Polyaxial Bone Anchor Bottom-Loading Modular Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polyaxial bone anchoring devices lack versatility and ease of handling, limiting their application in various clinical situations due to fixed configurations and difficulty in aligning multiple devices for rod insertion.
Innovation Solution
A modular polyaxial bone anchoring device with a bottom-loading design, featuring a receiving part with an upper and lower member and clamping mechanism that allows adjustable angular positioning of the anchoring element, enabling easy assembly and alignment of multiple devices for rod insertion, and made from bio-compatible materials like titanium or PEEK.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed configuration bone anchoring device is used, then the device structure is simple, but the adaptability to different clinical situations is limited
Solution Approach 1:
The receiving part is designed with a universal interface that can accommodate multiple types of anchoring elements (screws, nails, hooks, or other bone anchors) with different shank lengths, diameters, and anchoring types. This multi-functional design allows a single receiving part to serve various clinical needs without requiring multiple specialized devices.
Solution Approach 2:
The bone anchoring device is divided into separate modular components: the receiving part and various anchoring elements. This segmentation allows the receiving part to remain standardized while different anchoring elements can be selected based on specific clinical requirements, enhancing adaptability without increasing overall device complexity.
2Adaptability or versatility
If multiple fixed-configuration anchoring devices are used for different applications, then each device is optimized for its specific use, but the total number of implant parts increases
Solution Approach 1:
A single receiving part design serves multiple applications by accommodating different anchoring elements through a standardized interface. This universality reduces the total number of implant parts needed, as surgeons can select from various anchoring elements rather than requiring separate receiving parts for each application type.
Solution Approach 2:
The receiving part incorporates a dynamic clamping mechanism that can adjust to different anchoring element configurations. The clamping members can be positioned and tensioned to securely hold various types of anchors, allowing one receiving part design to adapt to multiple applications without requiring multiple specialized components.
3Ease of operation
If the anchoring element is fixed in position within the receiving part, then the assembly is simple, but the ability to align multiple devices for rod insertion is difficult
Solution Approach 1:
The anchoring element is held in the receiving part in an adjustable angular position rather than a fixed position. The clamping members can be tensioned to secure the anchoring element at the desired angle, allowing surgeons to align multiple devices appropriately for rod insertion while maintaining a relatively simple assembly structure.
Solution Approach 2:
The receiving part allows adjustment of the anchoring element's angular position as a variable parameter. By changing the angular parameter of the anchoring element within the receiving part, surgeons can optimize the alignment of multiple devices for subsequent rod insertion, balancing ease of operation with assembly complexity.
4Adaptability or versatility
If a top-loading design is used, then the anchoring element is inserted from above, but the modular system flexibility is reduced
Solution Approach 1:
Instead of the conventional top-loading design where the anchoring element is inserted from above, this invention uses a bottom-loading design where the anchoring element is inserted from the bottom of the receiving part. This inversion allows for greater modular system flexibility and easier assembly while maintaining ease of operation through the standardized interface and simple insertion procedure.
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 modular design provides a broad range of clinical applications by allowing different anchoring elements and configurations, reducing the number of implant parts needed and facilitating easier alignment and insertion of rods during surgery, enhancing surgical efficiency.
Implementation Method 1
The at least one clamping member and the stop provide for a friction fit of the head within the receiving part so that the head can be held in the receiving part in an adjustable angular position. The friction force can be overcome manually by pivoting the receiving part relative to the anchoring element
Data Source
AI summary
A receiving part of a polyaxial bone anchoring device includes a first member with a top end and a bottom end, a central axis, a head receiving portion having an inner wall defining a passage at the bottom end for introducing a head of a bone anchoring element, and a channel at the top end for receiving a rod, a second member having a bore and being connectable to the first member at the bottom end of the first member; and at least one clamping member configured to be positioned at or near the bottom end of the first member and to protrude into the passage. The second member is movable relative to the first member from a first position wherein the clamping member is movable radially, to a second position wherein the clamping member is prevented from moving, to hold a head of a bone anchoring element therein.