Medial-Lateral Distractor Instrument for Knee Joint Surgery
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Solution Overview
Problem
Current knee joint surgery distractor instruments obstruct access to the joint space and require larger incisions, as they need to be removed before subsequent steps can be performed, and they do not allow for precise tensioning of ligaments without displacing the patella.
Innovation Solution
A distractor instrument with pivotally connected arms extending medially or laterally, allowing tension to be applied across the joint without obstructing access, enabling procedures to be performed through smaller incisions and maintaining the patella in its anatomic position, with a spigot and socket assembly for ancillary instruments to facilitate precise cuts and measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional distractor instruments are used to apply tension across the joint, then ligament tensioning is achieved, but access to the joint space is obstructed and larger incisions are required
Solution Approach 1:
The arms are configured to extend generally in the medial-lateral direction rather than anteriorly, changing the spatial dimension of instrument placement. This allows tensioning while maintaining access to the joint space through smaller incisions, as the arms extend laterally away from the anterior joint approach
2Ease of operation
If traditional distractor instruments are used, then tension can be applied across the joint, but the patella must be displaced or everted to fit the plates
Solution Approach 1:
By extending the arms in the medial-lateral direction rather than anteriorly, the instrument allows plate placement without requiring patellar displacement. The lateral extension provides sufficient space for plate insertion while the patella remains in its anatomic position
3Productivity
If distractor instruments are removed before subsequent steps, then access is improved, but time is lost and productivity decreases
Solution Approach 1:
The instrument is designed to remain in place throughout the surgical procedure, transitioning from a static obstruction to a dynamic tool that can be adjusted. The arms can be positioned and locked in various configurations to apply tension at different stages without requiring removal, improving surgical efficiency
Data Source
AI summary
A distractor instrument for use in knee joint surgery is provided that includes a tibial plate, a femoral plate, a tibial arm having a plate end and a control end, wherein the tibial plate is fastened to the plate end of the tibial arm at its anterior edge, and wherein, when the tibial plate is engaged with the tibia, the tibial arm is configured to extend from the tibial plate generally medially or laterally of the knee joint. The distractor instrument also includes a femoral arm having a plate end and a control end, wherein the femoral plate is fastened to the plate end of the femoral arm, and wherein, when the femoral plate is engaged with the femur, the femoral arm extends from the femoral plate generally aligned with the tibial arm. The tibial arm and the femoral arm are pivotably connected to one another at a point between their respective plate and control ends so that pivotal movement of the femoral arm relative to the tibial arm reduces the distance between their control ends and causes the distance between the tibial plate end and the femoral plate end to increase.