Porous Orthopaedic Screw for Tissue Integration and Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing orthopaedic screws, both solid metal and resorbable polymer, face challenges such as difficulty in visualizing tissue near the screw using imaging devices due to 'white-out' effects, poor initial fixation, and high rates of soft tissue pull-out, which can lead to painful complications and additional surgeries.
Innovation Solution
Development of porous orthopaedic screws that can deliver therapeutic agents, featuring varying porosity and materials like PEEK, titanium, and radiolucent markers for improved tissue integration and visualization, along with mechanisms for local and long-term drug delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If solid metal screws are used, then initial fixation strength is improved, but tissue visualization via imaging devices deteriorates due to white-out effect
Solution Approach 1:
The patent employs porous PEEK material for screw construction, which reduces radiopacity interference while maintaining mechanical strength through controlled pore structures. The porous architecture allows imaging penetration while the solid matrix provides structural integrity for initial fixation.
Solution Approach 2:
The patent uses composite construction combining PEEK polymer matrix with porous structures and potentially radiopaque markers or metal-reinforced regions. This composite approach balances radiolucency for imaging with sufficient mechanical properties for fixation strength.
2Duration of action of stationary object
If resorbable polymer screws are used, then long-term tissue integration is improved, but initial fixation strength and pull-out resistance deteriorate
Solution Approach 1:
The porous structure of PEEK provides increased surface area for tissue ingrowth and bonding, enhancing long-term integration while the solid matrix maintains initial mechanical strength. The pore architecture facilitates cellular attachment and tissue penetration without compromising overall structural integrity.
Solution Approach 2:
The patent utilizes PEEK's ability to undergo controlled resorption or degradation parameter changes over time. The material transitions from providing initial mechanical support to allowing progressive tissue integration, with degradation rate controlled through composition and structure to match tissue healing timelines.
3Object-affected harmful factors
If resorbable polymer screws are used, then biocompatibility is improved, but pull-out resistance deteriorates due to fibrous tissue formation
Solution Approach 1:
The porous PEEK structure promotes organized tissue ingrowth into the pores rather than fibrous encapsulation around the implant. This controlled tissue integration within the porous matrix creates mechanical interlocking that resists pull-out forces while maintaining biocompatibility.
Solution Approach 2:
The patent converts the potential harmful effect of polymer resorption (which can cause fibrous tissue formation and reduce pull-out resistance) into a beneficial process. By controlling resorption rate and creating porous structures, the material degradation stimulates healthy tissue regeneration and integration rather than pathological fibrous encapsulation.
Data Source
AI summary
An orthopaedic screw having a plurality of regions, at least one of which may be porous. The orthopaedic screw includes a head, a tip and at least one thread. The porosity of the screw of the present invention can vary within the part or region, including changes in pore shape, size and density. These characteristics can vary along the length of the screw axis and/or radially (from the outer diameter to the axis). The orthopaedic screw may further include at least one solid region formed of any implantable polymer, reinforced polymer or metal.