Abstract:
A method of aligning implant components includes placing a first implant component in bone, followed by: coupling a first intermediate member to the first implant component; coupling a first alignment member to the first intermediate member; rotating the members as a unit to place the first intermediate member in an alignment position; removing the first alignment member from the first intermediate member; coupling a second alignment member to a second intermediate member; coupling the second intermediate member to the first intermediate member and rotating the second alignment member and the second intermediate member as a unit relative to the first intermediate member to provide a desired orientation of the second intermediate member. An alignment system for aligning first and second members includes a first alignment member having an offset channel dimensioned to receive the first member, and a second alignment member having a channel dimensioned to receive the second member.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority to and the full benefit of U.S. Provisional Application Ser. No. 61/453,328, filed Mar. 16, 2011, and titled “Compound Angle Guide,” U.S. Provisional Application Ser. No. 61/475,357, filed Apr. 14, 2011, and titled “Compound Angle Implant,” and U.S. Provisional Application Ser. No. 61/491,962, filed Jun. 1, 2011, and titled “Compound Angle Implant,” the entire contents of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to a compound angle implant. 
       BACKGROUND 
       [0003]    During joint replacement surgery, an implant is inserted into or attached to a bone that has been prepared to receive the implant. To simulate native anatomy during joint replacement surgery, it is known to provide the surgeon with modular, adjustable implant components. Modular, adjustable implant components can allow the surgeon to accommodate a large range of joint and bone configurations in patients without, for instance, having to maintain a large inventory of variously configured implant structures. 
       SUMMARY 
       [0004]    During joint replacement surgery, for example, in the shoulder, it is desirable to permit the surgeon to place the stem of the implant into the humeral bone without regard to the orientation of the humeral osteotomy. After placing the stem into the humeral bone, the surgeon selects an implant component that couples to the stem and is configured to anatomically orient the head of the shoulder implant. An inclination-retroversion guide aids the surgeon in selecting the implant component and provides the surgeon with the choice of measuring inclination and/or retroversion. 
         [0005]    According to one aspect, a method of aligning first and second implant components includes placing the first implant component in bone, followed by: coupling a first intermediate member to the first implant component; coupling a first alignment member to the first intermediate member; rotating the first alignment member and the first intermediate member as a unit to place the first intermediate member in an alignment position; securing the first intermediate member to the first implant component with the first intermediate member in the alignment position; removing the first alignment member from the first intermediate member; and coupling a second intermediate member to the first intermediate member and rotating the second intermediate member relative to the first intermediate member to provide a desired orientation of the second intermediate member. 
         [0006]    Implementations of this aspect may include one or more of the following features. The first alignment member is coupled to the first intermediate member without rotationally aligning the first alignment member relative to the first intermediate member. The first intermediate member includes an indicia. The first alignment member includes a plurality of indicia. The method includes fixing the second intermediate member to the first intermediate member with the second intermediate member in the desired orientation. The method includes coupling a second alignment member to the second intermediate member to rotate the second intermediate member. The second alignment member is coupled to the second intermediate member without rotationally aligning the second alignment member and the second intermediate member. The second intermediate member is in the desired orientation when the second alignment member is parallel to a bone osteotomy. The first intermediate member is in the alignment position when the first alignment member is parallel to a bone osteotomy. The method includes coupling the second member to the second implant component. 
         [0007]    According to another aspect, an alignment system for aligning first and second members of an implant connector includes a first alignment member having an outer surface for grasping by a user and a channel dimensioned to receive the first member, the channel extending non-transversely through the first alignment member; and a second alignment member having an outer surface for grasping by a user and a channel dimensioned to receive the second member. 
         [0008]    Implementations of this aspect may include the second alignment member channel extending transversely through the second alignment member. 
         [0009]    According to another aspect, a method of aligning first and second implant components includes coupling a first intermediate member to the first implant component, coupling an alignment member to the first intermediate member with indicia on the alignment member and indicia on the first intermediate member aligned, rotating the alignment member and the first intermediate member as a unit to an alignment position by aligning indicia on the alignment member with indicia on bone in which the first implant component is received, securing the first intermediate member to the first implant component with the first intermediate member in the alignment position, removing the alignment member from the first intermediate member, and coupling a second intermediate member to the first intermediate member and rotating the second intermediate member relative to the first intermediate member to provide a desired orientation of the second intermediate member. 
         [0010]    Implementations of this aspect may include one or more of the following features. The method includes fixing the second intermediate member to the first intermediate member with the second intermediate member in the desired orientation. The method includes coupling the alignment member to the second intermediate member to rotate the second intermediate member. The second intermediate member is in the desired orientation when the alignment member is parallel to a bone osteotomy. The indicia on the alignment member for aligning with the first intermediate member is different from the indicia on the alignment member for aligning with the bone indicia. The method includes coupling the second intermediate member to the second implant component. 
         [0011]    According to another aspect, an alignment system for aligning first and second members of an implant connector includes an alignment member having an outer surface for grasping by a user and first and second co-axial channels. The first channel is dimensioned to receive the first member and the second channel is dimensioned to receive the second member. The first channel has an undulating perimeter. The alignment member includes indicia visible to a user for aligning the first member with a bone osteotomy. 
         [0012]    Implementations of this aspect may include one or more of the following features. The alignment system includes an impaction tool having an undulating outer perimeter matching the first channel undulating perimeter for receipt within the first channel to contact the second member when the second member is received within the second channel. 
         [0013]    According to another aspect, an anatomic guide includes a first member, and a second member coupled to the first member such that the second member can slide and tilt relative to the first member. The second member includes a surface for contacting a bone osteotomy such that with the surface in contact with the bone osteotomy, the relative sliding and tilting of the second member relative to the first member identifies an anatomic implant for use with the osteotomy. 
         [0014]    Implementations of this aspect may include one or more of the following features. The guide includes indicators that identify the anatomic implant. The first member is a shaft. The second member is coupled to the shaft to be slidable along the shaft and tiltable relative to the shaft. The second member is a handle gage having first and second portions, the first portion being tiltable relative to the second portion and the first member. 
