Abstract:
A method, instrumentation and implants for a minimally invasive bone and joint treatments allow cuts in bones to be made simultaneously. This method produces a simple precise alignment of cuts on opposite sides of a joint or bone part. It eliminates many steps need to align the numerous cuts used in current joint replacement and bone treatments. In some cases only one cut will be needed. The cuts can also easily be adapted to different anatomical variation and allows implants to be implanted in a fashion where the implants oriented individually in several different planes. The method and instruments allows for other joint and bone treatments besides joint replacement.

Description:
[0001]     This application claims benefit of provisional application BONE TREATMENT METHOD No. 60/521421 that was filed on Apr. 22, 2004 16:42:16 EDT. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     Joint replacements are now very common procedures. There are artificial joints that are partial replacements and there are total joint replacements.  
         [0003]     Most joint replacements, especially total joint replacements, require more than one component and the method of implantation requires treatment of a bone or bone part for the implantation of each component. There are usually systems to guide the surgeon in making the necessary cuts and/or other preparations for the placement of each component. Components are typically on each side of the joint space that need to be aligned with the anatomy and aligned relative to each other.  
         [0004]     Currently there has been an increased focus on inter-component alignment, giving increased interest to the concept of computer navigation (CN). CN however typically focuses on each component with relation to the bone anatomy rather that specifically the relative positions of one component with the other component or components.  
         [0005]     The greater the number of steps needed to complete a portion of a procedure the greater the chances are for error, especially if one step builds on accomplishment of the previous step. Systems that build upon previous steps without references, cross references and checks to the landmarks and measurements of the preceding steps typically compound errors and dilute the utility of the guide system, especially when they do not take the relative component alignment into account. Reducing steps and linking references to anatomical landmarks and providing cross references will improve surgeon performance.  
         [0006]     The Bone Treatment method, instrumentation and implants simplify multi-step procedures and reduce errors in implantation for joint replacement and other technically demanding work.  
         [0007]     This is accomplished by making bone cuts, especially the first bone cuts substantially part of one step. The cuts are made simultaneously or simultaneously with respect to a group of sequenced cuts where some of the sequenced cuts cut more than one bone.  
       SUMMARY OF INVENTION  
       [0008]     The surgical procedure for a UKA will be presented briefly. The Bone Treatment Method Technique and Treatment Options will then be discussed in detail. The figures included in the application will substantially concentrate on the method, instruments and implants for a Unicondylar Knee. The method and instruments can be utilized for any joint or bone treatment. The specifics of the implants are for a Unicondylar knee. Many of the features of the UKA implants especially fixation elements can be utilized in other joint and bone applications.  
         [0000]     Brief Outline of Standard Unicondylar Knee  
         [0009]     1. Positioning of Tibial Cutting Guide and fixation pins. Aligned to surface anatomy of ankle.  
         [0010]     2. Tibial cut Two steps  
         [0011]     3. Placement of Tibial spacer  
         [0012]     4. Placement of Distal Femoral resection guide and fixation pins  
         [0013]     5. Distal Femoral Cut  
         [0014]     6. Placement of Femoral Post hole  
         [0015]     7. Placement of Chamfer Guide  
         [0016]     8. Anterior Chamfer Cut  
         [0017]     9. Posterior Chamfer Cut  
         [0018]     10. Placement of Femoral Fixation Template  
         [0019]     11. Placement of Femoral Trial  
         [0020]     12. Placement of Tibial Fixation Template  
         [0021]     13. Cutting of slot for Tibial keel  
         [0022]     14. Cement preparation  
         [0023]     15. Implantation of components.  
