 to the body 50 using the clamp or other securing means. The surgeon may then insert the cutting saw blade into the opening 76. The blade passes through the cutting slot 70 and contacts the medial side of the portion of the patella 42 received in the negative contour 56. Following the resectioning plane 72 defined by the cutting slot 70, the surgeon may perform the resectioning cut on the patient's patella 42 by moving the saw blade back and forth within cutting slot 70. As the blade cuts through the patella 42, the blade is received in the opening 82 of the cutting slot 70. In this way, the blade is captured on both the medial side and the lateral side of the patient's patella 42.
Referring now to
In the illustrative embodiment, the body 150 includes a bone-facing surface 154 having a customized patient-specific negative contour 156 defined therein. Similar to the negative contour 56, the negative contour 156 is configured to receive the corresponding positive contour 49 of the posterior side 48 of the patient's patella 42. The body 150 also includes a sidewall 158 extending upwardly from the bone-facing surface 154. The sidewall 158 is positioned on the lateral side 46 of the resectioning guide 140 such that the customized patient-specific contour 156 is positioned between the sidewall 158 and the cutting guide 152.
Similar to the embodiment of
The cutting guide 152 includes a cutting slot 170 sized to receive a cutting saw blade (not shown). The cutting slot 170 extends from an opening 174 defined in the medial side 44 of the resectioning guide 140 to an opening (not shown) in a bone-facing surface 176 of the cutting guide 152. The cutting slot 170 defines a resectioning plane 178 extending through the patient's patella 42 when the patella 42 is received in the customized patient-specific negative contour 156 of the body 150. The sidewall 158 intersects with the resectioning plane 178 and extends upwardly from the body 150 a length sufficient to prevent a cutting saw blade (not shown) from extending beyond the lateral side 46 of the resectioning guide 140 during use.
Similar to the embodiment of
In use, an orthopaedic surgeon may secure the patella 42 to the body 150 using the clamp or other securing means. The surgeon may then insert the cutting saw blade into the opening 174. The blade passes through the cutting slot 170 and contacts the medial side of the portion of the patella 42 received in the negative contour 156. Following the resectioning plane 178 defined by the cutting slot 170, the surgeon may perform a resectioning cut on the patient's patella 42 by moving the blade back and forth within the cutting slot 170. In this way, the blade is captured within the cutting guide 152 while the surgeon performs the resectioning cut. As the blade cuts through the patella 42, the sidewall 158 prevents the surgeon from pushing the blade beyond the resectioning guide 140.
Referring now to
The body 250 includes a bone-facing surface 254 having a customized patient-specific negative contour 256 defined therein. The negative contour 256 is configured to receive the corresponding positive contour 49 of the posterior side 48 of the patient's patella 42. Similar to the resectioning guide 140 of
Similar to the embodiment of
The non-captured cutting guide 252 includes a cutting surface 270 and the bone-facing surface 254. The cutting surface 270 extends from the medial side 44 to the bone-facing surface 254 of the body 250. That is, the cutting surface 270 and the bone-facing surface 254 are co-planar with each other. The cutting surface 270 defines a resectioning plane 272 that the surgeon follows to perform a resectioning cut on the patient's patella 42 when the patella 42 is received in the customized patient-specific negative contour 256 of the body 250. The sidewall 258 intersects with the resectioning plane 272 and extends upwardly from the body 150 a length sufficient to prevent a cutting saw blade (not shown) from extending beyond the lateral side 46 of the resectioning guide 240 during use.
Referring now to
Similar to the previous embodiments, the resectioning guide 340 has a medial side 44 and a lateral side 46. The resectioning guide 340 also includes a body 350, a cutting guide 352 positioned on the lateral side 46, and an enclosed housing 354 positioned on the medial side 44. The cutting guide 352 and the enclosed housing 354 are secured to the body 350. Similar to the embodiments of
In the illustrative embodiment of
The cutting guide 352 includes a cutting slot 370. The cutting slot 370 defines a resectioning plane 378 extending through the patient's patella 42 when the patella 42 is received in the customized patient-specific contour 356 of the body 350. The cutting slot 370 extends from an opening 374 defined in the lateral side 46 of the resectioning guide 340 to an opening (not shown) in a bone-facing surface 376 of the cutting guide 352. The cutting slot 370 is sized to receive a cutting saw blade (not shown).
The enclosed housing 354 has a rear wall 380 defined on the medial side 44 of the resectioning guide 340 and a front wall 382 opposite the rear wall 380. An aperture 384 having a closed back (not shown) is defined in the front wall 382. The aperture 384 is sized to receive the cutting saw blade and is coplanar with the resectioning plane 378 of the cutting slot 370.
In use, the cutting saw blade may be inserted into the opening 374, passed through the cutting slot 370, and received in the aperture 384. A surgeon using the resectioning guide 340 to resect the patient's patella may place the resectioning guide 340 in contact with both the posterior side 48 of the patient's patella and the distal end of the patient's femur prior to performing the resectioning cut. The surgeon may place the patient's patella into the resectioning guide 340 such that the positive contour 49 of the portion of the posterior side 48 of the patient's patella is received in the corresponding negative contour 356 of the patella bone-facing surface 356. The surgeon may also place the femoral bone-facing surface 358 in contact with the distal end of patient's femur (not shown) such that the positive contour 49 of the portion of the distal end of the patient's femur is received in the negative contour 360 of the femoral bone-facing surface 358. The surgeon may then apply pressure to the anterior side of the patient's patella to secure the patella, the resectioning guide 340, and the femur together.
The surgeon may insert a cutting saw blade into the opening 374. The blade passes through the cutting slot 370 and contacts the lateral side of the portion of the patient's patella received in the negative contour 356. Following the resectioning plane 378 defined by the cutting slot 370, the surgeon may perform a resectioning cut on the portion of the patient's patella within the negative contour 356 by moving the blade back and forth within the cutting slot 370. As the blade cuts through the patella 42, the blade is received in the aperture 384 of the housing 354. In this way, the blade is captured on both the medial side and the lateral side of the patient's patella. Additionally, bone fragments, dust, and other debris generated during the resectioning procedure are collected at the closed back of the aperture 384.
Referring to
In use, the orthopaedic surgeon may place the compressible foam material 462 in contact with the positive contour 49 of the portion of the distal end of the patient's femur. When the patella is secured to the resectioning guide 440, the surgeon may apply pressure to the anterior side of the patient's patella to secure the patella, the resectioning guide 440, and the femur together and perform the resectioning procedure as described above. It should be appreciated that in other embodiments the compressible foam material 462 may not be secured to the outer surface 458. In such embodiments, the compressible foam material 462 may be placed between the resectioning guide 340 and distal end of the femur during the resectioning procedure.
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
There are a plurality of advantages of the present disclosure arising from the various features of the method, apparatus, and system described herein. It will be noted that alternative embodiments of the method, apparatus, and system of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the method, apparatus, and system that incorporate one or more of the features of the present invention and fall within the spirit and scope of the present disclosure as defined by the appended claims.