230 results about "Joint prosthesis" patented technology

The invention relates to the technical field of joint prostheses, in particular to an ankle joint prosthesis implantation system based on zirconium-niobium alloy, which comprises a tibia prosthesis (10), a talus prosthesis (30) and a liner (20), the tibia prosthesis (10) and the talus prosthesis (30) are both made of zirconium-niobium alloy material and are integrally formed by 3D printing, the tibia prosthesis (10) comprises a tibia body (101), and the liner (20) is arranged on the tibia body (101). The first bone contact layer (100) is integrally formed on the tibia body (101), and the first bone contact layer (100) is of a porous structure of which the pore diameter is gradually reduced from outside to inside; the talus prosthesis (30) comprises a talus body (301) and a second bone contact layer (300) integrally formed on the talus body (301), and the second bone contact layer (300) is of a porous structure with the aperture gradually reduced from outside to inside.

An orthopaedic joint prosthesis assembly includes a head part of an orthopaedic joint prosthesis component and an alignment guide. The head part has a spherical bearing surface for articulation with a corresponding joint surface, and an assembly surface having a first bore formed in it for receiving a spigot on another part of the orthopaedic joint prosthesis. The bore has a first axis that extends perpendicular to the assembly surface. The alignment guide has an axial portion defining a second axis and an arm extending from the axial portion. The arm includes a distal portion which is configured to engage the assembly surface, with the axial portion being arranged to engage the bearing surface of the head part when the head part is mounted within the guide such that an impaction force applied along the second axis is directed along the first axis.

The invention discloses an artificial intelligence-assisted standard artificial temporomandibular joint automatic placement method. The method comprises the following steps: training a three-dimensional reconstruction model used for extracting a mandible and zygomatic bone zygomatic arch joint prosthesis placement area; based on an improved 3D U-Net neural network, carrying out segmentation extraction on the interested areas of the glenoid fossa and the mandibular branch, and obtaining a space geometric structure for prosthesis installation; the method comprises the following steps: extracting outer bone surface point cloud data of a zygomatic arch and a mandibular ramus on the basis of a space geometric structure of prosthesis installation, identifying anatomical key points, and generating a standard prosthesis fitting surface through geometric fitting and constrained optimization; determining the relative position relation between the maxillary joint fossa prosthesis and the mandibular branch prosthesis, and determining the installation direction, the hole position definition and the assembly reference point; and determining a contact area, a posture direction and a placement position of the prosthesis, and completing three-dimensional positioning and posture matching of the prosthesis in the patient model as a surgical planning scheme.

The utility model provides a multi-curvature ankle joint prosthesis which comprises a tibia prosthesis connected with a tibia, a talus prosthesis connected with a talus and a cushion block with one side connected with the tibia prosthesis, a joint contact surface is arranged on the other side of the cushion block, and a talus contact surface matched with the joint contact surface is arranged on one side of the talus prosthesis. The curvature of the sagittal plane Z in the talus contact face is reduced from front to back, and the instantaneous rotation center of the talus prosthesis on the joint contact face is in an arc shape. According to the multi-curvature ankle joint prosthesis, the talus contact face and the anatomical structure of the human body are high in consistency, the natural form and the motion mode of the ankle joint are accurately restored, the ankle joint prosthesis better conforms to biomechanics and kinematics in the motion process, the motion stability of the human body is improved, local friction stress of the ankle joint prosthesis is smaller, and the ankle joint prosthesis is more stable in motion. And the service life of the ankle joint prosthesis is prolonged, so that the durability of the ankle joint prosthesis is improved.

The invention discloses an artificial joint frictional wear simulation testing machine and a testing method thereof. The testing machine comprises a motion loading module, a sample clamping module and a motion coupling module, the motion loading module mainly drives an upper sample of the sample clamping module to generate fundamental frequency swing through a double four-bar-planetary gear train composite mechanism, and the sample clamping module integrates a quick disassembly and assembly clamp and a temperature control lubrication system to fix various joint prostheses and simulate the physiological environment of the human body. And the motion coupling module cooperates with the motion loading module based on the six-degree-of-freedom parallel platform to realize composite action and suppress vibration interference. Through cooperative control of the three modules, the problems that an existing artificial joint friction and wear simulation testing machine is limited to a single joint type and cannot adapt to various artificial joint prostheses, and the degree of freedom of motion is limited, so that various motion forms of the artificial joint cannot be completely restored are solved.

