A hip joint prosthesis for bone defects

Abstract

This invention discloses a hip joint prosthesis for bone defects, comprising a crescent-shaped acetabular rim filler assembly, a bone-metal defect block, an acetabular wall defect support block, a cylindrical support block, an angle pad, a locking screw, a locking nut, an assembly screw, an acetabular sealing screw, and an acetabular support block. The crescent-shaped acetabular rim filler assembly includes two sets of crescent-shaped acetabular rim fillers, which are assembled by engaging pins through pin holes. The outer circumference of the bone-metal defect block of the acetabular support block is connected to the crescent-shaped acetabular rim filler assembly via bone cement. This hip joint prosthesis for bone defects effectively fills irregular defect areas of the acetabular rim. The various screw holes and Kirschner wire holes on its surface provide multi-dimensional fixation options. The overall structure, through the synergistic action of multiple components, achieves precise reconstruction while ensuring biomechanical performance, significantly reducing the risk of postoperative prosthesis loosening and wear.

Description

Technical Field

[0001] This invention relates to the field of joint prostheses, and more particularly to a hip joint prosthesis for bone defects. Background Technology

[0002] In the field of bone defect repair and artificial joint replacement technology, existing prosthetic systems typically employ modular components for reconstruction to address the clinical needs of insufficient bone volume or anatomical abnormalities after hip replacement surgery. These prostheses must balance initial stability, long-term biological fixation, and functional recovery, but their structural design often faces multi-dimensional challenges: traditional locking mechanisms often use a single operating channel, requiring repeated adjustments to the fixation angle during surgery, leading to prolonged operation time and limited locking reliability due to operational space constraints; screw fixation channels are often unidirectionally pre-designed, making it difficult to adapt to the differences in bone orientation caused by complex anatomical variations, easily resulting in stress concentration at the prosthesis-bone interface; support structures typically employ standardized interface designs, either overemphasizing bone ingrowth at the expense of articular surface wear resistance, or pursuing smoothness leading to insufficient osseointegration, making it difficult to achieve both; furthermore, the contact surfaces of conventional support components are often planar or simple curved surfaces, forming point or line contacts with adjacent anatomical structures, easily generating local stress peaks during joint load transmission, accelerating prosthesis loosening or interface wear.

[0003] While existing technologies attempt to improve performance by increasing the number of components or adjusting material ratios, their core structures still suffer from the following drawbacks: the locking and fixation methods lack a rapid adjustment mechanism, significantly increasing the difficulty of handling complex cases; the fixed channel direction design limits the prosthesis's adaptability to individualized anatomical structures; the singular function of the support interface fails to simultaneously meet the requirements of osseointegration and wear resistance; and the insufficient matching degree between the contact surface geometry and human biomechanical characteristics leads to low load transfer efficiency. These problems directly affect the long-term stability of the prosthesis system, resulting in high rates of postoperative prosthesis loosening, interface wear, and reoperation, especially when facing severe bone defects or special anatomical variations, where traditional designs struggle to achieve precise mechanical reconstruction. Summary of the Invention

[0004] In view of the shortcomings of the prior art, this application provides a hip joint prosthesis for bone defects to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, this application provides the following technical solution: a hip joint prosthesis for bone defects, comprising a crescent-shaped acetabular rim filling block assembly, a bone-metal defect block, an acetabular wall defect support block, a cylindrical support block, an angle pad, a locking pin, a locking nut, an assembly screw, an acetabular sealing pin, and an acetabular support block. The crescent-shaped acetabular rim filling block assembly includes two sets of crescent-shaped acetabular rim filling blocks, which are assembled by engaging pins through pin holes. The outer circumference of the bone-metal defect block of the acetabular support block is bonded to the acetabular wall defect block with bone cement. The crescent-shaped acetabular rim filling block group is connected. The outer side of the crescent-shaped acetabular rim filling block group is provided with screw fixing holes and first Kirschner wire holes. The left and right sides of the outer side of the crescent-shaped acetabular rim filling block group are respectively provided with arc-shaped screw holes and arc-shaped inclined screw holes. The inner cavity of the screw fixing holes, the arc-shaped screw holes and the arc-shaped inclined screw holes are all equipped with assembly screws. The outer side of the crescent-shaped acetabular rim filling block group is provided with a semi-circular concave block, and the outer side of the semi-circular concave block is equipped with arc-shaped Kirschner wire inclined holes.

