Abstract:
An instrument for engaging a bearing configured to facilitate articulation of a femoral component and a tibial component. The instrument includes a first bearing engaging portion configured to engage a first end of the bearing, and a second bearing engaging portion configured to engage a second end of the bearing that is opposite to the first end. A coupling member of the instrument interconnects the first and the second bearing engaging portions. The coupling member is operable to move the second bearing engaging portion relative to the first bearing engaging portion to secure the bearing therebetween.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Application No. 61/791,223 filed on Mar. 15, 2013, the entire disclosure of which is incorporated herein by reference. 
    
    
     FIELD 
     The subject disclosure relates to a prosthetic system, and particularly to a knee prosthetic system. 
     BACKGROUND 
     This section provides background information related to the present disclosure, which is not necessarily prior art. 
     Various portions of an anatomy perform functions in a natural and, generally original, configuration. For example, bones can articulate relative to one another at joints. For example, at a knee joint a femur can articulate relative to a tibia in a generally natural state. The articulation between the femur and the tibia generally includes a medial condyle and a lateral condyle, and an inter-condylar region. 
     In the natural state, the articulation of the femur relative to the tibia can be pain-free and smooth due to various soft tissues between the two bones. Due to disease, injury, and other factors, the articulation between the femur and the tibia may become painful due to damage. The damage or painful region between the femur and the tibia may include all of the articulation regions or may only include damage to one of the condyles, such as the medial or the lateral condyle. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     The present teachings provide for an instrument for engaging a bearing configured to facilitate articulation of a femoral component and a tibial component. The instrument includes a first bearing engaging portion configured to engage a first end of the bearing, and a second bearing engaging portion configured to engage a second end of the bearing that is opposite to the first end. A coupling member interconnects the first and the second bearing engaging portions. The coupling member is operable to move the second bearing engaging portion relative to the first bearing engaging portion to secure the bearing therebetween. 
     The present teachings further provide for an instrument for engaging a bearing configured to facilitate articulation of a femoral component and a tibial component. The instrument includes a first bearing engaging portion configured to engage a first end of the bearing, and a second bearing engaging portion configured to engage a second end of the bearing that is opposite to the first end. A coupling member of the instrument includes an extension arm interconnecting the first and the second bearing engaging portions. The coupling member defines a throughbore from which the first bearing engaging portion extends. The extension arm extends parallel to and spaced apart from a longitudinal axis extending through an axial center of the throughbore. Rotation of the coupling member moves the coupling member along the longitudinal axis to move the second bearing engaging portion relative to the first bearing engaging portion. 
     The present teachings also provide for a method for positioning a bearing between a femoral component and a tibial component with a positioning instrument. The method includes the following: arranging a first bearing engaging portion of the instrument at a first end of the bearing; arranging a second bearing engaging portion of the instrument at a second end of the bearing that is opposite to the first end of the bearing; securing the instrument to the bearing by rotating in a first direction a coupling member of the instrument interconnecting the first and the second bearing engaging portions to move the second bearing engaging portion towards the first bearing engaging portion; positioning the bearing between the femoral component and the tibial component using the instrument; and rotating the coupling member in a second direction opposite to the first direction to move the first and the second bearing engaging portions apart and to decouple the instrument from the bearing. 