         [0000]     The Bone Treatment Method Technique for Single Compartment Knee Pathology  
         [0000]     Initial Cut  
         [0024]     1. Position patient&#39;s knee in adjustable cradle in slight flexion (approximately 7 degrees) to match tibial AP tilt. (The first cut can also be made with the femur and tibia at approximately 90 degrees or any angle preferred by the surgeon)  
         [0025]     2. Small Incision is made centered at the joint line to place the cutting guide device shaft  
         [0026]     3. Cutting guide device shaft with soft tissue protector is then inserted and soft tissue protector is deployed (The first cut can terminate before the cut is made all the way through, which would make the soft tissue protector optional)  
         [0027]     4. Cutting guide device shaft is oriented to the weight bearing axis through the knee, the mechanical axis of the femur and the tibia, the varus/valgus tilt of the tibia relative to the femur, the AP tilt of the tibia and the rotation in the vertical direction of the femur with respect to the tibia. This can be done anatomically, with guides that determine the mechanical axis or by CN.  
         [0028]     5. A computer guided cutting device can be used to orientate the cut to the femur and/or tibia bone anatomy or can be attached directly to the femur and/or tibia to guide the cuts.  
         [0029]     6. Patient&#39;s anatomy is then matched to their normal anatomy (good leg) or to a preferred mechanical axis (matched to their height, weight and sex) in terms of varus/valgus orientation, AP tilt and rotation  
         [0030]     7. Realignment of patient&#39;s knee is considered to correct for deformity or anatomy that would produce abnormal kinetics or kinematics. Pre-operative calculations are used to set the guide jig for the cutting device.  
         [0031]     8. Alignment of the first projected cut is checked with x-rays, fluoroscopy, computer navigation (CN) and/or ultrasound in more than one plane  
         [0032]     9. The guide mechanism is placed over guide pin and secured. Six degrees of freedom correction for alignment of cut is made.  
         [0033]     10. The cutting device, which can be a core cutter (annular type cutter) with a cannulated centering drill in the preferred embodiment, is introduced into the cutting guide over the guide shaft and through the obturator in the cutting guide.  
         [0034]     The core can be cut by any method that retains the bone cuttings as substantially whole pieces or a drill, bit or bore cutting device can be used.  
         [0035]     11. The orientation of the cut is checked in more than one plane.  
         [0036]     12. The core cut is made through the distal femur and the proximal tibia in one step.  
         [0037]     The core cut is made at low RPM. The wall thickness of the core cutter can be in the range of 0.01 in. to 0.005 in. or smaller if necessary.  
         [0038]     The core cut can be continued until the bone is cut all the way through and the protective shield is engaged or it can be terminated before the bone is completely cut through.  
         [0039]     13. The core is removed. It will be a composite of: 1) the distal femoral cartilage, cortical bone and cancellous bone and 2) the proximal tibial cartilage, cortical bone and cancellous bone. There will also be other joint and meniscus debris.  
         [0040]     14. The core is kept viable and saved for later use.  
         [0000]     Treatment Options—Knee.  
         [0000]     1. Allograft or Autograft  
         [0041]     a. A preferred method is to treat pathology of articular surface, i.e. meniscus, cartilage or bone by know and accepted means is accomplished on the core material and then the treated core composite is reinsert. The bone cut/fracture is secured to the femur/tibia and will proceed on to healing and revascularization of the removed bone.  
         [0042]     b. Another preferred method would be to use a fresh frozen composite allograft from a similar core cut that is a composite of femoral cancellous bone, cartilage, intact meniscus with associated tibial cartilage cortical bone and cancellous bone. The Allograft/Autograft is mechanically secured to the patient&#39;s native bone.  
         [0000]     2. Artificial Joint Resurfacing (AJR)  
         [0043]     a. Surface replacements are designed to conserve on bone removal and have modified limited fixation such as a peg instead of a stem. (Copeland Shoulder Resurfacing and the Birmingham, Cormet and Conserve Hip Resurfacings)  
         [0044]     b. The upper and/or lower parts of the Bone Treatment Method allograft core can be treated with a resurfacing and re-incorporated as a composite (resurfacing element plus bone or bone and cartilage into the patient. The AJR are typically placed in a non-cemented fashion. Frequently only one side of the joint is treated  
         [0045]     c. AJR can also be utilized with bone graft (allograft or autograft) or bone substitutes, bone matrix, BMP, as well as any metal, ceramic or carbon-based matrix of any type of such as a scaffold, lattice or matrix.  