[0006] The external surface of the bone metal defect block is provided with bottom screw fixing holes, second Kirschner wire holes, operating holes and arc Kirschner wire oblique holes. The two sets of operating holes are connected to locking pins, and locking nuts are provided on the outside of the locking pins. The external surface of the bone metal defect block is provided with arc-shaped positive holes and arc-shaped oblique holes, and the inner cavities of the arc-shaped oblique holes and arc-shaped positive holes are connected to the assembly screws.

[0007] The acetabular wall defect support block has a first bolt hole and a second bolt hole on its left and right sides, respectively. The bottom of the acetabular wall defect support block has a trabecular bone interface and a metal polishing interface. The left and right sides of the acetabular wall defect support block have a first concave arc surface and a second concave arc surface, respectively. The acetabular wall defect support block has an L-shaped insert on its exterior. Both sides of the acetabular wall defect support block have inclined surfaces.

[0008] Preferably, the outer side of the acetabular wall defect support block is connected to the angle pad, and a rectangular block is fitted on the outer side of the acetabular wall defect support block. The angle pad and the support block are combined to form an adjustable support system. The outer side of both the rectangular block and the angle pad is provided with a circular groove. The circular groove structure reduces weight and reserves space for bone cement filling. The outer side of both the angle pad and the rectangular block is provided with short nails. The short nail structure enhances anti-rotation stability.

[0009] Preferably, the column support block is assembled to the outside of the bone-metal defect block with bone cement, and the column structure fills the segmental bone defect and transmits the load; the column support block includes a connecting seat, and the modular connecting seat is adapted to column components of different diameters.

[0010] Preferably, the connector is externally fitted with an eccentric column, the eccentric design compensating for offset bone defects; the eccentric column is externally provided with an arc protrusion, the arc protrusion enhancing the contact area and anti-settlement performance.

[0011] Preferably, the outer surface of the arc protrusion is provided with a reinforcing pad, which disperses stress and prevents local crushing; the connecting seat includes an arc and a straight structure, and the connecting seat is connected to the bone metal defect block through bone cement, and the composite structure is adapted to the fixation requirements of different anatomical shapes.

[0012] Preferably, the connecting seat is externally fitted with a straight column, which provides axial rigid support; both the left and right sides of the straight column are planar, and the planar structure prevents the column from rotating or shifting.

[0013] Preferably, the acetabular occlusion screw is fitted to the outside of the bone metal defect block, and the acetabular occlusion screw is connected to the bone metal defect block by bone cement. The occlusion screw seals the medullary cavity to prevent tissue fluid leakage. The bottom of the acetabular occlusion screw is provided with an internal hexagonal groove, and the internal hexagonal structure is adapted to the operation of standardized surgical instruments.

[0014] Preferably, the trabecular bone interface and the metal polished interface include both a trabecular bone interface and a metal polished interface, and the dual-interface design takes into account both bone integration and wear resistance; the acetabular support block is provided with a screw hole structure on its exterior, and the multi-screw hole layout realizes a personalized fixation solution.

[0015] Preferably, the concave arc surfaces at the first and second concave arc surfaces are in contact with the outside of the crescent-shaped acetabular rim filler block assembly through bone cement. The arc surface contact design increases the contact area and improves the fixation strength.

[0016] Preferably, the angle pad has an adjustable angle of 5-30° on its exterior, which can be adapted to different anatomical variations in cases; and it has a light hole structure, which facilitates intraoperative X-ray fluoroscopy to confirm the position; the bottom of the locking screw is equipped with a screw body, and the screw body thread design prevents it from being pulled out and failing.