The invention relates to a hip joint prosthesis. The hip joint prosthesis comprises an interstitial acetabular prosthesis and a femoral head reconstruction device. The interstitial acetabular prosthesis is stably connected with a pelvic acetabular fossa through the interstitial acetabular cup, the fixing screw and the interstitial acetabular lining, and adaptability and stability are enhanced through multiple designs such as petal openings and damping parts; the femoral head reconstruction device comprises a joint friction surface prosthesis and a bone ingrowth supporting cage frame, and reconstruction and stable supporting of the femoral head are achieved. According to the hip joint prosthesis, the technical effects of improving the stability and durability of the hip joint prosthesis, reducing postoperative discomfort of a patient and promoting bone tissue growth are achieved.

The ankle joint prosthesis comprises a tibia prosthesis and a talus prosthesis, the tibia prosthesis is provided with a keel, the keel is used for being implanted into a tibia and extends in the front-back direction of the tibia prosthesis, the talus prosthesis is arranged on the lower side of the tibia prosthesis, the talus prosthesis is provided with a fixing rod, and the fixing rod is arranged on the lower side of the tibia prosthesis. The fixing rod is used for being implanted into the talus and obliquely extends downwards from front to back, an included angle alpha is formed between the extending direction of the keel and the extending direction of the fixing rod, and alpha is larger than or equal to 10 degrees and smaller than or equal to 85 degrees. The ankle joint prosthesis is reasonable in structural design, the stability of the ankle joint prosthesis in the human body movement process can be enhanced, and the dislocation risk of the prosthesis is reduced.

The invention provides a hip joint prosthesis. The hip joint prosthesis comprises a femoral stem body; the driving part is arranged on the femoral stem main body; the transmission part is movably arranged in the femoral stem main body, and the driving part drives the transmission part to move; the plug connector is telescopically arranged on the femoral stem main body to have a plug-in position and a first storage position, and the transmission part moves to drive the plug connector; when the plug connector is located at the plug-in position, the plug connector extends out of the femoral stem main body; when the plug connector is located at the first storage position, the plug connector retracts into the femoral stem main body; the force measuring piece comprises a dynamometer and a first elastic piece connected to the dynamometer, the dynamometer is movably arranged in the femoral stem body, and the dynamometer drives the first elastic piece to stretch out and draw back on the femoral stem body so that the first elastic piece can have a force measuring position and a second containing position. According to the technical scheme, the problem that the hip joint prosthesis in the related technology cannot give consideration to the stability after implantation and the convenience of later maintenance at the same time is solved.

The invention provides a knee joint prosthesis and a tibial plateau thereof, and the tibial plateau comprises a second supporting platform and a first supporting platform which are arranged at an interval, and the position of the second supporting platform can be adjusted relative to the first supporting platform; the first end of the transmission part is movably arranged on the first supporting platform, and the second end of the transmission part is arranged on the second supporting platform; the driving structure comprises a mounting part and a driving part rotatably arranged on the mounting part, the rotating axis of the driving part is perpendicular to the axis of the mounting part, and the mounting part is rotatably arranged on the first supporting platform around the axis of the mounting part, so that the driving part drives the transmission part to rotate around the axis of the mounting part; the driving part is in driving fit with the transmission part so as to drive the transmission part to rotate in the direction parallel to the rotating axis of the driving part. According to the technical scheme, the problem that in the prior art, the relative position of the first supporting platform and the second supporting platform of the tibial plateau is inconvenient to adjust is effectively solved.

The application relates to a wrist joint prosthesis and relates to the technical field of artificial joint prostheses. The wrist joint prosthesis comprises: a carpal bone assembly for being fixed with one side of a hand-shaped bone, which comprises a carpal bone pad, a carpal bone support block embedded in one side of the carpal bone pad, a carpal bone printing column and a screw connected to the other side of the carpal bone support block, and a support block adjusting device arranged on the embedded side of the carpal bone support block, one end of the support block adjusting device being located in the carpal bone pad, and the carpal bone pad being provided with a locking piece for locking the adjusted position of the support block adjusting device; and a radius bone assembly for being fixed with a radius bone marrow cavity, which comprises a radius bone support, the radius bone support being arranged on the side of the carpal bone pad away from the carpal bone support block. The wrist joint prosthesis has the advantages of shortening the waiting time for surgery.