         [0015]    The indicators include indicia that identify the relative tilt of the first portion. The indicators include indicia that identify the relative sliding of the second member. The indicators include a formation on the second member for use in indicating on the osteotomy a rotational alignment of the guide relative to the osteotomy. 
         [0016]    The indicators include indicia that identify the relative tilt of the second member, indicia that identify the relative sliding of the second member, and a formation on the second member for use in indicating on the osteotomy a rotational alignment of the guide relative to the osteotomy. 
         [0017]    The second member is coupled to the first member to tilt along more than one plane. The second member is coupled to the first member to rotate relative to the first member. 
         [0018]    According to another aspect, a method of selecting an implant component, includes coupling a guide to an implant, the guide having a first member and a second member; sliding the second member relative to the first member toward a bone osteotomy; rotating at least a portion of the guide relative to the implant; tilting the second member relative to the first member to orient the guide relative to the osteotomy; and using the orientation of the guide to aid in selecting an implant component. 
         [0019]    According to another aspect, a method of aligning first and second implant components includes aligning indicia on first and second intermediate members by relative rotation of at least one of the intermediate members, coupling the first and second intermediate members, coupling the first member to the first implant component, and coupling the second member to the second implant component. 
         [0020]    Implementations of this aspect may include one or more of the following features. The first and second intermediate members are aligned before being coupled. The first member is coupled to the first implant prior to aligning the indicia. The first and second members are aligned and coupled before the members are coupled to the implant components. The indicia on the first and second members are aligned with indicia on bone in which one of the implant components is received. The second member is coupled to the second implant after aligning the indicia. The first implant component is a shoulder stem. The second implant component is a shoulder head. 
         [0021]    According to another aspect, a method of aligning first and second implant components includes placing the first implant component in bone, marking indicia on the bone, coupling a first intermediate member to the first implant component with indicia on the first intermediate member aligned with the indicia on the bone, coupling a second intermediate member to the first intermediate member with indicia on the second intermediate member aligned with indicia on the first intermediate member, and coupling the second intermediate member to the second implant component. 
         [0022]    Implementations of this aspect may include one or more of the following features. The first intermediate member is coupled to the first implant component prior to coupling the second intermediate member to the first intermediate member. Alternatively, the second intermediate member is coupled to the first intermediate member prior to coupling the first intermediate member to the first implant component. 
         [0023]    According to another aspect, a connector for attaching first and second implant components includes a first member, a second member, and an interface. The first member is configured to be coupled to the first implant component. The interface is configured to couple the first member to the first implant component. The first member has a male taper angularly offset relative to an axis of rotation of the first member. The second member has a female taper for receiving the male taper. The female taper matches the male taper such that an axis of rotation of the second member is not aligned with the axis of rotation of the first member. The second member has a male taper that is angularly offset relative to the axis of rotation of the second member. The male taper of the second member is configured to couple the second member to the second implant component such that an axis of rotation of the second implant component is not aligned with the axis of rotation of the second member. 
         [0024]    Implementations of this aspect may include one or more of the following features. The first member offset is at an angle A and the second member offset is at an angle B such that relative rotation of the first and second members produces an offset angle up to A+B. The first member is configured to be rotatable relative to the first implant component when coupled thereto. 
         [0025]    The details of one or more implementations of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     
       DESCRIPTION OF DRAWINGS 
         [0026]      FIG. 1  is a cross-sectional side view of a connector coupling two implants. 
           [0027]      FIGS. 2 and 3  are exploded views of the connector and implants. 
           [0028]      FIGS. 4A-4C  are cross-sectional side views of the connector. 
           [0029]      FIGS. 5A and 5B  illustrate the orientation of a stem in a humeral bone. 
           [0030]      FIGS. 6A-6C  illustrate the connector coupled to the implant in the bone. 
           [0031]      FIGS. 7A and 7B  are each perspective views of a member of the connector. 
           [0032]      FIGS. 8A and 8B  are top and side views of an alignment member for a first member of the connector. 
           [0033]      FIGS. 8C and 8D  are top and side views of an alignment member for a second member of the connector. 
           [0034]      FIGS. 9A-9E  illustrate an example technique for using the alignment members of  FIG. 8 . 
           [0035]      FIGS. 10A and 10B  are top and side view of an alternative implementation of an alignment member for the first member of the connector. 
           [0036]      FIG. 10C  is a top view of the alignment member from  FIG. 10A  with alternative indicia. 
           [0037]      FIGS. 11A-11D  illustrate an example technique for using the alignment members of  FIGS. 8 and 10 . 
           [0038]      FIGS. 12A-13B  illustrate various techniques for using the alignment members of  FIGS. 8 and 10 . 
           [0039]      FIG. 14A  is a side view of an anatomic guide coupled to the stem in the bone. 
           [0040]      FIG. 14B  is a perspective view of  FIG. 14A . 
           [0041]      FIG. 15  is a perspective view of an alternative implementation of the anatomic guide of  FIG. 14 . 
           [0042]      FIG. 16A  is a side view of the anatomic guide of  FIG. 15 . 
           [0043]      FIG. 16B  is a cross-sectional view of the anatomic guide taken along lines  16 B- 16 B, in  FIG. 16A . 
           [0044]      FIG. 16C  is a cross-sectional view of the anatomic guide taken along lines  16 C- 16 C, in  FIG. 16A . 
           [0045]      FIG. 16D  is a cross-sectional view of the anatomic guide taken along lines  16 D- 16 D, in  FIG. 16A . 
           [0046]      FIG. 16E  is a side view of a shaft of the anatomic guide of  FIG. 15 . 
           [0047]      FIGS. 17A and 17B  illustrate the guide of  FIG. 14  in use. 
           [0048]      FIGS. 18A-18E  illustrate the use of the guide of  FIG. 15  for determining parameters for the connector. 
           [0049]      FIGS. 19A and 19B  illustrate a selected implant component. 
           [0050]      FIGS. 20A-20C  illustrate another alternative implementation of an anatomic guide. 
           [0051]      FIG. 21  illustrates another alternative implementation of an anatomic guide. 