     According to various embodiments, a tool or instrument can be provided to insert a trial-bearing member and/or a prosthetic bearing member between a tibial and a femoral component. The tool can engage the bearing member to firmly hold the bearing member for insertion between the tibial and femoral member. Trialing can occur between the tibial and femoral member either while the tool engages the trial bearing or after the tool has been disengaged form the trial bearing. Additionally, the tool or instrument can position a prosthetic bearing member between the tibial and the femoral component and disengage the prosthetic bearing member for implantation of the prosthetic bearing. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is an environmental view of a femur, tibia, and prosthesis between the femur and tibia; 
         FIG. 2  is a side view of the prosthesis of  FIG. 1 ; 
         FIG. 3  is a perspective view of the prosthesis of  FIG. 1 ; 
         FIG. 4  is an environmental view of a femur, tibia, and prosthesis between the femur and tibia in flexion; 
         FIG. 5  is an environmental view of a femur, tibia, and prosthesis between the femur and tibia in extension; 
         FIG. 6  is a perspective view of a bearing manipulation instrument according to various embodiments; 
         FIG. 7  is a perspective view of a bearing according to the present teachings; 
         FIG. 8  is a perspective view of another bearing manipulation instrument according to various embodiments 
         FIG. 9A  and  FIG. 9B  illustrate another bearing according to the present teachings; 
         FIG. 10  is a perspective view of an additional bearing manipulation instrument according to the present teachings; and 
         FIG. 11  is a perspective view of yet another bearing according to the present teachings. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     With reference to  FIG. 1 , a prosthetic system or prosthesis  20  is illustrated. The prosthetic system  20  can include a femoral component  22  that is interconnected with a femur  24  of a patient. The prosthetic system  20  can further include a tibial component  30  that is interconnected with a tibia  32 . As illustrated in  FIG. 1 , the prosthetic system  20  is a uni-condylar prosthesis that is positioned on a medial portion of a leg of the patient. It is understood, however, that the prosthesis  20  can be positioned in a lateral condylar surface as well. Moreover, the prosthesis  20  can be positioned on both the medial and the lateral condyles of a single leg. Moreover the prosthesis  20  can be positioned on a left or a right leg. 
     Nevertheless, the prosthetic system  20  can further include a bearing member or component  40  that is positioned between the femoral component  22  and the tibial component  30 . The bearing member  40  can articulate relative to the tibial component  30  and/or relative to the femoral component  22 . As is understood in the art, the tibia  32  can bend and articulate relative to the femur  24  and the bearing member  40  contacts and allows smooth movement of the femoral component  22  relative to the tibial component  30 . The bearing component  40 , however, need not be fixed to the tibial component  30  and/or the femoral component  22 . 
     As is further understood, although not specifically illustrated in  FIG. 1 , soft tissues can surround the knee near and within the condylar regions. For example, medial and lateral ligaments can extend exterior to the femur  24  and the tibia  32 . The ligaments can interconnect and tightly surround the condylar region and the prosthesis  20 . Moreover, as illustrated in  FIG. 1  and in  FIGS. 4 and 5 , the tibia and/or the femur may be resected and/or otherwise prepared to receive the respective components. As illustrated in  FIG. 1 , a tibial wall  50  may be formed due to resection of the tibia  32 . The tibial wall  50  can assist in maintaining the tibial component  30  in a selected position during placement and use of the prosthetic system  20 . Accordingly, for example, during placement of a uni-condylar or partial knee prosthesis system, a working area may be substantially small. Moreover, an incision for inserting the uni-condylar prosthetic system  20  may also be substantially small. Various uni-condylar or partial knee prosthetic systems can include the Oxford® Partial Knee System as sold by Biomet, Inc. 
     As illustrated in  FIGS. 2 and 3 , the prosthetic system  20  can include the femoral component  22  that has a substantially smooth and polished exterior articulating surface  60 . Additionally, post and/or fixation members can contact or be inserted into the femur. The post members can include a first post  62  and a second post  64 . The femur  24  can be prepared by resecting selected portions of the femur and/or drilling bores to receive the posts  62  and/or  64 . 
     The tibial component  30  can include a substantially polished and/or smooth upper surface  70 , which can be an articulation surface, and a sidewall  72  that can also be substantially polished and/or smooth. A tibial fixation member  74  can extend from a surface opposite to the upper surface  70 . Again, the tibia  32  can be prepared to receive the tibial component  30  by resecting the tibial component, such as forming the tibial wall  50 , and/or forming a slot or groove the receive the tibial fixation member  74 . 
