Hybrid Bone Insert Alignment Correction
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Solution Overview
Problem
In total knee arthroplasty surgeries, achieving accurate bone resection and implant alignment is challenging due to preoperative bone loss or deformity, leading to instability and pain, as existing methods lack precise adjustments for length and angular alignment of bone implants.
Innovation Solution
The use of hybrid bone inserts with pre-cured PMMA portions and stem portions made of materials like titanium and tantalum, featuring surface features that promote bone ingrowth, allows for adjustable implant positioning through manual insertion or drilling, enabling precise adjustments of implant length and angle relative to the bone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional bone resection and implant bonding methods are used, then the surgical procedure is simple, but the implant alignment precision and bone-implant bond strength are insufficient
Solution Approach 1:
The hybrid insert divides the correction function into two parts: a pre-cured PMMA portion for precise positioning and alignment correction, and a stem portion for structural bonding. This segmentation allows each component to specialize in its function, achieving high alignment precision without requiring complex surgical procedures.
Solution Approach 2:
The hybrid insert acts as an intermediary device between the bone and the implant. It provides a stable bonding interface that enhances the bone-implant connection while enabling precise alignment correction, thereby improving implant alignment precision without increasing surgical complexity.
2Strength
If liquid PMMA cement is used for bonding, then the bonding process is simple, but the bond strength and stability over time are insufficient
Solution Approach 1:
The hybrid insert combines two materials with complementary properties: pre-cured PMMA for immediate structural integrity and precise positioning, and a stem portion (metal or porous material) for long-term structural strength and bone ingrowth. This composite structure simultaneously achieves high bond strength and long-term durability.
Solution Approach 2:
The stem portion may be made of porous material that allows bone ingrowth, creating a biological anchor that strengthens the bond over time. This porous structure provides both immediate structural support and long-term biological integration, enhancing both bond strength and durability.
3Manufacturing precision
If bone loss or deformity is present preoperatively, then the surgical challenge increases, but existing methods lack the precision to correct alignment errors
Solution Approach 1:
The hybrid insert applies local quality correction by providing precise alignment adjustment at the specific location of the bone-implant interface. The pre-cured PMMA portion can be customized in thickness and shape to address local bone loss or deformity, enabling high-precision alignment correction adapted to specific patient anatomy.
Solution Approach 2:
The hybrid insert allows parameter changes in the bonding interface by varying the thickness, shape, and material properties of the insert. This enables adaptation to different degrees of bone loss and deformity while maintaining high alignment precision across various surgical scenarios.
4Productivity
If trial and error bone resection is performed, then the surgical process is straightforward, but surgical time is increased and patient outcomes are compromised
Solution Approach 1:
The pre-cured PMMA portion of the hybrid insert is prepared beforehand with precise dimensions and alignment features. This preliminary preparation eliminates the need for trial and error during surgery, allowing direct placement and immediate achievement of correct alignment, thereby improving both surgical efficiency and outcome reliability.
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
This approach enhances the stability and strength of the bone-implant bond, improves surgical accuracy, and reduces surgical delays by allowing for precise correction of resection errors, leading to better patient outcomes with improved pain reduction and function.
Implementation Method 1
The liquid PMMA cement is applied to the bone and implant in liquid form which structurally bonds the implant to the bone when the liquid PMMA hardens and cures
Implementation Method 2
stem portions made of materials like titanium and tantalum, featuring surface features that promote bone ingrowth
Data Source
AI summary
The strength of bone implant attached to a bone is improved by using hybrid inserts which have stems and wings having bone ingrowth surface features and caps having outer surfaces of cured polymethyl methacrylate (PMMA). The stems and wings of the hybrid inserts are inserted into living bone and the bone implant is attached to the hybrid inserts with PMMA cement. Over time, the bone grows into the bone ingrowth surface features. The bone ingrowth strengthens the bonding of the hybrid inserts and the bone implant with the bone over time. The hybrid inserts increase the shear, tensile and torque strength of the bone implants. Bone inserts that do not have ingrowth surface features loosen over time.