272 results about "Bone Cortex" patented technology

The invention relates to the technical field of vehicle safety, in particular to a pedestrian body model chest injury risk curve adjusting method. Comprising the following steps: analyzing the relationship between the speed and the chest injury risk, and drawing a first curve between the vehicle speed and the injury risk based on accident statistical data; fitting data of a rib cortical bone uniaxial stretching material mechanics experiment; constructing a vehicle-pedestrian side impact simulation experiment matrix under different working conditions, and generating a simulation sample number; extracting the rib strain of the human body model in the sampling model, calculating the fracture probability of a single rib of the chest of the human body model, and then calculating the maximum simple injury probability of the specified chest of the human body model; fitting the relationship between the vehicle speed in the simulation model and the chest injury risk of the human body model, and drawing a second curve between the vehicle speed in the sample and the chest injury risk of the pedestrian model; and constructing an objective function according to the difference between the first risk curve and the second risk curve. According to the technical scheme, the accuracy of accident damage prediction can be improved.

The invention provides a cortical bone screw automatic planning method and device based on a statistical morphology model. The method comprises the following steps: acquiring CT image data of any object; based on the CT image data, segmenting point cloud information of a vertebral body to be subjected to screw placement; acquiring a statistical shape model and cortical bone screw planning information corresponding to the serial number; and registering the statistical shape model to the point cloud information, and determining a cortical bone screw plan of the vertebral body to be subjected to screw placement. In the application, the preset screw placement planning of the cortical bone screw is performed through the statistical shape model, and the preset screw placement planning is mapped to the current spinal column three-dimensional model through registration, so that the preset screw placement planning only needs to be performed on the statistical shape model, and a screw placement model is not needed, thereby solving the problem that a large number of cases need to be collected to realize the screw placement model; therefore, the problem of nail placement of the cortical bone can be solved.

The invention discloses a modeling method and system for regulating and controlling bone healing through dynamic stress stimulation, which are applied to the technical field of bone healing, and the method comprises the following steps: establishing a geometric model of a fracture part; performing mesh generation on the geometric model to generate finite element models of bones and callus; assigning values to the material attributes in the callus at the initial moment; applying dynamic load constraint to the top end of the cortical bone based on the finite element model, and establishing a bone healing model; calculating attributes of new materials in tissue cells, and judging whether the attributes of the new materials reach a preset healing standard or not through the bone healing model; if the preset healing standard is reached, simulation is completed, otherwise, iterative simulation is carried out by dynamically adjusting mechanical parameters until the preset healing standard is reached, and final bone healing data are output. Through the bone healing model, loading parameters are adjusted in real time according to simulation data, and the accuracy and reliability of bone healing simulation are improved.

The invention provides a method and system for reconstructing a cartilage surface and electronic equipment, and the method comprises the steps: obtaining an outer contour model of a bone cortex and a mark point set of the cartilage surface, and converting the outer contour model of the bone cortex and the mark point set of the cartilage surface into a preset image coordinate system; obtaining a projection point of each mark point in the mark point set on the cartilage surface on the outer contour of the bone cortex, and determining a coverage area of the projection points; performing elastic stretching on the coverage area of the projection point, and further simulating the wear degree of the cartilage surface to obtain a reconstructed cartilage surface; the problem that muscle or ligament abrasion is caused due to the fact that the influence of cartilage is not brought into prosthesis planning in an existing joint replacement operation is solved, practical and effective guidance can be provided during prosthesis planning and adjusting, prosthesis planning and adjusting are better facilitated, and the prosthesis planning and adjusting efficiency is improved. The intelligent degree, usability and reliability of prosthesis planning in joint replacement are improved to a great extent.

Computer implemented methods, systems, and computer products employing program code or algorithms for use in customized patient specific hip implants or femoral stems or sleeves having an outer surface that corresponds more closely to the inner surface of the cortical bone of a patient's femur compared to conventional hip implant or femoral stems or sleeves based on population-based design.