         [0000]     3. Magnetic Interposition Arthroplasty (MIA)  
         [0046]     a. Magnetic Arrays can be placed in the upper and lower parts of the allograft core and re-incorporated as a composite (magnetic arrays plus bone or bone and cartilage into the patient)  
         [0047]     b. MIA can also be utilized with bone graft (allograft or autograft)or bone substitutes, bone matrix, BMP, as well as any metal, ceramic or carbon-based matrix of any type of such as a scaffold, lattice or matrix.  
         [0000]     4. Artificial Joint Unicondylar Knee Arthroplasty (UKA)  
         [0048]     a. A more conventional prosthesis using more substantial implants than the AJR can be used. Typically there is a femoral component and a tibial component. Either or both can be modular. Fixation is typically more substantial. Typically the components are cemented with PMMA.  
         [0049]     b. The upper and/or lower parts of the Bone Treatment Method allograft core can be treated with a resurfacing and re-incorporated as a composite(resurfacing element plus bone or bone and cartilage into the patient  
         [0050]     c. UKA can also be utilized with bone graft (allograft or autograft) or bone substitutes, bone matrix, BMP, as well as any metal, ceramic or carbon-based matrix of any type of such as a scaffold, lattice or matrix.  
         [0000]     5. Artificial Joint Medial and Lateral Unicondylar Knee Arthroplasties  
         [0051]     a. Simultaneous UKAs can be implanted as in 4 above (UKA)  
         [0052]     b. The implants can be placed using two sequential independent procedures  
         [0000]     6. Total Knee Replacement  
         [0053]     a. A modular TKA can be implanted and assembled in vivo or in situ.  
         [0054]     b. Two femoral condyle replacements with or without a bridging unit on the femoral side and two tibial articulating surfaces with or without a bridging unit between the tibial articulating surfaces with or without a patella treatment or resurfacing.  
         [0000]     Treatment Options other Joints  
         [0055]     A. Any other joint or bone part can treated in a like fashion if the clinical situation is appropriate.  
         [0056]     B. Other joints include but are not limited to:  
         [0057]     1. Temporal Mandibular Joint (TMJ)  
         [0058]     2. Acromioclavicular Joint (AC joint)  
         [0059]     3. Shoulder  
         [0060]     4. Elbow  
         [0061]     5. Wrist  
         [0062]     6. Carpal/Carpal  
         [0063]     7. Carpal/Metacarpal  
         [0064]     8. MCP  
         [0065]     9. PIP  
         [0066]     10. DIP  
         [0067]     11. Spine Facet  
         [0068]     12. Spine Disc (Amphiarthrosis)  
         [0069]     13. SI Joint  
         [0070]     14. Hip  
         [0071]     15. Knee  
         [0072]     16. Ankle  
         [0073]     17. Tarsal/Tarsal  
         [0074]     18. Tarsal/Metatarsal  
         [0075]     19. MTP  
         [0076]     C. Bone parts treated in this fashion can include  
         [0077]     1. Fractures i. Fresh fractures ii. Non-Union iii. Mal-Union iv. Pseudarthrosis  
         [0078]     D. Other bone pathology: 1. Tumors 2. Congenital/Genetic Pathologies 3. Metabolic Bone Disease 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0079]      FIG. 1  AP/PA Knee with lateral cut position  
         [0080]      FIG. 2  Lateral Knee—with lateral cut position  
         [0081]      FIG. 3 —Axial Views with and without menisci Total Uni-Compartmental Resection  
         [0082]      FIG. 4 —Axial Views with and without menisci Limited Uni-Compartmental Resection  