     Positioned between the femoral component  22  and the tibial component  30  can be the bearing member  40 . The bearing member  40  can include a tibial bearing side  80  and a femoral bearing side  82 . Each of the respective bearing sides can include contoured surfaces to engage the respective components, such as a substantially flat surface to engage the upper tibial surface  70  and a concave surface to engage and articulate with the articulating surface  60  of the femoral component  22 . Further, as discussed above, the bearing member  40  need not be fixed relative to either the femoral component  22  and/or the tibial component  30 . Accordingly, the bearing member  40  can articulate anteriorly and posteriorly generally in the direction of arrow  90  due to movement of the femur  24  relative to the tibia  32  which causes movement of the femoral component  22  relative to the tibial component  30 . 
     With reference to  FIG. 4 , the bearing member  40  can move posteriorly when the femur  24  is in flexion relative to the tibia  32 . Additionally, with reference to  FIG. 5 , the bearing member  40  can move anteriorly when the femur  24  is generally an extension relative to the tibia  32 . Therefore, the bearing member  40  is generally selected to provide an appropriate tension between the femur  24  and the tibia  32  of the soft tissue that is maintained between the femur  24  and the tibia  32 . Thus, the bearing member  40  may generally be positioned in a substantially or tight volume between the femur  24  and tibia  32 . The bearing member  40  may also generally be selected to provide an appropriate or selected tension of the soft tissues and/or prosthetic replacements that interconnect the femur  24  and the tibia  32  following the implantation of the prosthetic system  20 . The tensions of the soft tissue may provide a small and tight work area for insertion of the bearing member  40 . Accordingly, an instrument, as discussed herein, may assist in placement of the bearing member  40 . 
     According to various embodiments, therefore, with reference to  FIG. 6 , a bearing insertion system or instrument  100  is illustrated. The bearing insertion system  100  can engage a bearing member  40   a  ( FIG. 7 ) for positioning between the femoral component  22  and the tibial component  30 . It is understood that the bearing member  40   a  may be a trial bearing member for trialing tension and range of motion or a prosthetic bearing member for implantation during use of the prosthetic system  20 . It is further understood that the bearing member  40   a  may be both a trial bearing member and a prosthetic implant bearing member. Thus, a separate member for trialing and implantation for use of the prosthetic system  20  need not be provided. 
     The bearing insertion instrument  100  can generally include a graspable portion or handle  110 . The graspable portion  110  can include a handle or a first member or first section  112  that is positioned at an angle relative to a second member or second section  114 . The orientation of the first section  112  relative to the second section  114  can provide for a substantially ergonomic grasping of the instrument  100 . For example, the configuration of the first section  112  relative to the second section  114  can be substantially pistol or pistol grip shape. 
     The second section  114  can be interconnected with a coupling member  120 . The coupling member  120  can couple with a distal or terminal end of the second section  114  and/or pass over a length of the second section  114  such that a first bearing engaging portion  130  extends beyond the coupling member  120 . The coupling member  120  may define an internal thread that cooperates with an external thread of the second section  114 . Thus, rotating the coupling member  120  may move the coupling member  120  relative to the second section  114 . The first bearing engaging portion  130  can be a terminal end of the second section  114  or be provided as a portion that engages and/or extends from the coupling member  120  separate from the second section  114 . 
     According to various embodiments, however, the first bearing engaging portion  130  can be provided separate and opposed from a second bearing engaging portion  140 . The second bearing engaging portion  140  can be provided or formed with an extension and surrounding arm  150 . The two bearing engaging portions  130  and  140 , therefore, can be opposed to each other to engage the bearing member  40   a , as discussed further herein. The extension arm  150  can be coupled to the coupling member  120  according to various mechanisms, such as welding, adhesion, or being formed as a single piece with the coupling member  120 . Further, the first bearing engaging portion  130 , the second bearing engaging portion  140 , and/or the extension arm  150 , or other selected portions may be covered, coated, or overmolded with a selected material to cushion or protect the bearing member  40   a  and/or the anatomy. Selected covering materials can include silicone, radel, nylon, or other materials that can reduce or eliminate scratching of the prosthesis  20 . 
