Orthopedic Cable Bone Transport Device
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Solution Overview
Problem
Existing bone transport systems face challenges such as instability of the transport bone segment, increased complications due to multiple penetrations of soft tissues, and complexity in the process of transporting the intercalary bone segment, particularly with the Weber cable bone transport method.
Innovation Solution
A cable pulling device utilizing a mechanical transmission system with a reel and worm gear mechanism to incrementally pull a cable attached to the transport bone segment, ensuring stable fixation and controlled movement by minimizing external components and reducing tissue penetration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If transverse wires and/or pins are used to secure the transport segment to an intercalary external support, then sufficient stability of the transport bone segment fixation is achieved, but multiple long longitudinal cuts through the surrounding soft tissues are produced potentially resulting in pain, infection, and other complications
Solution Approach 1:
The invention extracts the cable from the traditional Weber method's external path and reroutes it through the bone segment's medullary canal. This removes the harmful external soft tissue penetrations while preserving the stabilizing function of cable fixation. The cable is inserted through a small incision and guided internally, eliminating multiple long longitudinal cuts through surrounding soft tissues.
Solution Approach 2:
The medullary canal acts as an intermediary pathway, allowing the cable to pass through the bone segment internally rather than externally. This intermediary route protects the cable from external damage, eliminates soft tissue complications, and provides stable fixation without the harmful effects of external wire/pin penetration.
2Ease of operation
If obliquely oriented wires are used to stabilize the transport bone segment, then bone transport can be performed, but difficulties in insertion and removal of wires, limited transport distance, pressure on surrounding soft tissues, and potential longitudinal misalignment occur
Solution Approach 1:
Instead of inserting wires obliquely through the bone segment as in traditional methods, the invention inverts the approach by inserting the cable axially through the medullary canal. This reversal of the insertion path eliminates the difficulties of oblique wire insertion and removal, allows for greater transport distances, and ensures proper longitudinal alignment of the transport bone segment.
3Productivity
If cable ends are placed into grooves of external supports and attached to threaded or telescopic rods for gradual pull, then bone transport can be performed, but the process is very complicated and rollers and pulling rods occupy space on external supports limiting places for other fixation elements
Solution Approach 1:
The invention extracts the cable pulling mechanism from the complex external support structure with rollers and threaded rods. Instead, the cable is directly attached to the transport bone segment and pulled through the medullary canal, eliminating the need for external redirection rollers and complex pulling mechanisms. This simplifies the overall system while maintaining the gradual pulling capability.
Solution Approach 2:
The invention changes the dimension of cable routing from external three-dimensional path with rollers to an internal linear path through the medullary canal. This dimensional change eliminates the need for external redirection components and simplifies the pulling mechanism while maintaining effective cable tension and bone segment transport capability.
4Productivity
If rollers and pulling rods are used for gradual cable pulling, then bone transport can be performed, but rollers and pulling rods occupy space on external supports limiting places for other connecting and wire/pin fixation elements
Solution Approach 1:
The invention extracts the cable pulling function from the external support structure, eliminating rollers and pulling rods that occupy valuable space on external supports. The cable is instead pulled directly through the medullary canal with attachment points on the bone segment itself, freeing up external support space for additional fixation elements and connecting components.
Data Source
AI summary
An orthopedic bone transport system includes an external fixation frame and a cable pulling device. The external fixation frame is attachable to a fixed bone segment with the external fixation frame oriented in a first plane. The cable pulling device includes a main body configured to be secured to the external fixation frame, a reel, and a transmission. The reel is rotatable about said main body and configured to wind up a cable to be secured to a transport bone segment to move said transport bone segment towards said fixed bone segment. The main body is secured to the external fixation frame with an axis of rotation of the reel oriented substantially parallel to the first plane, the axis of rotation of the reel thereby substantially lying on a transverse plane with respect to the fixed bone segment. The transmission drives the reel in order to wind up the cable.