         [0083]      FIG. 5  AP—with lateral cut position: 3 size cuts  
         [0084]      FIG. 6A —AP—with lateral cut position: a size cut  
         [0085]      FIG. 6B —AP—with lateral cut position: b size cut  
         [0086]      FIG. 6C —AP—with lateral cut position: c size cut  
         [0087]      FIG. 7A —AP—with lateral cut position: square shaped cut position  
         [0088]      FIG. 7B —AP—with lateral cut position: square shaped cut  
         [0089]      FIG. 8 —Example of one 6 Degrees Of Freedom medial &amp; lateral cuts (negative of cut without bone)  
         [0090]      FIG. 9 —AP—with lateral cut position: normal lateral joint line anatomy  
         [0091]      FIG. 10 —AP—with lateral cut position: normal lateral joint line anatomy restored with implant(Center Line—Asymmetric)  
         [0092]      FIG. 11 —AP—with medial cut position: varus medial joint line anatomy  
         [0093]      FIG. 12A —AP—with medial cut position: varus medial joint line anatomy Restoration of transverse alignment.  FIG. 12B —AP—with medial cut position: varus medial joint line anatomy Secondary femoral resection  
         [0094]      FIG. 12C -AP—with medial cut position: normal varus joint line anatomy Restoration of joint line height  
         [0095]      FIG. 13 —AP—with medial cut position: normal varus medial joint line anatomy Implant Correction Instruments  
         [0096]      FIG. 14 —Dissector/Tissue Protector Type I  
         [0097]      FIG. 15 —Dissector/Tissue Protector Type I Detail  
         [0098]      FIG. 16 —Dissector/Tissue Protector Type II  
         [0099]      FIG. 17 —Initial Cutting Guide—Type I  
         [0100]      FIG. 17A —Initial Annular Core Cutting Device  
         [0101]      FIG. 18 —Joint Line Distracter Type I—Plates  
         [0102]      FIG. 19 —Joint Line Distracter Type II Balloon, Jack, Wedge, etc.  
         [0103]     Implants  
         [0104]      FIG. 20A —Cylinder Symmetrical  
         [0105]      FIG. 20B —Cylinder Asymmetrical  
         [0106]      FIG. 21 —Cylinder Symmetrical Curved  
         [0107]      FIG. 22 —Cylinder Symmetrical Femoral Component  
         [0108]      FIG. 23 —Cylinder Symmetrical Femoral Component with Flat Tibial Component  
         [0109]      FIG. 24 —Cylinder Symmetrical Curved Tibial Component  
         [0110]      FIG. 25 —Cylinder Symmetrical Comparison of two Curved Tibial Components  
         [0111]      FIG. 26 —Cylinder Symmetrical Curved Tibial Component with peg and fins  
         [0112]      FIG. 27 —Cylinder Symmetrical Curved Tibial Component with Rebar  
         [0113]      FIG. 28 —Flat Tibial Component with curved keel  
         [0114]      FIG. 29 —Flat Tibial Component with curved keel and Magnetic Array  
         [0115]      FIG. 30  with Curved Tibial Component  
         [0116]      FIG. 31 —Cylinder Symmetrical Femoral Component with Flat Tibial Component and curved keel  
         [0117]      FIG. 32 —Cylinder Mobile Bearing with Fenestrated Fixation  
         [0118]      FIG. 33 —Cylinder Symmetrical Femoral Component with Fenestrated Fixation 
     
    
     DETAILED DESCRIPTION  
       [0119]      FIG. 1A  shows the Anterior-Posterior (AP) position of a medial joint line cut ( 101 ) that resects in general the bone of the femur and tibia within the outline.  FIG. 1B  shows the Posterior-Anterior (PA) position of a medial joint line cut ( 102 ) that resects in general the bone of the femur and tibia within the outline.  
         [0120]      FIG. 2  shows the path of cut ( 201 ) from the lateral side ( FIG. 1 ) of the knee showing the general direction of the medial cut.  
