Acetabular Cup Extractor With Curved Blade and Dome Guide
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Solution Overview
Problem
Conventional acetabular cup extractors are inefficient due to permanently attached blades, uncomfortable ergonomic design, and lack of optimal striking surfaces, leading to excessive bone removal during hip revision surgery.
Innovation Solution
An acetabular cup extractor system featuring a handle with a transverse lever assembly, a curved blade, and a dome guide assembly with a hemi-spherical dome, allowing for controlled and minimal bone extraction with improved ergonomics and striking surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional extractors use permanently attached blades or threaded fasteners, then the extractor structure is simple, but surgery time is prolonged
Solution Approach 1:
The extractor is divided into separate modular components: a handle assembly and a blade assembly that can be detached. The blade assembly includes a blade and a spherical head that can be separated from the handle during surgery, allowing for quick changes or removal of components without threading operations.
Solution Approach 2:
The spherical head is designed to be easily separable from the acetabular cup liner when the handle is struck, allowing the blade to be extracted or replaced quickly. This extraction mechanism eliminates the need for threaded fasteners and permanently attached blades, reducing surgery time while maintaining structural simplicity.
2Device complexity
If conventional extractors have flat cutting edges on blades, then the blade structure is simple, but substantial force is required to plunge the blade into bone
Solution Approach 1:
The blade is designed with a curved cutting edge instead of a flat edge. The curved geometry allows the blade to engage with bone more effectively, reducing the force required to plunge it into the bone while maintaining a relatively simple overall blade structure.
3Device complexity
If conventional extractors have non-ergonomic handles, then the handle structure is simple, but the user experiences discomfort due to substantial force requirements
Solution Approach 1:
The handle is designed with an ergonomic, curved configuration that fits comfortably in the user's hand. The curved shape distributes the substantial force required for extraction more evenly across the user's hand, improving comfort and reducing strain while maintaining structural simplicity.
4Device complexity
If conventional extractors have a single impact surface, then the extractor structure is simple, but the striking surface is not optimally positioned for striking
Solution Approach 1:
The extractor is designed with multiple impact surfaces positioned at different locations and orientations. This multi-dimensional arrangement provides optimally positioned striking surfaces for delivering effective blows to dislodge the blade, while maintaining overall structural simplicity.
5Ease of repair
If the spherical head is easily separable from the acetabular cup liner, then the extractor allows for blade extraction, but the user loses control over the point of insertion of the blade into bone
Solution Approach 1:
The spherical head acts as an intermediary element between the handle and the blade. It provides a stable interface that maintains control over the blade's insertion point while still allowing for easy separation and extraction of the blade assembly from the acetabular cup liner.
6Device complexity
If the blade makes an irregular cut of the surrounding bone, then the extraction process is simpler, but more bone than necessary is removed
Solution Approach 1:
The curved blade design enables the blade to follow a controlled, curved path through the bone during extraction. This curved trajectory allows for a more precise and regular cut pattern compared to flat blades, removing only the necessary amount of bone while simplifying the overall extraction process.
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
The system enables efficient and controlled extraction of acetabular cups with minimal bone removal, reducing surgery time and preserving bone integrity.
Implementation Method 1
The blade is curved in both its longitudinal direction and in a widthwise extent transverse to the longitudinal direction... a point of the blade extends to about a most distal point of the hemi-spherical shell-like guide
Implementation Method 2
The curved, concave guide is sized and shaped to substantially matingly engage with and cover a substantial portion of the hemi-spherical dome... the downwardly directed impact force transferred by the handle assembly causes the mating engagement surfaces of the curved, concave guide and the hemi-spherical dome to remain in contact with each other
Implementation Method 3
The proximal end has an impact surface in the form of a proximally facing strike plate adapted to be struck by a striking tool such as a hammer or the like
Data Source
AI summary
An orthopedic instrument in the form of an acetabular cup extractor system for reliably and efficiently extracting an acetabular cup implant from an acetabulum. The system includes a handle assembly, an extractor attachable to a distal end of the handle, and a dome guide assembly having a hemi-spherical dome for engaging the extractor and a centering body extending distally from the hemi-spherical dome for engaging an acetabular implant. The extractor includes a curved, concave guide and a curved blade. The curved, concave guide is sized and shaped to substantially matingly engage with and cover a substantial portion of the hemi-spherical dome. As a result of such an arrangement, a uniform cut is achieved by the curved blade thereby resulting in a minimum of bone being extracted from the acetabulum around the acetabular cup implant during a surgical procedure.