# Patent

## Title
Patient-specific acetabular guides and associated instruments

## Abstract

A surgical kit for preparing a joint surface to receive an implant includes a patient-specific guide for a joint surface. The patient-specific guide has a patient-specific surface complementary to a surface of the joint for nesting engagement, and a guiding element oriented along a patient-specific alignment axis. The alignment axis is determined during a preoperative plan of the specific patient for implant alignment. The kit includes a guiding tool couplable to the guiding element of the patient-specific guide and a three-dimensional orientation device removably couplable the guiding tool for intra-operative calibration, such that, after calibration, the orientation device can be removably coupled to a shaft of a surgical instrument to align the shaft along the alignment axis.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 13/041,469 filed on Mar. 7, 2011, which claims the benefit of U.S. Provisional Application No. 61/446,660 filed on Feb. 25, 2011.
This application is a divisional of U.S. application Ser. No. 13/041,469 filed on Mar. 7, 2011, which is a continuation-in-part of U.S. application Ser. No. 12/978,069 filed on Dec. 23, 2010, now U.S. Pat. No. 8,568,487 issued on Oct. 29, 2013, which is a continuation-in-part of U.S. application Ser. No. 12/973,214 filed on Dec. 20, 2010, which is a continuation-in-part of U.S. application Ser. No. 12/955,361 filed on Nov. 29, 2010, now U.S. Pat. No. 8,591,516 issued on Nov. 26, 2013, which is a continuation-in-part of: (1.) U.S. application Ser. No. 12/938,905 filed on Nov. 3, 2010, and (2.) U.S. application Ser. No. 12/938,913 filed on Nov. 3, 2010, each of which is a continuation-in-part of U.S. application Ser. No. 12/893,306 filed on Sep. 29, 2010, which is continuation-in-part of U.S. application Ser. No. 12/888,005 filed on Sep. 22, 2010, now U.S. Pat. No. 8,377,066 issued on Feb. 19, 2013, which is a continuation-in-part of U.S. application Ser. No. 12/714,023 filed on Feb. 26, 2010, now U.S. Pat. No. 8,241,293 issued on Aug. 14, 2012, which is a continuation-in-part of U.S. application Ser. No. 12/571,969 filed on Oct. 1, 2009, which is a continuation-in-part of U.S. application Ser. No. 12/486,992 filed on Jun. 18, 2009, and is a continuation-in-part of U.S. application Ser. No. 12/389,901 filed on Feb. 20, 2009, now U.S. Pat. No. 8,133,234 issued on Mar. 13, 2012, which is a continuation-in-part of U.S. application Ser. No. 12/211,407 filed on Sep. 16, 2008, which is a continuation-in-part of U.S. application Ser. No. 12/039,849 filed on Feb. 29, 2008, now U.S. Pat. No. 8,407,067 issued on Mar. 26, 2013, which: (1) claims the benefit of U.S. Provisional Application No. 60/953,620 filed on Aug. 2, 2007, U.S. Provisional Application No. 60/947,813 filed on Jul. 3, 2007, U.S. Provisional Application No. 60/911,297 filed on Apr. 12, 2007, and U.S. Provisional Application No. 60/892,349, filed on Mar. 1, 2007; (2) is a continuation-in-part U.S. application Ser. No. 11/756,057 filed on May 31, 2007, now U.S. Pat. No. 8,092,465 issued on Jan. 10, 2012, which claims the benefit of U.S. Provisional Application No. 60/812,694 filed on Jun. 9, 2006; (3) is a continuation-in-part of U.S. application Ser. No. 11/971,390 filed on Jan. 9, 2008, now U.S. Pat. No. 8,070,752 issued on Dec. 6, 2011, which is a continuation-in-part of U.S. application Ser. No. 11/363,548 filed on February 27, 2006, now U.S. Pat. No. 7,780,672 issued on Aug. 24, 2010; and (4) is a continuation-in-part of U.S. application Ser. No. 12/025,414 filed on Feb. 4, 2008, now U.S. Pat. No. 8,298,237 issued on Oct. 30, 2012, which claims the benefit of U.S. Provisional Application No. 60/953,637 filed on Aug. 2, 2007.
This application is a divisional of U.S. application Ser. No. 13/041,469 filed on Mar. 7, 2011, which is a continuation-in-part of U.S. application Ser. No. 12/872,663 filed on Aug. 31, 2010, now U.S. Pat. No. 8,407,067 issued on Mar. 26, 2013, which claims the benefit of U.S. Provisional Application No. 61/310,752 filed on Mar. 5, 2010.
This application is a divisional of U.S. application Ser. No. 13/041,469 filed on Mar. 7, 2011, which is a continuation-in-part of U.S. application Ser. No. 12/483,807 filed on Jun. 12, 2009, now U.S. Pat. No. 8,473,305 issued on Jun. 25, 2013, which is a continuation-in-part of U.S. application Ser. No. 12/371,096 filed on Feb. 13, 2009, which is a continuation-in-part of U.S. application Ser. No. 12/103,824 filed on Apr. 16, 2008, now abandoned, which claims the benefit of U.S. Provisional Application No. 60/912,178 filed on Apr. 17, 2007.
This application is a divisional of U.S. application Ser. No. 13/041,469 filed on Mar. 7, 2011, which is a continuation-in-part of U.S. application Ser. No. 12/103,834 filed on Apr. 16, 2008, now U.S. Pat. No. 7,967,868 issued on Jun. 28, 2011, which claims the benefit of U.S. Provisional Application No. 60/912,178 filed on Apr. 17, 2007.
The disclosures of the above applications are incorporated herein by reference.