         [0121]      FIG. 3A  shows an axial view of the top of the tibia with the menisci in place and the outline of a cut ( 301 ) that substantially resects the complete bone and cartilage of the proximal medial tibia.  FIG. 3B  shows an axial view of the top of the tibia without the menisci in place and the outline of a cut ( 302 ) that substantially resects the complete bone and cartilage of the proximal medial tibia.  
         [0122]      FIG. 4A  shows an axial view of the top of the tibia with the menisci in place and the outline of a cut ( 411 ) that substantially resects a portion of the bone and cartilage of the proximal medial tibia.  FIG. 4B  shows an axial of the top of the tibia without the menisci in place and the outline of a cut ( 421 ) that substantially resects a portion of the bone and cartilage of the proximal medial tibia.  
         [0123]      FIGS. 5 through 13  demonstrate variations in cuts at the joint line for the treatment of a knee. The pertinent anatomy has been labeled using letters. (V=Vastus Medialis, P=Patella, S=Sartorious, LC=Lateral Condyle of the femur, MC=Medial Condyle of the femur, PL=Patellar Ligament, LL=Lateral collateral ligament, LM=Lateral Meniscus, MM=Medial Meniscus, ML=Medial collateral ligament, T=Tibia and PE=Peroneal muscles.) These labels are to orient those less familiar with knee anatomy.  
         [0124]     The cuts represented by lines indicate the approximate position of the cuts at the joint. The overlay of the lines on soft tissues does not indicate that the cuts go through the overlying soft tissues. An orthopedic surgeon familiar with the art would understand that the soft tissues would need to be dissected and or retracted out of the region where a cut would be made so they would not be damaged.  
         [0125]      FIG. 5  shows three sizes of circular patterns for cuts at the lateral knee joint ( 501 ,  502 , &amp;  503 ). ( 503 ) designates a cut that would resect substantially the whole lateral joint line. ( 501 ,  502 ) are smaller and of non-specific size. More than one cut  501 ,  502  and  503  or any combination of ( 501 ) and/or ( 502 ) cuts can be made at a joint line or bone part interface. The direction of the cut after the entry cut is made can be in any direction substantially radiating from the center of the entry cut in the coronal or x-z plane.  
         [0126]      FIG. 6A  shows a typical ( 611 ) cut at the lateral joint line. The direction of the cut after the entry cut is made can be in any direction substantially radiating from the center of the entry cut in the coronal or x-z plane.  
         [0127]      FIG. 6B  shows a typical ( 621 ) cut at the lateral joint line.  
         [0128]      FIG. 6C  shows a typical ( 631 ) cut at the lateral joint line.  
         [0129]      FIG. 7A  shows a typical outline for an ( 711 ) cut at the lateral joint line. The cut outline is square. It could also be a rectangle or rhomboid. The square, rectangle or rhomboid can have any axis of rotation. The direction of the cut after the entry cut is made can be in any direction substantially radial from the center of the entry cut in the coronal or x-z plane.  
         [0130]      FIG. 7B  shows a substantially square entry cut ( 721 ) without defining the direction of the cut path.  
         [0131]      FIG. 8  A-D shows three views of substantially anatomic aligned CrossLink cuts for the knee. The drawings indicate the core or the negative of the cut.  FIG. 8A  show an AP projection of two CrossLink cuts. The cuts are for a left knee. The medial cut is on the left. The lateral cut is on the right. The medial (left) cut in  8 A is directed medial and downward. The lateral cut (right) is directed lateral and downward.  8 B shows the degree of medial and lateral diversions of the medial and lateral cuts.  8 D show the degree of the downward direction for both the medial and lateral cuts. These cuts in  FIG. 8  closely match the normal knee anatomy. Variations in the cut directions can be made for individual patient variations in anatomy or pathology. Each cut can be made to radiate from the center of the entry cut.  