[0017] In summary, this application provides a hip joint prosthesis for bone defects, which has the following beneficial effects:

[0018] This hip joint prosthesis for bone defects achieves precise adaptation to complex acetabular defect morphologies through modular design. The split structure of the crescent-shaped filling block group, combined with the pin connection method, allows for flexible adjustment of the assembly angle, effectively filling irregular defect areas of the acetabular rim. The Kirschner wire holes on its surface provide multi-dimensional fixation options, enhancing the initial stability between the prosthesis and the host bone. It provides a universal standardized prosthesis with diverse assembly options, saving surgical time and making it suitable for revision surgery or patients with tumors in the affected area.

[0019] This hip joint prosthesis for bone defects features a dual-operation port for the bone-metal defect block, facilitating rapid intraoperative locking and fixation. The arc-shaped holes on its surface can accommodate bone structures with different anatomical orientations, enhancing stress dispersion. The acetabular wall support block, through a composite design of the trabecular bone interface and the polished metal interface, promotes bone ingrowth while maintaining articular surface smoothness. Its L-shaped insert and concave arc surface structure provide surface contact support with adjacent anatomical structures, effectively dispersing joint loads. The beveled design reduces edge stress concentration during movement. Combined with the cylindrical support block and angled pads, it can provide customized support solutions for different defect sites. The overall structure, through the synergistic action of multiple components, achieves precise reconstruction while ensuring biomechanical performance, significantly reducing the risk of postoperative prosthesis loosening and wear. Attached Figure Description

[0020] Figure 1 This is an external schematic diagram of the crescent-shaped acetabular rim filling block of the present invention.

[0021] Figure 2 This is a partial cross-sectional view of the crescent-shaped acetabular rim filling block of the present invention.

[0022] Figure 3 This is an external schematic diagram of the acetabular wall defect support block of the present invention.

[0023] Figure 4 This is an external schematic diagram of the angle pad block of the present invention.

[0024] Figure 5 This is an external schematic diagram of the column support block of the present invention.

[0025] Figure 6 This is an external schematic diagram of the locking pin, locking nut, screw, and acetabular sealing pin of the present invention.

[0026] Figure 7 This is an example diagram showing the external shape of the acetabular wall defect support block of the present invention.

[0027] Figure 8 This is an example diagram showing the external shape of the crescent-shaped acetabular rim filling block assembly of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Crescent-shaped acetabular rim filling block assembly; 11. First Kirschner wire hole position; 12. Screw fixing hole position; 13. Fixed screw hole at the arc; 14. Inclined screw hole at the arc; 15. Semi-circular concave block; 16. Kirschner wire oblique hole position at the arc; 2. Bone-metal defect block; 21. Bottom surface screw fixing hole; 22. Second Kirschner wire hole position; 23. Operating hole; 24. Inclined Kirschner wire hole position at the arc; 25. Inclined hole at the arc; 26. Normal hole at the arc; 3. Acetabular wall defect support block; 31. First 32. Bolt hole; 33. Trabecular bone interface and metal polishing interface; 34. Second bolt hole; 35. First concave arc surface; 36. L-shaped insert; 37. Inclined surface; 48. Second concave arc surface; 49. Column support block; 40. Eccentric column; 41. Arc protrusion; 42. Connecting seat; 43. Straight column; 50. Angle pad; 51. Circular groove; 52. Short nail; 53. Rectangular block; 6. Locking nail; 61. Nail body; 7. Locking nut; 8. Screw; 9. Acetabular sealing nail; 10. Acetabular support block. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] This application provides a technical solution; please refer to [link / reference]. Figure 1 and Figure 2 A hip joint prosthesis with bone defects includes a crescent-shaped acetabular rim filling block group 1, a bone-metal defect block 2, an acetabular wall defect support block 3, a column support block 4, an angle pad block 5, a locking screw 6, a locking nut 7, an assembly screw 8, an acetabular sealing screw 9, and an acetabular support block 10.

[0032] The shapes of the acetabular wall defect support block 3 and the crescent-shaped acetabular rim filling block group 1 are diverse; please refer to [link / reference]. Figure 7 and Figure 8 Examples, including but not limited to those shown in the figure.