The invention provides a hip joint prosthesis which comprises an acetabular cup provided with a containing cavity, the acetabular cup is provided with a first magnetic part and a limiting ring groove, and the limiting ring groove is communicated with the containing cavity; the ball head is rotatably arranged in the accommodating cavity; the clamping ring is arranged outside the equator part of the ball head in a sleeving mode, the ball head can swing relative to the clamping ring, a second magnetic piece is arranged on the clamping ring, the second magnetic piece is matched with the first magnetic piece in a magnetic attraction mode so that the ball head can be connected with the acetabular cup, at least part of the clamping ring swings in the limiting ring groove along with the ball head, and the clamping ring can be matched with the side wall of the limiting ring groove in a limiting mode; and the femoral stem is fixedly connected with the ball head. According to the technical scheme, the problem that in the prior art, the movement range of a hip joint prosthesis is insufficient, and the joint flexibility is affected is effectively solved.

A knee joint prosthesis moves between an extended and flexion positions. The prosthesis includes a femoral component configured to be mounted to a femur, the femoral component having a femoral gear including a plurality of posts arranged along a helical trajectory. The prosthesis also includes a tibial component configured to (i) be mounted either directly or indirectly to a tibia, and (ii) engage the femoral component. The tibial component has a tibial gear including a plurality of recesses that are configured to mesh with the posts of the femoral gear. The tibial gear has two intersecting portions including a horizontally-oriented curved portion and a vertical portion, wherein each portion includes at least one of the recesses. The plurality of posts follow a helical trajectory to cause movement of the tibial component in either a medial or lateral direction as the knee joint prosthesis is moved to the extended position.

The invention relates to the technical field of biomedical materials, in particular to multi-material 3D printing bionic gradient soft-hard integrated hydrogel as well as a preparation method and application thereof. Based on a copolymerization system of high-strength supramolecular N-acryloylglycinamide and vinyl phosphoric acid, an NAGA aqueous solution and an NAGA-VPA aqueous solution are printed into hydrogel of a gradient structure by adopting a DLP multi-material printing technology, then the hydrogel is sequentially soaked in a calcium-phosphorus mixed aqueous solution (Ca / P = 1.67), ammonia water, a calcium chloride aqueous solution and deionized water, and the hydrogel is prepared through a hydrothermal method. Therefore, in-situ gradient deposition and curing of hydroxyapatite (HAP) are realized. The multi-material 3D printing bionic gradient soft-hard integrated hydrogel prepared by the method has a continuous biochemical-mechanical gradient, a surface layer low-modulus area is matched with cartilage performance, a deep layer high-mineralization area is integrated with bone tissue, the HAP crystallinity of a transition area is in spatial dependence distribution, and the hydrogel is suitable for osteochondral defect repair and manufacturing of bionic joint prostheses.

The present invention provides a tantalum metal wrist joint prosthesis with a gradual porous structure and a wear-resistant layer, comprising: a distal implant, a special-shaped ball head, and a proximal implant. The distal implant comprises a distal insertion plug, a proximal platform, and a circular pin. The overall shape of the special-shaped ball head is a small half-notch of an ellipsoid. One end of the special-shaped ball head is provided with a socket that matches the circular pin, so that the distal implant and the special-shaped ball head are plugged and fixed. The other end of the special-shaped ball head is a convex ball structure. The proximal implant comprises a concave joint ball and a gradual porous structure segment. The surface of the concave joint ball is provided with a coating. The coating contacts the surface of the convex ball structure of the special-shaped ball head, so that the proximal implant and the special-shaped ball head are connected to form a compensatory wrist joint. The technical solution of the present invention solves the problems of incomplete coordination between artificial wrist joint prostheses and muscles and soft tissues, severe wear at the joint, and short service life in the prior art.

