Abstract:
A precision adjustable surgical tool holder/driver is provided which is easily disassembled for cleaning and precisely reassembled. The holder/driver has a positionable handle allowing adjustment of the position of the handle about the spindle of the holder to enable the “handedness” of the holder to be changed in order to accommodate a user while operating from the left or right side of the patient, standing behind or in-front of the patient, or for use in different surgical methods. The holder/driver includes a “limited-play” capture mechanism, which connects the drive end of the housing to its locking sleeve via a limited-play locking device. The limited-play locking device utilizes a disengageable, precision fitted bayonet pin and seat combination in part to accomplish the precision reassembly feature of the present invention.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of prior filed U.S. Provisional Patent Application Ser. No. 60/765,692 filed 6 Feb. 2006, to which the present application is a regular U.S. national application, and of prior PCT application No. PCT/1B03/01725, filed 28 Apr. 2003, which in turn claimed the benefit of prior filed U.S. Provisional Applications Ser. No. 60/376,479 filed 30 Apr. 2002, 60/384,186 filed 30 May 2002 and 60/459,594 filed 2 Apr. 2003, the contents of all of which are incorporated herein by reference. 
     
     FIELD OF THE INVENTION 
       [0002]    The present invention is in the field of surgical tools and accessories for performing orthopedic surgery. More particularly, the present invention relates to handles tool holders useful in orthopedic surgical procedures, the handles/holders being precision surgical tool handles with a limited-play interconnect mechanism. 
       BACKGROUND 
       [0003]    Complicated mechanical devices have crevices and recesses that are difficult, if not almost impossible, to clean with ease. Devices that are not properly cleaned and sterilized contribute to the risk of disease transfer from patient to patient following the emergence of certain “prions” that are not killed by normal hospital sterilization and need to be physically removed by washing/rinsing. Although surgical tool handles are known in the field (see PCT/GB2002/02934 to Chana, incorporated herein by reference), those using “J-slot” (bayonet type) interconnect mechanisms can be subject to play at the interconnections. It would be beneficial in the field to have an interconnect mechanism that has the advantages of the existing “J-slot” interconnect mechanisms, but is less subject to play in the connection. 
       SUMMARY 
       [0004]    The present invention comprises an adjustable reamer spindle designed to aid a surgeon to better control the instrument. Adjustment of the position of the handle axis of the spindle enables the axis through the palm/grip of each hand to change in order to provide maximum control in different orientations. The adjustment is desirable in order to accommodate operating on the left or right side of the patient standing behind or in front of the patient, or the use of a different surgical approach. Further, adjustment is important to accommodate the differing needs of surgeons who are naturally left or right handed. In such an instrument that is intended for either right or left handed use, or both CW and CCW rotation in use, it is important to provide an interconnect mechanism that minimizes axial play when used with either hand, or both CW and CCW rotation. 
         [0005]    The present invention comprises a precision surgical tool holder/handle which is assemblable over and over again to precise radial, axial and length relationships of its components. The precision tool driver has a precision spindle housing in which a drive train is retained. The drive chain has a drive attachment end connectable to a means for rotating the drive chain, and a tool holder end connectable to a surgical tool head. The tool holder end has an axis of rotation relative to the spindle housing, and an axial displacement aspect relative to a tool end of the spindle housing. The axis of rotation is precisely defined by the relationship between the spindle housing and the drive chain at the tool holder end of the drive chain. The axial displacement aspect is definable as the distance between the tool end of the spindle housing and the tool holder end. 
         [0006]    The handle has a fitted locking sleeve which closely receives the spindle housing and drive chain combination. The locking sleeve has a sleeve axis which is disposed precisely parallel to the axis of rotation when the spindle housing and drive chain combination is received by the locking sleeve. The locking sleeve has a mating means interfacing with the spindle housing which precisely fixes a radial aspect relationship between the spindle housing and the locking sleeve when the spindle housing is received by the locking sleeve. 