           [0052]      FIGS. 22A-23B  illustrate another alternative implementation of an anatomic guide. 
           [0053]      FIGS. 24A and 24B  are side and cross-sectional views of an alternative implementation of an alignment member for use with the connector. 
           [0054]      FIGS. 25A-25G  illustrate the use of a trial connector and the alignment member of  FIG. 24 . 
           [0055]      FIG. 26A  illustrates the use of an impactor. 
           [0056]      FIGS. 26B and 26C  are side and cross-sectional views of the impactor. 
           [0057]      FIGS. 27A-27C  are top, side, and cross-sectional views of another alternative implementation of an alignment member. 
           [0058]      FIG. 27D  illustrates the use of an alternative implementation of an impactor. 
           [0059]      FIG. 28  is a top view of another alternative implementation of an alignment member. 
           [0060]      FIGS. 29A-29C  illustrate a three-part alignment member. 
           [0061]      FIG. 30  illustrates another use of a trial connector. 
           [0062]      FIGS. 31A-31B  illustrate an alignment of the connector. 
       
    
    
     DETAILED DESCRIPTION 
       [0063]    Referring to  FIG. 1 , a connector  10  permits intra-operative adjustment of the inclination and/or retroversion of a second implant component relative to a first implant component, for example, adjustment of a humeral head implant  12  relative to a stem  14  of a prosthesis  16  during shoulder arthroplasty. The adjustment can be made in infinite steps with a maximum angulation of, for example, about +/−20°, with the illustrated implementation showing a maximum angulation of +/−12°. The connector  10  includes a first intermediate member  20  that an surgeon fixes to the stem  14  with an interface, for example, a fixation member such as a screw  18  or a taper or snap-in interface, and a second intermediate member  22  that the surgeon fixes to the head implant  12  via, for example, a tapered press fit. 
         [0064]    The stem  14  can be attached to bone by distal fixation, and the connector  10  can be coupled to the stem  14  after the stem  14  is fixed in the bone. The stem  14  can be modular, having proximal portions provided in different lengths that the surgeon can choose from, with the proximal portion being rotatable relative to a distal portion of the stem prior to being fixed in position relative to the distal portion. 
         [0065]    Prior to being fixed to the stem  14 , the first member  20  can be coupled to the stem  14  by the screw  18  or other interface to be rotatable relative to the stem  14 . Referring to  FIGS. 2 and 3 , the first member  20  has a male taper  24  that is angularly offset relative to an axis of rotation, X, of the first member. The second member  22  has a female taper  26  for receiving the male taper  24 . The female taper  26  matches the male taper  24  such that an axis of rotation, Y, of the second member  22  is not aligned with the axis of rotation, X, of the first member  20 . The second member  22  also has a male taper  28  that is angularly offset relative to the axis of rotation, Y, of the second member  22 . The male taper  28  of the second member  22  is received by a female taper  30  in the head implant  12  to couple the second member  22  to the head implant  12  such that an axis of rotation, Z, of the head implant  12  is not aligned with the axis of rotation, Y, of the second member  22 . 
         [0066]    The relative rotary position of the first and second members  20 ,  22  determines the ultimate angular offset between axes X and Z. For example, in  FIG. 2 , the first and second members  20 ,  22  are positioned with the tapers  24  and  28  cancelling each other such that the axes X and Z are parallel. In  FIG. 3 , the first and second members  20 ,  22  are positioned with the tapers  24  and  28  being additive with the axes X and Z at their maximum offset angulation. In the illustrated implementation, axes X and Y are offset by an angle, A, for example, 6°, and axes Y and Z are also offset by and angle, B, for example, 6°, such that the maximum offset angulation is A+B, 12°.  FIG. 3  shows a +12° angulation. A −12° angulation can be obtained by rotating both of the first and second members  20 ,  22  by 180°.  FIGS. 4A-4C  illustrate 0°, 6° and 12° offset angulations of the first and second members  20 ,  22 . Rather than the plus and minus angles being in the inclination plane, as illustrated, the plus/minus angles could be anterior/posterior (version plane). 
         [0067]    The axis of rotation, Z, of the female taper  30  in the head implant  12  is offset relative to an axis of symmetry, M, of the head implant  12  such that rotation of the head implant  12  relative to the second member  20  about the axis of rotation, Z, provides another degree of freedom in adjusting the relative position of the stem and head. 
         [0068]    Referring to  FIGS. 5A and 5B , during a shoulder arthroplasty procedure, the surgeon typically creates an osteotomy  40  in the humeral bone  42  to form a flat bone surface  44 , and bores a channel  45  in the bone  42  to receive the stem  14 . The stem  14  has an interface axis, X′ ( FIG. 2 ), defined, for example, by a threaded hole  46  that receives screw  18 , that coincides with the axis of rotation, X, of the first member  20  when the first member  20  is coupled to the stem  14 . However, the axis, X′, may not be parallel to a normal vector  50  of the bone surface  44 . As illustrated in  FIGS. 6A and 6B , the surgeon can intra-operatively adjust the position of the head implant  12  relative to the bone surface  44 , for example, to make a surface  52  ( FIG. 2 ) of the head implant  12  parallel to the bone surface  44  (and thus axis, Z, parallel to vector  50 ), by adjusting the relative rotational position of members  20 ,  22  from the offset position of  FIG. 6A  to the parallel position of  FIG. 6B . The connector  10  as coupled to stem  14  can be seen in  FIG. 6C . 
         [0069]    The distance between surfaces  44  and  52  is determined by the length of the members  20 ,  22 . The surgeon can set the distance by, for example, selecting among members  20  having a range of lengths, L ( FIGS. 7A and 7B ). As illustrated in  FIGS. 7A and 7B , the member  20  has a stem contacting surface  54  with circumferential ridges  56  that mate with corresponding ridges on the stem  14  to aid in holding the rotational alignment of the member  20  and the stem  14 . 
