Flexible Wire Saw for Glenoid Component Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In revision surgery for shoulder replacement procedures, removing a previously implanted glenoid component from the scapula can be challenging due to damaged or missing subcondylar plates and defects in the cancellous bone, making fixation of a new glenoid component difficult.
Innovation Solution
A method and instrument using a flexible wire saw, such as a Gigli saw, positioned within a protective cannula to cut through anchors of the implanted glenoid component, allowing for its removal while leaving the anchors in the bone, and subsequently drilling them out, facilitating the removal of the component and preparation of the humeral head for prosthetic implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a previously implanted glenoid component is removed through conventional methods, then the component can be extracted, but significant bone loss occurs and fixation of a new component becomes difficult
Solution Approach 1:
The removal process is segmented into distinct phases: first cutting the anchors from the bone using a wire saw, then removing the platform, and finally extracting the cut anchors. This segmentation allows controlled removal that preserves bone stock while ensuring complete component extraction.
Solution Approach 2:
The invention extracts only the necessary parts (the glenoid component and its anchors) while leaving the surrounding bone structure intact. The wire saw cuts the anchors from the bone, allowing the platform to be removed without compromising the bone stock for future fixation.
2Ease of manufacture
If conventional removal methods are used to extract the glenoid component, then the component is removed, but the subcondylar plate becomes damaged or missing
Solution Approach 1:
The wire saw applies cutting action locally at the anchor-bone interface without affecting the broader subcondylar plate structure. This localized approach preserves the integrity of the subcondylar plate while successfully separating the anchors from the bone.
3Ease of operation
If the glenoid component is removed with anchors still attached, then removal is simpler, but large defects are created in the cancellous bone
Solution Approach 1:
The anchors are cut from the bone using a wire saw before the platform is removed. This preliminary action separates the anchors from the bone stock, allowing the platform to be extracted without creating large cancellous bone defects and enabling subsequent anchor removal with minimal bone disruption.
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 efficient removal of the glenoid component without causing significant bone loss, allowing for secure fixation of a new glenoid component and preparation of the humeral head for prosthetic implantation, thereby simplifying the revision surgery process.
Implementation Method 1
The flexible wire saw is then reciprocated so as to cut through one or more anchors extending from the medial surface of the platform of the implanted glenoid component
Data Source
AI summary
A surgical instrument for removing an implanted glenoid component from the glenoid of a patient includes a protective cannula and a flexible wire saw. The flexible wire saw is positioned in the protective cannula such that both ends of the flexible wire saw extend out of one end of the protective cannula, with a portion of the middle section of the wire saw forming a loop that extends out of the other end of the protective cannula. Surgical methods for the use of such a surgical instrument are also disclosed.