Bone Plate Geometry for Small-Tibia Fit in OWHTO
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional T-shaped bone plates for opening wedge high tibial osteotomy (OWHTO) do not fit well on the smaller tibia of small patients, leading to gaps and lifting from the tibial surface, which can affect surrounding tissues.
Innovation Solution
A bone plate designed with a band-like shape and screw hole arrangement that conforms to the tibia's shape, featuring a shaft portion and head portion with inclined screw axes forming a space truss structure, reducing gaps and lifting by optimizing hole placement and screw insertion angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional T-shaped bone plate is used on a small patient's tibia, then the bone plate can be applied to the tibia, but the anterior portion of the head portion is lifted from the epiphyseal surface, creating a gap
Solution Approach 1:
The bone plate is designed with different regional characteristics: the head portion has a curved lower surface that conforms to the epiphyseal surface of small tibias, while the shaft portion maintains appropriate length and contour. This local adaptation of the plate's geometry to match specific anatomical regions resolves the lifting problem at the head portion while maintaining overall applicability to small patient tibias.
2Ease of operation
If a conventional T-shaped bone plate is used on a small patient's tibia, then the bone plate can be applied to the tibia, but the shaft portion is too long, causing the bone plate to be lifted from the medial surface of the tibia
Solution Approach 1:
The shaft portion of the bone plate is designed with optimized length and contour specific to small patient tibias. The length is reduced compared to conventional plates, and the curvature is adjusted to match the medial surface anatomy of smaller tibias, preventing lifting while maintaining structural integrity and surgical applicability.
3Shape
If the shaft portion is made shorter to fit small tibias, then the bone plate fits better on the medial surface, but the structural stability may be compromised
Solution Approach 1:
The bone plate utilizes optimized material composition and internal structure to maintain structural stability despite reduced external dimensions. The plate incorporates structural design elements such as optimized thickness distribution, rib reinforcements, and controlled porosity that provide high strength-to-weight ratio, ensuring adequate mechanical stability for small patient applications while maintaining the shortened, anatomy-fitting shape.
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A bone plate (1) includes: a shaft portion (2) extending in a longitudinal direction (X); and a head portion (3) disposed on a proximal side of the shaft portion (2) and having four screw holes arranged in a quadrangular shape. The four screw holes include first and second screw holes (5a, 5c) arranged in the lateral direction (Y), and a third screw hole (5b) and a fourth screw hole (5d) located between the first screw hole (5a) and the second screw hole (5c) in the lateral direction (Y) and arranged further on the proximal side and distal side with respect to the first and second screw holes (5a, 5c), respectively.