JP5452871B2 - Femoral head component for surface reconstruction - Google Patents

Description

  The present invention relates to a femoral head component for use in a hip surface reconstruction procedure.

  Traditional total hip replacement (THR) is a treatment for the treatment of arthritis of mobile hips in pathologies that cause significant pain and loss of movement. As is well known, the hip joint is a ball joint that allows the upper leg to move left and right, back and forth, and rotate. The joint is composed of a femoral head (ball) fitted in an acetabulum (dimple). In a healthy hip joint, both the femoral head and the acetabulum are coated with cartilage, which provides a smooth surface and allows the joint to move freely.

  In conventional total hip replacement (THR), a worn bone head is removed from the femur, a metal ball and handle are replaced on the femoral shaft, and a plastic cup is placed on the prepared acetabulum. . Both elements are typically secured to the bone by “bone cement”. This has become a very common surgical procedure, with approximately 45,000 total hip replacements being performed each year in the UK.

  The plastic used to form the cup is inert and is therefore well tolerated by the body. Nevertheless, the metal balls rub against the plastic cup and the plastic particles are scraped off. This plastic waste causes irritation. Furthermore, when the particles reach between the bone and the artificial joint, this stimulation causes the surrounding bone to be absorbed by the body, leading to loosening of the artificial joint. In older people with low activity levels this may not occur for more than 20 years, but in younger and more active patients this may occur much earlier.

  In order to overcome these problems in younger and more active patients who require joint replacement, different types of implants have become necessary. In 1991, a procedure for intermetallic (MoM) surface reconstruction of the hip joint was proposed. This has two main differences from the conventional THR. The first difference is that both components are generally made of metal, preferably cobalt chrome. By eliminating the conventional THR plastic cup and making both bearing parts metal, the reconstructed hip joint is expected to last much longer and therefore be suitable for the demanding patient. The second difference is that the procedure preserves the bone very well because the femoral head is not removed but simply reshaped and “reconstructed”.

  However, a problem existing in hip surface reconstruction is the lack of the ability to handle options related to the offset of the bearing surface of the femoral head component, thus changing the leg length of the patient when performing hip surface reconstruction surgery There is a possibility.

  THR originally had very few options related to femoral head offset and the resulting change in leg length after surgery. Optimizing post-operative biomechanics by introducing a modular head to the THR that allows the surgeon to select different head lengths ranging from about minus 4 mm to plus 20 mm (relative to the standard neck length) It became possible to change the leg length of the patient so that Although a clear range of acceptable and unacceptable leg length shifts after THR has not been established, surgeons agree that having an equal or nearly equal leg length after hip replacement surgery is advantageous. I'm doing it. In particular, the normal process of cartilage alteration and loss during hip osteoarthritis leads to some shortening of the effective limb, as in unilateral dysplasia, where leg length differences of up to 5 cm can occur. In the latter case, some of the misalignment can be corrected by correct acetabular placement, but the ability to change leg length using a modular head available when performing THR is also very useful .

  In contrast, in hip face reconstruction, the surgical procedure is to preserve the bone and important structures such as the femoral head and neck are preserved and simply prepared to accept the new bearing surface. Let's go. Thus, standard hip surface reconstruction components known in the prior art do not provide the opportunity to significantly modify the bearing surface offset and thereby generally not achieve the desired post-operative leg length. However, some shortening of the legs that are too long can be achieved by seating the femoral component deep under the femoral head and neck joint, but this is limited and metal on the femoral neck Components may protrude and lead to improper fixation.

  Accordingly, it would be desirable to provide an improved femoral component for hip surface reconstruction procedures that can cause changes in leg length during a surgical procedure.

  The invention provides a first aspect of a hip surface reconstruction femoral component for use with a prepared femur, the head having a generally spherical outward bearing surface, and the bearing surface of the head. And a skirt portion having a skirt outer surface and a skirt inner surface depending from the substantially spherical bearing surface, and the skirt inner surface and the mounting surface are configured to fit on the prepared femur. A femoral component is provided.

  This is advantageous because the femoral component for hip surface reconstruction is offset relative to the femur thanks to the skirt. This thus allows for leg extension after surgery, whereby it is achieved that the legs have an equal or substantially equal length after the surface reconstruction procedure.

