DEVICES AND METHODS FOR HIP REPLACEMENT
Devices and methods for use in hip replacement surgery can incorporate computer models of a patient's acetabulum and surrounding bone structure, a first patient-specific jig designed from the computer model and configured to correspond to a final installation position and orientation of a prosthetic him implant, a second patient-specific jig, also designed from the computer model, configured to refine the procedure, if necessary, following use of the first patient-specific jig, and/or a third patient specific jig, designed from the computer model, configured to refine the procedure, if necessary, following use of the first and second patient-specific jigs, allowing the surgeon to properly position and orient the hip prosthesis. Also shown and described are novel devices for implanting an acetabular cup.
1. Technical Field
The present disclosure relates to devices and methods for the replacement of joints, and more particularly, to patient-specific hip replacement devices, including methods of manufacturing and using such devices for achieving accurate hip replacement based on computer generated imaging of a patient.
2. Background of the Invention
One known method of treating hip and other joints with arthritis and other medical conditions is to replace surfaces of articulating joints with prosthetic devices through surgical procedures. It is critical that such prosthetic devices are accurately designed and manufactured, and are installed correctly in order to relieve pain and provide an effective treatment method for such ailments. An orthopedic surgeon performing such joint replacement on a patient seeks to ensure, through surgery, adequate placement of the prosthetic and proper reconstruction of the joint being replaced. Prosthetic components used to replace a joint may placed optimally by templates and jigs according to the unique anatomy of a patient before surgery occurs. A particular patient's bone structure symmetry is one important consideration that a surgeon must consider when performing joint replacement surgery. Additionally, malposition of joint replacement prosthetics can result in premature wear of the bearing surfaces, which may require additional surgeries to correct.
In the case of a hip, the condition of the patient's joint may require a partial or total replacement. A partial hip replacement involves replacing the femoral head (the ball) of the damaged hip joint; however, the acetabulum (the socket) is not replaced in a partial hip replacement surgery. A total hip replacement includes replacing both the femoral head and the acetabulum with prosthetic devices. The femoral head is replaced with a femoral prosthetic that typically includes a head portion and a stem. The stem extends into the femur of the patient and is utilized to secure the femoral device to the femur, with the head portion protruding out from the femur. The acetabulum is then resurfaced and replaced with a cup-shaped acetabular device. The cup-shaped acetabular device provides a bearing surface for the head portion of the femoral prosthetic to allow a desirable amount of range of motion via the joint upon total hip replacement.
To replace the acetabulum effectively, a surgeon will typically enlarge the acetabulum with a reamer machine and reamer head to create a resurfaced cavity to receive a prosthetic acetabular cup, which may or may not be secured by cement or bone screws. One particular issue of concern during the reaming portion of the surgery is that the cutting portion of the reamer is hemispherical while the prosthetic acetabular cup is typically sub-hemispherical. If the acetabulum is reamed too deeply, the prosthetic acetabular cup will be positioned too deep within the reamed cavity. If the acetabulum is reamed too shallowly, the prosthetic acetabular cup will not be positioned deep enough. If the acetabulum is reamed at an improper angle, the prosthetic acetabular cup will not be installed properly. These imperfections can cause malalignment of the prosthetic hip joint. Thus, accurate reaming of the acetabulum and accurate positioning of the prosthetic acetabular cup are critical.
With the assistance of computer generated data derived from CT, MRI, or other scans, surgeons can more effectively determine proper alignment and positioning of the prosthetic acetabular cup in a patient through 3D modeling and rendering. While some surgeons use lasers during surgery in an attempt to properly place the prosthetic acetabular cup; however, accuracy and simplicity of existing devices and methods remain limited due to a variety of factors.
BRIEF SUMMARYThe present disclosure pertains to patient-specific hip replacement devices and methods of designing and manufacturing such devices for achieving accurate acetabular component placement during hip replacement surgery based on computer generated imaging of a particular patient. When an orthopedic surgeon recommends total hip replacement surgery for a particular patient, a variety of images may be obtained utilizing CT, MRI, and other scans to generate 3D modeling of the patient's bone structure, particularly the femur, the pelvic bone, and the coxal (hip) bone. From such 3D models, the surgeon may determine the specific, final location and orientation of an acetabular cup to be secured to the patient's acetabulum during surgery. Once the final location and orientation of the acetabular cup is determined, the surgeon (utilizing 3D images) may create a first patient-specific jig and a second—and in some cases a third—patient-specific jig to be inserted into the patient's acetabulum during the surgery to ultimately achieve accurate positioning of the prosthetics to be installed in the patient.