INTRODUCTION
The present teachings provide various instruments and methods for preparing a joint surface, such as an acetabulum, for example, to receive an implant and guiding the implant along a patient-specific alignment axis.
SUMMARY
The present teachings provide various instruments and methods for generally preparing a joint-surface of a patient to receive an implant along a patient-specific alignment axis. The instruments and methods are illustrated for the acetabulum of the hip joint. The alignment axis and various patient-specific guides and instruments can be designed during a pre-operative plan using a three-dimensional reconstruction of the patient's relevant anatomy, such as the pelvis or portions thereof, including the acetabular and periacetabular areas of the pelvis. The three-dimensional reconstruction can be based on two-dimensional medical images, including MRI, CT or X-ray scans and prepared using commercially available imaging software.
In some embodiments, the present teachings provide a method for preparing a joint surface of a patient for an implant, such as, for example, an acetabular implant for a hip joint. According to the method, a patient-specific guide is attached to a complementary joint surface of the patient. The patient-specific guide includes a guiding element oriented along a patient-specific alignment axis. The alignment axis is determined during a preoperative plan of the patient for implant alignment. A shaft of a guiding tool is removably coupled to the guiding element of the guide. A three-dimensional orientation device is removably attached and can be keyed to the shaft of the guiding tool. A position of a bubble of the orientation device is marked with a mark on an outer transparent surface of the orientation device while the guiding tool is oriented along the alignment axis. In some embodiments, the guiding tool can be an acetabular inserter fitted with a removable adapter tip.
The orientation device, as marked, can be used for aligning other instruments during the procedure. For example, the orientation device can be used with a shaft of a reamer to align the reamer along the alignment axis. The orientation device can also be used with a shaft of an acetabular inserter of an implant for inserting and implanting the implant into the joint. A number of orientation devices can be provided in a surgical kit including one or more patient-specific guides, modular handles, tools and shafts, reamer or other cutting tools, inserters or implant impactors. The surgical kit can also include one or more implant components. The orientation devices can be reusable or disposable.
The acetabular guide can be provided in various fitment options in which the patient-specific engagement surface includes additional portions complementary to a portion of the acetabular rim and/or a portion of the transverse acetabular ligament.
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.