         [0070]    Referring to  FIGS. 3 and 7B , the member  20  defines pin holes  20   a  that receives pins  20   b  that act to hold the screw  18  within the member  20 . The member  20 , the pin  20   b , and the screw  18  can be provided to the surgeon as a preattached assembly. Referring to  FIG. 4B , in the illustrated implementation of the member  22 , a surface  22   a  of the member  22  is perpendicular to the female taper  26 , and a surface  22   b  of the member  22  is perpendicular to the male taper  28 . 
         [0071]    As discussed above, the surgeon can make the surface  52  of the head implant  12  parallel to the bone surface  44  by adjusting the relative rotational position of members  20 ,  22  of the connector  10 . For example, referring to  FIGS. 8A-8D , a first alignment member  60  defines a bore  62  sized to receive the first member  20  in frictional engagement, and a second alignment member  64  defines a bore  66  sized to receive the second member  22  in frictional engagement. The bores  62 ,  66  extend transversely through the respective alignment members  60 ,  64 . The alignment members  60 ,  64  are relatively thin, for example, having a thickness, T, of about 6 mm or less, preferably about 3.5-4.5 mm, and are transparent, made from, for example, polyetherimide, to facilitate alignment of the first and second member  20 ,  22 , as discussed below. 
         [0072]    The alignment members  60 ,  64  can be used to attach the first and second members  20 ,  22  to the stem  14  without the need for additional angle guides or markings on the bone, as will be discussed further below. Referring to  FIGS. 9A-9E , an example method of using the alignment members  60 ,  64  includes creating a bone resection of the humeral head and implanting the stem  14  into the broached cavity of the bone using distal fixation ( FIG. 9A ). The surgeon then places the alignment member  64  about a pre-assembled trial connector having attached first and second trial members  66 . The attached first and second trial members  66  can be tilted relative to each other but rotate as a unit. The surgeon screws the alignment member  64 /trial members  66  assembly onto the stem  14 , and rotates the alignment member  64  and the pre-assembled trial connector as an unit about the screw axis until the user perceives by sight and feel that the alignment member  64  is parallel to the osteotomy face ( FIG. 9B ). The user then tightens the screw  18 . The trial phase of the procedure is completed by attaching the humeral trial head  12  ( FIG. 9C ) and testing the trial implant to determine if the connector length is appropriate. The trial phase determines the desired length of the first member  20  and determines whether the osteotomy angle can be corrected with the range provided by the first and second members  20 ,  22 . 
         [0073]    The surgeon then selects the first member  20  according to the length of the trial connector, and partially screws the first member  20  to the stem  14  using a tool  68 . The surgeon uses the alignment member  60  press fit over the first member  20  to rotate the first member  20  until the surgeon perceives that the alignment member  60  is parallel to the osteotomy face ( FIG. 9D ) by looking through the alignment member  60  or by judging the parallelism via side viewing. The alignment member  60  is press fit over the first member  20  without the need for rotationally aligning the alignment member  60  and the first member  20 . The surgeon then tightens the screw to fix the first member  20  to the stem and removes the alignment member  60 . The surgeon then press-fits the alignment member  64  over the second member  22  and places the second member  22  over the first member  20  and uses the alignment member  64  to rotate the second member  22  relative to the first member  20  until the surgeon perceives that the alignment member  64  is parallel to the osteotomy face (FIG.  9 E) by looking through the alignment member  64 . The alignment member  64  is press fit over the second member  22  without the need for rotationally aligning the alignment member  64  and the second member  20 . If the above steps do not provide the desired result, the surgeon can loosen the screw, rotate the first member  20  90 degrees for example, with reference to a marking  70  on the first member  20 , tightens the screw, and then re-align the second member  22  using the alignment member  64 . 
         [0074]    Referring to  FIGS. 10A and 10B , an alignment member  72  defines a bore  74  sized to receive the first member  20  in frictional engagement. The bore  74 , rather than extending transversely through the alignment member, as in the implementations described above, is offset at an angle, θ, in the range of, for example, four to six degrees, for reasons discussed below. The alignment member  72  includes a region  76  of increased thickness to facilitate manufacturing, and can also include a plurality of indicia  78  on the top surface  80 . Alternatively, the top surface  80  can include indicia  82  as shown in  FIG. 10C , the indicia  82  corresponding to, for example, a total angular range of the connector  10 . 
         [0075]    Rather than using the alignment member  60  with the first member  20 , the alignment member  72  having an offset bore can be used. Without the use of an offset bore, as in the alignment member  60 , it is possible that, due to the six degree offset of the second member  22 , after alignment of the first member  20 , the alignment member  64  with the second member  22  cannot be aligned parallel to the osteotomy face. However, if the bore is offset, for example, by 4 degrees, any error is distributed increasing the likelihood of parallel alignment. To minimize any error, the surgeon can use the alignment member  72  having a six degree offset, which simulates the second member  22 , and indicia  82 . 
         [0076]    Referring to  FIGS. 11A-11D , an example method of using the alignment members  72 ,  64  includes creating a bone resection of the humeral head and implanting the stem  14  into the broached cavity of the bone using distal fixation ( FIG. 11A ). The surgeon then selects the first member  20  having the appropriate length, for example, determined according to the length of the trial connector, and partially screws the first member  20  to the stem  14  ( FIG. 11B ). The first member  20  is provided with a single indicia  70  that the surgeon aligns with one of the alignment member indicia  78 ,  82  of the alignment member  72  when placing the alignment member  72  onto the first member  20  ( FIG. 11C ). Thus aligned, the surgeon rotates the alignment member  72  with the first member  20  to see if the alignment member  72  can be positioned parallel to the osteotomy face. The surgeon progresses through the plurality of indicia  78 ,  82  on the alignment member  72  until the surgeon perceives that the alignment member  72  is parallel to the osteotomy. If the alignment member  72  is parallel to the osteotomy, then the alignment member  64  with the second member  22  can likewise be positioned parallel to the osteotomy. The surgeon then tightens the screw  18  to fix the first member  20  to the stem and removes the alignment member  72 . The surgeon then press-fits the alignment member  64  over the second member  22  and places the second member  22  over the first member  20 . The surgeon uses the alignment member  64  to rotate the second member  22  relative to the first member  20  until the surgeon perceives that the alignment member  64  is parallel to the osteotomy face ( FIG. 11D ). The alignment member  64  is press fit over the second member  22  without the need for rotationally aligning the alignment member  64  and the second member  20 . 