The present invention provides a wrist joint prosthesis, comprising: a carpal prosthesis and a radial prosthesis; the carpal prosthesis having a first curved surface, the radial prosthesis having a second curved surface adapted to the shape of the first curved surface, the carpal prosthesis and the radial prosthesis being abutted against each other along a first direction via the first curved surface and the second curved surface; the carpal prosthesis being configured to be rotatable relative to the radial prosthesis about a second direction and a third direction perpendicular to the first direction, and one end of the carpal prosthesis for connection to the carpal bone being rotatable relative to one end of the radial prosthesis for connection to the radius about the first direction. With such a configuration, by configuring one end for connection to the carpal bone to be rotatable relative to one end of the radial prosthesis for connection to the radius about the first direction, the wrist joint prosthesis can realize the circumflex motion function of the radiocarpal joint, thereby improving the patient's wrist joint mobility and increasing patient satisfaction.

The present disclosure provides a knee joint osteotomy planning apparatus, an automatic knee joint osteotomy apparatus, and a related device, and relates to the technical field of robot control. In the present disclosure, according to prosthesis dimension information of a knee joint prosthesis to be assembled and tool dimension parameters of an osteotomy tool, relative pose relationships between osteotomy cutting-in poses for each tibial / femoral assembly surface of the knee joint prosthesis to be assembled and corresponding tibial / femoral prosthesis reference regions are determined in a reference coordinate system; upon acquisition of desired assembly pose information of the tibial / femoral prosthesis reference regions relative to the actual tibia / femur to be osteotomized in a base coordinate system of a surgical robot, desired osteotomy cutting-in poses for each assembly surface in the base coordinate system are calculated according to the desired assembly pose information and the relative pose relationships; then, in view of surface dimension information of the corresponding assembly surfaces, planar osteotomy trajectories for the corresponding assembly surfaces in the base coordinate system are planned, so as to realize the automatic osteotomy function of the surgical robot, thereby improving osteotomy accuracy and ensuring that the TKA surgery achieves expected outcomes.

The application provides a hip joint prosthesis, which comprises a first end of a first stem body connected with a ball head part, an accommodating space arranged in the inside of the first stem body, a first mounting port and a second mounting port arranged on the side wall of the first stem body, an operation hole arranged on the top of the first stem body and communicated with the accommodating space, a moving piece movably arranged in the accommodating space, a first transmission piece and a second transmission piece both movably connected with the moving piece, the moving piece moving being capable of driving the first transmission piece and the second transmission piece to move close to or away from each other, a first pressing piece connected with the first transmission piece and located outside the first mounting port, and a second pressing piece connected with the second transmission piece and located outside the second mounting port; and an adjusting piece penetrating through the operation hole and driving the moving piece to move. The technical scheme of the application effectively solves the problem of insufficient stability of the hip joint prosthesis after implantation in the related art.

The invention provides a multi-column integrated biological fixation partial femoral head replacement device, and relates to the field of medical instruments. The device comprises a bone nail, an auxiliary fixing piece and a joint prosthesis, the bone nail is provided with a first end part and a second end part nailed into a femoral neck medullary cavity, and the first end part, the auxiliary fixing piece and the joint prosthesis are integrally formed; the auxiliary fixture has a first surface and a second surface in contact with the conical osteotomy femoral head to prevent sinking and lateral rotation. The joint prosthesis only replaces the cut part of the necrotic femoral head, more normal sclerotin can be reserved, trauma is small, femoral head supporting and bearing are not affected or changed, long-term stability of the joint prosthesis is guaranteed, and meanwhile future rebuilding is facilitated. In addition, the first end part, the auxiliary fixing piece and the joint prosthesis are integrally formed, so that joint prosthesis failure caused by looseness or corrosion among the first end part, the auxiliary fixing piece and the joint prosthesis can be avoided.

The application discloses an ankle joint prosthesis, which comprises a tibia component, a pad and a talus component connected in sequence, and a plurality of bionic ligaments; the tibia component comprises a first intramedullary canal handle and a platform connected to the lower end of the first intramedullary canal handle; the pad comprises a pad body, and the upper surface of the pad body is provided with a cylindrical boss; the talus component comprises a second intramedullary canal handle and a connecting piece connected to the upper end of the second intramedullary canal handle; and the bionic ligaments are connected to the pad and the talus component respectively. The ankle joint prosthesis can completely replace the bone and cartilage of the ankle joint surface, thereby overcoming the problem that the cartilage surface cannot be repaired by an ankle arthroscopy surgery. The ankle joint prosthesis is used for replacing the original damaged ankle joint by using metal and polymer components, so that the discomfort symptom is relieved and the joint activity ability is reserved, and the ankle joint prosthesis is a full freedom ankle joint prosthesis which can completely reserve six activity modes of flexion, extension, inversion, eversion, internal rotation and external rotation.