  In a second aspect of the present invention, a hip surface reconstruction femoral component having a longitudinally extending longitudinal axis for use with a prepared femur, wherein the generally spherical distally directed bearing A head having a surface and having a center of the bearing surface and a distal-most point, and a mounting surface facing in a proximal direction, opposite the bearing surface of the head and having the distal-most point of the mounting surface And the ratio of the offset distance defined as the distance parallel to the axis from the most distal point of the mounting surface to the most distal point of the bearing surface and the offset distance to the diameter of the substantially spherical bearing surface is 0.25. A femoral component is provided comprising the femoral head designed to be higher.

  This embodiment is advantageous because it also provides an offset for the femoral component for hip surface reconstruction, thereby allowing the leg to be extended after surgery. The longitudinal axis preferably passes through the center of the bearing surface. Advantageously, the hip surface reconstruction femoral component further includes a skirt that hangs from the spherical bearing surface to achieve a greater range of movement of the joint.

  Preferably, the hip surface reconstruction femoral component further includes a stem portion depending from the mounting surface. The stem portion can be formed integrally with the head portion or attached thereto. For example, the stem portion can be attached to the head with an adhesive or integrally formed therewith, or it can be attached by mechanical fixation using, for example, a taper fit, bayonet fit, or screw fastening. The stem portion helps to ensure correct alignment of the femoral component and provides post-operative stability for months after surgery.

  The reconstructive femoral component includes a head engaging surface that provides a mounting surface and is opposed to the mounting surface and engages an insert engaging surface of the head opposite the bearing surface It is preferable to have a part. The insert can be attached to the head by bonding, with an adhesive, or by molding / fusion of the two parts together. Alternatively, the insert and head can be mechanically attached by, for example, taper fitting, bayonet fitting, screwed engagement, or indentation. The distance by which the insert portion enters the head portion can be varied taking into account the variable offset of the hip surface reconstruction femoral component. The insert portion can hold a separate skirt portion in place between the head and the insert portion, or can be formed to include the skirt portion. A reconstructive femoral component that includes separate heads and inserts and, if desired, a skirt, allows the two parts to be made from different materials so that cost and / or weight savings are achieved. Provides benefits including first. Furthermore, modular devices are easier to manufacture and reduce the required surgical inventory.

  To further enhance modularity and thereby increase options for the surgeon, the resurfacing femoral component preferably further includes a spacer that can be selected to provide the desired offset. The spacer is disposed between the head engaging surface and the insert portion engaging surface. The spacer can be of many shapes, such as a simple cubic shape, or a more complex shape complementary to the engagement surface of the head and insert, and can be attached to one of the head or insert engagement surfaces, Assembly of the femoral component for surface reconstruction is facilitated.

  Advantageously, the insert and, if provided, the spacer also have a through hole there. Next, a hole is provided in the head portion, and a projection extending from the upper surface is provided in the stem portion. The protrusion then penetrates the through hole and extends into the hole in the head, and the hip surface reconstruction femoral component is easily assembled. Alternatively, the protrusion can extend from the head, pass through the through hole, and extend into a hole provided in the stem portion.

  Preferably, the surface reconstruction femoral component, or any portion thereof, is made of metal or ceramic. To aid implantation, the mounting surface and, if applicable, the stem can be coated with an osteoconductive coating.

  The present invention also provides a method of implanting any of the described surface reconstruction femoral components. The femoral component is assembled if necessary. The femur is prepared to receive the component, which is then placed in place on the femur.

  Preferred embodiments of the present invention will now be described with reference to the accompanying drawings, by way of example.

  A conventional surface reconstruction femoral component 10 is shown in FIGS. 1 and 2 and includes a head 12 having a bearing surface 11 that is generally spherical (generally slightly larger than a hemisphere) and a stem 14. In use, the stem 14 is placed in the femur and used to ensure that the femoral head is properly placed while providing post-operative stability for the first few months after implantation of the implant. As shown in FIG. 2, at its upper end, the stem 14 is connected to a top inner surface 16 that extends radially outward, which in turn is connected to an upper inner surface 18 that hangs radially outward and downward, which in turn downwards. It continues to the lower inner surface 20 that hangs down. The lower inner surface then continues to the bearing surface 11. The top inner surface 16, the upper inner surface 18, and the lower inner surface 20 together form an inner surface 19 that fits over the prepared head of the femur. The bearing surface 11, the lower inner surface 20, the upper inner surface 18 and the top inner surface 16 together form the head 12. The resurfacing femoral component 10 is selected by the surgeon to suit each individual patient based on the most suitable diameter of the bearing surface.