[0033] The crescent-shaped acetabular rim filler block group 1 includes two sets of crescent-shaped acetabular rim filler blocks. The two sets of crescent-shaped acetabular rim filler blocks are assembled with pins through pin holes. Through modular combination design, it can be adapted to different acetabular rim defects. Its arc-shaped contact surface matches the anatomical shape of the human acetabulum. The modular design allows for the selection of filler blocks with different curvatures according to the defect range to achieve anatomical reconstruction.

[0034] Modular design also reduces medical costs by reducing the number of inventory specifications, and allows for rapid trial fitting and adjustment during surgery, shortening surgical exposure time and reducing the risk of infection.

[0035] Please see Figure 3 The outer circle of the bone metal defect block 2 of the acetabular support block 10 is connected to the crescent-shaped acetabular rim filling block group 1 by bone cement. The bone cement fills the gap to form a biomechanical locking structure. Mechanical locking is achieved by the bone cement penetrating to the microporous surface, which enhances the anti-rotation stability of the interface.

[0036] Microporous surface treatment technology enables bone cement to penetrate to a depth of 0.5–1.0 mm, forming a micro-mechanical interlocking structure. Biomechanical tests have confirmed that the torsional strength is increased by more than 40% compared to traditional planar connections.

[0037] The crescent-shaped acetabular rim filling block assembly 1 has screw fixing holes 12 and first Kirschner wire holes 11 on its outside. The multi-directional fixing structure enhances the initial stability, the Kirschner wire holes provide temporary fixing points, and the screw fixing holes 12 achieve permanent fixing, forming a double guarantee.

[0038] Please see Figure 4 The multi-directional fixation structure reduces the maximum shear stress at the interface to less than 60% of that of traditional fixation methods by dispersing stress concentration points, effectively delaying the prosthesis loosening cycle.

[0039] Please see 5 and Figure 6 The crescent-shaped acetabular rim filling block group 1 has a formal screw hole 13 at the arc and an inclined screw hole 14 at the arc on the left and right sides of the outside. The inclined hole design is adapted to the fixation requirements of asymmetric bone defects, and the inclined angle matches the anatomical axis of the acetabular column to optimize the holding force distribution of the screw 8.

[0040] The 15°-25° variable angle design of the inclined screw hole 14 at the inclined arc makes the angle between the axis of screw 8 and the principal stress direction ≤10°. Finite element analysis has confirmed that this can increase the holding force of screw 8 by 25% to 35%.

[0041] The inner cavities of the screw fixing hole 12, the formal screw hole 13 at the arc and the inclined screw hole 14 at the arc are all equipped with assembly screws 8. The tapered design of the screw 8 achieves the pressure fixing effect. The screw 8 generates pre-tightening force by squeezing the bone cement layer to eliminate interface micro-movement.

[0042] The 3°-5° taper design of screw 8 generates 0.1-0.3mm axial displacement when tightened, forming a continuous preload. Dynamic fatigue tests show that it can maintain interface stability for more than 10 years.

[0043] The crescent-shaped acetabular rim filling block group 1 has a semi-circular concave block 15 on its outside, and the semi-circular concave block 15 is fitted with an arc-shaped Kirschner wire oblique hole 16 on its outside. The oblique hole design facilitates temporary fixation during the operation, and the Kirschner wire can be inserted along the acetabular axis to reduce soft tissue interference.

[0044] The 20°-30° tilt angle design of the Kirschner wire oblique hole position 16 at the arc ensures that the insertion direction of the Kirschner wire is parallel to the direction of the joint capsule fibers, avoiding puncture damage to key vascular structures such as the medial circumflex femoral artery.

[0045] The external surface of the bone metal defect block 2 is provided with bottom screw fixing hole 21, second Kirschner wire hole position 22, operating hole 23 and arc Kirschner wire oblique hole position 24. The double Kirschner wire hole positions realize three-dimensional spatial positioning, and the orthogonally arranged Kirschner wire hole positions can construct a three-dimensional coordinate system to assist the precise alignment of the prosthesis.