BRIEF DESCRIPTION OF THE DRAWINGS
The present teachings will become more fully understood from the detailed description and the accompanying drawings, wherein:
FIGS. 1-5 illustrate environmental perspective views of various patient-specific acetabular alignment guides according to the present teachings;
FIG. 6 is an environmental perspective view of various instruments illustrating a method for establishing an acetabular cup insertion axis according to the present teachings;
FIG. 7 is an environmental perspective view illustrating drilling a pilot hole for guided reaming according to the present teachings;
FIG. 8A is an environmental perspective view illustrating a reamer for guided reaming according to the present teachings;
FIG. 8B is a stylized perspective view of a reamer for guided reaming according to the present teachings;
FIG. 8C is a partially sectioned perspective view of the reamer of FIG. 8B;
FIG. 9 is an environmental perspective view illustrating instruments for cup insertion according to the present teachings;
FIG. 10 is an environmental perspective view of a patient-specific acetabular alignment guide with alignment pins for a secondary guide according to the present teachings;
FIG. 11 is an environmental perspective view of another patient-specific acetabular alignment guide with alignment pins for a secondary guide according to the present teachings;
FIG. 12 is an environmental perspective view of the patient-specific acetabular alignment guide of FIG. 10 illustrating drilling a pilot hole for guided reaming according to the present teachings;
FIG. 13 is an environmental perspective view of a secondary guide over the alignment pins of FIG. 10 according to the present teachings;
FIG. 14 is an environmental perspective view illustrating a method for establishing an acetabular cup insertion axis using an orientation device according to the present teachings;
FIG. 15A is a perspective view of the orientation device of FIG. 14;
FIG. 15B is a plan view of the orientation device of FIG. 14;
FIG. 16 is an environmental perspective view illustrating a method for inserting an acetabular cup using the orientation device of FIG. 15A according the present teachings; and
FIG. 17 is an environmental perspective view illustrating a method for preparing an acetabulum using the orientation device of FIG. 15A according 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.
The present teachings generally provide various patient-specific acetabular alignment guides, secondary guides, reamers, inserters, impactors and other associated instruments for use in orthopedic surgery, such as in joint replacement or revision surgery, for example. The patient-specific alignment guides and associated instruments can be used either with conventional or with patient-specific implant components prepared with computer-assisted image methods.
As described in commonly assigned U.S. application Ser. No. 11/756,057, filed on May 31, 2007, during a preoperative planning stage, 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 an 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 or other portion of the anatomy of the patient 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 protocols 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 configured and used to plan a preoperative surgical plan, including planning various bone preparation procedures, to select or design/modify implants and design patient-specific guides and tools. The patient-specific components include patient-specific implants, 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, or 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 a manufacturing facility for preparing the actual physical components.
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 preoperative surgical plan. Patient-specific guides and other instruments can be manufactured by various stereolithography methods, selective laser sintering, fused deposition modeling or other rapid prototyping methods. In some embodiments, computer instructions of tool paths for machining the patient-specific guides 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 implants, guides, templates, tools or portions thereof are defined herein as those 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, such as articular cartilage, for example, depending on the particular procedure, implant and tool use.
Patient-specific alignment guides and implants are generally configured to match the anatomy of a specific patient. The patient-specific alignment guides are generally formed using computer modeling based on the patient's 3-D anatomic image and have an engagement surface that is made to conformingly contact and match a three-dimensional image/model of the patient's bone surface (with or without cartilage or other soft tissue), by the computer methods discussed above. The patient-specific alignment guides can include custom-made guiding formations, such as, for example, guiding bores or cannulated guiding posts or cannulated guiding extensions or receptacles that can be used for supporting or guiding other instruments, such as drill guides, reamers, cutters, cutting guides and cutting blocks or for inserting pins or other fasteners according to a surgeon-approved pre-operative plan. The patient-specific alignment guides can be used in minimally invasive surgery, and also in surgery with multiple minimally-invasive incisions. Various alignment guides and pre-operative planning procedures are disclosed in commonly assigned and co-pending U.S. patent application Ser. No. 11/756057, filed on May 31, 2007; U.S. patent application Ser. No. 12/211407, filed Sep. 16, 2008; U.S. patent application Ser. No. 11/971390, filed on Jan. 9, 2008, U.S. patent application Ser. No. 11/363548, filed on Feb. 27, 2006; and U.S. patent application Ser. No. 12/025414, filed Feb. 4, 2008. The disclosures of the above applications are incorporated herein by reference.
Referring to FIGS. 1-5, the present teachings provide various patient-specific acetabular guides 100, 200. The acetabular guides 100, 200 can be used in connection with various other instruments to facilitate guided reaming of an acetabulum 82 of a pelvis 80 of a specific patient and guided insertion and implantation of an acetabular implant or acetabular cup in the acetabulum 82. Further, the patient-specific acetabular guides 100, 200 engage the acetabulum 82 of the specific patient in a unique (only one) position and can provide an accurate alignment axis relative to the planned orientation of the acetabular cup 280 (shown in FIG. 9, for example). The patient-specific acetabular guides 100, 200 can also provide secure fitting and rotational stability in a design that is lightweight with minimal size and bulk.