The first patient-specific jig may be designed and manufactured based on a first patient-specific acetabulum male portion, while the second patient-specific jig may be designed and manufactured based on a second patient-specific acetabulum male portion. The first and second patient-specific acetabulum male portions can be developed as either physical components via a prototyping machine or visual representations in a 3D modeling software program based upon the 3D images of the patient. The male portion may or may not fully contact the patient's native acetabulum.
The first patient-specific jig can be a hemispherical shaped device or a sub-hemispherical shaped device, and can be comprised of composite material or other materials. The first patient-specific jig may include at least three alignment members for attachment to specific portions of the jig based on the specific bone structure of the patient's coxal bone. The at least three alignment members may assist with proper alignment of the first patient-specific jig in the patient's acetabulum during surgery. The three alignment members may include first, second, and third alignment members that are positioned at specific outer portions of the first patient-specific jig.
In some embodiments, the first, second, and third alignment members are designed and adapted to be hooked on or engaged with (or otherwise positioned at) particular portions of the coxal bone adjacent to the acetabulum to stabilize and properly orient the first patient-specific jig into the acetabulum during surgery. The first alignment member may be positioned on the first patient-specific jig to engage a particular portion of the medial rim of the acetabulum of the coxal bone. The second alignment member may be positioned on the first patient-specific jig to engage a particular portion of the greater sciatic notch of the coxal bone. The third alignment member may be positioned on the first patient-specific jig to engage a particular portion of the obturator foramen of the coxal bone. These alignment members may contact any three areas of bone peripheral to the acetabulum. Thus, the first patient-specific jig includes three reference points/members, specific to the patient's acetabulum of the coxal bone, to properly align the first patient-specific jig in the acetabulum during surgery and provide for proper orientation of the reaming machine when resurfacing the acetabulum.
The three alignment members may each comprise a pair of hooks or other devices that provide sufficient engagement with the particular portions of the coxal bone, as determined by the surgeon during preoperation. A person having ordinary skill in the art when reviewing this disclosure will understand that the three alignment members may be secured or removably attached or abutted to the first patient-specific jig by any currently or later known suitable means or attachment methods. The three alignment members may pivot, swivel or otherwise move relative to the first patient-specific jig, or they may be relatively immovable or inflexible to provide sufficient force against respective portions of the coxal bone to ensure proper orientation of the first patient-specific jig.
An aperture may be provided radially into or through the first patient-specific jig. The aperture is adapted to receive a guide pin or post extension through the aperture during surgery. The guide pin or extension is placed into the aperture and is removably secured to the coxal bone of the patient in a particular orientation and at a particular depth, as determined by the surgeon during preoperation. The first patient-specific jig is then removed while the guide post remains positioned in the coxal bone at the desired angle and position. The guide post may then serve as a guide for the reaming machine to accurately ream (resurface) the acetabulum to a predetermined depth and orientation for receiving the acetabular cup. The guide post and the reamer may have the same or similar central axes, as with conventional reaming machines and processes. In some embodiments the guide post may be removed prior to reaming and a surgeon at his discretion may use the guide post sinus tract as a guide to reaming without the guide post at a desired angle and to a desired depth.
As discussed above, it is critical to ream the acetabulum accurately and as determined during preoperation. Accordingly, the second patient-specific jig may be provided to assist in determining accurate reaming and proper alignment of the acetabular cup before the cup is implanted into the patient's acetabulum. As indicated below, a third patient-specific jig may also be used to progressively prepare the acetabulum to properly receive the prosthetic acetabular cup.
The second patient-specific jig may be designed and manufactured based on the second patient-specific male portion, but it may also be based on the first patient-specific male portion. The second patient-specific jig may include at least three alignment members, which may be based on the same or similar positions as the first, second, and third alignment members of the first patient-specific jig, or the positions may be different depending upon the patient's anatomy. The second patient-specific jig may also include an aperture having the same or similar position and orientation as the aperture in the first patient-specific jig, or it may be different. The second patient-specific jig may also have an axial length that is greater than a corresponding axial length of the first patient-specific jig due to the fact that the second patient-specific jig is utilized after some or all of the reaming of the acetabulum has occurred.