[0046] The three-dimensional coordinate system imports preoperative CT data into the navigation system, achieving sub-millimeter positioning accuracy and keeping the prosthesis placement error within ±1°.

[0047] The two sets of operating holes 23 are internally connected with locking pins 6, and locking nuts 7 are provided on the outside of the locking pins 6. The mechanical locking structure prevents the components from loosening, and the double nut anti-loosening design uses pre-tightening force to offset vibration load and avoid failure after long-term use.

[0048] The double-nut anti-loosening structure uses Bass washers for pre-tightening, and can still maintain more than 90% of the initial pre-tightening force under a 1000N cyclic load, which meets the requirements of ASTM F2028 standard.

[0049] The outer surface of the bone metal defect block 2 is provided with a circular arc-shaped hole 26 and a circular arc-shaped oblique hole 25. The inner cavity of the circular arc-shaped oblique hole 25 and the circular arc-shaped hole 26 is connected to the mounting screw 8. The combination of the circular arc-shaped and oblique holes is suitable for the repair needs of bone defects at different angles. The direction of the oblique hole is consistent with the stress trajectory of the acetabulum weight-bearing area, thus optimizing the load transmission path.

[0050] The 10°-15° tilt angle of the oblique hole 25 at the arc forms a 15°-20° angle with the normal direction of the acetabular joint surface, so that the load transmission path avoids the area of ​​weak bone and reduces the risk of femoral head collapse.

[0051] The outside of the acetabular wall defect support block 3 is connected to the angle pad block 5, and the outside of the acetabular wall defect support block 3 is equipped with a rectangular block 53. The angle pad block 5 and the support block are combined to form an adjustable support system. The 0-30° angle adjustment can be achieved by stacking modular pads to adapt to acetabular anteversion / valgus deformity.

[0052] The adjustable support system achieves incremental adjustments in 5° units through a combination of wedge-shaped pads, with an angle adjustment accuracy of ±2°, meeting the correction needs of complex deformities such as congenital hip dysplasia.

[0053] Both the rectangular block 53 and the angle pad block 5 have circular grooves 51 on their exteriors. The circular grooves 51 reduce weight and reserve space for bone cement filling. The circular grooves form a bone cement reservoir and enhance the interface bonding strength.

[0054] The honeycomb arrangement design of the circular groove 51 increases the amount of bone cement filling by 30% to 40% and improves the interfacial shear strength to over 15 MPa, which meets the ISO 7207-4 standard.

[0055] Both the angle pad 5 and the rectangular block 53 are provided with short nails 52 on their exterior. The structure of the short nails 52 enhances the anti-rotation stability. The conical short nails 52 are embedded in the host bone cortex to form a mechanical interlock.

[0056] The short nail 52 has a cone angle of 60°-75° and a spiral groove depth of 0.2-0.3mm on the surface of the nail body 61, which increases the pull-out force by more than 200% compared to the smooth nail body 61.

[0057] The column support block 4 is assembled to the outside of the bone metal defect block 2 with bone cement. The column structure fills the segmental bone defect and transmits the load. The hollow design reduces the stress shielding effect and promotes bone ingrowth.

[0058] The hollow honeycomb structure has a porosity of 60% to 70% and a pore size of 400-600 μm, which meets the optimal porosity parameters for bone ingrowth. The bone integration rate can reach more than 85% 6 months after surgery.

[0059] The connecting seat 43 is externally fitted with a straight column 44, which provides axial rigid support; both the left and right sides of the straight column 44 are flat, and the flat structure prevents the column from rotating or shifting.

[0060] The modular connector 43 adopts a Morse taper connection and, together with the locking pin, achieves a zero-clearance fit, with an axial load capacity of 3000N, meeting the needs of highly active patients.

[0061] The external part of the connector 43 is equipped with an eccentric column 41. The eccentric design compensates for the offset bone defect. The eccentric distance can be adjusted up to 5mm to correct the abnormal eccentric distance of the femoral neck.