The invention discloses a bone scaffold fusion design and preparation method based on mirror image registration, and the method comprises the steps: firstly, based on a three-dimensional medical image of a femoral defect region of a patient, combining an opposite-side complete femoral CT image, and achieving the automatic recognition and complementation of the defect region through the mirror image transformation and ICP registration technology; after defect boundary extraction is completed, three-dimensional reconstruction is carried out on the individualized outer contour of the left bone tissue, and an STL format model is exported. According to the femur functional partition characteristics, a Diamond structure is adopted in a cortical bone area to enhance mechanical support, and a Gyandroid structure is selected in a cancellous bone area to achieve porosity gradient filling, so that the permeability is optimized, and cell proliferation is promoted. Continuous transition among the structures is realized through a Sigmoid function, and the stability and the biological adaptability of the whole structure are improved. And finally, the stent model is subjected to selective laser melting, and a Zn-3Mg alloy material is utilized to complete printing manufacturing.

The utility model discloses a 3D printing porous pedicle screw which comprises a screw body part and a screw cap part, the screw body part comprises a cortical bone thread area close to one end of the screw cap part and a cancellous bone thread area far away from one end of the screw cap part, and a porous structure area is arranged at one end, not connected with the screw cap part, of the screw body part. The porous structure area comprises an inner core column extending in the axial direction of the nail body part, at least one reinforcing beam and a porous structure, the reinforcing beams extend outwards from the periphery of the inner core column, and the porous structure is annularly distributed on the outer periphery of the inner core column. The porous structure can efficiently induce bone tissue to grow in, the screw and a vertebral body are connected into a whole, stress is effectively dispersed, the stability of the screw is improved, the porous structure is arranged on the vertebral body at the front end of the screw, screw breakage caused by stress concentration of the screw in a vertebral pedicle area can be avoided, meanwhile, the stability of the screw can be better improved through the reinforcing beam, and the service life of the screw is prolonged. The possibility of fracture of a porous area of the screw is reduced, generalization performance is better, and the use experience feeling is improved.

The fixing device comprises an X-shaped steel plate and a straight steel plate which are located on the two sides of a bone respectively, a plurality of first penetrating holes are formed in the X-shaped steel plate, and a plurality of second penetrating holes are formed in the straight steel plate; a suture line, a loop turning line and a handle connecting line which are used for connecting the X-shaped steel plate and the straight steel plate are arranged in the first penetrating hole and the second penetrating hole in a penetrating mode, and the loop turning line is used for driving the straight steel plate to turn over relative to the X-shaped steel plate. The four corners of the X-shaped steel plate are all provided with stabs, and the stabs protrude out of the surface of the X-shaped steel plate and are used for stabbing into bone cortex. The X-shaped steel plate and the straight steel plate are arranged on the two sides of the fracture position respectively, meanwhile, the X-shaped steel plate is fixed to the fracture position through the spikes, the X-shaped steel plate and the straight steel plate are bound through the suture lines, so that fixation of the fracture position is achieved, and compared with a traditional operation, trauma is smaller, and fixation is firmer.

The embodiment of the invention provides an intelligent bone drilling self-adaptive control method for a mechanical arm, which comprises the following steps: acquiring displacement deviation of the tail end of a drill bit of an orthopedic surgical robot, obtaining an error change rate through differential calculation, and combining a bone layer type as an input variable of a fuzzy controller and a feeding speed as an output variable; input variables are fuzzified through a membership function, and a fuzzy language variable set is obtained; according to the set and a preset rule base, constructing a multi-rule group structure comprising three types of scenes of free space, cancellous bone and cortical bone, and setting corresponding fuzzy rule subsets for different bone layers; designing a ''minimum-maximum'' rule activation and combination strategy for reasoning by adopting a Mamdani type fuzzy reasoning method according to fuzzification input and a multi-rule group structure, and generating a fuzzification output variable set; and defuzzification is performed through a gravity center method to obtain a continuous speed instruction, and dynamic regulation and control of the drill bit feeding speed are achieved. When approaching a penetration point, the device automatically decelerates and safely stops, so that the safety and accuracy of an operation are effectively guaranteed, and over-drilling injury is prevented.