After the surgeon has removed the first patient-specific jig and reamed the acetabulum to a predetermined depth and orientation, the reamer device is removed from the acetabulum and the guide post may remain attached to the coxal bone or, in some instances, may be removed. The surgeon may then position the second patient-specific jig into the reamed acetabulum without a pin or, alternatively, onto the original guide pin or post extension, or alternatively over a different pin or post extension used to align the second patient-specific jig. Using the particular shape and size of the second patient-specific jig and, where applicable, the alignment of the aperture through the jig, the surgeon may then rotate and position the second patient-specific jig in the reamed acetabulum to determine whether additional reaming is required in one or more quadrants, or whether the acetabulum has been reamed accurately to receive the prosthetic acetabular cup. In furtherance of such determination, the surgeon may also utilize the alignment members attached to the second patient-specific jig, if they were designed and manufactured for attachment to the jig; it may be that the aperture and the shape of the second patient-specific jig is sufficient for purposes of accurate alignment of the prosthetic acetabular cup.
In some instances, if adequate remaining in any direction has not been accomplished and confirmed with only one or two jigs, there may be a need for additional reaming after which a third jig may be used. The third patient specific jig may be similar or different in regards to alignment members and guide post aperture orientation as the first and/or second patient specific jigs.
Once accurate reaming is accomplished through utilizing some or all of the above described devices and methods, the surgeon may then implant or secure the acetabular prosthetic cup to the reamed acetabulum in a traditional manner, such as with or without screws and with or without cement and with or without use of a guide pin or post extension.
The predetermined orientation of the apertures and the alignment members of both the first and second (and, as applicable, third) patient-specific jigs may provide the surgeon with a quick, accurate means to properly resurface the acetabulum without the use of additional devices and machines. This is possible because the positions of the alignment members of the first, second and third patient-specific jigs are based upon the patient's bone structure, thereby providing three reference points to accurately utilize the first jig, the guide post, the reamer, and the second and third jigs, as planned during preoperation based upon the 3D modeling images of the patient.
As mentioned above, the methods and systems of the present invention are based at least in part on pre-operating (pre-operative) imaging and at least in part on orthopedic surgical procedures based upon the pre-operative methods and systems. As is understood in the art, pre-operative imaging has a number of different purposes and generally is performed in order to subsequently guide the surgeon during the surgical procedure, allow for patient-specific tools and/or implants to be formed, etc. The present disclosure is part of a system for designing and constructing one or more patient-specific jigs for use in an orthopedic surgical procedure in which an acetabular component is prepared, orientated and implanted. The referenced systems and methods are now described more fully with reference to the accompanying drawings, in which one or more illustrated embodiments and/or arrangements of the systems and methods are shown. Aspects of the present systems and methods can take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.), or an embodiment combining software and hardware. One of skill in the art can appreciate that a software process can be transformed into an equivalent hardware structure, and a hardware structure can itself be transformed into an equivalent software process. Thus, the selection of a hardware implementation versus a software implementation is one of design choice and left to the implementer. Throughout this disclosure, the term “prosthetic implant” and “acetabular component” refer to cup-shaped implants that are installed into patients during hip replacement surgery.
In
At 106, the patient-specific device generator generates a first-patient specific jig image superimposed proximate the acetabulum of the bone surface image according to the installation position. At 108, a patient-specific device converter generates control data from the first patient-specific jig image and ends or moves to 110. At 110, the patient-specific device generator generates a second patient-specific jig image superimposed in the acetabulum of the bone surface image and ends or moves to 112. At step 112, the patient-specific device generator generates a third patient-specific jig image superimposed in the acetabulum of the bone surface image and ends.
