Modular Hip Spacer Mold for Defect-Free Bone Cement Forming
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Solution Overview
Problem
Current methods for producing joint spacers for infected joint endoprostheses, such as hip and shoulder joints, are inefficient and prone to microbial colonization, leading to infection and tissue damage, and require complex surgical procedures.
Innovation Solution
A multi-part mold system comprising a head element, stem element, and neck element, with modular designs and positive-locking connections, allowing for the production of one-piece spacers using polymethyl methacrylate bone cement, which can be filled separately to prevent air bubbles and facilitate easy removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional single-piece molds are used for spacer production, then manufacturing simplicity is maintained, but manufacturing precision and defect-free production are compromised due to air bubble formation and difficulty in removal
Solution Approach 1:
The mold is divided into multiple separable parts (first mold part and second mold part) that can be assembled and disassembled. This segmentation allows bone cement paste to be filled in sections, preventing air bubble entrapment, and enables easy removal of the hardened spacer without damage, thereby achieving defect-free production while maintaining manufacturing simplicity.
2Reliability
If complex surgical procedures are used for infected joint endoprostheses, then complete debridement and infection control are achieved, but surgical time and patient trauma increase
Solution Approach 1:
The spacer is pre-formed in a controlled manufacturing environment using aseptic techniques and sterilized components, ensuring complete infection control before implantation. This preliminary action eliminates the need for extensive intraoperative debridement and infection management, significantly reducing surgical time while maintaining high reliability in infection control.
3Ease of manufacture
If spacers are produced with fixed dimensions, then manufacturing simplicity is maintained, but adaptability to different patient anatomies and implantation sites is reduced
Solution Approach 1:
The mold system uses interchangeable and adjustable mold parts that can be configured in different combinations. This allows the production of spacers with variable dimensions, including different neck lengths and other custom specifications, while maintaining the simplicity of the manufacturing process through standardized modular components.
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 mold system enables efficient, aseptic production of spacers that reduce microbial colonization risks and simplify surgical procedures by allowing for defect-free, customizable spacers with variable neck lengths without the need for additional cutting or adjustments.
Implementation Method 1
Device for producing a spacer by hardening bone cement paste
Data Source
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AI summary
The invention relates to a mold for producing a hip joint spacer (100), which has a head element (110) comprising an upper shell (120) and a lower shell (130), optionally a neck element (140), and a stem element (150) comprising an upper shell (160) and a lower shell (170), wherein the mold has a locking element (101), and an upper shell and a lower shell of the head element and/or the stem element can be connected to each other by means of the locking element.