Finger Joint Prosthesis Instrument for Minimizing Bone Loss

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Solution Overview

Problem

Current finger joint replacement technologies face challenges such as pain, reduced mobility, tissue damage, and instability due to inadequate anchoring and material issues, leading to suboptimal functional outcomes and increased risk of complications like tendon deformities and bone loss.

Innovation Solution

A surgical instrument set and method for precisely positioning and anchoring a biocompatible, low-wear finger joint prosthesis using a lateral approach, minimizing tendon damage and bone loss, with a titanium hinge endoprosthesis coated with hydroxyapatite for stable integration and early mobility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional joint replacement methods are used, then joint function can be restored, but tissue damage and bone loss occur

Engineering Contradiction:

Improvejoint function restorationVSAvoidtissue damage and bone loss

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The surgical instrument is divided into multiple functional modules: a fixing frame for stabilization, a drilling slide for precise positioning, and a milling cutter for bone preparation. This segmentation allows each component to perform its specific function efficiently while minimizing overall tissue disruption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixing frame is attached to the finger before the actual prosthesis implantation. This preliminary action stabilizes the surgical field and enables precise subsequent steps, preventing unnecessary tissue manipulation and damage during the procedure.

Inventive Principle:

Principle #10Preliminary action

2Stability of the object's composition

If coupled joint implants are used, then joint stability is achieved, but loosening effects occur due to high tensile and frictional forces

Engineering Contradiction:

Improvejoint stabilityVSAvoidimplant loosening

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent extracts the coupling mechanism from the implant design, creating a non-coupled prosthesis where the joint surfaces are replaced but the bones remain uncoupled. This eliminates the tensile and frictional forces that cause loosening in coupled implants, while still providing joint stability through precise surface reconstruction.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of coupling the implant to achieve stability, the patent inverts the approach by using non-coupled surfaces with precise anatomy reconstruction. The stability is achieved not through mechanical coupling but through accurate anatomical replication and soft tissue balancing.

Inventive Principle:

Principle #13The other way round (Inversion)

3Manufacturing precision

If endoprostheses are implanted by stretching apparatus, then joint replacement is achieved, but tendon injury and fibroses occur

Engineering Contradiction:

Improvejoint replacement precisionVSAvoidtendon injury and fibroses

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The fixing frame is attached and the finger is positioned in full extension before any bone preparation or prosthesis implantation. This preliminary positioning prevents the need for stretching apparatus during surgery, eliminating tendon injury and fibrosis risks while maintaining precise implant placement.

Inventive Principle:

Principle #10Preliminary action

4Manufacturing precision

If finger is fixed in straight position during operation, then precise joint cylinder milling is achieved, but operation time increases

Engineering Contradiction:

Improvejoint cylinder milling precisionVSAvoidoperation time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The fixing frame with integrated positioning devices is attached at the beginning of surgery, establishing the straight position and all reference points in advance. This preliminary action allows rapid subsequent steps without repeated positioning adjustments, actually reducing total operation time despite the initial setup.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The fixing frame serves multiple functions simultaneously: it stabilizes the finger in straight position, provides reference points for drilling, and maintains alignment during milling. This multi-functionality eliminates the need for separate devices for each function, streamlining the procedure and reducing overall time.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution enables stable, long-lasting finger joint function with minimal bony substance loss, early post-operative mobility, and reduced risk of complications, effectively addressing the limitations of existing joint replacement methods.

Implementation Method 1

a titanium hinge endoprosthesis coated with hydroxyapatite for stable integration

Methodology Applied

Scientific EffectBiocompatible coating integration: Adsorption

Data Source

PatentUS8882778B2Instruments for carrying out an operating procedure on a joint

Publication Date: 2014.11.11 WALDEMAR LINK GMBH & CO KG

AI summary

The invention concerns instruments for carrying out an operating procedure on a finger joint, in which the damaged joint 4 is radially milled out by means of the instruments and is replaced by a hinge prosthesis 50.