As discussed above,
In
At step 602, three alignment members of the second patient-specific jig are respectively engaged with predefined selected areas proximate the acetabulum of the patient. At 604, a supplemental guide post is positioned through the aperture of the second patient-specific jig and is secured into the coxal bone of the patient. At 606, the second patient-specific jig is removed from the supplemental guide post and the acetabulum. At 608, the acetabulum is reamed with aid of a reaming machine. In some instances the guide post can be removed prior to reaming and the sinus tract in the bone from the guide post is used as a visual guide to ream at a desired orientation and to a desired depth. At 610, a third patient-specific jig is positioned in the reamed acetabulum of the patient. At 612, it is determined whether all three alignment members of the third patient-specific jig are engaged to respective selected areas proximate the acetabulum of the patient. If yes, at 616 the supplemental guide post may or may not be removed and the prosthesis implant is secured to the reamed acetabulum and then ends. If no, the method returns to 608 and the operations are repeated until it is determined that all three alignment members of the third patient-specific jig are engaged to respective selected areas proximate the acetabulum of the patient so that the prosthesis implant may be installed in the patient.
Once the installation position 708 is determined, a reference point 710 is established that represents a particular point in the coxal bone 704 of the patient for purposes of determining the depth to which a reaming machine will ream bone material, which will be further discussed below. The reference point 710 may be considered a point on the tangential plane of a hemispherical shaped surface, such as the outer surface shape of the acetabular component 700.
With continued reference to
The patient-specific jig 720 includes an aperture 722 and three alignment members 724a, 724b, 724c. The aperture 722 is formed through the patient-specific jig 720 at an angle that corresponds to the installation position 708 of the acetabular component 700. Depending upon the particular patient-specific jig 720 (i.e., the first, second, or third), the relative orientation of the aperture 722 may vary depending upon the required amount of bone to be removed and the particular required angle of a reaming head during operation, which is ultimately determined by the installation position 708 of the acetabular component 700. The angles of the various apertures for the various jigs are discussed further below.
The three alignment members 724a, 724b, 724c are attached to the patient-specific jig 720 at positions around a circumference end 726 (or distal end) of the patient-specific jig 720 depending upon the particular bone structure of the particular patient. The three alignment members 724a, 724b, 724c may be formed integral with the jig or may be attached to the jig with any suitable attachment means. The purpose of the three alignment members 724a, 724b, 724c help the surgeon: 1) determine the proper orientation of a guide post to be installed in the patient (
The positions of the three alignment members 724a, 724b, 724c will depend on which particular jig (i.e., first, second, or third jigs) the three alignment members are attached to. However, the positions the three alignment members 724a, 724b, 724c may be the same on each jig depending on the preoperative requirements determined by the surgeon and the computing systems. In one example and as shown on
The first patient-specific jig 730 includes an aperture 740 that extends from a reference end 742 to the circumference end 734 of the first patient-specific jig 730. The aperture 740 is sized and configured to receive a guide post positioned in a patient (
The second patient-specific jig 744 includes an aperture 750 that extends from a reference end 752 to the circumference end 748 of the second patient-specific jig 744. The aperture 750 is sized and configured to receive a supplemental guide post positioned in a patient (
The third patient-specific jig 754 includes an aperture 764 that extends from a reference end 766 to the circumference end 758 of the third patient-specific jig 754. The aperture 764 is sized and configured to receive the supplemental guide post positioned in a patient (
It will be appreciated that each or all of the alignment members of any one of the patient-specific jigs may be formed in various configuration and shapes. For example, an alignment member may be an arc shaped or other non-linear shaped member, or it may have two or more angles surfaces. The exact shape, position, and alignment of each alignment member is determined by the surgeon and the computing system during preoperative planning depending upon the specific bone structure of the patient and the installation position of the acetabulum component.
During preoperative planning and with reference to
With particular reference to
In other instances and where additional bone reaming is necessary but at a different angle than with respect to
The surgeon will then install the acetabular component 700 according to known techniques or over a supplemental guide post using a cannulated acetabular impactor and mallet device as described herein. For purposes of discussion,
The impactor tool 800 includes a head 802 and a handle 804. The head 802 includes a guide aperture 806 having a central axis X. During surgery and once the acetabulum is reamed to a desired depth, the acetabular component 700 is partially inserted into the reamed acetabulum. An elongated guide post 808 is installed in the coxal bone 704 and extends through a hole in the acetabular component 700, as known in the art. A cannulated acetabular impactor device 810 includes a cannulated channel 812 that receives the elongated guide post 808; the cannulated acetabular impactor device 810 may be threaded or slidably received over the elongated guide post 808. The cannulated acetabular impactor device 810 includes a distal end 814 biased against the cup portion of the acetabular component 700, and a proximal end 816 with a surface 818 to be impacted by the impactor tool 800. The guide aperture 806 of the impactor tool 800 slidably receives a portion of the guide post 808.