         [0007]    A precision locking device is retained on the locking sleeve. The locking device has an annular collar slideable on the drive end of the locking sleeve, between a sleeve shoulder and a collar ring. The annular collar has a handle attached to it, a collar axis, and an attachment point at which the handle is fixed to the annular collar. Typically, the attachment point is disposed on a radius of the collar axis. The collar ring is releaseably engageable to bias the collar against the sleeve shoulder at a precision radial interface to precisely fix the radial aspect relationship between the attachment point and the collar radius. 
         [0008]    A releaseable capture mechanism is provided to integrate the assemblies of the present invention into a working whole. The capture mechanism is embodied in part in each of: the spindle housing/drive chain, locking sleeve and locking device assemblies. The capture mechanism comprises a precision bayonet-type connection cooperatively involving the spindle housing, the locking sleeve and the locking device. The precision bayonet connection includes the collar ring which has an internal surface from which at least two bayonet pins extend radially inward. The bayonet pins pass through retainer slots disposed in the locking sleeve, as described elsewhere. When the locking sleeve assembly is slid over the spindle housing/drive chain assembly, the bayonet pins are received into bayonet slots on the spindle housing corresponding to the retainer slots on the locking sleeve. The bayonet slots are disposed to releaseably engage the bayonet pins. At least one of the bayonet slots has a precision pin seat to engage a precision bayonet pin head on its corresponding bayonet pin. 
         [0009]    When the capture mechanism is engaged, the spindle housing/drive chain assembly, the fitted locking sleeve assembly and the locking device all cooperate through the capture mechanism to provide the present precision surgical tool driver repeatably assembleable to precise radial, axial and length aspect relationships of its components and the device overall. 
         [0010]    The releaseable capture mechanism has a precision bayonet-type connection between the spindle housing, the locking sleeve and the locking device. The collar ring has an internal surface from which at least two bayonet pins extend radially inward, and pass through retainer slots disposed in the end of the locking sleeve. The retainer slots correspond to bayonet slots in the spindle housing. The bayonet slots are disposed to releaseably engage the bayonet pins. At least one of the bayonet slots has a precision pin seat to engaging a precision bayonet pin head on its corresponding precision bayonet pin. 
         [0011]    The spindle housing and drive chain combination, the fitted locking sleeve, the locking device and the capture mechanism all cooperating to provide the present repeatably assembleable precision surgical tool driver. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]      FIG. 1  is a side view of the reamer spindle of the present invention. 
           [0013]      FIG. 2  is a top view of the reamer spindle of the present invention. 
           [0014]      FIG. 3  is a section view taken along line  3 - 3  shown in  FIG. 2 . 
           [0015]      FIG. 4  is a plan view showing a traditional reamer spindle of the prior art being used in a minimally invasive approach for reaming the acetabular socket. 
           [0016]      FIG. 5  is a plan view showing the reamer spindle of the present invention being used in a minimally invasive approach for reaming the acetabular socket. 
           [0017]      FIG. 6  is an exploded assembly of an alternative embodiment of the present invention. 
           [0018]      FIG. 7  is an alternative shape housing of the alternative embodiment shown in  FIG. 6 . 
           [0019]      FIG. 8  is a perspective view of an alternate embodiment of the invention having a repositionable handle. 
           [0020]      FIG. 9A  is an exploded view of the alternate embodiment of  FIG. 8 . 
           [0021]      FIG. 9B  is a close up of a portion of the exploded view of the alternate embodiment of  FIG. 8 . 
           [0022]      FIG. 9C  is a cross-sectional view of the adjustable handle portion of the alternate embodiment of  FIG. 8 . 
           [0023]      FIG. 9D  is a perspective drawing of the principle assemblies of the present invention illustrating their axial, radial and length aspects wherein the precision features of the device reside. 
           [0024]      FIG. 10  is a perspective view of key components of the alternate embodiment of  FIG. 8 . 