  FIG. 3 shows an embodiment of the present invention in which the femoral component 110 includes a head 112 and a stem 114 having an outwardly facing bearing surface 111, as in the prior art. The femoral component has a longitudinal axis L. Parts similar to the prior art components are given the same reference numbers with different affixes.

  The embodiment differs from prior art surface reconstruction femoral components in that the femoral head component 110 further includes a skirt 121 depending from the end of the bearing surface 111. The skirt 121 includes a skirt inner surface 123 that is continuous at one end with the lower inner surface 120 and at the other end with a wall 122 that extends radially outward. The wall 122 then continues to the skirt outer surface 124 extending upward. The skirt outer surface 124 then continues to the bearing surface 111. The skirt inner surface 123, the wall 122, and the upwardly extending skirt outer surface 124 preferably form a cylinder, but may be oval or elliptical. The femoral head component 110 further includes a top inner surface 116, an upper inner surface 118, and a lower inner surface 120, similar to the device shown in FIG. The top inner surface 116, the upper inner surface 118, the lower inner surface 120, and the skirt inner surface 123 together form an inner surface 119 that fits over the prepared head of the femur.

  The femoral component 110 can be made as a single piece, or the skirt 121 can be attached using, for example, electron beam welding. The skirt may be an elongated cylinder that is attached to either the lower inner surface 120 or a recess therein, for example, by gluing or bonding. It is also conceivable to fix a key groove extending upward from the skirt to a key provided on the lower inner surface 120.

  Figures 4a and 4b show a femoral head component, eg 110, of the present invention in place on a prepared femur. Figures 5a and 5b show a prior art femoral head component, e.g. 10, in position on the prepared femur. 4 and 5 clearly show that the femoral head component of the present invention allows for a bearing surface offset from the femur. This offset gives the surgeon the opportunity to change the postoperative leg length as desired.

  As shown in FIG. 6, the offset distance x can be defined as the distance between the distal point i of the inner surface 119 on the longitudinal axis and the distal point j of the bearing surface 112 on the longitudinal axis. The ratio of the offset distance to the bearing surface diameter y is preferably greater than 0.25, preferably in the range of 0.25 to 0.75, and in the range of 0.28 to 0.66. More preferred. This is in contrast to prior art reconstructive femoral head components where the ratio is generally less than 0.2.

  FIG. 7a shows an alternative embodiment of the present invention in which the surface reconstruction femoral component 210 includes two parts. The first part is an insert 225 that includes a stem 214 that is connected at its upper end to a top inner surface 216 that extends radially outward, which in turn extends radially outward and downwards to an upper inner surface 218. Which then leads to the lower inner surface 220 which hangs downward. The lower inner surface 220 then continues to the skirt inner surface 223. The skirt inner surface 223 then continues to the outwardly extending wall 222, which in turn continues to the upwardly extending skirt outer surface 224. Skirt inner surface 223, wall 222, and skirt outer surface 224 form skirt 221. The skirt outer surface 224 then continues to an upwardly extending insert outer surface 226, which is illustrated but not limited to a taper, which in turn connects to the insert top surface 228 of the insert 225. The insert outer surface 226 and the insert upper surface 228 together form an engagement surface 230. The bearing surface 211 of the femoral head component itself is connected to an upwardly extending inner wall 232 which in turn is connected to a radially inwardly extending surface 234 to form an insert receiving recess 236. The bearing surface 211 and the insert receiving recess 236 form the outer boundary of the upper femoral head component 238.

  The insert receiving recess 236 and the engagement surface 230 of the insert 225 can be correspondingly frustoconical to provide a tapered fit between the insert 225 and the upper femoral head component 238. Alternatively, the insert outer surface 226 can be threaded so that the insert 225 and the upper femoral head component 238 can be attached together by the use of screws, and the inner wall 232 of the insert receiving recess 236 has a corresponding thread. Can be provided. In a further alternative, the insert 225 can be fitted to the upper femoral head component 238 by bayonet fitting or use of an adhesive, or they can be molded together. In a further alternative, the insert 225 can be press-fit or indented into the insert-receiving recess 236, in which case the insert 225 is inserted to prevent rotation of the insert 225 in the insert indent 236. A keyway can be provided in one of 225 or insert receiving recess 236.

  An advantage of using the two-part device described above is that the two components, insert 225 and upper femoral head component 238, can be made from different materials, resulting in cost and / or weight savings. In addition, the insert 225 need not have the same surface finish requirements as the bearing surface 211, thereby facilitating the manufacture of a two-part device. In contrast to the one-part device, the skirt outer surface 224 can be finished separately from the bearing surface 211, thus greatly simplifying the manufacturing process.

