Orthopedic Implant Nut With Spherical Contour For Angular Locking

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Solution Overview

Problem

Existing orthopedic implants face challenges in achieving optimal spatial orientation and compactness while maintaining effective locking and holding qualities in bone material, particularly in complex anatomical sites.

Innovation Solution

The orthopedic device features a support structure with a housing and orifice system, including a nut with internal threads and a screw head with truncated spherical shapes, allowing for angular adjustment and self-centering, along with a clip mechanism for secure nut placement, optimizing compactness and retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the implant structure is made compact with reduced thickness, then the device bulk is decreased, but the complexity of achieving effective locking and angular orientation increases

Engineering Contradiction:
Improvedevice bulk thicknessVSAvoidlocking mechanism complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The nut is nested within a housing that is integrated into the support structure, with the nut's peripheral contour fitting within the housing's internal cavity. This nesting arrangement allows the locking mechanism to be contained within the support structure's thickness, achieving compactness while maintaining the angular orientation capability through the nut's degree of freedom within the housing.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The nut and housing utilize truncated spherical contours with complementary curved surfaces. The nut's peripheral contour in the form of a truncated sphere fits within the housing's truncated spherical cavity, allowing angular inclination while maintaining rotational locking. The curved geometry enables the nut to tilt within a predetermined range while remaining constrained against rotation around its axis.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If the nut is allowed to incline within a predetermined range, then the spatial orientation capability is improved, but the precision of rotational locking may be compromised

Engineering Contradiction:
Improvespatial orientation capabilityVSAvoidrotational locking precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The nut is designed with dynamic characteristics, allowing it to tilt within a predetermined angular range relative to the housing axis while maintaining rotational locking. The degree of freedom for inclination enables adaptation to different screw orientations, while the locked rotational constraint ensures precise positioning once the desired angle is achieved. This dynamic adaptability resolves the contradiction between versatility and precision.

Inventive Principle:
Principle #15Dynamics

3Volume of moving object

If the screw head and nut are designed with truncated spherical shapes, then the compactness is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveimplant compactnessVSAvoidmachining complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The screw head and nut are designed with truncated spherical contours that provide compact geometry while enabling angular orientation. The curved surfaces allow the components to fit together in a space-efficient manner, with the nut's peripheral contour complementing the housing's internal cavity. While curved machining is more complex than flat surfaces, the standardized spherical geometry simplifies the overall design and assembly process.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2139414B1Implantable orthopaedic device composed of a support structure having at least one orifice associated with a nut, for the passage of a locking screw
Publication Date: 2017.05.03 UNKNOWN
  • EP2139414B1 patent drawingFigure 1~2
  • EP2139414B1 patent drawingFigure 3
  • EP2139414B1 patent drawingFigure 4

AI summary

This implantable orthopaedic device comprises a support structure (2) having an orifice (3) that delimits a seat (5) for receiving a nut (6) intended to cooperate with a locking screw (4). The seat (5) comprises an upper part (5a) and a lower part (5b), both shaped as truncated spheres and concentric to each other. Furthermore, the nut (6) has a spherical contour (11), and the screw head (15) has a lower part (15b), also with a spherical contour, and an upper part (15a) provided with a thread (17). The upper (15a) and lower (15b) parts of the screw head (15) cooperate respectively with the complementary thread (14) of the nut (6) and with the lower part (5b) of the receiving seat (5) such that, in the final phase of screwing, they tend to move said nut (6) away from the part (5b) of the seat (5) and thus bring about the forced bearing of the spherical contour (11) of the nut (6) against the upper spherical part (5a) of the seat (5), and of the lower part of the screw head (15b) against the lower spherical part (5b) of the seat (5).