         [0077]    Referring to  FIGS. 12A and 12B , in an alternative technique, a modified angle guide  84  is used to facilitate alignment of the first and second members  20 ,  22 . After the trial phase, a rod  86  is fixed in line with the threaded, screw receiving hole of the stem  14 . The angle guide  84 , having single or multiple through holes  88  each set at an angle to a distal disc part  90  of the guide  84 , for example, five holes at 0°, 3°, 6°, 9°, and 12°, is slid over the rod  86  and against the bone osteotomy, with the rod extending through one of the holes  88 . The guide  84  is rotated about the axis of the rod to find the angle which best matches the distal disc surface  90  of the guide  84  to the bone osteotomy. The rod  86  can be slid through different holes  88  until the best angle match is found. The value of the angle is marked as a digit on the guide  84 . 
         [0078]    Referring particularly to  FIG. 12B , in this technique the first member  20  and the alignment member  72  each include angle indicia  92 ,  82 , respectively. In addition, the alignment member  72  has a 6° eccentric bore  94 . In use, the first member  20  and the alignment member  72  are aligned at the same digit as determined by the guide  84 . The surgeon then rotates the alignment member  72  and the first member  20  until the alignment member  72  is perceived to be parallel to the osteotomy. The surgeon then employs the second alignment member  64 , as described above. 
         [0079]    Referring to  FIGS. 13A and 13B , in an alternative technique, a set of modified angle guides  96  are used to facilitate alignment of the first and second members  20 ,  22 . After the trial phase, a rod  98  is fixed in line with the threaded, screw receiving hole of the stem  14 . Each angle guide  96  has a different, single through hole  100  set at an angle to a distal disc part  102  of the guide  96 , for example, five guides each with a holes at 0°, 3°, 6°, 9°, or 12°. Each angle guide  96  in turn is slid over the rod  98  and against the bone osteotomy, with the rod extending through the hole  100 . The guide  96  is rotated about the axis of the rod to find the angle which best matches the distal disc surface  102  of the guide  96  to the bone osteotomy. The rod  98  is slid through different guides  96  until the best angle match is found. The guides  96  each have an indicia  104 , and when the best fit is determined, the indicia of the best fit guide is transferred to the bone resection as a mark  106  on the osteotomy. 
         [0080]    A first member  20  having an indicia  70  is attached to the stem  14  using the screw  18 , with the indicia  70  on the first member  20  aligned with the osteotomy mark  106  ( FIG. 19B ). The surgeon then employs the second alignment member  64 , as described above. 
         [0081]    Referring to  FIGS. 14A and 14B , an anatomic guide  110  includes a first member  112  and a second member  114  coupled to the first member  112  such that the second member  114  can slide and tilt relative to the first member  112 . The second member  114  includes a surface  116  for contacting a bone osteotomy  40  such that with the surface  116  in contact with the bone osteotomy  40 , the relative sliding and tilt of the second member  114  relative to the first member  112  identifies an anatomic implant component  120  ( FIG. 19A ) for use with an implant stem  14 . The guide  110  includes indicators  122 ,  124 , and  126  that aid in identifying a desired anatomic implant component  120 . 
         [0082]    Referring to  FIG. 15 , in an alternative implementation of the anatomic guide  110 , a first member  212  of an anatomic guide  210  includes a shaft  230  with a terminal nipple  232 . In use, the terminal nipple  232  is received by the shoulder stem  14  ( FIG. 14A ) to align the guide  210  with the shoulder stem  14  and to allow rotation of the guide  210  relative to the shoulder stem (arrow A). A second member  214  is received over the shaft  230  to be slidable along the shaft (arrow B) and liftable relative to the shaft (arrow C). The unrestrained relative sliding and tilting of the second member  214  relative to the first member  212  positioned in alignment with the stem  14  makes it possible to provide measurement of the angle of the inclination-version combination. The second member  214  includes a handle gage  240  having a first portion  242  and a second portion  244 . The portions  242 ,  244  slide together relative to the shaft  230 , and the first portion  242  is tiltable relative to the second portion  244  and the shaft  230 . 
         [0083]    Referring again to  FIGS. 14A and 14B , the indicator  122  includes indicia  150  on both sides of a second portion  144  of a handle gage  140  that identify the relative tilt of a first portion  142  of the handle gage  140 , and the indicator  124  includes indicia  152  that identify the relative sliding of the handle gage  140 . The indicator  126  includes a formation, for example, a cut-out  154 , on the handle gage  140  that is used to indicate on the osteotomy the rotational alignment of the guide  110  relative to the osteotomy  40 . The cut-out  154  is located in the same plane as the plane within which the first portion  142  tilts. 
         [0084]    Referring again to  FIG. 15 , the handle gage  240  is coupled to the shaft  230  by a pin  260  and a thumb screw  262 . The pin  260  and the thumb screw  262  are received within axial slots  263  in the shaft  230  such that the handle gage  240  can slide axially along a longitudinal axis, X, relative to the shaft  230 . The first portion  242  of the handle gage  240  tilts relative to the second portion  244  about an axis, Y, of the pin  260 , and indicia  250  ( FIG. 16A ) indicate the relative tilt. The shaft  230  and the handle gage  240  rotate together about the axis, X, due to the non-circular shape formed by engaging flat surfaces  265  ( FIG. 16D ) of the shaft  230 , first portion  242 , and second portion  244 . The shaft  230  and the handle gage  240  are also coupled by a lock pin  264  that is used to lock the relative axial position of the shaft  230  and the handle gage  240 . 