[0062] The 5-level adjustable scale design of the eccentric column 41 enables the eccentricity adjustment accuracy to reach 1mm, and precise adjustment can be completed through intraoperative X-ray fluoroscopy, avoiding repeated disassembly and assembly.

[0063] The eccentric column 41 is provided with an arc protrusion 42 on its outside. The arc protrusion 42 enhances the contact area and anti-settlement performance. The height of the protrusion matches the host bone density to prevent long-term sinking.

[0064] The radius of curvature of the arc protrusion 42 matches the curvature of the host bone cortex surface, increasing the contact area by more than 50% and reducing the pressure per unit area to below the bone resorption threshold.

[0065] Doctors used 3D CT reconstruction to determine the type and extent of the acetabular defect. For cases of acetabular rim defects, the basic module of the crescent-shaped acetabular rim filler block group 1 was selected first. This component consists of two sets of crescent-shaped filler blocks with different curvatures, pre-assembled with matching pins through pin holes. The modular design allows for the selection of 15°, 30°, or 45° arc module combinations according to the curvature of the defect, with its anatomical arc surface forming surface contact with the host acetabular fossa. For partial defects at the anterior or posterior rim, a single set of filler blocks can be used; when a full circumferential defect is involved, the two sets of modules are spliced ​​into a complete ring using a dovetail joint structure, and the splice seam is filled with bone cement to form a continuous mechanical structure.

[0066] The crescent-shaped acetabular rim filler block assembly 1 employs two sets of crescent-shaped structures, assembled with pins through pin holes. It can be modularly combined according to the acetabular defect morphology, achieving precise alignment through pin positioning. The externally located screw fixing holes 12, the screw holes 13 at the arc, and the inclined screw holes 14 at the arc form a multi-directional fixation structure. Combined with the assembly screws 8, it achieves three-dimensional mechanical locking. The combination design of the semi-circular concave block 15 and the inclined Kirschner wire holes 16 at the arc not only meets temporary fixation needs but also avoids Kirschner wire interference with the main structure assembly. The bone-metal defect block 2 is connected to the crescent-shaped acetabular rim filler block assembly 1 via bone cement. Its bottom screw fixing holes 21 and the second Kirschner wire hole 22 constitute a dual fixation system. The operating hole 23, together with the locking pin 6 and the locking nut 7, forms an adjustable locking mechanism. The staggered layout of the positive hole 26 and the oblique hole 25 at the arc makes the assembly screw 8 form a cross-fixing structure, effectively resisting rotational displacement. The acetabular wall defect support block 3 achieves multi-point rigid connection through the first bolt hole 31 and the second bolt hole 33. The composite design of the trabecular bone interface and the metal polished interface 32 takes into account both bone ingrowth requirements and wear resistance. The first concave arc surface 34 and the second concave arc surface 37 conform to the natural curvature of the acetabulum. The L-shaped insert 35 enhances the edge support strength. The oblique surface 36 disperses stress concentration. All components form an integrated mechanical transmission path through the assembly screw 8 and the acetabular sealing pin 9, effectively restoring the biomechanical environment of the hip joint.

[0067] In the initial fixation phase, a multi-directional fixation structure designed on the surface of the crescent-shaped acetabular rim filler block assembly 1 is utilized. First, a 2.0 mm Kirschner wire is inserted into the oblique hole 16 at the arc of the semi-circular concave block 15, and driven obliquely into the host bone along the acetabular axis to achieve temporary spatial positioning. Subsequently, a 4.5 mm diameter assembly screw 8 is implanted into the screw fixation hole 12. The tapered design of the screw 8 allows the screw body 61 to form an interference fit with the hole wall, compressing the bone cement layer to produce an axial displacement of 0.2–0.3 mm, and eliminating interfacial micromotion through the material creep effect. For asymmetric defect areas, a locking screw 6 with a locking nut 7 is implanted into the inclined screw hole 14 at the arc. The inclination angle forms a 15° angle with the anatomical axis of the acetabular column, so that the holding force direction of the screw 8 coincides with the principal stress trajectory.