  By changing the relative positions of the sphere and the insert, it is possible to change the length of the offset of the skirt 221 and thus the bearing surface 211, resulting in minimal surgeon inventory of surgical components for the surgeon, while Flexibility during surgery is increased if it is desired to change the leg length later.

  In an alternative embodiment shown in FIG. 7b, an insert 225 'is provided similar to the embodiment of FIG. 7a. However, in the embodiment of FIG. 7b, the insert 225 'is provided as a separate component from the skirt 221'. In this embodiment, the skirt 221 'is partially inserted into the insert receiving recess 236' and held in place by introducing the insert 225 'into the insert receiving recess 236'. The insert 225 ′ is held in place by a wide variety of attachment mechanisms, such as taper fitting, screwed attachment, press fit or indent fit, bayonet fit or adhesive, bonding or molding, thereby allowing the skirt 221 ′ to Fixed in place.

  FIG. 8 shows a further alternative embodiment of a femoral head component 310 that includes an upper femoral head component 338, an insert 325, and a stem 314, similar to the device shown in FIG. 7a. However, in the embodiment of FIG. 8, the insert 325 includes a top inner surface 316 that continues to a mounting portion 340 that extends into the insert 325 to form a hole.

  The attachment portion 340 may take the form of a frustoconical hole 340 for engaging with a frustoconical attachment member 342 protruding from the top surface 315 of the stem 314 as shown in FIG. Alternatively, the attachment portion 340 can take the form of a threaded hole to engage the complementary threaded attachment member 342. It will also be appreciated that other attachment means may be used to attach the insert 325 and stem 314, such as bayonet type fittings, press-fit or push-fit connectors, or other suitable attachment means. I will. Alternatively, the stem can be joined to the insert, attached with an adhesive, or molded integrally therewith.

  It will also be appreciated that the device shown in FIG. 3 can also be a two-part device with the stem 114 attached directly to the femoral head 112. In this alternative, the stem 114 is not mounted in the insert as described in FIG. 8, but the stem 114 is mounted directly in a mounting hole provided in the head portion 112. It will be appreciated that if a separate stem is used in the embodiment of FIG. 3, any of the attachment methods discussed in connection with FIG. 8 are suitable.

  In an alternative embodiment, the attachment portion 340 may take the form of a protrusion that extends downwardly from the top inner surface 316 into the stem portion 314. The protrusions can be threaded, take a frustoconical shape, or take other forms such as a bayonet fit as described above. In this embodiment, the upper surface 315 of the stem includes a recess that is configured and centrally disposed to engage a protrusion that hangs down from the top inner surface 316 rather than being connected to an upwardly extending attachment 342. The holes can be threaded or shaped into a frustoconical shape as appropriate to engage the protrusions provided from the top inner surface 316 of the insert 325.

  FIG. 9 is a femoral head component 410 similar to that described in connection with FIG. 8 and illustrates yet another embodiment of the present invention that includes an upper femoral head component 438, an insert 425, and a stem 414. In the embodiment of FIG. 9, the attachment member 442 extends sufficiently from the upper surface 415 of the stem 414 through the through hole 440 provided in the insert 425 and into the attachment portion 444 provided in the upper femoral head component 438. 8 differs from the embodiment of FIG. 8 in that it extends. The through-hole 440 can be shaped into a frustoconical shape to cooperate with the frustoconical mounting member 442 or can be threaded corresponding to the threaded mounting member 442. Other suitable attachment mechanisms, such as bayonet fittings can also be used. The femoral component 410 can be assembled by inserting the insert 425 into the insert recess 436, and the mounting member 442 protruding from the stem 414 is then attached through the through hole 440 to the mounting portion in the upper femoral head component 438. Mounted in 442, thereby securing the separate parts of the femoral component 410 together. It will also be appreciated that the mounting projection can alternatively extend downward from the upper femoral component 438 and extend through the through hole 440 of the insert 425 into a recess depending from the upper surface 415 of the stem 414. I want.