The present application belongs to the field of biomedical materials and computer aided design technology, and discloses a kind of porosity gradient adjustable hip joint prosthesis porous coating topological optimization method.The present application is aimed at solving the problems of existing design, such as unadjustable porosity distribution, gradient mutation, difficult to balance mechanical properties and bone integration, and the gap between topological optimization and manufacturing constraints.The method introduces nonlinear porosity gradient constraints and adaptive optimization mechanism in the process of topological optimization through the steps of geometric modeling and boundary condition definition, nonlinear porosity gradient field generation, finite element analysis, sensitivity analysis, density filtering and porosity constraint processing, optimization criterion updating and convergence judgment, and realizes the smooth transition of porosity from the core to the surface of the prosthesis.The present application can optimize the mechanical support and biological integration performance simultaneously, eliminate non-manufacturable structures, and adjust the gradient parameters and modularize the extension, providing an efficient and reliable calculation method for personalized hip joint prosthesis design, and having significant engineering and clinical application value.

The invention relates to the technical field of joint prostheses, in particular to an interchangeable joint prosthesis which comprises a thighbone prosthesis, a tibia platform and a tibia liner. The femoral prosthesis comprises a half-shell prosthesis, a first stand column, a second stand column and a bone trabecula structure. The first stand column and the second stand column are fixedly arranged on the inner wall of the half-shell prosthesis. A dismounting table is arranged on the surface of the tibia platform, a clamping groove matched with the tibia liner is formed in the surface of the tibia platform, a press-fit edge matched with the clamping groove is fixedly arranged on the surface of the tibia liner, and the tibia liner is used for supporting a thighbone prosthesis to move; a fixing wing and a fixing stand column are arranged on the surface of the other side of the tibial plateau. By arranging the thighbone prosthesis, the tibia platform and the tibia liner, the size of the joint prosthesis can be freely changed in the actual operation process, operation prosthesis selection can be conveniently adjusted in the operation, finally, the joint prosthesis is used for biological fixation, and the long-term stability of the prosthesis after implantation is guaranteed.

A method for measuring a relative movement between bones and a method for acquiring a joint rotation axis of bones are provided, which can effectively improve rotational stability of a prosthesis of knee arthroplasty, thereby improving surgical outcomes. A population average bone joint most stable axis (a-MSA) is acquired through the method, so that the design of a joint prosthesis can be improved and a reference of a population average position can be provided for intraoperative placement of a prosthesis. An individual bone joint MSA (i-MSA) of a patient is acquired through the method before surgery, so that individual position information can be provided for intraoperative placement of a prosthesis, thereby further improving rotational stability of a surgical prosthesis.

The invention provides a universal ball shaft type anti-dislocation tumor knee joint prosthesis containing a CFR-PEEK material, and belongs to the technical field of medical equipment. Comprising a prosthesis, a tibia liner is installed in the middle of the prosthesis, a connecting disc is installed at the bottom of the tibia liner, and a universal ball shaft is installed in the middle of the inner wall of the prosthesis; and the auxiliary anti-disengaging assembly is used for limiting the universal ball journal, and the auxiliary anti-disengaging assembly is connected with the connecting disc. By arranging the auxiliary anti-falling assembly, in the process of installing the upper assembly and the lower assembly of the prosthesis, use of some reinforcing parts is omitted, on one hand, redundant steps during disassembly and assembly can be reduced, and the disassembly and assembly flexibility and convenience are improved; on the other hand, after the knee joint prosthesis is used for a period of time, the stability of the middle position of the prosthesis cannot be reduced due to looseness of reinforcing parts, and subsequent normal use of the knee joint prosthesis is facilitated.

The present invention provides a hip joint prosthesis, which comprises: a proximal end portion of a femoral stem; an extension stem; a filling member disposed between the proximal end portion of the femoral stem and the extension stem to connect the proximal end portion of the femoral stem and the extension stem; and a height adjustment assembly, at least a part of which is disposed between the proximal end portion of the femoral stem and the filling member and is telescopically arranged to adjust the height of the hip joint prosthesis by adjusting the distance between the proximal end portion of the femoral stem and the extension stem. This hip joint prosthesis solves the problem that the relative position between the filling block and the prosthesis in the prior art is fixed.