     The coupling member  120  can be rotated generally in the direction of Arrow  160 . Rotating the coupling member  120  can rotate the extension arm  150  around an axis  114   a  of the second section  114 . Accordingly, the extension arm  150  can be rotated to various orientations relative to the first section  112 . Thus, the extension arm  150  can be rotated to provide clearance for positioning the bearing member  40   a  relative to the positioned femoral component  22  and tibial component  30 , such as for clearing the resected tibial wall  50  and soft tissue portions relative to the knee. Also, the extension arm  150  can be rotated for use with either the right or left knee. 
     Additionally, rotating the coupling member  120  can move the coupling member  120  relative to a distal end  132  of the first bearing engaging portion  130 , such as via the threads discussed above. Also, a slot and groove engagement can provide axial movement of the coupling member  120  during rotation of the coupling member  120 . The movement of the coupling member  120  relative to the distal end  132  of the first coupling portion moves a distal end  142  of the second coupling portion relative to the distal end  132  of the first bearing engaging portion  130 . In this manner, the bearing member  40   a  can be engaged and disengaged from the instrument  100  by moving the second bearing engaging portion  140  generally in the direction of Arrow  170  to engage and disengage the bearing member  40   a.    
     The bearing member  40   a  can be engaged and disengaged with the instrument  100  relative to a first bore  180  and a second bore  184  in the bearing member  40   a  ( FIG. 7 ). The first bore  180  can be engaged in the first bearing engaging portion  130  and a second bore  184  can be engaged with the second bearing engaging portion  140 . The second bearing engaging portion  140  can be moved via the coupling member  120  to move the second bearing engaging portion  140  into the second bore  184 . Further rotation of the coupling member  120  can urge the bearing member  40   a  to move the first bore  180  over the first bearing engaging portion  130 . It is understood, however, that the bearing member  40   a  can be engaged between the first bearing engaging portion  130  and the second bearing engaging portion  140  by rotation of the coupling member  120  in an appropriately selected manner. 
     With reference to  FIG. 8 , an instrument  1000  can include the first section  112  and at least a portion of the second section  114 , as discussed above. A coupling member  1120  can be provided to rotate relative to the second section  114  in a manner similar to that discussed above. Nevertheless, a first engaging portion  1130  can be formed as an elongated bar to extend from a first end  1131  and a second end  1132 . A second engaging portion  1140  can include a second bar that extends from an end  1141  to a region  1142  that is coupled and extends from a coupling arm or extension arm  1150 . Rotating the coupling member  1120  can move the second engaging portion  1140  generally in the direction of Arrow  1170  relative to the first engaging portion  1130 . It is understood that the second engaging portion  1140  can move in either direction based upon rotation of the coupling member  1120 . Rotation of the coupling member  1120  can move the first engaging portion  1130  relative to the second engaging portion  1140  to engage a bearing member  40   a.    
     Bearing member  40   b  illustrated in  FIGS. 9A and 9B  can be a prosthetic implant bearing member or a trial bearing member, or a combination thereof. The bearing member  40   b  can include a first groove or depression  1200  and a second groove or depression  1210 . The first groove or depression  1200  can be engaged by the first engaging portion  1130  and the second groove or depression  1210  can be engaged by the second engaging portion  1140 . The bearing member  40   b , once engaged, can be manipulated relative to the femoral component  22  and the tibial component  30 . Again, the extension arm  1150  can be rotated relative to the graspable portion of the instrument  1000  to provide a clearance of various soft tissues and/or the bone portions, such as the tibial wall  50 . Accordingly, the bearing member  40   b  can be positioned relative to the positioned femoral component  22  and tibial component  30  with the instrument  1000 . 
     With reference to  FIG. 10 , an instrument  2000  can include portions similar to the instrument  100 , such as the first section  112  and at least a portion of the second section  114 . The instrument  2000 , however, can include a coupling portion  2120  that is positioned over the second section  114  and includes a detent, a first engaging portion, or a first coupling portion, member, or section  2130 . Extending from the coupling member  2120  can be a second engaging portion or a second coupling portion  2140  that extends from an end  2141  to a section  2142 . An extending arm  2150  can extend from the coupling member  2120  to the second engaging portion  2140 . The coupling member  2120  can be rotated generally in the direction of Arrow  160 , as discussed above, to move the first coupling section  2130  relative to the second coupling section  2140 . Movement of the first coupling section  2130  relative to the second coupling section  2140  can allow for engagement and coupling to a bearing member  40   c  illustrated in  FIG. 11 . 