Porous-based bone implants with the integration of Triply Periodic Minimal Surface, TPMS, porous architectures are designed to support the growth and proliferation of bone tissue, bone marrow, and capillaries. This disclosure intends to reduce the adverse effect of conventional implants such as bone resorption over time, which is called the “stress shielding effect”. The “stress shielding effect” is caused by the mismatch between the implant and natural bone stiffness. Triply Periodic Minimal Surface, TPMS, porous architectures exhibit interconnected pore features. The interconnection of the porous network allows the TPMS to have a higher permeability than that of other porous structures, leading to more favorable nutrient transport. In addition, many physical characteristics of the TPMS structures including surface-to-volume ratio, pore size, elastic modulus, and fluid behaviors can be controlled precisely through mathematical manipulation. As a result, TPMS-based implants could be physical features, which are vaned based on different bone regions. In other words, the medical implants may exhibit non-uniform or gradient physical features, which can match the characteristic of trabecular and cortical bones. Therefore, TPMS-based implants could adjust the features to mimic neighboring bone regions. As a result, we can achieve medical implants, which have superior mechanical and biological responses, resulting in optimal cell growth and better medical treatment.

The invention relates to a preparation method and application of a functional gradient layered bone-imitating GBR (Guarantee Boron Reactor) membrane, the GBR membrane is a novel GBR membrane obtained by taking decellularized fish scales as a base material, constructing an EGCG-fish scale complex through EGCG cross-linking modification and then combining biomimetic mineralization, and the GBR membrane has certain mechanical properties and can maintain a space required by bone regeneration; meanwhile, mineralized hydroxyapatite wraps fish scale collagen, so that the degradation speed of fish scales is reduced, the action time is prolonged, and sufficient time is provided for bone repair; in addition, the mineralized fish scales are similar to natural cortical bones in structure and composition, a cell growth microenvironment is simulated, good biocompatibility is achieved, adhesion and differentiation of osteoblasts are promoted, and the healing speed is increased.

Surgical systems and methods for manipulation of an anatomy that includes cortical and cancellous bone. A surgical manipulator has a robotic arm to move an instrument with an energy applicator. A sensor senses forces / torques applied to the energy applicator. Controller(s) obtain a tool path for the energy applicator to traverse. A segment of the tool path transitions into, or between, cortical bone and cancellous bone. The controller(s) control the manipulator to advance the energy applicator along the tool path according to a first feed rate to manipulate the cortical or cancellous bone and detect, with the sensor, a change in the forces / torques being indicative of the transition. In response to detection of this change, the controller(s) control the manipulator to advance the energy applicator along the tool path according to a second feed rate, greater / less than the first feed rate.

The invention provides a gradient density metal implant additive manufacturing method, and relates to the technical field of selective laser melting additive manufacturing, according to the method, continuous gradient density distribution of a metal implant from an outer layer to an inner layer is achieved through multi-mode sensor fusion and a self-adaptive control algorithm, biomechanical characteristics of a skeleton are accurately simulated, and the manufacturing precision of the metal implant is improved. The step of designing a porous structure is omitted; cortical bone (high density) and cancellous bone (porous) structures of human bones can be accurately simulated, and the biomechanical suitability of the implant is improved.

The invention relates to a spine bone structure and bone mineral density automatic measurement method based on a CT image. The method comprises the following steps: performing CT scanning on a phantom with known bone mineral density to obtain a real bone mineral density calculation formula; all CT images in the DICOM format are read, DICOM analysis is carried out, and three-dimensional CT value data and other main information of all the images are obtained; performing outer contour segmentation on the whole spine in the CT image by using a deep learning network to obtain an outer contour of each vertebral body in the image; the method comprises the following steps: carrying out preliminary segmentation on cortical bones and cancellous bones by adopting a dynamic threshold method aiming at each vertebral body, selecting a preliminarily segmented cancellous bone region, using a maximum connected domain algorithm in a three-dimensional direction, retaining a maximum connected region, and further measuring the bone mineral density, namely calculating overall topology parameters, the bone mineral density and the bone mineral content of the current vertebral body; calculating the rubbing parameters, the bone mineral density and the bone mineral content of the current vertebral cortical bone and cancellous bone; and measuring the content of the cross section of the cone.