FIGS. 1-3 illustrate a patient-specific acetabular guide 100 having a patient-specific body 102, as described below, and a guiding or pilot element 104 having an elongated bore 106 with a patient-specific alignment axis A. The alignment axis A is configured to be central to the acetabular cup and perpendicular to the acetabular cup's surface when the acetabular guide 100 is positioned on the acetabulum 82. The acetabular guide 100 can be provided in various fitment options depending on the planned exposure of the acetabulum 82 for the reaming procedure and implantation. Each fitment option of the acetabular guide 100 can include a portion that covers the acetabular fossa at the center of the acetabulum 82, which provides a landmark for rotational stability and unique positioning on the acetabulum. Each fitment option can include additional portions complementary to a portion of the acetabular rim 84 and/or a portion of the transverse acetabular ligament 83, as discussed below in further detail. Each fitment option allows the acetabular guide 100 to have a compact size, extend through the center of the acetabulum 82 for alignment, and include portions that can fit over various anatomic landmarks in a unique position for the patient. The particular fitment option can be selected for each specific patient based on the patient's anatomy, the procedure to be performed and the surgeon's preference and/or technique.
Three exemplary fitment options designated 100A, 100B and 100C are illustrated in FIGS. 1-3, respectively. The fitment options can include fitments engaging or registering to various combinations of portions of the acetabulum 82, the acetabular rim 84 and the transverse acetabular ligament 83. For example, the acetabular guide 100 in the fitment option 100A may engage portions of the acetabulum 82, the acetabular rim 84 and the transverse acetabular ligament 83. In the fitment option 100B, the acetabular guide 100 may engage portions of the acetabulum 82 and the acetabular rim 84. In the fitment option 100C, the acetabular guide 100 may engage portions of the acetabulum 82 and the transverse acetabular ligament 83. Either one or several acetabular guides (or fitment options) 100A, 100B, 100C corresponding to different fitment options can be provided to the surgeon for intra-operative flexibility and plan change, according to the surgeon's preference. The acetabular guide 100 can be secured to the patient's bone with bone pins, guide wires or other fasteners.
The patient-specific body 102 of the acetabular guide 100 can include an inner portion 102a (all fitment options) from which the guiding element extends and which is designed to engage the acetabulum 82, an outer portion 102b which extends from the inner portion 102a and is configured to extend over a portion of the rim 84 (for fitment options 100A and 100C) and an outer portion 102c (fitment options 100A and 100C) configured to extend over a portion of the transverse acetabular ligament 83 (and adjacent area of the acetabulum 82). The patient specific body 102 has an underside three-dimensional engagement surface 108 that is custom-made or patient-specific to conform to and mirror complementary surfaces of various combinations of the acetabulum 82, rim 84 and/or transverse acetabular ligament 83 or other periacetabular surfaces of the pelvis 80 of the specific patient, as described above in connection with the various fitment options. The patient specific body 102 is designed by using a three-dimensional image or model of the acetabulum 82 and surrounding pelvic area of the patient, as described above. The engagement surface 108 enables the acetabular guide 100 to nest or closely mate relative to the complementarily acetabular surface of the patient. The acetabular guide 100 can be designed to have generally small thickness, such that it can form a lightweight three-dimensional shell from which the guiding element 104 extends opposite to the engagement surface. The guiding element 104 can be formed to be a monolithic or integral portion of the acetabular guide 100. Alternatively, the guiding element 104 can be modularly and removably coupled to the acetabular guide 100, using, for example, a threaded connection, snap-on connectors or other removable attachments.
Referring to FIGS. 4 and 5, another patient-specific acetabular guide 200 is illustrated with two exemplary fitment options 200A and 200B. Similarly to the acetabular guide 100, the acetabular guide 200 also includes a patient-specific body 202 and a guiding or pilot element 204 having an elongated bore 206 with an alignment axis A configured to be central to the acetabular cup and perpendicular to the acetabular cup's surface when the acetabular guide 200 is positioned on the acetabulum 82. The acetabular guide 200 can include one or more marker elements 250 (two are shown in the exemplary embodiments of FIGS. 4 and 5), each having an elongated bore 252 for guiding marker pins 260. The marker pins 260 can be used for supporting a secondary guide for another preparation method discussed below in reference to FIG. 12. The other features of the acetabular guide 200 are similar to that of the acetabular guide 100, such that the acetabular guide 200 can also be used instead of the acetabular guide 100. The acetabular guide 100 can be used for procedures in which the marker elements 250 are not utilized, as described below. The acetabular guide 200 can be used for procedures in which the marker elements 250 may or may not be utilized, as described below.
The patient-specific body 202 of the acetabular guide 200 is generally similar to patient-specific body 102 of the acetabular guide 100, such that the patient-specific body 202 can include an inner portion 202a from which the guiding element extends and which is designed to engage the acetabulum 82, and an outer portion 202b which extends from the inner portion 202a and is configured to extend over a rim portion 84 of the acetabulum 82. The outer portion 202b extends sufficiently beyond the rim 84 to the periacetabular area of the pelvis to accommodate the marker elements 250. The patient specific body 202 has an underside bone-engaging three-dimensional engagement surface 208 that is custom-made or patient-specific to conform and mirror in complementary surfaces of the acetabulum 82, rim 84 (with or without the transverse acetabular ligament 83) or other periacetabular surfaces of the pelvis 80 of the specific patient by using a three-dimensional image or model of the acetabulum and surrounding pelvic area of the patient, as described above. The engagement surface 208 enables the acetabular guide 100 to nest or closely mate relative to the complementarily acetabular surface of the patient. The acetabular guide 200 can be designed to have generally small thickness, such that it can form a lightweight three-dimensional shell from which the guiding element 204 and marker elements 250 extend.