Embodiments of the present invention provide a patellar prosthesis and a total knee joint prosthesis. In this embodiment of the invention, the patellar prosthesis is used to cooperate with a femoral prosthesis. The femoral prosthesis includes a medial condyle, a lateral condyle, and an intercondylar fossa for corresponding cooperation with the tibia. The medial and lateral condyles have a recessed groove in the middle to form a trochlear groove for receiving the patellar prosthesis. The width of the intercondylar fossa is L7. The patellar prosthesis includes a patellar articular surface that cooperates with the femoral articular surface. When the human body is flexed greater than 90°, the patellar prosthesis cooperates with the intercondylar fossa. The width of the overlap between the patellar prosthesis and the lateral condyle is L6, and the width of the overlap between the patellar prosthesis and the medial condyle is L5. When the human body is flexed between 90° and 135°, L5 / L7 is 0.11 to 1.30, and L6 / L7 is 0.11 to 1.42. Therefore, the patellar prosthesis according to embodiments of the present invention has the advantage of improving the stability of the patellar joint.

This invention provides a fixation device and assembly method for pericondylar fractures of the knee joint prosthesis. The knee joint prosthesis includes a femoral condyle, a tibial plateau, and a tibial pad. The femoral condyle includes an anterior condyle, two posterior condyles, and an intercondylar fossa. A fixation device is installed in the intercondylar fossa, comprising an intramedullary fixation pin and a connecting fixation block. The connecting fixation block is installed within the intercondylar fossa and engages with the force-applying end of the intramedullary fixation pin. The connecting fixation block includes a main body with a top surface facing the tibial pad and a bottom surface opposite the top surface. The bottom surface extends away from the top surface to form a protrusion, and a through hole is formed within the protrusion, which is used to accommodate and fix the force-applying end of the intramedullary fixation pin. This invention embeds the entire connecting fixation block within the intercondylar fossa, fully utilizing the existing intercondylar fossa space of the PS-type prosthesis to establish a precise channel for the intramedullary fixation pin, thereby fixing the pericondylar fracture through structural fit.

The present invention relates to the technical field of medical orthopedic bionic materials, specifically a printed metal and polyethylene integrated knee joint prosthesis and a preparation method. Any one of tantalum, titanium, titanium alloy, zirconium-niobium alloy, and cobalt-chromium alloy is used to print a 3D printed metal component. The 3D printed metal component is integrally formed by 3D printing, and from top to bottom, there are a porous structure 1, a solid structure, and a porous structure 2. The porous structure 2 is combined with the polyethylene component by injection molding or hot pressing. The middle is the solid structure, and the bottom layer is the porous structure 2. The porous structure 2 is combined with the polyethylene. The polymer polyethylene material is ball milled to make the solid powder of the polymer polyethylene after molding more evenly distributed and the gap smaller, thereby improving the mechanical properties and internal wear properties of the material, and avoiding adverse events such as ion poisoning caused by metal wear debris.

The present invention discloses a method for calculating the physiological parameters of a model in hip prosthesis planning and an electronic device. The method includes obtaining a pelvic model, a left femoral model, a right femoral model, a first feature point set, a second feature point set, a third feature point set, a pelvic prosthesis model, and a femoral prosthesis model; determining a pelvic-pelvic prosthesis assembly model and a femoral-femoral prosthesis assembly model; updating the first feature point set and the target feature point set; splicing the pelvic-pelvic prosthesis assembly model, the femoral-femoral prosthesis assembly model, and the second femoral model according to a first splicing method and a second splicing method, respectively, and calculating the hip joint offset and the hip joint length based on the coordinates of the feature points in the second feature point set and the third feature point set, respectively. The present application calculates the hip joint offset and the hip joint length based on the feature points in the second feature point set and the third feature point set, respectively, and can accurately obtain the numerical values ​​of the postoperative hip joint physiological parameters through the preoperative planned model.

The present invention relates to a ceramic femoral component (200) of a knee prothesis comprising • - an inner surface of the femoral component, and • - at least one, preferably at least two projections (207a, 207b) extending inwardly away from the inner surface of the femoral component for guiding the ceramic femoral component on the patient's femur in anterior-posterior direction and positioning the ceramic femoral component on the patient's femur by formfit or pressfit.