The invention discloses a fine-grained segmentation method and system for a three-dimensional CBCT skull image. The method comprises the following steps: firstly, constructing a first training data set; thirdly, in combination with the first training data set, training the secondary segmentation neural network model to obtain a trained secondary segmentation neural network model; then, segmenting a to-be-processed three-dimensional CBCT skull image by using the trained secondary segmentation neural network model to obtain a segmentation result of each structure of the skull; and finally, segmenting the bone cortex and cancellous bone of the upper and lower jawbones by using an improved region growing method to obtain a bone cortex and cancellous bone segmentation result corresponding to the upper and lower jawbones, thereby completing fine-grained segmentation of the three-dimensional CBCT skull image. According to the method provided by the invention, fine-grained areas of the oral maxillofacial region can be separated, and the fine-grained areas comprise intact skull, upper and lower jawbone, teeth, bone cortex, cancellous bone, neural tubes, maxillary sinus, incisor canals and other structures.

A tibial implant may include a plurality of implant subunits. The implant subunits may be configured for individual insertion within a wedge-shaped-void of the tibia. The implant subunits may further be configured for assembly in order to provide an implant substantially covering an exposed portion of cortical bone formed when performing a surgical osteotomy. Methods and kits for insertion and assembly of implants are further described.

The invention belongs to the field of biology, particularly relates to a preparation method, a composition and application of yak bone collagen hydrolysate capable of preventing and treating osteoporosis, and further provides an oral liquid composition which comprises the following raw materials in percentage by mass: 6% of yak bone collagen hydrolysate, 2% of glucosamine sulfate, 0.4% of chondroitin sulfate and the balance of water. The yak bone collagen hydrolysate and oral liquid composition prepared by the method can improve pathological changes of bone tissues of mice with osteoporosis, promote regeneration of collagen in osteoporosis tissues, improve BMD, BV / TV, Tb.N and Tb.Th of cortical bones, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, improve osteoporosis, and improve osteoporosis. The Tb.Sp and Po of cortical bones are reduced, and the excellent function of preventing and treating osteoporosis is achieved.

The invention relates to the technical field of medical implants, in particular to a 4D printing-based porous Niti alloy bionic bone gradient structure construction method, which comprises the steps of patient bone data acquisition, bionic gradient model design, NiTi powder preparation, 4D printing, thermal treatment activation of memory effect, surface functionalization treatment and mechanical / biological performance test. The method is characterized by comprising the following preparation steps: accurately acquiring bone structure data through CT / MRI, combining Mimics pretreatment and UG / NX modeling, designing aperture and porosity for differentiation of cortical bone (low porosity of 30%-40%) and cancellous bone (high porosity of 50%-70%), simulating typical load working conditions through ANSYS, enabling the elastic modulus (3-15 GPa) and compressive strength (80-200 MPa) to be close to natural bone, and finally obtaining the bone structure data through the CT / MRI, the pore diameter and porosity of the cortical bone (low porosity of 30%-40%) and the porosity of the cancellous bone (high porosity of 50%-70%). According to the design, the elastic modulus difference between the implant and the host bone is remarkably reduced, the bone resorption problem caused by stress shielding is avoided, meanwhile, continuous porosity transition is achieved through the power gradual change technology, and the structural stability under the complex load is improved.

The invention discloses a shape memory alloy bone scaffold imitating a Haversian system as well as a 4D printing preparation method and application of the shape memory alloy bone scaffold. According to the 4D printing preparation method, the stress state and function requirements of the bone scaffold are fully considered, a bone scaffold porous structure with an imitated Haversian system is designed by adopting a function bionic method, and the bone scaffold is prepared by adopting a 4D printing technology. The inner layer imitated cancellous bone porous structure designed in the preparation method not only meets the requirement that the inner layer has good elasticity and toughness, but also facilitates cell adhesion to guide cell growth and maintains blood supply; the designed artificial cortical bone porous structure with the Haversian system on the outer layer meets the requirement that the outer layer has good compression resistance and bending resistance, and the Haversian system is more beneficial to ingrowth of blood vessels and nerves and maintains skeleton metabolism and repair. The shape memory alloy bone scaffold simulating the Haversian system, disclosed by the invention, has a wide application prospect in the field of bone implants.

An attachment device with a radially expandable section is disclosed. The attachment device can have helical threads, for example, to facilitate screwing the attachment device into a bone. Methods of using the same are also disclosed. The attachment device can be positioned to radially expand the expandable section in cancellous bone substantially surrounded by cortical bone.