During installation of the actabular component 700, the surgeon holds the handle 804 and slidably engages the guide aperture 806 of the impactor tool 800 with the guide post 808. The surgeon then repeatedly impacts the surface 818 of the proximal end 816 of the cannulated acetabular impactor device 810 with the impactor tool 800, causing an impacting force against the acetabular component 700, until the acetabular component 700 is in its final position. Typically several impacts with the impactor tool 800 will suffice, and typically the surgeon can hear when the acetabular component 700 is seated flush against the acetabulum in its final position. One advantage of the impactor tool 800 is that impact against the elongated member 810 (and ultimately the acetabular component 700) occurs at approximately the same impact location upon each repeated impact with the tool 800. Typically, the surgeon uses a mallet or hammer without the assistance of any guidance, which can result in improper installation of the acetabular component 700. The guide aperture 806 of the impactor tool 800 ensures repeatable impact location and position of the impactor tool 800, which reduces or eliminates the possibility for human error during repeated impacts with a mallet or hammer.
The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.
These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
Claims
1-22. (canceled)
23. A method, comprising:
- using at least one bone surface image to generate three dimensional data corresponding to a bone structure of a patient;
- generating a prosthesis implant image superimposed over an image of an acetabulum and positioned according to a final installation position based on the three dimensional data;
- generating a patient specific jig image superimposed over the image of the acetabulum according to the installation position, the patient specific jig image having a body with at least three alignment members at positions corresponding to the installation position of the prosthesis implant image; and
- generating control data from the patient specific jig image, the control data configured to control operation of a machine for making a patient-specific jig.
24. The method of claim 23 wherein generating a prosthesis implant image includes generating a guide post image at least partially positioned through the image of the acetabulum, the guide post image oriented corresponding to the installation position of the prosthesis implant image.
25. The method of claim 24 wherein generating the patient-specific jig image includes generating an aperture image through the body image of the patient-specific jig image, said aperture image in a position corresponding to the guide post image.
26. The method of claim 24, further comprising generating a second patient-specific jig image superimposed proximate the image of the acetabulum, the second-patient specific jig image having a body image with at least three alignment member images corresponding to the installation position of the prosthesis implant image.
27. The method of claim 26 wherein generating the second patient-specific jig image includes generating an aperture image through the body image of the second patient-specific jig image, said aperture image in a position corresponding to the guide post image.
28. The method of claim 26, further comprising generating a third patient-specific jig image superimposed proximate the image of the acetabulum, the third patient-specific jig image having a body image with at least three alignment member images corresponding to the installation position of the prosthesis implant image.
29. The method of claim 28 wherein generating the third patient-specific jig image includes generating an aperture image through the body image of the second patient-specific jig image, said aperture image in a position corresponding to the guide post image.
30. The method of claim 29, wherein the body images of the patient specific jig, the second patient specific jig, and the third patient specific jig have different distances between respective proximal and distal ends thereof.
31. A method, comprising:
- positioning a first patient-specific jig in an acetabulum of a patient, the first patient-specific jig formed according to a predetermined installation position of a prosthesis implant to be secured to the patient, the first patient-specific jig having an aperture and three alignment members attached at respective positions to the first patient-specific jig corresponding to the installation position of the prosthesis implant;
- engaging each of said three alignment members to a predefined selected area of a coxal bone adjacent the acetabulum of the patient;
- positioning a guide post through the aperture of the first patient-specific jig and securing the guide post to the patient, the guide post positioned corresponding to the installation position of the prosthesis implant;
- removing the first patient-specific jig from the guide post; and
- reaming the acetabulum with a reaming machine, the guide post configured to guide the reaming machine in a desired position during reaming, with or without the guide post in place.
32. The method of claim 31, further comprising:
- determining whether the reaming machine reached a reference point of the installation position;
- if the reaming machine reached the reference point, removing the guide post and installing the prosthesis implant in the patient using a second patient specific jig and over a guide post;
- if the reaming machine has not reached the reference point, removing the guide post and positioning a second patient-specific jig in the reamed acetabulum of the patient, the second patient-specific jig formed according to the predetermined installation position, the second patient-specific jig having an aperture and three alignment members disposed at respective positions on the second patient-specific jig corresponding to the installation position;
- engaging each of said three alignment members to a predefined selected area of the coxal bone proximate the acetabulum of the patient;
- positioning a supplemental guide post through the aperture of the second patient-specific jig and securing the supplemental guide post to the patient, the supplemental guide post positioned corresponding to the installation position of the prosthesis implant;
- removing the second patient-specific jig from the supplemental guide post and the acetabulum; and
- reaming the acetabulum with a reaming machine, one of the supplemental guide post and the pilot hold sinus tract being used to guide the reaming machine in a desired position during reaming.
