Knee Orthosis Straps Preventing Anterior Tibia Sliding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current knee orthoses fail to effectively prevent the anterior drawer, or forward sliding of the tibia, in cases of complete rupture of the anterior cruciate ligament.
Innovation Solution
A knee orthosis design featuring strategically positioned and angled straps, with specific angular orientations and distances relative to the knee's center of rotation, to prevent the anterior tibia from sliding forward, utilizing a combination of elastic and non-elastic straps to provide stability and traction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If conventional orthoses with articulated frames and reinforcement systems are used, then knee stability against varus and valgus forces is improved, but the ability to prevent anterior drawer (forward sliding of tibia) is insufficient
Solution Approach 1:
The orthosis divides the stabilizing function into multiple independent strap systems: articulated frame reinforcements for varus/valgus control, and separate anterior/posterior straps for anterior drawer prevention. Each strap is positioned and angled independently to address specific instability directions, allowing optimized performance for each function without compromise.
Solution Approach 2:
Different parts of the orthosis have specialized configurations for different functions: the articulated reinforcements provide lateral stability, while the anterior and posterior straps with specific angular orientations (e.g., 30-45 degrees relative to tibial axis) provide anterior-posterior stability. Each component is locally optimized for its specific stabilizing role.
2Reliability
If surgical ligamentoplasty is performed to reconstruct the anterior cruciate ligament, then ligament function is restored, but the knee remains unstable during pivot activities requiring additional orthotic support
Solution Approach 1:
The orthosis provides preventive stabilization before pivot activities that stress the reconstructed ligament. The straps are pre-positioned and pre-tensioned to maintain knee stability during high-risk activities, protecting the reconstructed ligament from excessive strain while allowing controlled movement.
Solution Approach 2:
The orthosis acts as an intermediary support system between the reconstructed ligament and external forces during pivot activities. The straps and articulated frame distribute and reduce the load on the reconstructed ligament, allowing the patient to perform rehabilitation exercises and daily activities with reduced risk to the healing structure.
3Stability of the object's composition
If functional treatment with muscular and proprioceptive rehabilitation is used, then knee stability can be achieved, but it requires prolonged use of orthosis during pivot activities
Solution Approach 1:
The orthosis uses adjustable and removable straps that can be adapted to the patient's rehabilitation progress. As muscular and proprioceptive strength improves, the orthosis can be adjusted to provide less support, allowing gradual weaning and reducing the overall duration of required use while maintaining stability during critical rehabilitation phases.
Data Source
Figure 1~3
Figure 4~6
Figure 7~9
AI summary
The invention relates to an orthosis comprising an articulated structure (1) - (2) arranged in such a way as to be fixed to the thigh and to the leg, on either side of the knee. According to the invention, the orthosis comprises restraining means in the form of straps (4), (5), (6) and (7) coupled to said structure and able to surround the thigh and the leg, leaving the patellar area free, and to be crossed and placed one over the other on the rear side facing the cutaneous surface of the popliteal fossa (D), at the same height as the centre of rotation of the knee, in order to prevent the front part of the tibia from sliding forwards, each strap (4), (5), (6) and (7) being held in a rigid guide (9) on the leg and the thigh, and being held together by a non-extendible sleeve where they cross over at the popliteal fossa (D). The first strap (4), that is the shortest, is arranged on the outside, as far back as possible, and the last strap, that is the longest, is arranged on the inside, as far forward as possible, facing the cutaneous surface of the popliteal fossa.