Tibial Baseplate Spacer Coupling for Ligament Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current knee arthroplasty procedures face challenges in minimizing invasiveness while accurately positioning and aligning knee components, particularly in preserving ligamentous and soft tissue structures to ensure proper kinematics and patellar tracking.
Innovation Solution
The development of an assembly that includes tibial and femoral intramedullary rods connected by a torque bolt, allowing controlled distraction of the tibia and femur during cut positioning across various flexion angles. This assembly features quick-release components and cutting guides that attach to the IM rods, facilitating minimally invasive approaches and accurate resection guidance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If resection guides are firmly supported relative to the bone to ensure accurate positioning, then manufacturing precision is improved, but the invasiveness of the procedure increases due to greater disruption of soft tissue structures
Solution Approach 1:
The patent introduces ligament tensioning devices as intermediary elements that transmit forces through the ligaments themselves to guide and stabilize the resection guides. By using the ligaments as mediators rather than directly anchoring to bone, the system achieves accurate positioning while minimizing soft tissue disruption, as the ligaments naturally guide the instrumentation without requiring extensive exposure or fixation.
Solution Approach 2:
The patent replaces traditional mechanical fixation systems (screws, pins, direct bone anchoring) with a ligament-based tensioning system. Instead of mechanically securing guides to bone which requires invasive fixation, the system uses ligament tension forces to position and stabilize the guides, substituting a biological mechanical system for a purely surgical mechanical fixation approach.
2Reliability
If soft tissue structures are preserved to maintain ligament tension and normal kinematics, then reliability of knee function is improved, but the ease of operation deteriorates due to limited access for instrumentation
Solution Approach 1:
The patent utilizes the third dimension by positioning ligament tensioning devices and resection guides at different depths and angles within the joint space. Instruments are introduced through minimally invasive portals and positioned in three-dimensional space to access target areas without requiring wide exposure, allowing soft tissue preservation while maintaining operational accessibility through spatial arrangement.
Solution Approach 2:
The patent employs nested instrumentation where cutting guides and tensioning devices are housed within or attached to larger positioning fixtures that are themselves contained within the joint space. This nested arrangement allows multiple functions to be achieved through a single minimally invasive access point, preserving soft tissue while providing comprehensive instrumentation access.
3Measurement precision
If ligament tensions are used to guide placement of resection guides, then measurement precision is improved, but the device complexity increases due to additional tensioning mechanisms
Solution Approach 1:
The patent employs ligament tensioning devices that utilize the natural tension and elasticity of the ligaments themselves to provide measurement and positioning information. The ligaments serve as both the object being measured and the measuring instrument, eliminating the need for complex external measurement devices. The tension forces naturally generated by the ligaments guide the placement of resection guides without requiring additional active measurement mechanisms.
Solution Approach 2:
The system incorporates feedback mechanisms where ligament tension forces provide real-time information about proper guide placement and positioning. As the resection guides are positioned, the ligament tension changes provide feedback to the surgeon about correct positioning, allowing precise placement without complex measurement devices. The biological feedback from ligament mechanics replaces electronic or mechanical measurement systems.
Data Source
AI summary
A tibial baseplate is described. While the baseplate can include any suitable component, in some instances, it includes a first surface and a second surface, the second surface being substantially opposite to the first surface and the first surface being configured to be seated on a resected surface at a proximal end of a tibia. In some cases, the baseplate also includes a first spacer coupling that is configured to couple a first spacer to at least one of a lateral side and a medial side of the baseplate such that the spacer is disposed between, and is configured to maintain a set minimal distance between, the proximal end of the tibia and a distal end of a femur when the tibial baseplate is seated on the resected surface at the proximal end of the tibia and the spacer is coupled to the tibial baseplate. Other implementations are discussed.