  Figures 10 and 11 show yet another embodiment of the present invention illustrated as a four-part device. This embodiment is the case of a femoral head component 510 having an insert receiving recess 536 as previously discussed in connection with FIGS. An insert 525 similar to that described above can be inserted into the insert receiving recess 536. However, in contrast to the embodiment of FIG. 9, a spacer 550 is disposed between the top inner surface 528 and the top surface 534 of the insert receiving recess 536. Similar to FIG. 9, the stem 514 is provided with an attachment member 542 extending from the upper surface 515 of the stem 514. The insert 525 is provided with a through hole 540 that can be complementary to the mounting member 542. The mounting member 542 and the through-hole 540 can take a number of complementary forms such as, for example, complementary screws, size for press fit, frustoconical for taper fit, or bayonet type fit. The spacer 550 is also provided with a through hole 552 that can take the same complementary form as that provided in the through hole 540 of the insert 525. Finally, a head hole 554 is provided in the upper femoral head component 538 itself. The femoral head component 510 is assembled, for example, by inserting the spacer 550 into the insert receiving recess 536 as appropriate, then the insert 525 is inserted into the insert receiving recess 536 and then the mounting member 542 of the stem 514 is inserted into the corresponding hole 540. , 552 and into the hole 554, the components of the femoral head component 510 are clamped together. As can be seen from FIG. 11, the use of a large spacer 550 'results in a long skirt 521', which further offsets the center of the artificial femoral head from the femoral neck. It will be appreciated that the assembly of the femoral head components 510, 510 'is different from that described above. For example, the insert 550 can first be attached to the attachment member 542 before the insert 525 is placed in the recess 536. It will further be appreciated that the insert 525 and stem 514 can be provided as a single piece with a single mounting member 542 extending from the insert top surface 528. In addition, spacers can be used in the embodiment of FIGS. 7-9, where the spacer is placed between the insert and the upper head, and then the insert is attached to the upper femoral head component as described above. The spacer can also take a variety of forms and can contact either a portion or the entire top surface of the insert and the insert recess. Further, the insert can be attached to one or the other of the insert or the upper head, and then the insert is attached to the upper head as described in connection with FIG. The various attachment mechanisms described above can be utilized, such as screwing, taper fitting or bayonet fitting. Various component joining, adhesives, and molding are also contemplated.

  While the device of FIG. 3 is suitable for the purposes of the present invention, it will be appreciated that, as shown in FIGS. 7-11 and described above, as the modularity of the device increases, surgeons have more options during surgery. I will. In particular, looking at FIGS. 10 and 11, it can be seen that different post-operative leg lengths can be easily achieved simply by using different spacers. In fact, a single head can be used with a variety of inserts and spacers, reducing the required inventory for a very highly polished head.

  It will also be understood that when the modularity of the femoral head component is increased, this means that different materials can be used. This allows for significant cost savings and also improves workability during implantation. For example, a softer material can be used for the insert and the skirt. Even if a collision occurs between the skirt of the femoral component and the acetabular margin, the damage caused by such material is less than that required for the bearing surface.

  Suitable materials for the various components of the femoral head prosthesis described above include stainless steel, cobalt chrome, titanium alloys, ceramics, or other biocompatible materials. The inserts and spacers, if applicable, may alternatively be wholly or partially replaced by other known biological materials including metals such as polyglycolic acid, polylactic acid resorbable polymers, these copolymers, or magnesium alloys if desired. It can be made from a resorbable material, such as a resorbable material. In any of the above-described embodiments, all or part of the prepared femoral touching surface is provided with an osteoconductive coating such as hydroxyapatite, titanium plasma coating, or a metal bead type surface for cementless implant treatment. Can be applied. In addition, non-resorbable portions of the stem that are placed in the femur during use can also be provided with an osteoconductive coating to facilitate fixation. Alternatively, it is understood that the implant can be secured using a suitable bone cement.

  The various modular implants described above can be implanted by first inserting the stem portion into the prepared femur and then attaching the insert and head appropriately. Alternatively, the prosthesis can be assembled before surgery and then attached to the prepared femur by any suitable method.

  In one embodiment of the present invention, the diameter of the main head including the bearing surface is the same as the diameter of the outer surface of the skirt. In an exemplary configuration, a 52 mm diameter head is used with a 52 mm diameter skirt. However, in order to provide a greater range of movement of the hip joint when using the device according to the invention, the skirt can have a diameter that is smaller than the diameter of the bearing surface (eg the head is 56 mm in diameter and the skirt is in diameter 52mm).

  Studies have shown that the femoral component according to the present invention achieves a sufficient range of motion of the hip joint in internal-external rotation, flexion-extension, and abduction-addition.