     The bearing member  40   c  can be a trial bearing member, an implantable prosthetic bearing member, or a trial and implantable bearing prosthetic. The bearing member  40   c , however, can define or include a first bore  2200  to engage or receive the first engaging portion  2130 . The bearing member  40   c  can further include a groove or a depression  2300  to engage or receive the second engaging portion  2140 . Accordingly, the bearing member  40   c  can include a depression and a groove to receive respective projections and elongated members of the instrument  2000 . Engagement of the bearing member  40   c  onto the instrument  2000  can provide for a substantially rigid connection to the first projection  2130  due to its receipt within the first bore  2200 . The groove  2300  can then efficiently engage the second coupling portion  2140  without requiring precise placement of a second projection. Thus the instrument  2000  can allow for coupling to the bearing member  40   c  in a precise and rigid manner with speed and efficiency. During various operative procedures, it can be selected to perform the procedure with brevity for various purposes, such as reducing infection, time under anesthetic, and other patient concerns. 
     According to various embodiments, the first bearing engaging portions  130 ,  1130 ,  2130 , the second bearing engaging portions  140 ,  1140 ,  2140 , and/or the extension arms  150 ,  1150 ,  2150  or other selected portions may be covered, coated, or overmolded with a selected material to cushion or protect the bearing member  40   a ,  40   b ,  40   c  and/or the anatomy. Selected covering materials can include silicone, radel, nylon, or other materials that can reduce or eliminate scratching of the prosthesis  20 . The instrument, according to various embodiments, however, may engage the bearing member in an appropriate manner. 
     Further, the bearing member, according to various embodiments, can be engaged in the instrument in various and selected manners. The bearing member, according to various embodiments, can be engaged within the instrument according to various engagement systems and techniques. For example, as discussed above, the second section  114  can extend through the coupling member  120 , according to various embodiments, such that rotating the coupling member moves the second bearing engaging portion to engage and draw the bearing member towards the first engaging portion. In addition, or alternatively thereto, the coupling portion can be biased in either an open or a closed position, such as with a biasing spring. A user can overcome the biasing force on the coupling member to either engage or disengage the bearing member. For example, the coupling portion can be biased towards the first section  112  of the handle  110  into a closed position such that a user overcomes the biasing force to open the instrument to insert the bearing member and then the user allows the member to bias closed to engage the bearing member. The first engaging portion may also, or alternatively, be biased in either an open or a closed position. The bearing member can be inserted into the instrument against the biasing force of the first bearing engaging portion and the biasing force can then close the first bearing engaging portion to engage the bearing member. Additionally, or alternatively thereto, the first bearing engaging portion can be telescopically received or moveably received within the second section  114 . A screw drive or threaded member, for example, can move the first bearing engaging section between an open and closed engaging position relative to the bearing member. Accordingly, it is understood that the bearing member can be engaged within the instrument, according to various embodiments, to hold the bearing member relative to the instrument, according to various embodiments, for inserting the bearing member relative to the other prosthetic portions. 
     Accordingly, it is understood that an instrument can be provided to engage a bearing member on at least two ends of the bearing member. The bearing member can include an end that is generally positioned near the anterior portion of the patient and an end that is positioned near a posterior portion of a patient. The instrument, according to various embodiments, as discussed herein, can engage the bearing member tightly and precisely for efficient positioning of the bearing member relative to the femoral component  22  and the tibial component  30 . Additionally, the instrument, according to various embodiments can engage the bearing member by rotation of the coupling portion to tightly and securely engage the bearing member during a procedure. Nevertheless, rotation of a coupling member can also efficiently position portions of the instrument relative to the anatomy for reducing contact with portions of the anatomy and clearance for positioning the bearing member. Thus, the instrument can provide for efficient placement of the bearing for implantation and/or trialing of a prosthetic system. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.