[0068] When acetabular wall bone defects are present, the support system assembly stage begins. The acetabular wall defect support block 3 is combined with the angle pad 5, achieving precise alignment through the circular groove 51 structure of the rectangular block 53. The angle pad 5 is available in four sizes: 0°, 10°, 20°, and 30°, and angle adjustment is achieved through modular stacking. During adjustment, the base angle pad 5 is first inserted, and the conical tip of the short screw 52 forms a mechanical interlock with the host bone cortex. Then, the corresponding angle pad 5 is stacked according to preoperative measurements, with each layer of pads chemically bonded by filling the circular groove 51 with bone cement. For cases with abnormal anteversion angles, while stacking the angle pad 5 at the outer edge of the acetabulum, a reverse angle compensation block is implanted at the corresponding position at the inner edge of the acetabulum to correct the abnormal angle through a wedge effect.

[0069] For segmental columnar bone defects, a column support system is installed. The connector 43 of the column support block 4 is aligned with the bone-metal defect block 2, and the eccentric column 41 compensates for the femoral neck eccentricity through a 5mm adjustable range. During installation, a connector 43 matching the diameter of the host's medullary cavity is first selected, and the eccentric column 41 is rotated to the optimal compensation position, utilizing the arc-shaped protrusion 42 to form multi-point contact with the host's bone cortex. The hollow structure of the column is filled with calcium phosphate bone cement, which is injected under pressure through a 3mm diameter operating hole 23, allowing the bone cement to penetrate into the microporous structure of the column surface, creating a mechanical interlocking effect.

[0070] During the multi-component coordinated fixation phase, the bone metal defect 2 is rigidly connected to the host pelvis through the bottom screw fixation hole 21. A dual-plane fixation strategy is adopted: two 6.5mm diameter assembly screws 8 are implanted in the anteroposterior projection direction, with the axis of screw 8 forming a 30° angle with the weight-bearing surface of the acetabulum; a third screw 8 is implanted in the lateral projection direction through the oblique hole 25 at the arc, with the direction of the oblique hole forming a 15° angle with the normal direction of the acetabular joint surface. The three screws 8 form a spatial triangular fixation structure, which, together with the temporary fixation at the second Kirschner wire hole 22, constructs a three-dimensional mechanical stability system. After the locking screw 6 passes through the double operating holes 23, the preload of the locking nut 7 eliminates the thread gap, and the double nut structure generates a continuous torque of 1.5Nm to counteract the vibration load generated by postoperative functional exercises.

[0071] In the final integration stage, the crescent-shaped acetabular rim filler block 1 and the bone-metal defect block 2 were biologically fixed with bone cement. When filling the gap, the bone cement was first injected into the micropores of the filler block assembly, where the porosity was 35%. Negative pressure was used to allow the bone cement to penetrate to a depth of 2–3 mm. Subsequently, pressure injection was performed at the positive hole 26 on the arc of the bone-metal defect block 2, causing the bone cement to form a radial filling pattern along the oblique holes 25 on the arc. The final interfacial bonding strength was ensured through the following mechanisms: micro-mechanical interlocking of the bone cement-metal interface; permeable fusion of the bone cement-host bone; and macro-mechanical constraint of the screw system 8.

[0072] Postoperative stability verification includes: 1. Confirming the positional relationship of each component using C-arm fluoroscopy, with a focus on checking whether the tilt angle of the angle pad 5 is consistent with the preoperative plan; 2. Performing stress testing, applying an axial load of 500N to the semicircular concave block 15 of the crescent-shaped acetabular rim filler block group 1, and measuring the interface displacement, which should be less than 0.5mm; 3. Confirming the density of bone cement filling using ultrasound, requiring a micropore filling rate ≥85%.

[0073] This prosthetic system achieves anatomical reconstruction through modular design, ensures initial stability through multi-level fixation mechanisms, and extends prosthesis lifespan through biomechanical optimization. Each component can be used independently to address a single type of defect or combined to form a composite repair plan, making it particularly suitable for complex acetabular bone defects such as Paprosky type III. Its innovation lies in the organic integration of mechanical fixation principles with biological fixation mechanisms, ensuring surgical reversibility while achieving long-term functional reconstruction of the bone defect area.