           [0025]      FIGS. 11A and 11B  are end-on views of the drive ends of the spindle housing and the locking sleeve assembly, illustrating a limited play interconnection between the housing and the sleeve, with the fitted bayonet pin disengaged from its seat (A), and engaged in its seat (B). 
           [0026]      FIG. 11C  is an alternative embodiment of the fitted bayonet pin and seat features of the limited-play interconnection of  FIGS. 11A and 11B . 
           [0027]      FIG. 12  is a perspective end view of the spindle housing showing the bayonet pin J-slots, one of which includes a close tolerance, fitted bayonet pin seat. 
           [0028]      FIGS. 13A and 13B  are instructional illustrations of a manner in which the locking device can be operated. 
           [0029]      FIG. 14  is a plan view of a surgical reamer kit of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0030]    Referring now to the drawings, the details of embodiments of the present invention are graphically and schematically illustrated. Like elements in the drawings are represented by like numbers, and any similar elements are represented by like numbers with a different lower case letter suffix. 
         [0031]    In one embodiment, the present invention comprises a reamer spindle  115  as shown in  FIGS. 1-3 , and  5 . The reamer spindle  115  has a housing  113  containing a drive shaft  107 . The drive shaft  107  has a proximal end drive fitting  104  adapted to be attachable to a controllable motive source (not shown). The motive source is provided to rotate the drive shaft  107  inside the reamer spindle  115 . The drive shaft  107  has a distal end tool holder fitting  120  for holding a tool head  10 , such as a reamer in the embodiment illustrated (see  FIG. 5 ). The drive fitting  104  and the tool holding fitting  120  are disposed to mate with a complimentary fitting on a motive source and a tool head  10 , respectively. 
         [0032]    In the embodiments illustrated, the tool holding fitting  120  is illustrated as comprising a complementary part of a bayonet-type connection mechanism. However, as further illustrated below, a complementary part of a bayonet-type mechanism can be used at other connections on a tool spindle  115 . The tool holding fitting  120  had a slide  106  carrying a pin  111 . The pin  111  works cooperatively with the catch  110  located in the head  108  to form the bayonet for capturing the complementary fitting on a tool head  10 , while allowing easy release. The tool heads  10  (reamers in this embodiment) selected for use with the reamer spindle  115  can be shaped and sized for cutting different osseous sites within the body. It is widely known that reamers can be designed to cut the patella in a knee or the glenoid in a shoulder or the socket  45  in an acetabulum  40  as shown in  FIGS. 4 and 5 . 
         [0033]    Referring to  FIGS. 4 and 5 , the reamer spindle  115  of the present invention and the spindle  15  of the prior art invention are shown passing through a miniature incision  35  in the patient&#39;s skin  30 . In prior art  FIG. 4 , the reamer spindle  15  is shown approaching the acetabulum  40  in a preferred orientation for reaming the socket  45 . A difficulty with the prior art spindle  15  is that, as shown, the shaft  3  can impinge on the miniature incision  35  at edge  37  of the incision. The current surgical protocols are being pushed to the limits and the incision sizes are being reduced with the intent of increasing the patient&#39;s recovery speed. In some cases, surgeons are using a two-incision approach, one to reach the acetabulum and the other to reach the femur. Depending on the situation, either the one incision or the two incision technique can result in less trauma to the patient, thus requiring the instruments to be flexible and more optimally designed to make up for the lack of operating space. 
         [0034]    The reamer  115  of  FIG. 3  shows a present reamer spindle  115 , which has a bent housing  113  containing the drive shaft  107 . The drive shaft  107  can be selected from a variety of current torque transmitting mechanisms or devices including a Nickel Titanium shaft, a flexible round or flat wire wound cable, a series of gear driven shafts, or a series of shafts interconnected by universal joints. The drive shaft  107  can also be selected from any torque transmission mechanism or device deemed appropriate for the application, as selectable by one of ordinary skill in the art for practice in the present invention. As illustrated, the drive shaft  107  can be held to the housing  113  with an optional series of bearing surfaces  118  &amp;  119  which keep the drive shaft  107  from bearing against/riding on the inside of the housing  113 , and can act as a shield to protect the inner housing from blood. Other means for holding the shaft to the housing would be acceptable. The most important feature of the drive shaft  107  is that it conforms to the selected housing  113  and sufficiently supplies torque to the tool head  10 . In these examples, the housing  113  is hollow and maintains the drive end fitting  104  substantially collinear with the tool holder fitting  120  (see  FIGS. 3 and 6 ), but as illustrated below, other configurations are intended as well. 
