Double Loop Stitching With Segmented Needle Assembly
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Solution Overview
Problem
Conventional methods for graft preparation in ligament replacement surgeries, such as the whip stitch and Krackow stitch, result in non-uniform stitch positioning and spacing due to the lack of fixation of the proximal graft portion, leading to potential graft movement and increased surgical time, which can weaken the graft and require revision surgeries.
Innovation Solution
A two-part sewing needle assembly with a first needle portion and a removably connected second needle portion allows for simultaneous passage through the graft material, creating a double loop stitch that maintains both ends of the graft fixed, ensuring consistent and stronger stitching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional whip stitch or Krackow stitch methods are used with single needle, then the stitching process can be completed, but non-uniform stitch positioning and spacing occur due to lack of fixation of proximal graft portion
Solution Approach 1:
The single needle is divided into two separate needles (first needle and second needle), each independently passing through the graft from opposite sides. This segmentation allows both proximal and distal graft portions to be simultaneously fixed, eliminating the movement issues that cause non-uniform stitch positioning and spacing.
Solution Approach 2:
The stitching operations of two separate needles are coordinated to work simultaneously on the same graft. By merging the fixation functions of both needles, the system achieves uniform stitch positioning and spacing while maintaining ease of operation through coordinated bilateral stitching.
2Reliability
If proximal graft portion is not fixed during stitching, then the stitching process can proceed, but graft movement occurs leading to non-uniform stitches and potential graft failure
Solution Approach 1:
The stitching system is segmented into two independent needle paths that work in parallel. This allows both ends of the graft to be fixed simultaneously, preventing graft movement and ensuring uniform stitch formation, thereby improving reliability without significantly increasing operational complexity.
Solution Approach 2:
Both needles are prepared and positioned before the stitching process begins, with each needle already configured to pass through specific portions of the graft. This preliminary preparation ensures that when stitching commences, both proximal and distal graft portions are immediately secured, preventing movement and ensuring consistent stitch quality.
3Productivity
If conventional single-needle stitching is used, then the procedure can be completed, but surgical time increases due to repeated manual repositioning of the graft
Solution Approach 1:
By dividing the stitching function into two simultaneous needle operations, the system eliminates the time-consuming sequential process of manually repositioning the graft between stitches. Both needles work in parallel to create uniform stitches, dramatically improving surgical efficiency and reducing operative time.
Solution Approach 2:
The dual-needle system maintains continuous stitching action without interruption. While one needle creates a stitch, the other needle simultaneously creates another stitch, eliminating idle time and manual repositioning operations. This continuous productive action maximizes surgical efficiency and minimizes time loss.
4Manufacturing precision
If multiple manual repositioning operations are performed, then stitch completion is achieved, but the graft is weakened and revision surgery may be required
Solution Approach 1:
The dual-needle segmentation allows both graft ends to be fixed simultaneously, preventing the repeated manual handling that weakens the graft. Each needle independently creates uniform stitches without requiring the graft to be repositioned, thereby maintaining graft integrity and strength while achieving consistent stitch quality.
Data Source
AI summary
In a method for providing a double loop stitch, a needle assembly having a first needle portion and a second needle portion that is removably connected to the first needle portion is provided. Opposing ends of a thread are connected to the needle portions, forming a loop that is placed around a sewing material. The needle assembly is inserted through the sewing material at an insertion point. The thread is then partially pulled through the sewing material at the insertion point such that a pair of loops of thread, separated by the insertion point, remain adjacent a first face of the sewing material. The needle portions are then separated and are passed around opposite sides of the sewing material from adjacent a second face back adjacent the first face. Each needle portion is then passed through one of the loops. The loops are then cinched and locked in place.