The present invention is in the field of orthopedic surgical instrumentation (class 606/53). Specifically, the present invention relates to surgical instrumentation for use in bone reparation for the manipulation, placement or removal of an internal bone prosthesis (class 606/53; 86). More specifically, the present invention relates to prosthesis inserters, such as impactors, adapted to place or remove a bone repairing means through forceful contact, in which momentum is transferred from the force transferring means to the reparation means (class 606/53; 86; 99).
Surgical procedures for the implantation of orthopedic prosthetic assemblies often requires specialized tools specifically adapted for insertion of a particular component of the prosthetic assembly. In the field, a number of different inserter handles for use in a surgical procedure to hold and manipulate a prosthesis component during its implantation in a patient. Typically, inserter handles have a front end (mount end) adapted to receive and hold a particular prosthesis component during implantation, and to release the component upon completion of its installation. An example of such an existing inserter handle is described in WIPO Publication Number WO 2005/044153 to Lechot & Desarzens, the content of which is incorporated herein by reference.
In this type of inserter handle, the mount end is adapted to releasably mate with a prosthesis component via a threaded interface. The action for achieving the threaded interface between the mount and the component of the prosthetic assembly is accomplished using a screw knob disposed at the impactor end of the inserted handle. Rotating the screw knob rotates the threaded interface at the mound end of the inserter handle to securely engage or to disengage the prosthetic component. In practice, the prosthetic component is first securely screwed to the mount end of the inserter handle by the user rotating the screw knob. The combination of the inserter handle with the prosthetic component attached is used to seat the prosthetic component at its intended implantation site in the patient utilizing the impactor feature/function of the inserter handle. Once the prosthetic component is seated in a proper relationship in the installation site in the patient, the user counter-rotates the screw knob to disengage the threaded interface of the mount end from the prosthetic component, and the inserter handle is removed from the patient leaving the component in situ.
A disadvantage of this practice is that, once the proper relationship of the prosthetic component is achieved in the installation site, it is necessary as well to hold the positional relationship of the inserter handle relative to the installation site during the disengagement of the threaded interface of the mount end from the prosthetic component. Holding this positional relationship during disengagement can be problematic (e.g., because of the relatively substantial mass and length of the inserter handle, the time and amount of manipulation required to reverse the securely threaded interface, etc.). Therefore, it would be advantageous to the field to have an interface between the inserter handle and the prosthetic component that is quickly disengageable and requires little manipulation to accomplish. Additionally, it would be beneficial to have an interface that could accommodate a variety of prosthetic component configurations for combination with a given inserter handle.
The present invention is a mount adaptor/holder that is attachable to the mount end of an existing inserter handle, which adapts the inserter handle to quickly engage and to quickly disengage a component of an orthopedic prosthesis assembly. An example of an orthopedic prosthesis assembly is an artificial ball and rotator cup joint, comprising a ball prosthetic component receivable in a rotator cup prosthetic component. Such orthopedic prosthesis joint assemblies are known in the art.
The present adaptor/holder is designed to attach to the mount (or tool) end of an inserter handle via an existing threaded interface mechanism of the handle. The adaptor/holder then utilizes the inserter handle's existing mount tensioning mechanism to accomplish the quick engagement and disengagement of a component of an orthopedic prosthesis assembly. Upon activation of the inserter handle's tensioning mechanism, the adaptor mount receives and fixes a prosthetic component to the tool end of the inserter handle for use. Deactivation of the inserter handle's tensioning mechanism is quickly accomplished with minimal manipulation to rapidly release the prosthetic component. In the cases illustrated herein, the prosthetic component to be installed is a cup insert.
An important feature of the present prosthetic component holder is that it enables the prosthetic component to be detached from the inserter handle, in situ, without having to operate the drive assembly of the handle to release the component after its installation in a patient. This feature of the present holder and handle combination eliminates the need for a threaded interface on the prosthetic component. A benefit of this feature is that, unlike prior inserter devices, the entire instrument (the handle with the holder still attached) can be quickly removed from the surgical site without having to maintain the positioning of the handle relative to the prosthetic component (e.g., an insert cup) inside the patient, while unscrewing the drive linkage assembly to separate the handle from the insert cup. Additionally, in prior inserter handles, where the inserted cup is screwed to the tool end of the drive linkage, the unscrewing of the drive linkage assembly can apply rotational torque to the installed prosthesis cup, which can potentially cause the cup to move from its set position or even to become dislodged.
Referring now to the drawings, the details of preferred embodiments of the present invention are graphically and schematically illustrated. Like elements in the drawings are represented by like numbers, and any similar elements are represented by like numbers with a different lower case letter suffix.
As shown in
As also illustrated in
A cavity 66 is set into the front housing surface 44 of the housing 42. The cavity 66 communicates with the annular opening 54, and is a widening of the annular opening 54 disposed to receive the coupling mechanism 70 of the holder 40. The coupling mechanism 70 has a coupling yoke 72 slideably receivable into the cavity 66. The yoke 72 itself has a yoke bore 74 with a central yoke axis 76. The yoke 72 is slidably (and in the embodiments illustrated, rotatably) received within the cavity 66, and disposed to provide that the axis 76 of the yoke 72 is held substantially coaxial with the annulus axis 56 of the housing 42.
