Expanding Hip Joint Fixation Without Bone Cement
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Solution Overview
Problem
Current hip joint prosthetics face complications such as loosening and dislocation due to abnormal strain, often caused by the use of materials harder than bone and the bodily reaction to bone cement or orthopedic screws, which can lead to instability and reduced mobility.
Innovation Solution
A medical device with an expanding portion that inserts into the femoral bone to provide fixation without penetrating or using bone cement, featuring a plurality of expansion members that distribute force evenly and can adapt to the bone's anatomy, along with a stabilizing member to enhance stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional fixation methods using bone cement or orthopedic screws are used, then the prosthetic can be securely fixed to the bone, but the patient experiences loosening and dislocation due to abnormal strain and bodily macrophage reaction
Solution Approach 1:
The invention extracts and eliminates the harmful components of traditional fixation systems - specifically bone cement and orthopedic screws - replacing them with an expanding portion that integrates directly with the bone structure. This removal of problematic materials eliminates the source of macrophage reactions and fixation failure while maintaining secure attachment through radial expansion forces.
Solution Approach 2:
The expanding portion transitions from a static implant to a dynamic fixation system that can adapt to physiological loads. The device allows for controlled movement and deformation in response to abnormal strains, enabling the fixation to absorb impact forces rather than rigidly resisting them, thereby preventing loosening while maintaining strength.
2Strength
If materials harder than bone are used for the prosthesis, then the prosthetic can withstand mechanical loads, but the prosthesis causes loosening due to stress concentration and bodily reaction
Solution Approach 1:
The invention changes the physical parameters of the fixation interface by using an expanding portion that distributes mechanical stresses over a larger surface area of the bone. This parameter change - from concentrated point contact to distributed surface contact - reduces stress concentration and eliminates the harmful effects of rigid material interfaces while maintaining load-bearing capacity.
3Ease of manufacture
If bone cement is used for fixation, then the prosthesis can be easily installed, but the bone cement causes loosening due to bodily macrophage reaction
Solution Approach 1:
The invention completely removes bone cement from the fixation process, replacing it with a mechanical expansion system. This extraction eliminates the biological incompatibility of cement materials while preserving the simplicity of installation through a single-step expansion mechanism that requires no additional bonding materials or complex assembly procedures.
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 solution achieves stable fixation of the prosthetic hip joint without the need for bone cement or screws, allowing for slight movement in response to force, thereby reducing the risk of loosening and improving long-term joint function and patient mobility.
Implementation Method 1
The expanding portion comprises a plurality of expansion members adapted to expand radially away from the longitudinal axis
Implementation Method 2
the bone contacting surface is placed in contact with the inside of the femoral bone for fixating the medical device to the femoral bone
Data Source
AI summary
A medical device for fixation in a femoral bone of a patient is provided, the medical device comprises: a connecting portion adapted to be connected to a prosthetic hip joint contacting portion, an expanding portion, and a bone contacting surface on the expanding portion. The expanding portion could be adapted to be at least partially inserted into the femoral bone of a patient and to expand within the femoral bone, such that the bone contacting surface is placed in contact with the inside of the femoral bone for fixating the medical device to the femoral bone. By the fixation using an expanding portion a sturdy fixation is achieved without the need to go into or penetrate bone, or the need for fixation using bone cement.