         [0035]    Referring now to  FIG. 6 , an alternative embodiment is shown. Similar to  FIGS. 1-3  and  5 , the reamer spindle  215  has a housing  113  in two parts  213  &amp;  214  containing a drive shaft  207 . The drive shaft  207  has a proximal end drive fitting  204  adapted to be attachable to a controllable motive source (not shown). The motive source is provided to rotate the drive shaft  207  inside the reamer spindle  215 . The drive shaft  707  has a distal end tool holder fitting  220  for holding a tool head  10 . The drive fitting  204  and the tool holding fitting  220  are disposed to mate with a complementary fitting on a motive source and a tool head  10 , respectively. The drive shaft  207  can be selected from a variety of current torque transmitting mechanisms or devices including a Nickel Titanium shaft, a flexible round or flat wire wound cable shaft, a series of gear driven shafts, or a series of linkages  208  interconnected by universal joints  209 . The drive shaft  207  can also be selected from any torque transmission mechanism or device deemed appropriate for the application. In this embodiment, the shaft  207  is constructed from a series of linkages  208  containing universal joints  209  and bearing members  218  which rest against journey supports  218   a  in the housing parts  213  and  214 . 
         [0036]    The drive shaft  207  can be flexible substantially through out its length, but is required to be flexible only along portions of its length received in curved portions of the housing  113 , since it is not necessary to feed drive shaft  207  into the housing  113 . Along straight portions of its length, the drive shaft  207  can be rigid. Flexibility in drive shaft  207  is required only to allow its rotation within curved portions of the housing  113 . As noted above, the drive shaft  207  can be conventional, wound-wire cable flexible along its length, and having one or more alternating layers wound in opposite directions. A protective, friction reducing sheath (not shown) can be provided on such a drive shaft. Other types of flexible drive shafts also can be used. Spaced bearing journals (not shown) and/or lubricant can be provided within outer shaft  50 , to allow proper position of drive shaft  56  in outer shaft  50 , and to reduce resistance to rotation of drive shaft  56  within outer shaft  50 . 
         [0037]    The tool holder fitting  220  preferably comprise a complementary part of a bayonet-type mechanism with a slide  206  carrying a pin component  211 . The pin  211  works cooperatively with the catch  210  located in the head  208  to form the bayonet for capturing different size reamers while allowing their easy release for size interchangeability and cleaning. The drive shaft  207  is set in housing parts  213  &amp;  214 , which are separable for cleaning, 
         [0038]    There are many ways of connecting the housing part  213  &amp;  214  together. For example, the drive shaft  207  can include a capture mechanism  247  which is adapted to receive the front ends of the housing parts  213  &amp;  214  aligning each with one another and encapsulating the drive shaft  107  to protect the patient&#39;s skin from contacting the torque transmitting shaft  207  during operation. Once the housing parts  213  &amp;  214  are aligned, a locking mechanism  250  comprised of a ring  255  and a catch  260 , which is located in the housing member  213 , interact with one another to retain the housing parts  213  &amp;  214  in a closed fashion. As with the embodiment described in  FIGS. 1-3 , and  5 , it is preferable to have the drive end  204  substantially collinear with the holding mechanism  220  along axis  216 . The housing parts  213  &amp;  214  are shown preferably in  FIG. 6  a bent configuration. However, the reamer spindle  215  can embody housing in two parts, wherein the housing parts  313  &amp;  314  are straight and have no bend, as shown in  FIG. 7 . 
