Universal Hip Prosthetic Head with Conical and Spherical Coupling
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Solution Overview
Problem
Existing hip prostheses are not adaptable between conventional and inverse types, limiting their application to specific patient needs and muscle movements.
Innovation Solution
A universal prosthetic head designed with a hemispherical cap body, featuring a truncated-conical portion and a projection forming an annular step, allowing conical coupling with inserts, and a rough surface for bone growth, suitable for both conventional and inverse hip prostheses, providing primary and secondary stability through press-fit and screw fixation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a prosthetic head is designed specifically for conventional or inverse hip prosthesis, then the coupling stability is ensured, but the adaptability to different prosthesis types is limited
Solution Approach 1:
The prosthetic head is designed with a universal interface system that can accommodate both conventional and inverse hip prosthesis types. The internal surface of the prosthetic head body is configured with a truncated-conical portion that provides conical coupling capability, while the projection forming an annular step provides spherical coupling capability. This multi-functional design allows the same prosthetic head to be used with different prosthesis configurations, achieving versatility without compromising coupling stability through the well-defined geometric interfaces.
2Adaptability or versatility
If a universal prosthetic head design is implemented, then the adaptability to different prosthesis types is improved, but the device complexity increases
Solution Approach 1:
The prosthetic head is segmented into distinct functional zones: a body portion with a truncated-conical internal surface for conical coupling, and a projection element forming an annular step for spherical coupling. This segmentation allows each zone to perform its specific coupling function independently, simplifying the overall design by breaking down the universal coupling requirement into manageable geometric features rather than requiring a completely complex multi-interface structure.
Solution Approach 2:
Instead of designing separate prosthetic heads for conventional and inverse prosthesis types, the invention inverts the approach by creating a single prosthetic head design that can accommodate both types. The internal surface configuration with truncated-conical portion and annular step projection provides interface compatibility for different prosthesis configurations, simplifying the system by eliminating the need for multiple specialized components.
3Stability of the object's composition
If conical coupling mode is used with inserts, then the primary stability is achieved, but the manufacturing precision requirements increase
Solution Approach 1:
The prosthetic head incorporates a truncated-conical internal surface with specific geometric parameters that optimize the conical coupling interface. By carefully selecting the cone angle and surface dimensions, the design achieves stable conical coupling while accommodating reasonable manufacturing tolerances. The geometric parameters are chosen to provide sufficient mechanical interlocking and load-bearing capacity without requiring extremely tight precision, balancing stability with manufacturability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the prosthetic head to be used in both conventional and inverse hip prostheses, enhancing stability and adaptability, preventing displacement, and facilitating bone regeneration, thus catering to diverse patient requirements.
Implementation Method 1
The external surface of the prosthetic head may have a rough shape in order to facilitate the bone growth
Implementation Method 2
providing primary and secondary stability through press-fit and screw fixation
Implementation Method 3
providing primary and secondary stability through press-fit and screw fixation
Data Source
Figure 1~2
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AI summary
A prosthetic head (1) comprises: a body (10) having the shape of a cup shaped as a hemispherical cap provided with an external surface, an internal surface and a lower edge (19) shaped as a circumference, fixing means to fix the prosthetic head to the cotyle, and a projection (11) abutting from the internal surface of the prosthetic head in such manner to define an annular step (12), a truncated-conical portion (17) obtained in the internal surface of the body of the prosthetic head starting from said lower edge (19) of the prosthetic head, said truncated-conical portion (17) of the prosthetic head being suitable for being coupled in conical coupling mode with a truncated-conical part (73) of an insert (7) intended to be inserted in the prosthetic head; wherein said projection (11) is shaped as a portion of a spherical cap.