The invention belongs to the technical field of biotechnology and tissue engineering, and particularly relates to application of pilose antler bud cell secretions in preparation of anti-osteoporosis drugs. The pilose antler bud cell secreta is obtained by adopting gradient centrifugation, and cell experiments show that the pilose antler bud cell secreta provided by the invention has the effect of promoting osteogenic differentiation of cells; animal experiment results show that the cornu cervi pantotrichum bud cell secreta provided by the invention can significantly improve the bone mineral density, bone volume fraction, bone trabecula number, bone trabecula thickness, bone trabecula separation degree and cortical bone mineral density of mice, increase the bone trabecula area of primary osteogenesis and secondary osteogenesis centers of the mice, improve osteoporosis symptoms of the mice, and improve osteoporosis of the mice. The effect is obviously better than that of bone marrow mesenchymal stem cell secretions, part of indexes are equivalent to the treatment effect of diphosphates, and the antler bud cell secretions provided by the invention can be used for preparing medicines for preventing, relieving or treating osteoporosis.

The invention relates to the technical field of medical instruments, and provides a unilateral cortical bone needle which comprises a needle cylinder and a needle core, the needle cylinder is hollow and forms a penetrating hole channel, and the needle core penetrates through the penetrating hole channel and is in threaded connection with the needle cylinder; the needle cylinder comprises a connecting sleeve and inserting strips, one end of each inserting strip is connected to the end face of the connecting sleeve, the multiple inserting strips are arranged around the central axis of the connecting sleeve, and a deformation groove is formed between every two adjacent inserting strips; inserting blind holes are formed in the surface of the human sternum, and the ends, away from the connecting sleeve, of all the inserting strips are folded towards the penetrating hole channel in a normal state so as to be inserted into the inserting blind holes. The unilateral cortical spicule can reduce the possibility that the pleura of a patient is punctured by the spicule.

The present invention discloses a bionic lumbar spine bone with X-ray imaging and its preparation method, which relates to the field of bionic technology of medical polymer materials. The technical solution is to stir and mix the raw materials of rigid polyurethane foam and then pour them into a lumbar spine bone mold for foaming to prepare the cancellous bone material of the bionic lumbar spine bone; use the blend modification of styrene-acrylic emulsion and SAN emulsion to prepare the material for bionic cortical bone; and then use the spraying or dipping process to attach the prepared cortical bone to the outer surface of the cancellous bone to form a bionic lumbar spine bone with X-ray imaging. By adding a water-soluble imaging agent in the emulsion synthesis, the present invention realizes the fine distribution of the imaging agent, significantly improves the contrast and clarity of X-ray imaging. Compared with the traditional materials relying on high-concentration inorganic imaging agents, the water-soluble imaging agent not only improves the biocompatibility and environmental protection, but also strengthens the hardness and wear resistance of the material through SAN resin, is applicable to diversified medical and industrial applications, and shows broad market potential.

The application discloses a kind of three-dimensional CBCT skull image fine granularity segmentation method and system.The present application includes the following steps: first, construct first training dataset;Then, in combination with first training dataset, after training secondary segmentation neural network model, obtain trained secondary segmentation neural network model;Then, using trained secondary segmentation neural network model to the three-dimensional CBCT skull image to be processed is segmented, and the segmentation result of each structure of skull is obtained;Finally, using the improved region growing method is carried out the segmentation of the bone cortex and bone marrow of upper and lower jaw bones, and the bone cortex and bone marrow segmentation result corresponding to upper and lower jaw bones is obtained, so as to complete the fine granularity segmentation of three-dimensional CBCT skull image.The method proposed in the present application can separate the fine granularity region of oral and maxillofacial region, including complete skull, upper and lower jaw bones, teeth, bone cortex, bone marrow, nerve canal, maxillary sinus, incisor canal and other structures.

An osteogenic composition comprises growth-factor augmented cortical bone and cancellous bone having viable endogenous osteogenic cells that remain adherent to the cancellous bone. The growth-factor augmented cortical bone comprises demineralized cortical bone amplified with growth factors derived from a demineralized bone, and the cancellous bone not having been subjected to a loosening agent. The osteogenic composition is cryopreserved or lyopreserved. A method for preparing an enhanced graft composition with improved osteoinductive properties includes processing demineralized cortical bone; solubilizing growth factors from demineralized bone; and mixing the demineralized cortical bone with the solubilized growth factors.