[0074] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0075] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hip joint prosthesis for bone defects, comprising a crescent-shaped acetabular rim filler assembly, a bone-metal defect block, an acetabular wall defect support block, fitting screws, and an acetabular support block, characterized in that: The crescent-shaped acetabular rim filler block assembly includes two sets of crescent-shaped acetabular rim filler blocks. The two sets of crescent-shaped acetabular rim filler blocks are assembled by engaging pins through pin holes. The outer circumference of the bone-metal defect block of the acetabular support block is connected to the crescent-shaped acetabular rim filler block assembly through bone cement. The outer side of the crescent-shaped acetabular rim filler block assembly is provided with screw fixing holes and first Kirschner wire holes. The left and right sides of the outer side of the crescent-shaped acetabular rim filler block assembly are respectively provided with arc-shaped formal screw holes and arc-shaped inclined screw holes. The inner cavities of the screw fixing holes, arc-shaped formal screw holes and arc-shaped inclined screw holes are in contact with the outer side of the mounting screws. The outer side of the crescent-shaped acetabular rim filler block assembly is provided with a semi-circular concave block, and the outer side of the semi-circular concave block is equipped with arc-shaped Kirschner wire inclined holes. The external surface of the bone metal defect block is provided with bottom screw fixing holes, second Kirschner wire holes, operating holes and arc Kirschner wire oblique holes. The two sets of operating holes are connected to locking pins, and locking nuts are provided on the outside of the locking pins. The external surface of the bone metal defect block is provided with arc-shaped holes and arc-shaped oblique holes, and the inner cavities of the arc-shaped oblique holes and arc-shaped holes are connected to the assembly screws. The acetabular wall defect support block has a first bolt hole and a second bolt hole on its outer left and right sides, respectively. The bottom of the acetabular wall defect support block has a trabecular bone interface and a metal polishing interface. The outer left and right sides of the acetabular wall defect support block have a first concave arc surface and a second concave arc surface, respectively. The acetabular wall defect support block is provided with an L-shaped insert on its outer side. The outer sides of the acetabular wall defect support block are both provided with inclined surfaces. It includes an angle pad, which is connected to the outside of the acetabular wall defect support block, and a rectangular block is fitted on the outside of the acetabular wall defect support block. Both the rectangular block and the angle pad have circular grooves on their outsides to reduce weight and reserve space for bone cement filling. Both the angle pad and the rectangular block are provided with short nails on their outsides. The acetabular sealing screw is externally fitted to the bone-metal defect block and is connected to the bone-metal defect block by bone cement. The bottom of the sealing screw is provided with an internal hexagonal groove. The trabecular interface and the metal polished interface include the trabecular interface and the metal polished interface. The acetabular support block is provided with a screw hole structure on its exterior.

2. The hip joint prosthesis for bone defects according to claim 1, characterized in that: It also includes a column support block, which is assembled to the outside of the bone-metal defect block by bone cement, and the column support block includes a connecting seat.

3. A hip joint prosthesis for bone defects according to claim 2, characterized in that: An eccentric column is fitted to the outside of the connector, and an arc protrusion is provided on the outside of the eccentric column.

4. A hip joint prosthesis for bone defects according to claim 3, characterized in that: The outer surface of the arc-shaped protrusion is provided with a reinforcing pad, and the connecting seat is connected to the bone metal defect block through bone cement.

5. A hip joint prosthesis for bone defects according to claim 2, characterized in that: The connector is externally fitted with a straight column, and both the left and right sides of the straight column are flat.

6. A hip joint prosthesis for bone defects according to claim 1, characterized in that: The concave arc surfaces at the first and second concave arc surfaces are in contact with the outside of the crescent-shaped acetabular rim filler block assembly through bone cement.

7. A hip joint prosthesis for bone defects according to claim 1, characterized in that: The angle pad has an adjustable angle of 5-30° on its exterior and a light hole structure. The bottom of the locking pin is fitted with a pin body.

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