         [0132]      FIG. 9  shows a general implant for a lateral joint line treatment. ( 901 ) is the femoral component, ( 902 ) is the restored joint line and ( 903 ) is the tibial component. This implant has a thicker femoral portion and a proportionately smaller tibial portion.  
         [0133]      FIG. 10  shows a different general implant for a lateral joint line treatment. ( 1001 ) is the femoral component, ( 1002 ) is the restored joint line and ( 1003 ) is the tibial component. This implant has a femoral portion and a tibial portion that are substantially the same size.  
         [0134]     Variations of the position of the joint line in the component similar to  FIG. 9  and  FIG. 10  can be used to correct joint line height and orientation.  
         [0135]      FIG. 11  shows a medial joint line in varus with the leg placed in a valgus stress to restore the lateral joint line to a normal position. ( 1101 ) is the top portion of the cut. ( 1102 ) is the deformed joint line and ( 1103 ) is the deformed medial tibia plateau.  FIG. 11i s also the position of the cut to treat the varus by osteotomy or implant.  
         [0136]      FIG. 12A  shows the cut in  FIG. 11r otated after the cut to correct the orientation of the joint line ( 1212 ).  
         [0137]      FIG. 12B  is a secondary cut outline for the femur to remove a bone graft and allow elevation of the joint line ( 1225 ).  
         [0138]      FIG. 12C  show the elevation of the joint line and insertion of the bone graft from the femur in the tibia below the initial core, re-establishing the joint line ( 1234 ).  
         [0139]      FIG. 13  shows another method in which an implant is used to correct the varus deformity. ( 1301 ) is the femoral component, ( 1302 ) is the joint line and ( 1303 ) is the tibial component.  
         [0140]      FIG. 14  shows a cutting guide shaft with a tissue protector. The tissue protector protects the soft tissue and neurovascular structures at the back of the knee. The tissue protector can be expanded or inflated.  
         [0141]     ( 1401  is the tissue protector inlet,  1402  is the metal shaft over the inlet to the tissue protector.  1403  is the tissue protector.  1404  is the hard material deployed in a radial pattern fibers to stop the cutting edge from cutting the tissue protector)  
         [0142]      FIG. 15  shows a detail of the expandable portion of the tissue protector ( 1501 ) is the tissue protector inlet, ( 1502 ) is the hollow portion of part ( 1501 ) and ( 1503 ) is the expandable tissue protector.  
         [0143]      FIG. 16  is another embodiment of a tissue protector/guide pin. ( 1601 is the expandable portion in can be shaped such that it will be efficient in moving or dissecting the soft tissue and neurovascular structures.  1602  is a hard material collar that stops the cutting device before it reaches the tissue protector,  1603  is a hard material sleeve that can act as a guide pin,  1604  is the extension of the tissue protector to deploy the tissue protector,  1605  is the hollow portion of the extension.)  
         [0144]      FIG. 17  is an embodiment of a guide mechanism to fix to the bone and control a core cutter or a drill, bit, bore, etc. ( 1701 ) is one panel of the housing. The housing is shown with two separated thin flat panels. This enables the cutting device to be positioned in a smaller incision as the first or most forward panel can be on the bone under the tissue and the other panel can remain outside the tissue, allowing the tissue to rest between the inner and outer panels without undue tension on the soft tissue. The panels can be curves especially the front panel. ( 1702 ) is a connector piece that connects the two panels. It can be fixed or one or both of the panels can move on the two connector pieces. ( 1703 ) are multiple pins that move in the connecting piece. Here  18  pins are shown in each connecting piece.  
