Bone Screw with Internal Conduit for Local Antibiotic Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current treatments for infected bone fractures, particularly those involving screw and plate osteosyntheses, face challenges in effectively delivering pharmaceutical fluids directly to the infected site while maintaining mechanical stabilization of the fracture. Existing solutions, such as antibiotic-releasing carriers, may not be sufficient for Gentamicin-resistant microorganisms, and methods like external fixators require additional bone holes, complicating treatment.
Innovation Solution
A device comprising bone screws with a fluid-permeable conduit and axial grooves that allow for the local application and flushing of pharmaceutical fluids directly to the infected bone site. The device includes a cap with a connecting element for detachable connection to the bone screw, enabling the delivery of pharmaceutical fluids through a hose connected to the cap, with the fluid outlet positioned distally from the screw head to prevent pressure buildup in the bone marrow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional bone screws are used for mechanical stabilization, then fracture stabilization is achieved, but pharmaceutical fluids cannot be delivered directly to the infected site
Solution Approach 1:
The bone screw is divided into functional segments: the screw body provides mechanical stabilization, while separate conduits and grooves provide pharmaceutical fluid delivery pathways. The conduit in the screw body and the axial groove in the outer thread are distinct fluid delivery channels that can be independently configured.
Solution Approach 2:
The bone screw is designed to perform multiple functions simultaneously: mechanical stabilization of the fracture through the screw thread, and delivery of pharmaceutical fluids through the integrated conduit and axial groove system. This multi-functionality eliminates the need for separate delivery devices.
2Ease of operation
If external fixators are used to stabilize infected bones, then mechanical stabilization is achieved, but additional bone holes are required which complicates treatment
Solution Approach 1:
The pharmaceutical fluid delivery function is merged with the existing bone screw structure used for mechanical stabilization. The conduit and axial groove are integrated into the screw body, allowing fluid delivery through the same access points already created during screw insertion, eliminating the need for additional bone holes.
3Productivity
If bone cement paste is injected through the conduit, then vertebral body filling is achieved, but pressure buildup in the bone marrow occurs
Solution Approach 1:
The fluid outlet opening is extracted from the screw head and repositioned to the distal end of the screw body. This spatial separation allows pharmaceutical fluids to be delivered deep into the bone tissue away from the screw head region, preventing pressure buildup in the bone marrow while maintaining effective fluid delivery to the infected site.
4Reliability
If Gentamicin-releasing carriers are used, then local antibiotic application is achieved, but they are insufficient for Gentamicin-resistant microorganisms and have short duration of action
Solution Approach 1:
The system enables dynamic control of pharmaceutical fluid delivery through the axial groove and conduit, allowing repeated applications over extended periods. The fluid can be delivered continuously or intermittently based on clinical needs, providing long-term antibiotic therapy beyond the limitations of static antibiotic-releasing carriers.
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
Enables the local and temporary delivery of pharmaceutical fluids to infected bone tissue, allowing for repeated application over long periods without removing the device. This approach effectively stabilizes the fractured bone, reduces the need for additional bone holes, and prevents pressure buildup in the bone marrow, thereby minimizing complications such as embolisms.
Implementation Method 1
at least one conduit (38) is disposed in the screw body (2), wherein the at least one conduit (38) is fluid-permeable
Implementation Method 2
at least one axial groove (34) penetrating the outer thread (2) of the bone screw (1) which extends from the at least one fluid outlet opening (32) in the screw body (2) through to the screw head (3)
Data Source
AI summary
A device having a bone screw with a body, an outer thread and a proximal screw head. A fluid-permeable conduit is disposed in the body, begins at the head and opens out into a fluid outlet opening that is spaced apart from the head in the distal direction. An axial groove extends from the fluid outlet opening to the screw head. The base of the groove is deeper than the base of the outer thread. A cap detachably connects with the screw head, in which a fluid-permeable conduit is disposed, which opens out into the conduit of the bone screw. A hose for feeding fluid is connected or connectable in a fluid-permeable manner with the inlet opening on the cap so that a pharmaceutical fluid is pressable out of the fluid outlet opening through the hose, through the conduit of the cap and through the conduit of the bone screw.