Orthopaedic Implant Snap-Fit Attachment for Anchor Preservation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing orthopaedic implant systems require the removal or disturbance of bone anchors for prosthesis replacement, which can be invasive and complicated.
Innovation Solution
A prosthesis assembly with a snap-fit engagement mechanism between the prosthesis body and bone anchor, featuring an attachment portion with a receiving portion and a retaining portion of different cross-sectional widths, allowing for secure fixation and easy replacement without disturbing the bone anchor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the prosthesis is secured to the bone using a bone anchor with a cable and plug system, then the prosthesis is firmly fixed in place, but the bone anchor must be removed or disturbed for prosthesis replacement
Solution Approach 1:
The system is divided into three separable components: the bone anchor (remained in bone), the attachment portion (on prosthesis), and the fastening member (connects them). This segmentation allows the prosthesis and attachment portion to be removed and replaced while the bone anchor remains undisturbed in the bone.
Solution Approach 2:
The fastening member acts as an intermediary component that connects the bone anchor to the prosthesis. It can be independently removed and replaced, enabling prosthesis replacement without disturbing the bone anchor while maintaining secure fixation during use.
2Device complexity
If the attachment portion uses a simple opening for the fastening member, then the structure is simple, but the fastening member may become loose or disengage
Solution Approach 1:
The opening in the attachment portion has an asymmetric geometry with a wider receiving portion and a narrower retaining portion. This asymmetric design allows the fastening member to be easily inserted through the wider portion while the narrower portion prevents it from becoming loose or disengaging, providing secure retention without complex fastening mechanisms.
3Ease of manufacture
If the opening has a uniform cross-sectional width, then the manufacturing is simpler, but the fastening member cannot be securely retained
Solution Approach 1:
The opening has different cross-sectional widths at different locations: a wider receiving portion for easy insertion and a narrower retaining portion for secure retention. This local variation in geometry provides both secure fastening and manufacturing simplicity, as it can be formed as a single piece without complex assembly.
Data Source
AI summary
A prosthesis assembly (100) for orthopaedic implantation comprises a prosthesis body (110) and an attachment portion (112) coupled to the prosthesis body (110) for attaching the prosthesis assembly (100) to a bone by way of a bone anchor (120) or other fixating means. The attachment portion (112) comprises an opening (130) having a receiving portion (132) with a first cross-sectional transverse width and a retaining portion (134) extending from the receiving portion (132), the retaining portion (134) having a second cross-sectional transverse width, which is less than the first cross-sectional transverse width. A system comprising the prosthesis assembly (100) includes a bone anchor (120) having a fastening member (124) for engaging the opening (130) and a stem (122) for securing to the bone.