Expandable Suture Knot Anchors for Low-Trauma Tissue Repair
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Solution Overview
Problem
Existing suture anchors often cause significant surgical trauma, require larger incisions, and have mechanical weaknesses, particularly in minimally invasive procedures, and nonmetallic anchors may fail due to cheese-wiring or sharp edges.
Innovation Solution
A method and device for anchoring sutures using a preformed knot configuration that expands in cross-sectional dimension to form an anchoring knot, which can be deployed behind or within tissue, minimizing surgical trauma and enhancing retention strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If physically larger anchors are used to maximize retention strength, then anchor retention strength is improved, but surgical trauma increases due to larger incisions and deeper penetration required
Solution Approach 1:
The anchor device transitions from a compressed delivery configuration to an expanded deployed configuration. The body expands radially outward upon deployment to engage tissue walls, transforming from a small profile suitable for minimally invasive delivery to a large profile that maximizes retention strength through increased surface area and mechanical interlocking with surrounding tissue.
Solution Approach 2:
The anchor body is designed to be nested within itself or within the delivery device in a compressed state during delivery, then expands outward to its full functional size after implantation. This allows the large anchor structure to be delivered through small incisions by temporarily reducing its dimensions, then restoring its full retention-capable size in situ.
2Object-affected harmful factors
If nonmetallic materials are used to reduce surgical trauma, then ease of operation is improved, but mechanical strength decreases leading to cheese-wiring or anchor failure
Solution Approach 1:
The anchor device incorporates composite construction combining biocompatible polymeric materials with high-strength metallic reinforcement elements. The polymer matrix provides biocompatibility and flexibility while the embedded metal components (such as axial reinforcement rods or helical wire structures) provide the necessary mechanical strength and structural integrity to prevent cheese-wiring and anchor failure.
Solution Approach 2:
Different regions of the anchor device have different material properties optimized for their specific functions. The body portion contacting tissue is made from biocompatible polymer to minimize trauma, while critical load-bearing regions incorporate high-strength metal reinforcement. This localized material differentiation allows the device to simultaneously achieve both biocompatibility and mechanical strength.
3Strength
If sharp edges are included on anchor components for mechanical retention, then anchor retention strength is improved, but harmful factors increase due to tissue damage during implantation
Solution Approach 1:
The anchor device features predominantly curved and rounded surfaces without sharp edges or corners. The body is designed with smooth transitions and radiused edges that distribute mechanical stresses uniformly during both delivery and deployment, preventing localized tissue damage while maintaining effective engagement with surrounding tissue through gentle compression and radial expansion forces.
Solution Approach 2:
The design converts the potential harm of sharp edges into benefit by using controlled radial expansion forces. Instead of relying on sharp cutting edges that damage tissue, the anchor uses its expansion mechanism to gently compress and engage the surrounding tissue walls, achieving mechanical retention through uniform radial pressure that distributes forces beneficially across the tissue interface without concentrated stress points.
4Strength
If deeper penetration is used to maximize anchor retention, then anchor retention strength is improved, but surgical trauma increases due to deeper incisions and tool requirements
Solution Approach 1:
The anchor device dynamically changes its dimensional profile during deployment, expanding from a compact delivery configuration to an expanded functional configuration. This allows the anchor to achieve deep effective engagement and high retention strength without requiring proportionally deep delivery channels or complex implantation tools, as the expansion occurs in situ after minimal penetration.
Solution Approach 2:
The anchor achieves enhanced retention strength by expanding in radial dimensions rather than requiring increased axial penetration depth. By transitioning from a small compressed profile to a large expanded profile perpendicular to the delivery axis, the device maximizes its engagement surface area and mechanical interlocking with surrounding tissue without proportionally increasing the depth of the delivery incision or channel required.
Data Source
AI summary
Methods and devices are provided for anchoring suture to tissue, incorporating anchoring devices constructed substantially from suture. The anchoring devices are constructed as longitudinally extended, preformed knot configurations that upon deployment are reconfigured to form anchoring knots having an increased cross-section relative to the preformed knot configuration, for secure lodging in tissue. The anchoring devices are suitable for single and multi-anchor surgical procedures in soft tissue or bone, and multiple anchors can be delivered using a single delivery device.