33. The method of claim 32, further comprising:
- positioning a third patient-specific jig in the reamed acetabulum of the patient, the third patient-specific jig formed according to the predetermined installation position, the third patient-specific jig having an aperture to receive the supplemental guide post, the third patient-specific jig having three alignment members disposed at respective positions on the third patient-specific jig corresponding to the installation position of the prosthesis implant;
- determining whether each of said three alignment members of the third patient-specific jig are engaged to said selected area proximate the acetabulum of the patient;
- if each of said three alignment members of the third patient-specific jig are not engaged to said selected area, repeating said reaming operation of the previous claim and the positioning operation of the present claim until all of said three alignment members of the third patient-specific jig are engaged to said selected areas, respectively; and
- if each of said three alignment members of the third patient-specific jig are engaged to said selected area, thereby indicating information that the installation reference point has been reached, securing the prosthesis implant to the reamed acetabulum over the guide post, with or without the guide post in place.
34. The method of claim 32 wherein securing the prosthesis implant includes impacting the prosthesis implant with an impactor tool, the impactor tool having a guide aperture with a central axis and configured to slidably receive a guide post secured to the patient.
35. The method of claim 34 wherein impacting the prosthesis implant with the impactor tool comprises repetitively impacting the prosthesis implant such that the guide aperture repetitively guides the impactor tool along the central axis, whereby each impact occurs approximately at the same impact point relative to the prosthesis implant.
36. The method of claim 35 comprising engaging a cannulated acetabular impactor device with the prosthesis implant, the cannulated acetabular impactor device having an aperture that receives the guide post, the cannulated acetabular impactor device having a first end biased to the prosthesis implant and a second end for impacting with the impactor tool.
37. A tool used for a joint replacement prosthesis comprising a body usable to cause impact to a prosthesis implant positioned in an acetabulum of a patient, the body having an aperture with a central axis, the aperture configured to slidably receive a guide post secured to a bone of the patient and configured to guide the body along the guide post.
38. The tool of claim 37 wherein the central axis of the guide aperture is coextensive with a central axis of the guide post.
39. The tool of claim 37 wherein the aperture is configured to repetitively guide the body along the guide post such that impact caused against the prosthesis implant occurs substantially at the same impact point relative to the installation position.
40. The tool of claim 37 wherein the body is configured to impact the prosthesis implant via an elongated member positionable between the prosthesis implant and the tool.
41. A device for use in implanting an acetabular cup having an exterior surface for being positioned against a patient and an opposing interior surface, the device comprising:
- an elongated shaft having an opening extending the length thereof;
- an enlarged impacting end having an exterior surface shaped to complement the interior surface of the acetabular cup, the impacting end having an opening extending therethrough, the opening being aligned with the opening in the elongated shaft; and
- a striking end, opposite the enlarged impacting end, the striking end having an opening therethrough, the opening being aligned with the opening in the elongated shaft.
42. The device of claim 41, further comprising:
- a rod sized to be received by the openings in the elongated shaft and impacting and striking ends of the device, the shaft being sufficiently long to project beyond both terminal ends of the device, a first end of the elongated shaft being adapted for engagement with the patient; and
- a weighted mass having an opening therethrough adapted to closely receive the rod such that the mass can slide along the rod and collide with the striking end of the device at one terminal end of its stroke, the rod maintaining the mass and the device in a desired alignment for seating the acetabular cup.
43. The method of claim 31 wherein the patient is a human.
Type: Application
Filed: May 30, 2013
Publication Date: Jun 26, 2014
Inventors: Michael Gillman (Laguna Beach, CA), Benjamin A. Gillman (Laguna Beach, CA)
Application Number: 13/906,234
International Classification: A61F 2/30 (20060101); A61F 2/34 (20060101); A61F 2/46 (20060101); A61B 17/17 (20060101);