Apparatus for knee surgery and method of use

Abstract

The present invention comprises a set of instruments and a method for their use in preparing a knee joint to receive knee implants. The inventive instruments and method are generally suitable for knee joint surgery. Furthermore, they include features that make them suitable for performing a minimally invasive knee surgery in which a smaller than normal incision is made and oriented to preserve the quadriceps mechanism and protect the suprapatellar pouch. The instruments permit switching from a minimally invasive technique to a standard open technique at any point in the procedure. An illustrative set of instruments for total knee arthroplasty and an associated minimally invasive technique are described.

1 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, a medial side and a lateral side, the patella resection guide comprising:
 a first jaw for engaging said medial side of said patella;   a second jaw for engaging said lateral side of said patella;   means for moving the first jaw relative to the second jaw from a first position in which the jaws are disengaged from said medial and lateral sides of said patella to a second position in which the jaws are engaged with said medial and lateral sides of said patella, the means being actuable from a location that is medial or lateral of said patella; and   means for guiding a cutter to cut said patella.   
   
   
       2 . The patella resection guide of  claim 1  further comprising means for gauging the amount of bone to be resected. 
   
   
       3 . The patella resection guide of  claim 1  further comprising means for gauging the amount of bone that will remain after the patella is cut. 
   
   
       4 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, a medial side and a lateral side, the patella resection guide comprising:
 a first jaw shaped to engage said medial side of said patella;   a second jaw shaped to engage said lateral side of said patella;   a handle connecting the first and second jaws in translating relationship, the handle being actuable to move the jaws from a first position in which the jaws are disengaged from said medial and lateral sides of said patella to a second position in which the jaws are engaged with said medial and lateral sides of said patella, the handle being actuable from a location that is medial or lateral of said patella.   
   
   
       5 . The patella resection guide of  claim 4  wherein the jaws are have curved faces for engaging curved sides of said patella. 
   
   
       6 . The patella resection guide of  claim 4  wherein the handle comprises a guide arm connecting the first and second jaws, at least one of the first and second jaws mounted for translation along the guide arm to move from the first position to the second position. 
   
   
       7 . The patella resection guide of  claim 6  wherein the jaws remain parallel as they are moved from the first to second positions. 
   
   
       8 . The patella resection guide of  claim 7  wherein the handle comprises an actuator pivotably mounted on the handle at a first end and connected to one of said first and second jaws at a second end such that pivoting the actuator moves the jaws between the first and second positions. 
   
   
       9 . The patella resection guide of  claim 6  wherein the handle further comprises a first grip portion connected to the first jaw and a second grip portion connected to the second jaw, the first and second grip portions being parallel to one another, such that pressing the first and second grip portions together in parallel manner causes at least one of the first and second jaws to translate along the guide arm from the first position to the second position. 
   
   
       10 . The patella resection guide of  claim 4  further comprising a depth gauge removably mountable on the first side of the resection guide to indicate the amount of bone to be removed from said patella and alternately mountable on the second side of the resection guide to indicate the amount of bone to remain on said patella. 
   
   
       11 . The patella resection guide of  claim 4  further comprising a cutter guide to guide a cutter. 
   
   
       12 . The patella resection guide of  claim 11  wherein the cutter is selected from the list consisting of a saw blade, a side cutting reamer, a end cutting reamer, and a water jet cutter. 
   
   
       13 . A patella resection guide comprising:
 a first side;   a second side; and   a depth gauge removably mountable on the first side of the resection guide to indicate the amount of bone to be removed from said patella and alternately mountable on the second side of the resection guide to indicate the amount of bone to remain on said patella.   
   
   
       14 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, and a periphery around the patella, the patella resection guide comprising:
 a first jaw member shaped to engage said periphery of said patella;   a second jaw member shaped to engage said periphery of said patella, the second jaw member connected to the first jaw member in translating relation;   a first handle connected to the first jaw member;   a second handle connected to the second jaw member, the second handle being actuable to move the second jaw member in a motion plane toward and away from the first handle; and   a cutter guide adjacent the jaws, the cutter guide able to guide a cutter to cut in a plane parallel to the jaw motion plane.   
   
   
       15 . A patella resection guide for guiding a cutter to cut a patella having an anterior side, an opposite posterior side, and a periphery around the patella, the patella resection guide comprising:
 a first jaw member shaped to grip said periphery of said patella;   a second jaw member shaped to grip said periphery of said patella;   a support member connecting the first jaw member in translating relationship to the second jaw member, the support constraining the jaw members to remain parallel when they move relative to one another;   a handle actuable to move the first and second jaw members in a motion plane from a first position in which the jaw members are further from one another to a second position in which the jaw members are nearer one another;   a cutter guide adjacent the jaws, the cutter guide able to guide a cutter to cut in a plane parallel to the jaw motion plane.   
   
   
       16 . A method comprising the steps of:
 providing a patella resection guide having patella gripping jaws and a cutter guide;   making an incision on at least one of the medial and lateral sides of a knee to expose said patella from the side;   gripping the medial and lateral sides of the patella with the jaws of the patella resection guide while the patella remains in its normal orientation relative to the femur; and   guiding a cutter with the cutter guide through the incision from the side of the knee to resect the patella.   
   
   
       17 . The method of  claim 16  further comprising the steps of:
 providing a gauge alternately connectable to a first side of the patella resection guide to indicate the amount of bone to be removed and to a second side of the patella resection guide to indicate the amount of bone to remain;   determining whether to gauge the amount of bone to remove or the amount of bone to remain;   attaching the depth gauge to the appropriate side; and   cutting the bone.   
   
   
       18 - 114 . (canceled)