Hip Endoprosthesis Socket with Conical Self-Locking Insert
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing joint sockets for hip endoprostheses face challenges in precisely orienting the socket insert within the socket shell due to material limitations and the difficulty of precise insertion, which can lead to instability and misalignment.
Innovation Solution
A joint socket design featuring a socket shell with a conically narrowing accommodating space allows the socket insert to be freely rotated and tilted, with a self-locking mechanism that secures the insert in place using a minimal amount of pressure, preventing misalignment and leveraging issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the socket insert is fixed using pointed projecting teeth that dig into the outer surface, then the socket insert can be secured in position, but the choice of material is limited and precise positioning becomes difficult
Solution Approach 1:
The invention changes the geometric parameters of the accommodating space from a spherical shape with pointed teeth to a conical shape with a narrowing radius of curvature. This parameter change allows the socket insert to be secured through geometric interlocking rather than material interpenetration, freeing material selection while maintaining fixation stability
Solution Approach 2:
Instead of having the socket insert engage with protruding teeth on the socket shell, the invention inverts the approach by having the socket shell's accommodating space narrow inward to clamp the socket insert. This reversal eliminates the need for material interpenetration while achieving secure fixation
2Reliability
If the socket insert is pressed onto the teeth of the socket shell to fix it in position, then the socket insert can be secured, but it becomes difficult to insert the socket insert in a precisely positioned manner
Solution Approach 1:
The conical accommodating space is pre-formed in the socket shell with a narrowing radius of curvature. This preliminary geometric configuration guides the socket insert into precise positioning automatically during insertion, eliminating the need for forceful pressing and preventing misalignment before fixation occurs
3Ease of operation
If the accommodating space has a spherical shape with the same radius as the socket insert, then the socket insert can be freely rotated and tilted, but additional fixing mechanisms with teeth are required
Solution Approach 1:
The accommodating space transitions from a spherical shape with constant radius to a conical shape with a narrowing radius of curvature. This parameter change enables the socket insert to be freely rotated and tilted during insertion while the narrowing geometry automatically provides self-locking fixation without additional teeth or complex mechanisms
Solution Approach 2:
The invention extracts and eliminates the need for pointed projecting teeth and additional fixing mechanisms. The narrowing conical geometry of the accommodating space alone provides both the freedom of movement during insertion and the self-locking fixation, simplifying the overall device structure
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
This design enables precise orientation and stable fixation of the socket insert within the socket shell, ensuring optimal positioning and reducing the risk of loosening during loading, while allowing for easy and instrument-free insertion and re-clamping.
Implementation Method 1
The inner surface of the socket shell, which defines the accommodating space, narrows toward the pole of the accommodating space in such a manner that the radius of curvature in the region of contact between the socket insert and socket shell is always greater than a spherical radius of the outer surface of the socket insert. The socket insert is arranged so as to be clamped in a self-locking manner in the accommodating space.
Data Source
AI summary
A joint socket of a hip endoprosthesis includes a socket shell implantable in the pelvic bone and a socket insert for providing a bearing for the joint head. The socket shell has an accommodating space having a conical inner surface in which the spherical outer surface of the socket insert is inserted. As a result, the socket insert can be clamped in a self-locking manner in any desired position of rotation and tilt in the accommodating space of the socket shell.