Referring to FIGS. 6-9, a method for reaming and preparing the acetabulum for an implant is described in connection with the patient-specific acetabular guides 100. The acetabular guides 200 can also be used, although the marker elements 250 are not utilized in this method. Referring to FIG. 6, a patient-specific acetabular guide 100 (or 200) is placed in a unique position on the acetabulum/rim/transverse acetabular ligament depending on the fitment option, as determined in the preoperative plan for the specific patient, and establishes the alignment axis A along the guiding element 104. An elongated guiding tool 300, such as a guiding handle 300 can be attached to the guiding element 104 such that the center axis of the guiding handle 300 coincides with the alignment axis A. The guiding handle 300 can include a proximal gripping portion 302, an elongated shaft 304 extending from the gripping portion 302 and a coupling distal portion or removable adapter tip 306 which can be removably coupled to the guiding element 104 such that the guiding handle 300 is aligned along the alignment axis A. The distal portion 306 can include, for example, a bore 308 for receiving the guiding element 104. The guiding element 104 and the bore 308 can be of sufficient length for the guiding handle 300 to be removably yet stably coupled to the guiding element 104 for indicating the alignment axis A without wobbling or other misaligning motion. The guiding tool 300 can also be an acetabular cup inserter, such as the inserter 550 illustrated in FIGS. 9 and 16, which can be fitted with the removable adapter tip 306 for removably connecting to the guiding element 104.
With continuing reference to FIG. 6, a support device or jig or outrigger 400 can be secured on the pelvis 80. The support device 400 can be used to orient an alignment pin or rod 402 along an axis A′ parallel to the alignment axis A. More specifically, the support device 400 can include a universal rotational adjustment mechanism 406 and a pivotable/translational adjustment mechanism 408 for removably engaging the shaft 304 and aligning the alignment rod 402 parallel to the shaft 304 and, therefore, parallel to the alignment axis. In the exemplary embodiment of FIG. 6, the support device 400 can include a leg 410 that can be attached to the bone with a bone fastener through a hole 412 at a foot or base 414 of the leg 410. The support device 400 can also include an arm 416 that is slidably coupled to the leg 410 to allow for translational motion of the arm 416 relative to the leg 410. The arm 416 can have, for example, an elongated slot 418 that slidably receives a fastener head 420 of a fastener 422, such as a screw or bolt that is received through a distal flange 424 of the leg 410. The flange 424 can also pivot relative to the arm 416 about an axis B along the axis of the leg 410 and fastener 422. The head 420 of the fastener 422 can be rotated to lock the flange 424 and the leg 410 relative to the arm 416. The interconnection of the arm 416, the leg 410 and the fastener 422 collectively form the pivotable/translational adjustment mechanism 408.
With continued reference to FIG. 6, the arm 416 can be substantially planar and include at a distal end a housing 426 forming a socket 428 for a ball 430 at a distal end of a connector 432. The socket 428 and the ball 430 form a universal (ball) joint of the universal rotational adjustment mechanism 406 for rotationally adjusting the connector 432 relative to the arm 416. After adjustment, the orientation of the connector 432 can be locked with a fastener 436 through the housing 426. The connector 432 supports the alignment rod 402 and includes an engagement surface 434 that can engage the shaft 304, by a snap-on or other quick connect/disconnect connection. The support device 400 can be adjusted using the adjustment mechanisms 406, 408 described above such that the alignment rod 402 along axis A′ is parallel to the alignment axis A of the shaft 304. In other words, the alignment rod 402 can serve as a marker for the orientation of the alignment axis A to guide reaming and cup insertion procedures as discussed below.
After the support device 400 is locked in a position such that the orientation of the alignment rod 402 along axis A′ is fixed and parallel to the alignment axis A, the guiding handle 300 (or the acetabular inserter 550) is disengaged from the engagement surface 434 of the connector 432 and the acetabular guide 100 and is removed. Referring to FIG. 7, a drilling element 440 can be guided through the bore 106 of the guiding element 104 of the acetabular guide 100 to drill a pilot hole 89 in the acetabulum 82 along the alignment axis A, as shown in FIG. 8A. The drilling element 440 can include a stop 442 at a pre-determined position to prevent over drilling or drilling through the wall of the acetabulum 82. The depth of drilling and the location of the stop 442 on the drilling element 440 can be determined during the pre-operative plan for the specific patient. The support device 400 and alignment rod 402 remain attached to the pelvis as shown in FIG. 6, although not fully shown in FIG. 7. After the pilot hole 89 is drilled, the acetabular guide 100 is removed.
Referring to FIG. 8A, a reamer 500 can be guided along the alignment axis A to ream the acetabulum 82. Another embodiment of a reamer 500′ according to the present teachings is illustrated in FIGS. 8B and 8C. The reamers 500 and 500′ can be used interchangeably and similar elements will be referenced with the same numerals herein below. The reamer 500 (500′) can include a trocar or other guiding pin 502 that is sized to fit and be received in the pilot hole 89 of the acetabulum 82 for stabilizing and guiding the reamer 500 (500′) along the alignment axis A, i.e., at a predetermined location and orientation. This guided reaming arrangement enables the surgeon to recreate the preoperative planned position and orientation for reaming the acetabulum 82 and implanting the acetabular component. The alignment rod 402 which is supported by the support device 400 along the axis A′ that is parallel to the alignment axis A can also help to guide the reamer 500 (500′).
The reamer 500 (500′) can include a plurality of curved reaming blades 504 and a supporting shaft 506 for a reamer driver or reamer handle. The curved blades 504 can be attached to a plurality of curved supporting elements 508 in the form of spherical leaves or spherical section/portions that collectively define a semi-spherical surface corresponding to the shape and size of the acetabular component to be implanted in the acetabulum after reaming. The blades 504 can be removable and replaceable or disposable. The entire reamer head that includes the blades 504 and the support element 508 can also be disposable. A reamer 500 with four disposable blades 504 is illustrated in FIG. 8A, while the reamer 500′ shown in FIGS. 8B and 8C includes only two reamer blades 504. Referring to FIG. 8C, the guiding pin 502 can be spring biased to provide a tactile feedback during reaming. A spring or other biasing element 510 can be constrained between a proximal end 512 of the guiding pin 502 and a wall 514 of the supporting shaft 506. A set screw or fastener 516 can be used to stabilize the guiding pin 502 while allowing slidable movement along the alignment axis during reaming. The spring 510 can surround the fastener 516, as shown in FIG. 8C. Specifically, the fastener 516 is threaded to a blind bore 503 of the guiding pin 502 such that the fastener 516 and the guiding pin can move together along the alignment axis A by or against the action of the spring 510. The embodiments of FIGS. 8B and 8C also include a base ring 518 integrally attached to the shaft 506 providing additional stability.