         [0039]    Referring now to  FIGS. 8  et seq., alternatively, the drive end  404  is situated along an axis parallel to, but offset from, the axis  416  of the tool holder fitting  420 . A bend  480  in the housing is optimally placed at a location to pass through the miniature incision (see  FIG. 5 ) without impinging on the skin  30  at location  37  while still maintaining the same surgical protocol. The drive end fitting  404  and the tool holder fitting  420  have parallel axes, so that an inline force applied to the drive fitting  404  results in an axial force applied to the tool holder fitting  420 . This allows the surgeon to maintain the existing surgical technique and accomplish the same result as when a prior reamer spindle  15  is used with its straight drive shaft  3  (see  FIG. 4 ). Thus, the surgeon is able lo apply a load directly along the path of reaming. 
         [0040]    In the embodiment of the reamer spindle  515  illustrated in  FIG. 8 , the drive end  404  is situated along an axis parallel to, but offset from, the axis  416  of the tool holder fitting  420 . Further, as shown in  FIGS. 9A and 9B , a repositionable handle  500  doubles as a component of the capture device  450  in order to hold the two housing parts  413  &amp;  414  together. The capture mechanism  447  and capture device  450  slide over the front ends  448  of the housing parts  413  &amp;  414 , aligning each with one another and thus encapsulating the drive shaft  507  in order to protect the patient&#39;s skin from contacting the torque transmitting shaft  507  after the present device is assembled. 
         [0041]      FIGS. 9A ,  9 B and  9 C show how the housing parts  413  &amp;  414  are aligned and locked in place in this embodiment of the spindle  515 . The housing parts  413  &amp;  414  are oriented with respect to each other when the locking sleeve  502  (having an internal diameter larger than the outside diameter of the assembled housing  413 ,  414 ) slides over them and abuts against a bend  480  in the housing parts  413  &amp;  414 . Optionally, a facilitating surface may be disposed between the housing parts  413  &amp;  414  and the locking sleeve  502  to facilitate assembly, such as a thin Teflon® coating or sleeves (not shown). A mouth section  502 ′ of the locking sleeve  502  cradles the bend  480  of the assembled housing parts  413  &amp;  414  and prevents rotation of the locking sleeve relative to the housing parts  413  &amp;  414 . 
         [0042]    The sleeve drive end  548  of the locking sleeve  502  comprises a capture mechanism  447  which connects the housing drive end  448  of the housing parts  413  &amp;  414  to the locking sleeve  502  via a locking device  450 . In one embodiment, the locking device  450  had an annular collar  482  onto which a handle  500  was affixed. The collar  482  includes a face  482 ′ having pin recesses  482 ″ into which sleeve pins  484  are receivable. The sleeve pins  484  are fixed to a sleeve shoulder  502 ″ of the locking sleeve  502 . The sleeve pins  484  are disposed to be received into the pin recesses  482 ″. The relationship between the sleeve pins  484  and pin recesses is disposed to provide torsionally rigidly to hold the handle  500  in any one of a number of positions (eight in one embodiment) according to the preference of the surgeon. Alternatively, the sleeve shoulder  502 ″ can have fingers or other projections (not shown) that mate with the recesses  482 ″. A collar spring  486  biases the annular collar  482  into engagement with the sleeve pins  484  by a bias against the annular collar  482 . In the embodiment illustrated this is accomplished by the collar spring  486  applying spring pressure against an internal shoulder  482 ′″ in the annular collar  482  and against a collar locking ring  455 . The collar locking ring  455  includes collar pins  490  which are affixed thereto. The collar pins are received in and extend through sleeve bayonet slots  492  in the drive end  548  of the locking sleeve  502 . At least one of the sleeve bayonet slots  492  has a close-end  493  (see  FIG. 9B ), thus retaining the locking device  450 , including the collar ring  455  and bias spring  486 , on the drive end  548  of the locking sleeve  502 , thus keeping the component part of the thus the capture mechanism  447  together when the spindle  515  is disassembled. 