         [0145]     When the guide mechanism is placed on the femur and tibia the pins adjust or move relative to the housing. They form a negative of the femur and tibia as they engage the bone. Once the pins have conformed to the shape of the bones they are locked into place. After they are locked into place they pins provide several functions. First they stabilize the guide mechanism until the two pins ( 1704 ) and the two pins ( 1706 ) are placed. The pins ( 1703 ) continue to stabilize the guide mechanism after the fixation pins are in place. The pins act as individual probes that are linked with a guidance system such as a computer navigation system. A CN system contains a  3 D data base map of the patient&#39;s anatomy especially the bone anatomy. Currently a CN system uses a probe with a single point that is placed on the bone and then moved in a fashion such that the infrared sensors correlate the position of the probe tip and the probe with the bone anatomy data in the processor. The device shown provides multiple probes ( 36 ) that are also calibrated with respect to each other optically, electrically and/or mechanically to enhance the computer recognition. The combination of each group of  18  pins can only be on a bone in one position with their relative lengths individually displaced to create a negative of the bone anatomy. The distance each pin tip is from the sensor (for example sensors positioned in the connector piece) will be transmitted to a processor and incorporated with information obtained from the probe by more standard current methods. The core cutter shown here is cannulated to go over the previously placed guide pin shaft or it can be fit over another probe or drill bit so that its position can be detected by the CN system.  
         [0146]      FIG. 17A  is a core cutter (annular cutter). This core cutter is unique in that it has flutes on the outside to decrease friction and remove debris. Flutes can be on the inside of the annular cutter not shown) as well or just on the inside of the annular cutter. The wall can be very thin. Another device allows wall thickness in the range of 0.005-0.001 in or smaller. There is a cannulated centering device or drill bit. ( 1711  shaft,  1712  cannulated hole in drill bit,  1713  drill bit  1714  thin walled core cutter with flutes on the outside.)  
         [0147]      FIG. 18  shows a joint distracter. The distracter can be used on one or both the medial and the lateral sides of the joint to balance joint, evaluate soft tissue constraints or distract the joint. The surfaces of the distracter ( 1801 ,  1802 ) are shaped to match the distal femur and proximal tibia so that the distracter is easy to insert, stable before and during deployment and the distraction force is spread out over a large area. The distracter surfaces ( 1801 ,  1802 ) are made material that is strong enough to tolerate forces but not too rigid or sharp to damage the joint, cartilage or soft tissues. The distracter surfaces can be substantially flexible to allow them to be more conforming to surfaces without damaging them. The distracter can be placed on the well (non-operative) side while the other side is treated or it can be placed on the operative side and cut over.  
         [0148]      FIG. 19  shows a detail of one embodiment of the distracter. The unit ( 1903 ) between the upper ( 1901 ) and lower ( 1902 ) surfaces separates the surfaces. The mechanism of the unit can have a piston, a telescoping element, a balloon, a mechanical jack or hydraulic jack to force and hold the surfaces apart. The distracter can be calibrated for pressure and timed for duration of application to prevent damage to the soft tissues and cartilage. Typically the distracter is used briefly and intermittently. A miniature version can be place through an incision on one side (operative side) and placed on the opposite side. Similarly the distracter can be placed in the middle of the joint as long as it does not damage the ACL, fat pad or menisci.  
         [0149]      FIGS. 20-33  show some implants specifically for the Unicondylar knee. General implants for other joints and those used in other orthopedic treatments of other bones will be incorporated in this application by association of the methods, instrumentation and fixation elements of this Unicondylar application.  
         [0150]      FIG. 20  shows a simplified joint prosthesis that can be use in a knee or any other appropriate joint. For the knee ( 2011 ,  2021 ) would be the femoral component and ( 2012 ,  2022 ) the tibial component. There are curvatures of the surfaces that closely matched the normal knee joint surfaces in both the AP and ML directions similar to current Unicondylar knee replacements.( 2011 ,  2022 ) differ from ( 2021 ,  2022 ) in that the joint line is at a different level and the amount of femoral or tibia material differs from( 2011 ,  2022 ) which are nearly the same to ( 2021 ,  2022 ) which are different. By changing the size of the implants and the curvature in the AP and ML directions the basic implant can be adjusted to fit into any joint. Particulars of fixation, shape and size will be built into the design for other joint applications.  