         [0085]    The first portion  242  of the handle gage  240  includes a skirt  266  that defines a surface  216  in contact with the bone osteotomy  40 , and a pair of arms  268   a ,  268   b . The skirt  266  defines a through hole  270  for receiving the shaft  230 , and the second portion  244  of the handle gage  240  is received between the arms  268   a ,  268   b . The hole  270  provides clearance between the skirt  266  and the shaft  230  to permit the tilting motion of the skirt  266 . The arms  268   a ,  268   b  terminate in pointers  269   a ,  269   b  ( FIG. 18C ) that point to the indicia  250  to indicate relative tilt. Each arm  268   a ,  268   b  defines a through hole  271  for receiving the pin  260 , and the arm  268   a  defines a second, slotted through hole  272  for receiving thumb screw  262 . The slotted through hole  272  provides clearance with the thumb screw  262  to permit the tilting motion. The second portion  244  of the handle gage  240  defines a lumen  274  for receiving the shaft  230 , and a pair of opposed through holes  276  for receiving the thumb screw  262 . 
         [0086]    The pin  260  and the thumb screw  262  are centrally aligned along the axis, X. However, the lock pin  264  is positioned off axis such that the lock pin  264  engages with an outer surface of the shaft  230 , as described below. The second portion  244  of the handle gage defines a through bore  278  for receiving the lock pin  264 . 
         [0087]    Referring to  FIGS. 16A-16E , the guide  210  includes three biasing springs  280 ,  282 , and  284 . The shaft  230  defines an axial lumen  286  ( FIG. 16B ) in which the spring  280  is located, between the nipple  232  and the pin  260 . The spring  280  acts upon the pin  260  to bias the handle gage  240  in a direction away from the nipple  232 . The axial slots  263  communicate with the lumen  286  to permit passage of the pin  260  and thumb screw  262  through the shaft  230 . The spring  282  ( FIG. 16C ) is located in the lock pin through bore  278  and biases the lock pin  264  into engagement with the shaft  230 . The spring  284  ( FIGS. 15 and 16B ) is a torsion spring that acts between pin  260  and the second portion  244  of the handle gage  240  to bias first portion  242  toward a neutral tilt position. 
         [0088]    Referring particularly to  FIGS. 16C-16E , the lock pin  264  defines a groove  290  forming a shelf  292 . The shelf  292  engages in detents  294  formed on the surface of the shaft  230 . To slide the handle gage  240  relative to the shaft  230 , the user pushes on the first portion  244  of handle gage  240 . In doing so, engagement between a cam face  293  of the lock pin shelf  292  and a mating cam face  295  of the shaft  230  forces the lock pin  264  further against the spring  282 , thereby disengaging the shelf  292  from the detent  294 . When the user reaches a certain axial position along the shaft  230 , the spring  282  forces the shelf  292  of the lock pin  264  into engagement with the next detent  294 . Indicia  252  indicate the relative axial location of the handle gage  240 . To return the guide  210  to a neutral axial position, the user depresses the lock pin  264 , compressing the spring  282 , allowing the spring  280  to return the shaft  230  to a neutral position relative to the handle gage  240 . Contact between the thumb screw  262  and the slot  263  of the shaft  230  serves as a hard stop. 
         [0089]    Referring again to  FIGS. 5A and 5B , during shoulder replacement surgery, the surgeon forms a bore in the bone to receive the implant stem  14 , and forms the humeral osteotomy  40 . The bore includes a channel  45  in which the implant stem  14  sits. The implant stem  14  defines a hole  46  in which the nipple  32  can be placed. As can be seen in  FIG. 5B , the implant stem  14  is typically not oriented parallel with the osteotomy  40 . To select an implant component that will provide a known orientation of the implant relative to the osteotomy  40 , for example, a parallel orientation, the surgeon uses the guide  210 . 
         [0090]    Referring now to  FIGS. 17 and 14 , in use, the surgeon seats a guide nipple (not shown) in the stem hole  46  and slides the handle gage  140  down the shaft  130  toward the osteotomy  40 . By rotating the guide  110  relative to the stem  14  and tilting the handle gage  140 , the surgeon finds the orientation of the guide at which the surface  116  of the skirt  166  lies flush with the osteotomy  40  ( FIG. 14A ). 
         [0091]    Referring to  FIGS. 18A-18E , in use, after creating the osteotomy  40  and the channel  45  for the stem  14  in the humerus  42  ( FIG. 18A ), the surgeon places the stem  14  in the channel  45 . The compound angle guide  210  can then be used to determine the location of a mark  296  on the bone surface  44 , as well as the desired angulation and length of, for example, the component  120  ( FIG. 19 ). The surgeon manipulates the guide  210  ( FIG. 18B ) until an the skirt portion  266  of the guide  210  lies flush on the bone surface  44  ( FIG. 18C ). For example, by rotating the guide  210  relative to the stem  14  and tilting the handle gage  240  about the axis, Y, of the pin  260 , the surgeon finds the orientation of the guide at which the surface  216  of the skirt  266  lies flush with the osteotomy  40 . The surgeon then turns the thumb screw  262  to lock the relative tilt of the second portion  244  of the handle gage  240 , and marks a spot  296  ( FIG. 18D ) on the osteotomy corresponding to cutout  254  to indicate the rotational alignment. The lock pin  264  automatically locks the relative axial position of the handle gage  240 . As illustrated in  FIG. 18E , indicia  250 ,  252  on the guide  210  indicate the desired angulation and length, respectively, the component  120 . 
         [0092]    The surgeon then removes the guide  210  from the stem  14  and selects an implant component  120  that corresponds to the indicated tilt and height (axial position) to produce the desired component orientation ( FIGS. 19A and 19B ). When implanted, a notch or mark  298  on the implant is aligned with the marked spot  296 . The tilt indicia and the marked spot  296  account for the off-parallel orientation of the channel  45  relative to the osteotomy face  40 , and the height indicia accounts for the fact that the depth of the channel  45  that the surgeon forms, and therefore how far the stem  14  is recessed within the bone, can vary between patients. 