This invention pertains to spinal pedicle screws, specifically locking spinal pedicle screws, including perforated pedicle screws and cortical bone screws that work with them. The proximal end of the self-locking master screw is thickened. A through-hole is provided in the thickened section of the pedicle screw, and the cortical bone screw is driven into the through-hole and fixed to the upper and lower cortical bone layers of the pedicle to form a triangular fixation. After the pedicle screw is implanted, both ends of the through-hole of the pedicle screw are located inside the pedicle. A hole is drilled from the posterolateral aspect of the pedicle using a special aiming device, passing forward and upward through the oblique hole of the pedicle screw, and then through the anterior and superior cortical bone of the pedicle. After measuring the length, a suitable cortical bone screw is selected, screwed in, and locked, fixing the posterolateral cortical bone, the pedicle screw, and the anterior and superior cortical bone of the pedicle. The screw is positioned in a safe area of ​​the superior cortical bone of the pedicle. The cortical bone screw is fixed to the upper and lower cortical bone of the pedicle by passing through the oblique hole, thus locking the position of the pedicle screw.

The invention discloses an infectious bone defect bionic repair hydrogel stent and a preparation method and application thereof, and is characterized in that the infectious bone defect bionic repair hydrogel stent is composed of an upper antibacterial-vascularization layer simulating a periosteum structure, a middle support layer simulating a bone cortex structure and a lower regeneration-regulation layer simulating a cancellous bone structure; the upper antibacterial-vascularization layer is prepared from photoresponse CuxO / SiC heterojunction powder, the middle support layer is prepared from silk fibroin, and the lower regeneration-regulation layer is prepared from HAP (at) Cur-CNDs-Pt NPs composite nanoparticles. The multi-dimensional structure and function integration realizes the full-period regulation and control of antibiosis-barrier-regeneration, breaks through the limitation of the traditional single-function stent, and provides an integrated solution for infectious bone defect repair.

The invention discloses a bone-like osteoma microwave ablation thermal injury assessment method based on all-optical parameters, which comprises the following steps: respectively considering thermal injury models of cortical bone and cancellous bone under different microwave ablation conditions by constructing a simulation model conforming to bone tissue characteristics; according to the method, construction of an incomplete P5 approximation model is proposed, bone tissue all-optical parameter anti-construction research based on steady-state radiance is carried out, the accuracy is high, calculation is convenient, temperature parameters and biological tissue all-optical parameters are analyzed in a combined mode, a tissue thermal damage model of the temperature and tissue all-optical parameters is established through theoretical research, and due to the characteristics of different bone tissues, the tissue thermal damage model can be used as a tissue thermal damage model of the temperature and tissue all-optical parameters. The tissue types are considered in the thermal damage model, and effective bone tissue thermal damage factors are designed based on different tissues, so that the evaluation accuracy is ensured.

The invention discloses a porosity gradient discrete embedded type composite bone tissue modeling method. The method comprises the following steps: establishing a three-phase composite bone tissue geometric model of cortical bone, cancellous bone and cortical bone with discrete random pores; establishing material constitutive models of a cortical bone model and a cancellous bone model in the three-phase composite bone tissue geometric model; and performing grid division on the three-phase composite bone tissue geometric model to obtain a composite bone tissue model. According to the porosity gradient discrete embedded type composite bone tissue modeling method, the composite structure of the bone tissue in transition from cortical bone to cancellous bone can be effectively simulated, the accuracy of bone model simulation is improved, and the problem of constitutive homogeneous distortion of an existing bone tissue cutting simulation material is solved.

The utility model provides a femoral stem, and relates to the field of passive medical instruments. Comprising a femoral stem conical part, a femoral stem neck part, a femoral stem shoulder part and a stem body, one end of the femoral stem neck part is connected with the stem body through the femoral stem shoulder part, and the other end of the femoral stem neck part is connected with the femoral stem conical part; at least two first protrusions are evenly arranged on the handle body and around the circumference of the handle body, the length of the first protrusions is equal to that of the handle body, and a second protrusion is arranged between every two adjacent first protrusions. The femoral stem can adapt to marrow cavities of different shapes and sizes, and can better adapt to anatomical features of cortical bones and thighbones of the marrow cavities of patients.