         [0151]      FIG. 21  shows a joint implant (shown for the knee) that is curved in sagittal, coronal and axial planes. The size of the implant and shape of all three curvatures can be designed appropriately for any joint. The guide mechanism or guide pin will need to be designed to aid in the cutting and to account for the curvature. (i.e. curved guide pin and flexible reamers.) Femoral component ( 2102 ), tibial component (  2101 ).  
         [0152]      FIG. 22  shows a specific Unicondylar Femoral Prosthesis. It is made to be used with the CrossLink method and instrumentation. The special features include two fins that are deep and have fenestrations for bone in growth. The femoral component can be made of UHMWPE used with a metal tibial tray that has many significant advantages concerning the biomechanics and the tribology of the Unicondylar Knee. These include wear characteristics of the PE, von Meise forces in the PE, plastic deformation, load concentration, thickness of components, tendency of metal tray to re-shape UHMWPE, third body wear, wear particle size, etc. ( 2201 articular surface,  2202  post,  2203  a fin,  2204  fenestration).  
         [0153]      FIG. 23  shows femoral component ( 2301 ) from  FIG. 22  and a rectangular tibial component ( 2302 ). The tibial component is shaped in the axial plane as a truncated triangle (See  FIG. 24 ) with the medial side being shorter. The tibial component is concave to substantially match the AP and ML contours of the femoral component.  
         [0154]      FIG. 24  shows a rounded tibial component with a convex upper surface ( 2401  convex upper surface,  2402  joint line,  2403  body of tibial component).  
         [0155]      FIG. 25  compares two substantially round tibial components. The diameters are the same. The Joint line is at different levels. ( 2501  mid joint line,  2502  elevated joint line).  
         [0156]      FIG. 26  shows a substantially rounded tibial component with fins and an elongation or post to enhance fixation. ( 2601  body of tibial component,  2602  post,  2603  fin).  
         [0157]      FIG. 27  shows a substantially rounded tibial component ( 2701 ) with rebar fixation ( 2702 ). The rebar can be in virtually any structural reinforcing pattern that maximizes the fixation to cement and bone. Proper combinations of rebar patterns, materials and ratio of PMMA to rebar volume can approximate bone physical properties more closely than a homogenous material. The rebar can be made of PE, metal or any appropriate material including carbon-based materials. Rebar fixation ( 2702 ) can be used in cemented and non-cemented applications. It is very effective in cemented applications especially when there is bone loss requiring cement to fill voids. Rebar fixation can also be used with bone graft or native bone in non-cemented applications.  
         [0158]      FIG. 28  shows a more conventional shaped tibial component ( 2801 ) with a rounded keel ( 2802 ). The rounded keel fits in a core or bore made with the CrossLink technique. Additional fixation can be used to add additional stability.  
         [0159]      FIG. 29  shows a conventional type of tibial component ( 2901 ) with a Magnetic Array to be combined with a mobile bearing with a Magnetic Array ( 2903 ) or a femoral component with a Magnetic Array. A mobile bearing with or without a Magnetic Array or Arrays can be placed between a femoral component a tibial component that both have arrays.  
         [0160]      FIG. 30  shows a femoral component ( 3001 ) with a substantially round tibial component ( 3002 ).  
         [0161]      FIG. 31  shows the femoral component ( 3101 ) from  FIG. 22  and the tibial component ( 3102 ) from  FIG. 28 .  
         [0162]      FIG. 32  shows the femoral component ( 3201 ) from  FIG. 22  with a substantially rounded Mobile bearing ( 3202 ) and a substantially rounded tibial component ( 3204 ) with fenestrated Crown &amp; Post Fixation ( 3201 femoral component,  3202  mobile bearing,  3203  tibial tray,  3204  fenestrated Crown and Post fixation)  
         [0163]      FIG. 33  shows a basic femoral component ( 3301 ) with shelled out body and fenestrations ( 3302 ) for fixation. Other fixation methods can be added.