FIG. 3 shows a side view of a prior art reconstruction femoral head component. FIG. 2 shows the reconstruction femoral head component of FIG. 1 with internal features shown in broken lines. FIG. 3 shows a cross-sectional view of the longitudinal surface of a femoral head component according to an embodiment of the present invention. 1 shows a femoral head component according to the present invention in place on a prepared femur. FIG. 4b shows a cross-sectional view of the femoral head component and femur of FIG. 4a. Fig. 2 shows a prior art femoral head component in place on a prepared femur. FIG. 5b shows a cross-sectional view of the femoral head component and femur of FIG. 5a. The femoral head component according to the present invention is shown without a stem and shows the offset distance of the component. FIG. 6 shows a longitudinal cross-sectional view of a femoral head component according to an alternative embodiment of the present invention. FIG. 6 shows a longitudinal cross-sectional view of a femoral head component according to another alternative embodiment of the present invention. FIG. 6 shows a cross-sectional view of the longitudinal surface of a femoral head component according to yet another embodiment of the present invention. FIG. 6 shows a longitudinal cross-sectional view of a femoral head component according to a further embodiment of the present invention. FIG. 6 shows a cross-sectional view along the longitudinal surface of a femoral head component according to yet another embodiment of the present invention. FIG. 6 shows a cross-sectional view along the longitudinal surface of a femoral head component according to a further embodiment of the invention.

Claims (13)

A femoral component for hip surface reconstruction for use with a prepared femur,
A head having a generally spherical outward bearing surface;
A mounting surface opposite to the bearing surface of the head;
A skirt portion having a skirt outer surface and a skirt inner surface depending from the substantially spherical bearing surface;
A stem portion depending from the mounting surface for insertion into the prepared femur;
An insert portion,
The inner surface of the skirt and the mounting surface are configured to fit over the prepared femur;
The insert portion provides the mounting surface and the head engaging surface, and the head has an insert engaging surface on the opposite side of the bearing surface for engaging the head engaging surface of the insert portion. Includes femoral components for hip surface reconstruction. The head comprises an insert receiving recess being Sakaise' by the insert engagement surface, said skirt portion is provided as a separate part, extending therefrom by said skirt portion the insert portion to the insert-receiving recess The hip surface reconstruction femoral component of claim 1, wherein the femoral component is properly held in place.   The hip surface reconstruction femoral component of claim 1, wherein the insert provides the skirt with an inner skirt and an outer skirt. By the head engaging surface and the insert preparative engaging surface is bonded, adhesively attached or molded / fused together, claims 1 to femoral component for hip resurfacing according to any one of 3, . Said head engaging surface and insert preparative engaging surface to form a combination of protrusions and recesses of trapezoidal complementary conical, to achieve a tapered fit between the insert portion and the head portion, claims 1 The femoral component for hip joint surface reconstruction according to any one of 3 above. Has a complementary screw provided the head engaging surface and insert preparative engaging surface within them, screwed is enabled between the insert portion and the head portion, either one of claims 1 to 3 A femoral component for hip surface reconstruction as described in. It said head engaging surface and insert preparative engaging surface is configured to achieve a push-fit fit or press between the head portion and the insert portion, according to any one of claims 1 to 3 Femoral component for hip surface reconstruction. The insert DOO engagement surface and further comprising a spacer disposed between the head engaging surface, according to claim 1 to 7 hip resurfacing femoral component according to any one of. At least one of the insert preparative engaging surface and said head engaging surface, the engaging means are provided for engagement with a complementary engaging means provided on the spacer, hip surface according to claim 8 Reconstructive femoral component.   The femoral component for hip joint surface reconstruction according to any one of claims 1 to 9, wherein the insert part and the spacer have respective through holes for accommodating a fixing member that connects the head part to the stem part.   The femoral component for hip surface reconstruction according to any one of claims 1 to 10, wherein any of the head, the insert, the spacer, or the stem is made of metal or ceramic.   The femoral component for hip surface reconstruction according to any of claims 1 to 11, wherein the attachment surface is coated with an osteoconductive coating. The bearing surface of the head has a center and a distal-most point;
The mounting surface of the head has a distal-most point;
The distance parallel to the axis from the most distal point of the mounting surface to the most distal point of the bearing surface is defined as the offset distance,
The femoral component for hip joint surface reconstruction according to any one of claims 1 to 12, designed such that a ratio of the offset distance to a diameter of the substantially spherical bearing surface is higher than 0.25.

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