         [0093]    Referring to  FIGS. 20A and 20B , in an alternative implementation, a guide  300  includes a first member, for example, a shaft  302 , and a second member, for example, a handle gage  304  formed from a unitary portion, that slides axially and tilts relative to the shaft  302 . In contrast to guide  110 ,  210  described above, rather than providing continuous adjustability along a single tilt plane, the handle gage  304  of guide  300  can be set at a number of discrete tilt angles by tilting along a number of discrete planes. In the illustrated implementation, the handle gage  304  can be set at four angles (0°, 2.5°, 5°, and 7.5°) by tilting along two discrete planes,  306 ,  308 . 
         [0094]    The shaft  302  includes indicia  309  for indicating the relative sliding of the handle gage  304 , and a skirt  310  of the handle gage  304  includes formations, for example, cutouts  312 ,  314 ,  316 , and  318  for indicating on the osteotomy  40  the relative rotation of the guide  300 . 
         [0095]    Referring also to  FIG. 20C , the handle gage  304  has a wall  320  defining a lumen  321  that receives the shaft  302 . The wall  320  has four quadrants  322 ,  324 ,  326 , and  328 , each set at a different angle with respect to the shaft  302 . The handle  304  and shaft  302  are coupled by a pin  330  located within a cannulation  332  of a spherical ball  334 . The shaft  302  defines a lumen  344  for receiving the ball  334 , and slots  346  for receiving the pin  330 . The clearance between the pin  330  and a wall  336  of the spherical ball  334  defining the cannulation  332  allows for the relative tilting of the handle gage  304  along planes  306 ,  308 . 
         [0096]    The shaft  302  includes a terminal nipple  340  for receipt within the stem  14 , and a spring  342  located within shaft lumen  344  between the nipple  340  and the ball  334  to bias the handle gage  304  in a direction away from the nipple  340 . 
         [0097]    In use, the surgeon places the guide  300  on the implanted stem, picks one of the four tilt angles, and tilts the handle gage  304  relative to the shaft  302  to place the handle gage  304  at the selected angle. While holding the handle gage  304  at the selected angle, the surgeon advances the handle gage  304  toward the osteotomy  40  and rotates the guide  300  to determine how flat the skirt  310  sits on the osteotomy surface  44 . The surgeon can repeat this process for all four angles to determine the best orientation of the handle gage  304 . 
         [0098]    The surgeon then marks the rotation orientation on the osteotomy  40  using the cutout located opposite the angled surface, e.g., if a 7.5° tilt provides the best fit, the surgeon would use cutout  318  to mark the rotational orientation, for example as marking  331 . The surgeon then notes the axial indicia  309  for selecting the implant height, and the tilt angle for selecting the implant angle. 
         [0099]    Referring to  FIG. 21 , to aid in indicating the relative sliding of the handle gage  304 , the guide  300  can include a separate sliding component  350  that moves with the handle gage  304  relative to the shaft  302 . When the handle gage  304  is released and moves upward under the force of the spring  342 , the sliding component  350  remains in place relative to the indicia  309 . The sliding component  350  has a spherical surface  352  that meets with a spherical chamfer  354  at the end of the handle gage wall  320  to facilitate the tilting of the handle gage  304 . 
         [0100]    An additional alternative implementation of a guide is shown in  FIGS. 22 and 23 , which includes a shaft  400  a series of handle gages  402 . In the illustrated implementation, three handle gages  404 ,  406 , and  408  are shown, though more or fewer handles gages  402  can be used with shaft  400 . Each handle gage  402  includes a bore  410  oriented at an angle, for example, 0°, 5°, and 10°. The shaft  400  has a threaded end  412  for threadedly engaging the stem  14 . Each of the handle gages  402  includes a cut-out  414  for marking the rotational alignment of the handle gage  402  on the osteotomy. 
         [0101]    In use, the surgeon attaches the shaft  400  to the stem  14 , and selects one of the handles gages  402 . The surgeon slides the handle gage  402  down the shaft  400 , with the handle gage  402  oriented relative to the shaft  400  at the angle of the bore  410 , and rotates the handle gage  402  relative to the shaft  400  to try to align the surface  416  of the handle gage  402  with the osteotomy  40 . The surgeon can repeat this process with each handle gage  402  to determine the angle that provides the best alignment. 
         [0102]    Referring to  FIG. 25B  and  FIGS. 6A-6C , to aid the surgeon in setting the angulation of the connector  10 , the first member  20  is provided with an indicia  560 . By aligning the indicia  560  with indicia on an alignment member  586  (described below), which in turn is aligned with a mark  564  ( FIG. 25D ) on the bone surface  44 , the first member  20  is set at the desired angulation; the mark  564  having previously been determined by the surgeon to correspond to the alignment point that produces the desired inclination and retroversion, as described above. In use, to align vector  50  and axis, Z, after the first member  20  is fixed to the stem  14 , the second member  22  is coupled to the first member  20  and rotated until the vector  50  and axis, Z, align. 
         [0103]    The surgeon uses an alignment member  586 , illustrated in  FIGS. 24A and 24B , to rotate the first and second members  20 ,  22  about the screw axis, X. The alignment member  586  defines a first bore  602  sized to receive the first member  20  in frictional engagement, and defines a second, larger bore  604  sized to receive the second member  22  in frictional engagement. The alignment member  586  outer circumference  606  is knurled to facilitate hand turning of the alignment member and frictionally engaged member. 
         [0104]    Referring to  FIGS. 25A-25D , the surgeon then uses a trial connector  580  to check that the angulation, length, and alignment mark  564  produce the desired result.  FIG. 25B  shows indicia  560  on a first trial member  582  (corresponding to member  20 ) of the trial connector  580  aligned with a corresponding indicia  591  (the zero indicia) on the alignment member  586 . To position the first trial member  582  as shown in  FIG. 25B , after the surgeon couples the first trial member  582  to the stem  14  using the screw  18  ( FIG. 25A ), the surgeon slides the alignment member  586  over the first trial member  582  with indicia  560 ,  591  aligned. The surgeon then rotates the alignment member  586  and the first trial member  582  as a unit about the screw  518  to align angle indicia  588  (corresponding to the angulation indicated by the guide  110 ,  210 ,  300 ) with the mark  564  ( FIG. 25C , here the angle is 8.5°). The surgeon then tightens the screw  18  to fix the position of the first trial member  582 . 