         [0043]    In order for the locking device  450  to the engage and connect to the drive end  448  of the assembled housing parts  413  &amp;  414 , the collar pins  490  ( 490   a  &amp;  490   b ) extend through the sleeve bayonet slots  492  sufficiently to additionally be received in the housing bayonet slots  392  on the assembled housing parts  413  &amp;  414  (see  FIG. 10 ). As shown in  FIG. 10 , the housing  413 ,  414  is held together via the collar pins  490  which engage the bayonet slots  392  in each of the housing parts  413  &amp;  414 . The illustration in  FIG. 10  has the annular sleeve  502 , the collar spring  486  and the locking collar  482  are removed for clarity. 
         [0044]    The collar pins  490  of the collar locking ring  455  and the housing bayonet slots  392  interact with one another to retain the housing parts  413  &amp;  414  in an assembled condition, while concurrently biasing the collar spring  486  so as to engage the annular collar  482  (and thus the handle  500 ) with the sleeve pins  484 . Optionally, the bias force of the collar spring  486  can be selected to enable the surgeon to selectively disengage the collar  482  from the sleeve pins  484  and reposition the angle of the handle  500  relative to the locking sleeve  502  in an alternative position, while avoiding disassembly of the spindle  515 . 
         [0045]    A most important object of the present invention is a precision surgical tool driver which is repeatably assembleable to precise radial, axial and length aspect relationships of its component assemblies. The precision of the device reside in its features which allow it to be disassembled multiple times, and upon each reassembly, the physical dimensions defined by the aspect relationships between its component assemblies are precisely duplicated in the reassembled tool driver. See  FIG. 9D . The present precision tool driver comprises three main assemblies and a capture mechanism for precisely interconnecting the main assemblies. 
         [0046]    One assembly is a combination spindle housing/drive chain  615 . The precision spindle housing  413 , 414  has an interior disposed to receive and retain the drive train (or drive shaft)  207 . The drive chain has a drive attachment end  404  and a tool holder end  420 . The drive attachment end  404  is configured to interface with a motive means (not shown) for rotating tire drive chain  207 . Such motive means are known in the field. The tool holder end is configured to connect to a surgical tool head, such tool holder connector configuration being known in the field. The tool holder end  420  of the drive chain  207  has an axis of rotation aspect A which is parallel relative to the tool end  620  of the spindle housing  413 ,  414  from which it extends. The precision of the axis of rotation aspect A is defined by the relationship between the spindle housing  413 , 414  and the drive chain  207  at the tool holder end  420  of the drive chain. More specifically, this relationship is defined by the high precision of the bearing or bushing interface between the spindle housing  413 ,  414  and the drive chain  207  at the tool end  620  of the housing. This relationship is that the spindle tool end  620  and the tool holder end  420  are always substantially coaxial along the axis of rotation A when the drive chain  207  and the spindle housing  413 ,  414  are assembled. The tool holder end  420  also has an axial displacement aspect d relative to the tool end  620  of the spindle sleeve. The axial displacement aspect d is the distance between an end point  620  on the spindle housing  413 ,  414  and the tool holder end  420 . The precision of the axial displacement aspect d is defined by the relationship between the spindle housing and the drive chain at the tool holder end of the drive chain, which aspect is substantially always the same when the drive chain  207  and the housing  413 ,  414  are assembled. 
         [0047]    Another assembly is the precision filled locking sleeve which closely receives the spindle housing and drive chain combination  615 . In the embodiment illustrated, the drive end  404  of the spindle housing/drive chain assembly  615  slides into and is closely received by the locking sleeve  502 . The locking sleeve  502  has a sleeve axis B. The locking sleeve  502  is configured to precisely receive and retain the spindle housing  413 ,  414  so that the sleeve axis B is parallel to the axis of rotation aspect A of the tool holder end  420  of the drive chain  207 . The locking sleeve  502  also has a mating means  502  which interfaces with the spindle housing  413 ,  414  to precisely fix the radial aspect of the locking sleeve  502  relative to the spindle housing  413 ,  414  upon receipt of the spindle housing by the locking sleeve. This is to say, the mating means  502 ′ assures the spindle housing  413 ,  414  is repeatably receivable in the locking sleeve in the same radial orientation relative to each other. Additionally, in the embodiment illustrated, the mating means  502 ′ provides a precise travel limit on how far the locking sleeve  502  can slide along the spindle housing  413 ,  414 . 
