Temporary Modular Antimicrobial Cement Spacers for Stable Implantation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current treatments for localized infections in the intramedullary canal of long bones, such as the tibia, lack standardized, regulatorily approved products for temporary antimicrobial-eluting spacers, leading to issues like complexity, instability, and non-uniformity in handmade implants.
Innovation Solution
Modular antimicrobial-eluting cement spacer implants with customizable length, antimicrobial agent selection, and securement options, allowing perioperative design and stable implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If handmade tibial spacer nails are made intraoperatively using PMMA cement mixed with antimicrobials, then antimicrobial treatment is provided, but the implant lacks stability and uniformity
Solution Approach 1:
The implant is divided into modular components: a pre-formed rod with anchoring features and a separate PMMA cement coating applied intraoperatively. This segmentation allows the structural rod to provide stability while the cement provides antimicrobial treatment, resolving the contradiction between stability and ease of manufacture.
Solution Approach 2:
The rod component is pre-formed with locking features and anchoring holes before surgery. This preliminary preparation reduces intraoperative complexity while ensuring the structural stability is already designed in, allowing only the cement application step to be performed during surgery.
2Strength
If PMMA cement is hand-rolled with an inserted metallic core for rigidity, then rigidity is achieved, but cement fracture occurs and uniformity is lost
Solution Approach 1:
The implant separates the structural function (rod with locking features) from the antimicrobial function (PMMA coating). The rod provides consistent rigidity without the variability and fracture risks associated with hand-rolled cement, while the cement coating uniformly applies antimicrobial agents.
Solution Approach 2:
The rod acts as an intermediary structure that provides mechanical stability and serves as a substrate for cement application. This intermediary approach ensures uniform cement distribution and prevents the cement from needing to bear structural loads alone, reducing fracture risk.
3Adaptability or versatility
If off-label products are used to fashion temporary spacers, then antimicrobial treatment is provided, but limited control of localized release rate is achieved
Solution Approach 1:
The PMMA cement coating is applied locally around the rod with controlled thickness and composition. This local quality control allows adjustment of antimicrobial release rates by modifying cement formulation, thickness, or adding porosity features, while maintaining standardized rod dimensions for consistent mechanical properties.
Solution Approach 2:
The design allows modification of cement parameters (composition, thickness, porosity, antimicrobial concentration) to control release rates. These parameter changes can be made systematically to achieve desired antimicrobial delivery profiles while maintaining standardized rod geometry for reliability.
4Productivity
If chest tube or hand-rolled methods are used to shape cement, then implant is formed, but time and complexity increase intraoperatively
Solution Approach 1:
The rod is pre-formed with all structural features (locking holes, anchoring features, dimensions) before surgery. This preliminary preparation eliminates time-consuming intraoperative shaping operations, allowing rapid cement application and significantly reducing surgical time while maintaining structural integrity.
Solution Approach 2:
The complex structural formation operations are extracted from the intraoperative process and performed beforehand. Only the simple cement coating step remains for intraoperative application, dramatically improving productivity while the pre-designed rod ensures structural reliability.
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
Provides stable, customizable, and efficient treatment of surgical site infections by allowing surgeons to design and secure temporary spacers intraoperatively, ensuring uniformity and effective antimicrobial release.
Implementation Method 1
injecting bone cement material including one or more antimicrobial agents into the mold body lumen through the fluid pathway so as to form a cement coating around the outer surface of the rod; curing the bone cement material on the outer rod surface so as to form a cement coating
Data Source
Figure 1A~1B
Figure 1C~1D
Figure 2A~2C
AI summary
The present disclosure is directed to temporary antimicrobial-eluting cement spacer implants (1), and assemblies, kits, and methods for forming the same. Particularly preferred disclosures are to modular spacers, assemblies, and kits, as well as methods of manufacturing the same, where the modular nature of the spacer permits the selection of specific desired length spacers, as well as specific selection of antimicrobial compounds and dosages, along with the components and processes for forming the same.