Porous Antibiotic Bone Cement Spacer for Hip Revision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current two-stage joint replacement revision procedures for addressing infections in hip replacements require multiple surgical stages and involve the use of temporary implants that either require removal of the mold or have limited antibiotic diffusion, complicating the process and recovery.
Innovation Solution
A temporary femoral implant system featuring a flexible mold pre-assembled with a femoral component, filled with uncured antibiotic bone cement, allowing antibiotic diffusion while preventing cement contact with bone, facilitating infection reduction and simplifying implant removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a temporary implant with antibiotic bone cement is used in a two-stage joint replacement revision procedure, then infection management is improved, but the procedure complexity and recovery time are increased due to multiple surgical stages and mold removal requirements
Solution Approach 1:
The mold is pre-assembled with the femoral component before cementation, allowing the cement to cure within the pre-positioned mold structure. This preliminary assembly eliminates the need for separate mold insertion and removal steps, simplifying the overall procedure while maintaining effective antibiotic delivery to the bone interface
Solution Approach 2:
The mold is nested within the femoral component, creating a hierarchical structure where the mold serves as an internal form for the bone cement. This nested configuration allows the mold to remain in place during cementation and curing, eliminating the need for separate mold handling operations and reducing procedural complexity
2Manufacturing precision
If a rigid mold is used to contain bone cement, then manufacturing precision is improved, but adaptability to bone cavity variations and ease of operation are reduced
Solution Approach 1:
The mold is constructed from flexible material that can be compressed and manipulated during insertion into the bone cavity. This flexibility allows the mold to adapt to variations in bone cavity geometry while maintaining its structural integrity, enabling precise cement containment without requiring rigid, custom-fitted molds for each patient
Solution Approach 2:
The mold transitions from a flexible, compressible state during insertion to a stable, form-retaining state during cementation and curing. This dynamic behavior allows the mold to be easily inserted and positioned, then maintain precise geometric definition when containing the bone cement, resolving the contradiction between flexibility and precision
3Ease of operation
If the mold prevents bone cement from contacting bone, then ease of operation is improved, but antibiotic diffusion to the exterior surface is reduced
Solution Approach 1:
The mold is made from a porous material that physically contains the bone cement while allowing molecular diffusion of antibiotic substances through its structure. This porous architecture enables the mold to serve dual functions: maintaining cement containment for ease of surgery while permitting antibiotic delivery to the bone interface for effective infection management
Solution Approach 2:
The porous mold acts as an intermediary structure between the bone cement and the bone cavity. It mediates the interaction by containing the cement to simplify surgical handling while simultaneously allowing antibiotic diffusion through its porous walls, thus resolving the contradiction between operational ease and antibiotic delivery
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 system reduces the complexity of the two-stage revision procedure by enabling antibiotic diffusion and simplifying implant removal, thereby shortening recovery time and improving infection management.
Implementation Method 1
the mold is adapted to allow the antibiotic to diffuse to the exterior surface
Implementation Method 2
prevent bone cement from contacting bone
Implementation Method 3
filled with a cement composition comprising uncured bone cement and an antibiotic
Data Source
AI summary
A temporary femoral implant system has a porous mold and a femoral component. The system fits at least partially in a femoral cavity. The mold has a wall with an interior surface and an exterior surface forming an interior space for receiving an antibiotic bone cement. The mold allows the antibiotic to diffuse through the wall to the exterior surface. The femoral component has a stem portion received within the mold. A method of using the implant system includes providing an implant system comprising a mold and a femoral component, inserting the mold into the femoral cavity with the exterior surface facing the femoral cavity, inserting the stem portion of a femoral component into the interior space of the mold and filling the interior space of the mold with an antibiotic bone cement.