         [0048]    The third assembly noted above is the precision locking device  450 , which is retained on the locking sleeve  502 . The locking device  450  comprises an annular collar  482  slidable on the drive end  483  of the locking sleeve  502  between a sleeve shoulder  502 ″ and a collar ring  455 . The collar ring  455  retains the collar  482  on the locking sleeve  502 , and incorporates features of a precision bayonet connection, further described elsewhere herein. The collar  482  has a handle  500  attached to it, a collar axis B′ through its centerline and a point of attachment  625  of the handle  500  to the collar  482 . The collar axis B′ is substantially collinear with the sleeve axis B, and in the embodiment illustrated, is coaxial. The point of attachment  625  is disposed along a selected radius C of the collar axis. The collar ring  455  is releaseably engageable to bias/hold the collar  482  against the sleeve shoulder  502 ″ at a precision radial interface  484  &amp;  482 ′, a first part  484  of which is on the sleeve shoulder  502 ″ and the second part  482 ′ being on the annular collar  482 . The precision radial interface precisely fixes the radial aspect relationship between the point of attachment and the collar axis radius. In the embodiment illustrated, the radial aspect relationship between the point of attachment of the collar axis to the locking sleeve axis B. 
         [0049]      FIGS. 11A-11C  and  12  illustrate the “limited-play” features of the capture mechanism  447 , which connects the housing drive end  448  of the housing  413 ,  414  to tile locking sleeve  502  via the locking device  450 .  FIGS. 11A and 11B  are end-on views of the drive ends of the spindle housing and the locking sleeve assembly, with the fitted bayonet pin disengaged from its seal  620  (in  FIG. 11A ), and engaged in its seat  620  (in  FIG. 11B ). In the embodiment shown in  FIG. 11A , to engage the housing  413 ,  414 , locking device  450  of the capture mechanism  447  has two collar pins  490   a  &amp;  490   b  held by the collar ring  455 . One is a fixed collar pin  490   a  and the other is an extendable collar pin  490   b . The extendable collar pin  490   b  has a fitted bayonet pin head  600  at the end of the collar pin  490   b  disposed in the interior of the collar ring  455 , and a push-button cap  604  at the other end of the collar pin  490   b  disposed anterior to the collar ring  455  and a pin spring  614  disposed about the shaft of the pin  612 . The extendable collar pin  490   b  is slideably received in a pin passage  610  in the collar ring  455 . In the embodiment shown, the pin passage  610  also serves a spring chamber for receiving the pin spring  614 . The pin spring  614  provides a biasing force against the push-button cap  604  and the collar ring  455 , which normally displaces the push-button cap  604  away from the collar ring  455 . 
         [0050]    The collar pins  490   a  &amp;  490   b  are received in and extend through sleeve bayonet slots  492   a  &amp;  492   b  in the drive end  548  of the locking sleeve  502  (also see  FIG. 10 ). The collar pins  490   a  &amp;  490   b  extend through their respective sleeve bayonet slots  492   a  &amp;  492   b  sufficiently be received in their respective housing bayonet slots  392   a  &amp;  392   b  on the assembled housing parts  413 ,  414  (also see  FIG. 10 ). The fitted bayonet slot  390   b  for receiving the fitted bayonet pin  490   b  includes a head seat  620 . The head seat  620  is disposed to closely receive and securely engage the bayonet pin head  600  of the fitted bayonet pin  290   b  tinder the bias force of the pin spring  614 . The relationship of the configuration of the pin head  600  and the head seal  620  is disposed to enable the close and securely engagement of the pin head in the head seat. This may be accomplished by any of a number of means known to the ordinary skilled artisan for practice in the present invention, including chamfering or beveling the surface of the head seat  620  to closely receive a complementary surface of the pin head  600 . 