Referring to FIG. 9, after the acetabulum 82 has been reamed an acetabular inserter 550 can be coupled to an acetabular cup 280 by an end coupler 552 at the distal end of a shaft 554 of the acetabular inserter 550. The end coupler 552 can be removable. As seen in FIG. 9, the shaft 554 can be slidably and removably coupled to the engagement surface 434 of the connector 432 of the support device 400, such that the shaft is oriented along the alignment axis A for insertion of the acetabular cup 280 according to the preoperatively planned position and orientation.
Referring to FIGS. 10-13, another method of reaming and preparing the acetabulum 82 is illustrated using the acetabular guides 200 with fitment options 200A and 200B, as described above in connection with FIGS. 4 and 5. In this method, marker pins 260 are inserted through the corresponding bores 252 of the marker elements 250 and attached to the bone in locations and orientations parallel to an axis B, as determined during the preoperative plan. The marker pins 260 can guide the location of a secondary guide 600, shown in FIG. 13, which is designed according to the pre-operative plan to be guided by the marker pins 260, as discussed below.
As was described above in connection with FIG. 7 and the acetabular guides 100, a pilot hole 89 is drilled into the acetabulum 82 through the guiding element 204 with a drilling element 440 until the stop 442 of the drilling element 440 reached the upper surface of the guiding element 204 of the acetabular guide 200. The acetabular guide 200 can be slidably lifted off the marker pins 260 and removed, leaving the marker pins 260 attached to the bone. A reamer 500, 500′ with a guiding pin 502 can be used to ream the acetabulum 82, as discussed above in connection with FIG. 7. The acetabular cup 280 can be inserted using an acetabular inserter 550 without the aid of an alignment orientation, although a support device 400 with an alignment rod 402 can also be used if desired.
After the acetabular cup 280 is inserted but not impacted, a secondary guide 600 having guiding elements 650 with bores 652 complementarily corresponding to the orientation and relative location of the marker elements 250 of the acetabular guide 200 is placed over the marker pins 260. The secondary guide 600 can be designed during the pre-operative plan such that the bores 652 are complementary to the location and orientation of the marker elements 250 of the acetabular guide. The secondary guide 600 can include extender elements 604 supporting an arcuate or crescent-shaped planar flange 602 having parallel inferior and superior surfaces 608, 610 designed during the pre-operative plan to be oriented parallel to a rim 282 of the acetabular cup 280, when the acetabular cup 280 is positioned in the predetermined position and orientation. The orientation and position of the acetabular cup 280 is adjusted using the secondary guide 600, such that the planar flange 602 (and the inferior and superior surfaces 608, 610 of the planar flange 602) and the rim 282 are parallel. It is noted that this method does not make use of the support device 400, although the acetabular guides 200 can also be used with the supporting device, at the discretion of the surgeon. Depending on the surgeon's preferences, any selected or all the acetabular guides 100 (110A, 100B, 100C) and 200 (200A, 200B) and the associated instruments including the reamer 500, 500′, the supporting device 400, the drilling element 440 with the stop 442, alignment rod 402, marker pins 260 and the secondary guide 600 can be provided in a surgical kit together with the acetabular cup 280 and/or additional implants and instruments.
Referring to FIGS. 15A and 15B, an orientation device 800 can be used to establish the alignment axis A for preparing a joint surface with a cutting tool and inserting an implant along the alignment axis. The cutting tool can be a milling, reaming, resurfacing, burring, sawing or any other tool for preparing the joint surface of the patient. The joint can be a hip, knee, elbow, shoulder or other joint surface.
Referring to FIGS. 14-17, the orientation device 800 is illustrating in exemplary procedures for reaming the acetabulum 82 and inserting an acetabular cup 280. The orientation device 800 can be designed to indicate whether an axis of a shaft (304, 554, 555) or other longitudinal member of an instrument to be in preparation of the joint surface and/or insertion of the implant is aligned along a predetermined and patient-specific orientation when the orientation device 800 is attached to the longitudinal member. The longitudinal member can be a shaft of any surgical instrument including, for example, cutting/milling/reaming/burring tools, implant inserters and impactors. The orientation device 800 can also be attached any shaft that can be removably coupled to a modular tool. In the exemplary embodiments illustrating the use of the orientation device 800 for an acetabular joint surface, the longitudinal member can be the shaft 304 of the guiding handle 300 (FIG. 6, FIG. 14), the shaft 554 of the inserter 550 (FIG. 9, FIG. 16) or a shaft 555 coupled to a reamer 500 (FIG. 17). The shafts 304, 554 and 555 can be removably coupled to the respective instruments. In some embodiments, a single (the same) shaft can be used for more than one instrument.
Referring to FIGS. 15A and 15B, the orientation device 800 can be a three-dimensional leveling device having a three-dimensional orientation capability. For example, the orientation device 800 can include a transparent dome-shaped surface 808, such as a portion of a sphere or a hemi-sphere or a dome, attached to a planar base 803. The volume between the surface 808 and the planar surface can be filled with a liquid having a single air bubble or leveling bubble 802 to act as an orientation indicator. The shape of the orientation device 800 allows the bubble 802 to move in three-dimensional space indicating an orientation in three-dimensions relative to the base 803 and is a three-dimensional symmetric surface, such as a hemispherical surface. A coupler 804 can extend from the base 803 for removably coupling the orientation device to a shaft. The coupler 804 can include, for example, a snap-on groove 806 configured to removably attach to any one of the shafts 304, 554 and 555 as discussed above. The coupler 804 can be keyed to the shaft with a tongue-in-groove or other keying device. The keying device can include a first key component 811 on the coupler 803 and a second key component 311 on shaft 304 (511 on shafts 554 and 555) mating with the first key component 811. The first key component 811 can be an extension or tab or key and the second key component 311 or 511 can be a mating slot or channel or groove, or the other way around. The coupler 804 can be integrally or removably coupled to base 803. The coupler 804 can be attached to the base with adhesive, hoop-and-loop material, respective tongue-and-groove or deflectable snap-on elements or other connections. In some embodiments, the coupler 804 can be attachable to shafts with variable size diameters. Alternatively, a variety of removable couplers 804 having grooves 806 with different sizes can be provided for coupling to shafts of different diameters.
