[Correction of deformities with conventional and hexapod frames--comparison of methods]
1Klinik und Poliklinik für Allgemeine Orthopädie, Universitätsklinikum Münster. roedl@uni-muenster.de
Zeitschrift Fur Orthopadie Und Ihre Grenzgebiete
|February 28, 2003
Summary
The hexapod external fixation frame offers superior correction for rotational and translational deformities compared to conventional frames. However, conventional frames are better for extensive angulation and shortening corrections, and hexapod frames may be limited in pediatric cases.
Area of Science:
- Orthopedic surgery
- Biomechanical engineering
- External fixation devices
Background:
- Distraction osteogenesis is a key technique for correcting bone deformities.
- External fixators, particularly the Ilizarov apparatus, are widely used.
- Hexapod robotic technology (e.g., Taylor-Spatial-Frame/TSF) simplifies frame mounting for complex corrections.
Purpose of the Study:
- To analyze the clinical value of the hexapod principle in external fixation.
- To compare the workspace and correction potential of hexapod frames versus conventional frames.
Main Methods:
- Comparative analysis of hexapod and conventional external fixation frames.
- Evaluation of frame geometry, workspace, minimal/maximal frame heights, and correction potential.
- Analysis of angulation, shortening, translation, and rotation correction capabilities.
Main Results:
- Hexapod frames have a higher minimal frame height than conventional Ilizarov frames.
- Standard hexapod frames correct 23° angulation, 36mm shortening, 71mm translation, and 43° rotation without rod changes.
- Standard conventional frames correct 90° angulation, 100mm shortening, 25mm translation, and 12.5° rotation without remounting.
Conclusions:
- Hexapod frames excel in correcting translational and rotational deformities due to their workspace.
- Conventional frames are more effective for extensive angulation and shortening deformities, often requiring less complex adjustments.
- The increased minimal frame height of hexapod constructs may limit their application in pediatric orthopedics.
Related Concept Videos
01:30Frames
Frames are essential components of various mechanical and structural systems used daily. These structures are known for their stability and ability to bear heavy loads. A frame is constructed using two-force and multi-force members, interconnected using pin joints. In contrast, trusses are made entirely of two-force members.
Frames are versatile and widely used in various applications such as structural supports for beams and columns, automobile chassis construction, and in the construction...
Frames are versatile and widely used in various applications such as structural supports for beams and columns, automobile chassis construction, and in the construction...
01:11Deformation of Member under Multiple Loadings
When a rod is made of different materials or has various cross-sections, it must be divided into parts that meet the necessary conditions for determining the deformation. These parts are each characterized by their internal force, cross-sectional area, length, and modulus of elasticity. These parameters are then used to compute the deformation of the entire rod.
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...
In the case of a member with a variable cross-section, the strain is not constant but depends on the position. The deformation of an...