Anatomical ACL Reconstruction Using C-Shaped Bone Tunnels

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Solution Overview

Problem

Conventional ACL reconstruction methods fail to anatomically reconstruct the natural insertion sites of the anterior cruciate ligament (ACL) on the tibia and femur, leading to suboptimal biomechanical stability and increased risk of re-rupture due to mismatched graft dimensions and distorted tissue distribution post-injury.

Innovation Solution

A system and method for creating C-shaped and slit-shaped bone tunnels that mimic the native ACL insertion sites, using devices for sequential drilling and burring to recreate the natural footprints, and preparing grafts to maintain a ribbon-like appearance, ensuring accurate anchoring and biomechanical stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional ACL reconstruction methods are used, then the surgery can be performed with standard techniques, but the natural insertion sites of the ACL cannot be anatomically reconstructed

Engineering Contradiction:

Improveanatomical accuracy of insertion sitesVSAvoidcomplexity of drilling and burring devices

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The insertion site reconstruction is divided into multiple sequential drilling and burring steps, where each drill creates a portion of the final C-shaped or slit-shaped tunnel. This segmentation allows precise anatomical reconstruction through controlled sequential operations rather than attempting to create the complex shape in a single step.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The invention transitions from conventional single-plane drilling to multi-dimensional bone tunnel creation. The C-shaped and slit-shaped tunnels are formed by combining multiple drill paths in different orientations and planes, enabling anatomical reconstruction that matches the natural three-dimensional footprint of the ACL insertion sites.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If conventional bone tunnel drilling is used, then the procedure is simpler, but the graft dimensions do not match the natural ACL footprint

Engineering Contradiction:

Improvematch between graft dimensions and native footprintVSAvoidease of creating bone tunnels

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The bone tunnel parameters (shape, size, orientation) are specifically modified to match the natural ACL footprint characteristics. C-shaped tunnels are created at the tibial insertion site while slit-shaped tunnels are created at the femoral insertion site, with dimensions and geometries that replicate the native ligament attachment areas.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If conventional reconstruction methods are used, then the procedure is faster, but biomechanical stability is suboptimal

Engineering Contradiction:

Improvebiomechanical stability of knee jointVSAvoidsurgical procedure time

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The bone tunnels are prepared in advance with precise C-shaped and slit-shaped geometries before graft insertion. This preliminary preparation ensures that when the graft is placed, it immediately achieves optimal anatomical fit and biomechanical function, reducing the need for intraoperative adjustments and improving overall surgical efficiency.

Inventive Principle:

Principle #10Preliminary action

4Manufacturing precision

If conventional drilling methods are used, then fewer devices are needed, but the tissue distribution becomes distorted post-injury

Engineering Contradiction:

Improveaccuracy of tissue distributionVSAvoidnumber of drilling and burring devices

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

Different drilling and burring techniques are applied to different locations within the insertion site. The tibial side receives C-shaped tunnel preparation while the femoral side receives slit-shaped tunnel preparation, with each location receiving treatment optimized for its specific anatomical requirements and tissue characteristics.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10799334B2System, devices and methods for anatomically correct reconstruction of ligaments

Publication Date: 2020.10.13 MEDACTA INT SA

AI summary

A method, system and devices for the reconstruction of ribbon shaped ligaments following the anatomical native insertion sites of the ligaments in the corresponding bones is described. The reconstruction of the anterior cruciate ligament of the human knee is depicted. The system includes a device for positioning and creating bone-tunnels, the preparation of grafts and the fixation thereof. The devices intended for bone tunnel creation take into account the ribbon-shaped nature of the ligament and can be adjusted to patient specific anatomy and take into consideration the various typologies of the ligament insertion sites. The method and devices for graft preparation are construed to reflect the anatomy of ligaments under consideration as close as possible to native ligaments by imitating the ribbon-like nature of native ligaments. The presented fixation methods follow this principle and are intended to support the ribbon-like nature of the grafts and are intended to support in-growth of the grafts. Furthermore, accessories supporting preparation of the grafts are presented.