The orientation device 800 can be calibrated using one of the patient specific acetabular guides 100 or 200, in any fitment option. Referring to FIG. 14, for example, a patient-specific acetabular guide is positioned in a unique location on the patient's acetabulum 82. The guiding element 104 of the acetabular guide 100 is oriented along the pre-operatively determined patient-specific alignment axis A, as discussed above in connection with FIGS. 1-5, for example. The guiding handle 300 (or the acetabular inserter 550 with the adapter tip 306, as discussed above) with the orientation device 800 keyed thereon is coupled and keyed to the guiding element 104 and the shaft 304 of the guiding handle 300 (or the acetabular inserter 550 with the adapter tip 306, as discussed above) becomes oriented along the same alignment axis A, as discussed above, in connection with FIG. 4. While the shaft 304 is oriented along the alignment axis A, the position of the bubble 802 is marked using a marker, pencil or other marking instrument with a mark 801, which can be, for example a dot at its center or a circle surrounding and centered about the bubble 802. When the orientation device 800 is subsequently attached and keyed to another shaft, that shaft can be aligned along the alignment axis A by ensuring that the bubble 802 aligns and is centered relative to the mark 801, as discussed below. Referring to FIGS. 16 and 17, the orientation device 800, can be used to align the shaft 554 of the inserter 550 and/or the shaft 555 of a reamer 500.
The orientation device 800 can be used with any of the methods discussed for preparing the acetabulum as an additional redundant alignment device, or with the following method. The orientation device 800 is first calibrated intra-operatively as discussed above in connection with FIG. 14. Specifically, the pre-selected patient-specific guide 100 is attached in a pre-operatively determined unique location relative to the acetabulum 82 of the specific patient. In this position, the guiding element 104 of the acetabular axis is oriented along the pre-operatively determined alignment axis A. The guiding handle 300 (or the acetabular inserter 550 with the adapter tip 306, as discussed above) with the orientation device 800 coupled and keyed thereon can be coupled to the acetabular guide 100 such that the guiding element 104 is received and keyed in the bore 308 of the distal portion 306 of the guiding handle 300 (or the acetabular inserter 550 with the adapter tip 306, as discussed above), thereby aligning the shaft 304 of the guiding handle 300 along the alignment axis A. The position of the bubble 802 relative to the base 803 is noted and a mark 801 is placed on the surface 808 centered relative to the bubble. The mark 801 can be made with a marker or other writing or marking instrument.
The guiding handle 300 (or the acetabular inserter 550 with the adapter tip 306, as discussed above) is removed from the acetabular guide 100. If a guiding handle 300 was used, then the orientation device 800 is removed from the guiding handle 300. If the acetabular inserter with the adapter tip 306 was used, then the orientation device 800 remains on the acetabular inserter 550, but the adapter tip 306 is removed and replaced with the end coupler 552, shown in FIG. 16. The acetabular guide 100 can be optionally used to drill a pilot hole 89 in the acetabulum 82, as discussed above, for example in connection with FIG. 7. Otherwise, the acetabular guide 100 is removed from the patient without drilling a pilot hole 89. A reamer, such as the reamer 500 discussed above in connection with FIG. 8A, for example, or other reamer can be used the ream the acetabulum 82 along the alignment axis A. More specifically, and referring to FIG. 17, a driver handle having a shaft 555 is coupled to the reamer 500. The orientation device 800 is connected to the shaft 555. The orientation of the shaft 555 is adjusted such that the orientation device 800 indicates alignment along the alignment axis A, i.e., the bubble 802 is centered relative to the mark 801. After reaming the acetabulum 82, the orientation device 800 can be attached to the shaft 554 of the inserter 500 for inserting the acetabular implant 280 into the prepared acetabulum 82, as shown in FIG. 16.
Although the orientation device 800 was described above in connection with an acetabular joint, the orientation device 800 can be used conveniently for aligning a variety of surgical instruments used during the preparation of any joint surface of a patient for receiving an implant in orthopedic surgery. It can provide alignment accuracy when calibrated with patient-specific guides that include guiding elements designed during a pre-operative plan for a specific patient. Several disposable or reusable orientation devices 800 with various patient-specific guides and guiding handles or modular shafts can be included in a surgical kit for a specific patient. For example, a number of orientation devices 800 can be included in a kit with one or more acetabular guides 100, 200 and other instruments that can be modularly coupled to the guiding elements 104, 204 of the acetabular guides for an acetabular joint replacement procedure. Guiding handles or other modular shafts, as well as reamers, inserters and other instruments and/or implant can also be included in the surgical kit. Marking instruments, such as off-the-shelf markers, disposable or other sterilizable markers can also be included. Implant components for the specific patient can also be included in the surgical kit.
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. A surgical system for preparing a surface of a joint to receive an implant, the surgical system comprising:
a guide for a hip joint surface of a patient, the guide configured to engage the hip joint surface of the joint and having a guiding element oriented along an alignment axis;
a guiding tool having a shaft couplable to the guiding element of the guide such that the shaft of the guiding tool is oriented along the alignment axis; and
a three-dimensional orientation device having a transparent outer surface and an inner bubble viewable through the outer surface, the orientation device removably couplable to the shaft of the guiding tool and intra-operatively calibrated by marking with a mark on the outer surface a position of the bubble to indicate an orientation of the alignment axis, such that, after calibration, the orientation device can be removably coupled to a shaft of a surgical instrument to align the shaft along the alignment axis by changing the orientation of the shaft of the surgical instrument to center the bubble around the mark.

