Modular Hip Trial Collet for Anteversion Angle Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current modular hip replacement systems lack precision in replicating the anatomic anteversion rotational angle of the femur, leading to limitations in rotational stability and increased surgical complexity due to the need for discrete angle adjustments and insufficient coupling between trial and distal body components.
Innovation Solution
A modular hip implant kit with a proximal trial housing and a resiliently collapsible collet that allows full 360-degree rotation and angular locking of the distal implant, providing stable coupling and enabling precise anteversion angle adjustment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If discrete angle adjustments are used in modular hip replacement systems, then the device complexity is reduced, but the measurement precision of the anteversion angle is compromised
Solution Approach 1:
A laser alignment system serves as an intermediary between the surgical anatomy and the prosthesis components. The system uses laser markers placed on bony landmarks (greater trochanter, femoral shaft) to define the anteversion angle, and a prosthesis with a laser indicator that can be aligned with these markers. This intermediary optical system enables precise angular measurement without requiring complex mechanical adjustment mechanisms in the prosthesis itself.
2Reliability
If a resiliently collapsible collet is used to couple the proximal trial to the distal body, then the reliability of the coupling is improved, but the device complexity increases
Solution Approach 1:
The collet's physical state is changed from collapsed to expanded through parameter changes in its structural configuration. The collet features radially extending arms that can transition between a compressed state (during insertion) and an expanded state (during locking). This parameter change enables the collet to grip the distal body securely while maintaining a relatively simple overall structure.
3Adaptability or versatility
If full 360-degree rotation is allowed during trial assembly, then the adaptability of the system is improved, but the control of rotational positioning becomes more difficult
Solution Approach 1:
The system incorporates visual feedback through laser indicators and alignment markers. The proximal trial assembly includes a laser indicator that projects or aligns with laser markers defined on the distal body and patient anatomy. This feedback mechanism allows the surgeon to rotate the proximal trial through 360 degrees and visually determine the correct anteversion angle position, making the unlimited rotation advantageous rather than problematic.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enables accurate evaluation and replication of the femur's anatomic anteversion angle, enhancing rotational stability and reducing the complexity of the surgical procedure by allowing continuous and precise adjustments.
Implementation Method 1
a collapsing member for engaging the portion of the distal implant and for forcing the top surface portion of the collet toward the bottom surface portion of the collet along a first axis, thereby forcing the outer wall portion in a direction generally perpendicular to the first axis
Implementation Method 2
contacting the wall of the bore with the outer wall portion of the collet such that the distal implant is angularly locked to the proximal trial housing
Data Source
AI summary
A system and method for trialing a modular hip replacement system permits evaluation and replication of the anatomic anteversion rotational angle of the femur. In one embodiment, a femoral hip implant kit includes at least one distal implant and a plurality of femoral heads, each of the plurality of femoral heads having a diameter different from the diameter of the other of the plurality of femoral heads. The kit includes a proximal trial housing with a bore within the housing, the bore configured to receive a portion of the distal implant, a collet located within the bore, the collet including an outer wall portion extending between a top surface portion and a bottom surface portion, a collapsing member for engaging the portion of the distal implant and for forcing the top surface portion of the collet toward the bottom surface portion of the collet along a first axis.