In the embodiments illustrated, two yoke linkages 80 pivotably connect the yoke 72 to the housing 42. Although two are shown, it is anticipated that only one such linkage is necessary to provide for satisfactory precision and performance of the coupling mechanism. However, it is clear to one of skill in the art that three or more such linkages could be practiced as well. In the present embodiment, each yoke linkage 80 included a link member 82 connected at a first link end 84 to the yoke 72 by a sliding pivot coupling 86 and at a second end 92 to the housing 42 by a simple pivot coupling 94. The couplings 86 & 94 each have a pivot pin 90. In the simple coupling 94, the pivot pin 90 passes through a clearance aperture 96 in the second end 92 of the link member 82, to be fixedly received in a pivot pin hole(s) 98 in the yoke 72. In the sliding coupling 86, the pivot pin 90 passes through a clearance slot 88 in the first end 84 of the link member 82, to be fixedly received in a pivot pin hole(s) 98 in the housing 42. The pivot pins 90 and pin holes 98 in the illustrated embodiment are friction/wedge fitted together. However, the ordinary skilled artisan knows how to select and substitute other pivot coupling equivalents to these and anticipated by the present invention, such as screw pins and threaded pivot pin holes.
A prosthesis contacting face 100 is disposed on each link member 82. The prosthesis face 100 is disposed to normally interface with a mounting surface 112 of prosthesis component 12 to be secured by the holder 40, and a drift pin 102 is fixed to the link member 82 and projects perpendicularly from the prosthesis face 100 relative to the drift axis 104 of the drift pin 102. The length L that the drift pin extends beyond the prosthesis face 100 is important, and is chosen as noted below.
As illustrated in
A biasing mechanism 116 is disposed within the cavity 66, and applies a force to the yoke 72 to slide the yoke 72 out of the cavity 66. Although, the biasing mechanism 116 in the embodiments illustrated was a single coil helical spring, other biasing mechanisms are anticipated for practice in the present invention. For example, multiple springs or resilient pads can be used. The movement of the yoke 72 out of the cavity 66 acts via the linkages 70 to hold the stop seat 110 of the link member 82 against the limit set pin 108 of the travel limiter 106. By this action, the angular relationship drift axis 104 of the drift pins 102 is set to normally be substantially parallel with each other and with the yoke axis. In this configuration, the drift pins 102 are disposed to be received into drift receivers 114 in the mounting surface 112 of the prosthesis component 12.
As shown in
As shown in
In use, the present holder 40 is attached to the drive end boss 18 of the inserter handle 10. In a first step A as shown in
Once the holder 40 is attached to the drive end boss 18 and engaged with the drive assembly 30, the prosthesis component 12 is positioned on the front surface 44 of the housing 42. In the embodiment illustrated, the prosthesis component 12 is a cup insert as is known in the field. To fully secure the prosthesis component 12 to the holder 40, and in turn, the holder 40 to the boss 18, the drive assembly lever 34 is pushed down and locked to draw the drive piston 20 into the boss 18 in a final step D. This actuates the coupling mechanism 70 of the holder 40 and causes the securing of the component 12 to the holder 40 and the holder 40 to the boss interface 16, as described above.
After the inserter handle 10 with the holder 40 and prosthetic component 12 attached is used to properly position the prosthetic component 12, in situ, in the patient's body, the drive assembly lever 34 is unlocked and released to free handle 10 and mount 40 combination from the prosthetic component 12. The inserter handle 10 and mount 40 are quickly free and removable from the having to unthread the draw piston 20 from the holder 40.
An advantage of the present invention is that, once the proper relationship of the prosthetic component is achieved in the installation site, it is not necessary to hold the positional relationship of the inserter handle relative to the installation site during the disengagement of the threaded interface of the mount end from the prosthetic component. An advantage of the present invention is that it allows an existing inserter handle to be quickly disengageable from an attached prosthetic component, and requires little manipulation to accomplish. An additionally advantage is that the present holder can provide an interface that can accommodate a variety of prosthetic component configurations for combination with a given inserter handle.
Multiple variations and modifications are possible in the embodiments of the invention described here. Although certain illustrative embodiments of the invention have been shown and described here, a wide range of modifications, changes, and substitutions is contemplated in the foregoing disclosure. While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another preferred embodiment thereof. In some instances, some features of the present invention may be employed without a corresponding use of the other features. Accordingly, it is appropriate that the foregoing description be construed broadly and understood as being given by way of illustration and example only, the spirit and scope of the invention being limited only by the appended claims.
The present application claims the benefit of prior filed U.S. Provisional Patent Application Ser. No. 60/871,300 filed 24 Dec. 2006, the content of which is incorporated herein by reference.
Number | Date | Country | |
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60871300 | Dec 2006 | US |