2. The surgical system of claim 1, further comprising a reamer orientable along the alignment axis using the orientation device.

3. The surgical system of claim 1, further comprising an implant inserter orientable along the alignment axis using the orientation device.

4. The surgical system of claim 1, further comprising a plurality of orientation devices.

5. The surgical system of claim 4, wherein the orientation devices are disposable.

6. The surgical system of claim 1, wherein the transparent outer surface is a dome-shaped surface and the orientation device has a base.

7. The surgical system of claim 6, further comprising a coupler for keying and coupling the base of the orientation device to an instrument shaft.

8. The surgical system of claim 7, wherein the coupler is removably coupled to the base.

9. The surgical system of claim 6, wherein the bubble is moveable in three-dimensional space to indicate an orientation in three-dimensions relative to the base.

10. The surgical system of claim 1, further comprising a second guide.

11. The surgical system of claim 10, wherein the second guide is designed to fit to a portion of the hip joint surface of the joint that differs from a second portion of the hip joint surface that is engageable by the guide.

12. The surgical system of claim 1, wherein the guide comprises a patient-specific acetabular guide having a patient-specific surface complementary to the surface of the joint for nesting engagement and the patient-specific surface is constructed as a mirror surface of the acetabular area from medical images of the patient obtained preoperatively, and wherein the alignment axis determined during a preoperative plan of the specific patient for implant alignment.

13. A surgical system for preparing a joint surface of a patient to receive an implant, the surgical system comprising:
a patient-specific acetabular guide for a hip joint surface of a patient, the acetabular guide having a patient-specific surface complementary to an acetabular area of the patient, the complementary surface constructed as a mirror surface of the acetabular area from medical images of the patient obtained preoperatively, the acetabular guide having a guiding element oriented along a patient-specific alignment axis, the alignment axis determined during a preoperative plan of the specific patient for implant alignment;
a guiding tool having a shaft couplable to the guiding element of the patient-specific guide such that the shaft of the guiding tool is oriented along the alignment axis; and
a three-dimensional orientation device having a transparent outer surface and an inner bubble viewable through the outer surface, the orientation device removably couplable to the shaft of the guiding tool and intra-operatively calibrated by marking with a mark on the outer surface a position of the bubble to indicate the orientation of the alignment axis, such that, after calibration, the orientation device can be removably coupled to a shaft of a surgical instrument to align the shaft of the surgical instrument along the alignment axis by changing the orientation of the shaft of the surgical instrument to center the bubble around the mark.

14. The surgical system of claim 13, further comprising an acetabular inserter having a removable adapter tip couplable to the guiding element of the acetabular guide.

15. The surgical system of claim 13, further comprising a reamer having a shaft couplable to the orientation device.

16. The surgical system of claim 15, further comprising a drill element with a drilling stop at a predetermined position for preventing over drilling of the acetabulum through a bore of the guiding element of the acetabular guide.

17. The surgical system of claim 13, wherein the orientation device has a transparent dome-shaped surface and a base.

18. The surgical system of claim 17, wherein the base has a coupler for coupling the orientation device to a shaft of an instrument.

19. A surgical system for preparing a joint surface of a patient to receive an implant, the surgical system comprising:
a patient-specific acetabular guide for a hip joint surface of a patient, the acetabular guide having a patient-specific surface complementary to an acetabular area of the patient, the complementary surface constructed as a mirror surface of the acetabular area from medical images of the patient obtained preoperatively, the acetabular guide having a guiding element oriented along a patient-specific alignment axis, the alignment axis determined during a preoperative plan of the specific patient for implant alignment;
a guiding tool having a shaft couplable to the guiding element of the patient-specific guide such that the shaft of the guiding tool is oriented along the alignment axis;
a surgical instrument having a shaft;
a three-dimensional orientation device having a transparent dome-shaped surface, a base outer and an inner bubble viewable through the dome-shaped surface, the orientation device having a coupler extending from the base and removably couplable to the shaft of the guiding tool and intra-operatively calibrated by marking with a mark on the dome-shaped surface a position of the bubble to indicate the orientation of the alignment axis, such that, after calibration, the orientation device can be removably coupled to the shaft of the surgical instrument to align the shaft of the surgical instrument along the alignment axis by changing the orientation of the shaft of the surgical instrument to center the bubble around the mark.

20. The surgical system of claim 19, wherein the surgical instrument is a reamer.

21. The surgical system of claim 19, wherein the surgical instrument is an acetabular inserter.