         [0051]    As shown in  FIG. 11B , the housing parts  413  &amp;  414  are held together via the collar pins  490   a  &amp;  490   b  which engage their respective bayonet slots  392   a  &amp;  392   b  in each of the housing parts  413  &amp;  414 . The collar pins  490   a  &amp;  490   b  of the collar locking ring  455  and the housing bayonet slots  392   a  and  392   b  interact with one another to retain the housing parts  413  &amp;  414  in an assembled condition. Thus, the locking device  450  can engage and connect to the drive end  448  of the assembled housing parts  413  &amp;  414 . When the depicted embodiment of the present invention is in its assembled condition, as in  FIG. 11B , depressing the push-button cap  604  to over come the bias force causes the pin head  600  to be disengaged from the head seat  620  and to extend beyond the bayonet slot  392   b . While the push-button cap is so depressed, the bayonet connection of the locking device  450  can be disengaged in a conventional manner, and the spindle housing  413 ,  414  can be separated from the capture mechanism  447 . 
         [0052]      FIG. 11C  is an alternative embodiment of the fitted bayonet pin and seat features of the limited-play interconnection of  FIGS. 11A and 11B . In this embodiment, head seat  620   a  comprises both the spindle housing  413 ,  414  and the locking sleeve  502 . This configuration of the pin head seat  620   a  allows the pin head  600  to be closely receive by and to securely engage with both spindle housing  413 ,  414  and the locking sleeve  502 , to reduce further the possibility of play in the interconnection between the two assemblies. 
         [0053]    Its form helps it to lodge itself in the diameter cut at the end of one of the J-slots in the external locking sleeve. This cut diameter is identical to the largest diameter of the mobile pin. The path of the J-slot outside of this specific diameter is sized according to the smaller diameter of the mobile pin. The pin then slides the length of the J-slot and clicks into the diameter cut at the end of one of the J-slots in the external locking sleeve. The corresponding slot in the internal Z sleeve must be cut in order that the large diameter of the mobile pin can slide the entire length of the external J-slot. This slot is in fact an L-slot of which the diameter is that of the larger diameter of the fixed pin. 
         [0054]      FIG. 12  is a perspective end view of the spindle housing  413 ,  414  showing the bayonet J-slots  392   a  &amp;  392   b . In some of the embodiments illustrated, one of the two bayonet slots  390  included a close tolerance, fitted bayonet pin seat  620 . However, as known to the ordinary skilled artisan, more than two bayonet slots may be practiced in the present invention. Additionally, as shown in  FIG. 12 , there may be multiple bayonet slots  392   b  each having a close tolerance, fitted bayonet pin seat  620 .  FIGS. 13A and 13B  are instructional illustrations of a manner in which the locking device can be operated to engage ( FIG. 13A ) or to disengage ( FIG. 13B ) the drive end of the spindle housing. 
         [0055]    Referring now to  FIG. 14 , collectively, these different types of housing parts  213 - 214 ,  313 - 314 , and  413 - 414  can be provided as a kit  600  having a selection of different sized reamer housings  113 , tool heads  10 , an impactor  602 , acetabular implants (not shown), femoral hip prostheses  604 , and acetabular cup prostheses  606 , the selection of different reamer housing configurations allowing the surgeon to select between a bent, offset configuration or a straight configuration of the reamer spindle depending on the surgeons approach, which may vary during the same operation of between different patients. 
         [0056]    While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of one or another preferred embodiment thereof. Other variations are possible, which would be obvious to one skilled in the art. Accordingly, the scope of the invention should be determined by the scope of the appended claims and their equivalents, and not just by the embodiments.