         [0105]    To place a second trial member  584  (corresponding to member  22 ) of the trial connector  580 , the surgeon removes the alignment member  586  from the first trial member  582 , slides the second trial member  584  ( FIG. 25D ) over the first trial member  582 , flips over the alignment member  586  and slides the alignment member  586  over the second trial member  584  ( FIG. 25E ). The surgeon rotates the alignment member  586  and the second trial member  584  as a unit until a flat surface  593  of the alignment member is parallel with the bone surface  44 . The second trial member  584  is selected to provide the desired length indicated by the guide  110 ,  210 ,  300 . A trial head component  594  ( FIG. 25G ) is then coupled to the trial connector  580  and the head  594  is rotated to a position that provides optimal coverage of the bone surface  44 . The surgeon then takes the implant through a trial range of motion. 
         [0106]    If the trial connector  580  provides the desired functionality, the surgeon removes the trial connector  580 , selects a member  20  having the desired length, and repeats the procedure described above for the trial connector to connect members  20 ,  22  to the stem  14 . Once properly aligned ( FIG. 25F ), the surgeon uses an impactor  600  ( FIGS. 26A-26C ) to impact the member  22  such that the tapers  24 ,  26  ( FIG. 2 ) fix the member  22  to the member  20 , and removes the impactor  600  and alignment member  586 . The surgeon then slides the head  12  over the member  22 , rotates the head  12  to the position that provides optimal coverage of the bone surface  44 , and impacts the head  12  such that the tapers  28 ,  30  ( FIG. 2 ) fix the head  12  to the member  22 . 
         [0107]    Referring to  FIGS. 27A-27C , in an alternative implementation, an alignment member  610  includes an internal petal pattern  612  that is cut through the wall  614  of the smaller bore  602  and into the wall  616  of the larger bore  604 . The alignment member  610  is used with an impactor  620  ( FIG. 27D ) having a corresponding petal pattern  622  that is received within petal pattern  612 . This allows the impactor  620  to directly contact the second member  22  such that the impaction force is applied directly to the second member  22  rather than through the alignment member, facilitating the ease of removal of the alignment member  610  from the second member  22 . Alternatively, as illustrated in  FIG. 28 , an alignment member  630  includes two parts  632 ,  634  joined by a hinge  636 . Each part  632 ,  634  includes a finger tab  638   a ,  638   b  that the surgeon presses toward each other to open the parts  632 ,  634  for removal from the second member  22 . The parts  632 ,  634  can each define a petal pattern as illustrated in  FIGS. 27A-27C . 
         [0108]      FIGS. 29A-29C  illustrate a three part alignment member  640  having first and second parts  642 ,  644  that are secured together by an outer ring  646 . To remove the alignment member  640  from the outer member  22 , the surgeon slides off the outer ring  646  and separates the parts  642 ,  644 . 
         [0109]    Referring to  FIGS. 31A and 31B , to aid the surgeon in setting the angulation of the connector  10 , the first member  20  is provided with angle indicia  660 , for example, indicia representing 0-12°, and the second member  22  is provided with angle indicia  662 , for example, indicia representing 0-12°. By aligning the same angle indicia on the members  20 ,  22 , here 9.0° is illustrated, the connector is set at the desired angulation. In use, to align vector  50  and axis, Z ( FIG. 6A ), the surgeon aligns the same angle indicia with a mark  664  on the bone surface  44 ; the mark  664  having previously been determined by the surgeon to correspond to the alignment point that produces the desired inclination and retroversion, as described above. 
         [0110]    Referring to  FIG. 30 , the surgeon can use a trial connector  680  to check that the angulation, length, and alignment mark  664  produce the desired result.  FIG. 30  shows first and second members  682 ,  684  of the trial connector  680  aligned with each other at the angulation indicated by the mark  664 . The surgeon can then select the second member  684  that provides the desired length indicated by the guide  110 ,  210 ,  300 , couples a trial head component  594  ( FIG. 25G ) to the trial connector  680 , and rotates the head  594  to a position that provides optimal coverage of the bone surface  44 . The surgeon then takes the trial through a trial range of motion. 
         [0111]    Referring again to  FIGS. 31A and 31B , if the trial connector  680  provides the desired functionality, the surgeon selects a member  20  having the desired length and uses screw  18  to couple the member  20  to the stem  14 . The surgeon rotates member  20  about axis, X, to align the indicia  660  corresponding to the desired angulation with the mark  664 . The surgeon then tightens the screw  18  to fix the member  20  to the stem  14 , slides the member  22  over the member  20 , and rotates the member  22  to align the indicia  662  corresponding to the desired angulation with the corresponding indicia  660  on the member  20  and the mark  64 . The surgeon then impacts the member  22  such that the tapers  24 ,  26  fix the member  22  to the member  20 , slides the head  12  over the member  22 , rotates the head  12  to the position that provides optimal coverage of the bone surface  44 , and impacts the head  12  such that the tapers  28 ,  30  fix the head  12  to the member  22  ( FIG. 2 ). 
         [0112]    A number of implementations of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, the member  20  can be an integral component of the stem  14  that is not movable relative to the stem  14 . Such an integral component would have more limited adjustability. The stem  14  itself can be a single integral component or the stem  14  can include a stem body  14   a  and a proximal body  14   b  ( FIG. 3 ), which can be coupled to and rotatably adjusted relative to the stem body  14   a  prior to fixing the proximal body  14   b  to the stem body  14   a . Additionally, rather than the first member  112 ,  212  and the second member  114 ,  214  rotating together relative to the stem  14  ( FIGS. 14 and 15 ), the second member  114 ,  214  can rotate relative to the first member  112 ,  212 . The wall  320  of  FIG. 20C  can have more or fewer quadrants and be able to tilt about more or fewer planes. The anatomic guide  110 ,  210 ,  300  is illustrated in use with a stem implanted in the humeral bone. However, the anatomic guide  110 ,  210 ,  300  can be used with implants in other bones. 
         [0113]    Accordingly, other implementations are within the scope of the following claims.