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Published on: March 12, 2021
Direct measurement of acetabular radiographic version using an ordinary goniometer: a precision study
Chen-Kun Liaw1, Tai-Yin Wu, Rong-Sen Yang
1Department of Orthopaedics, Tao-Yuan General Hospital, Taiwan. d92008@csie.ntu.edu.tw
Summary
Wan's goniometer method accurately measures acetabular version in total hip arthroplasty when less than 20°. Mathematical correction is needed for precise measurements of larger acetabular versions.
Area of Science:
- Orthopedic surgery
- Radiographic imaging
- Surgical navigation
Background:
- Acetabular version is a key prognostic factor in total hip arthroplasty.
- Accurate measurement of acetabular version is crucial for verifying surgical outcomes.
- Computer navigation offers precision but requires reliable verification methods.
Purpose of the Study:
- To evaluate the precision of Wan's goniometer method for measuring acetabular radiographic version.
- To investigate the necessity of mathematical correction for this measurement technique.
Main Methods:
- Derived the mathematical principle behind Wan's method.
- Developed a correction formula and chart.
- Validated the method using 48 synthesized and 10 real radiographs, analyzing intra-observer variability.
Main Results:
- Wan's method showed a significant difference in measuring acetabular version compared to synthetic radiographs (p < 0.05).
- Mathematical correction eliminated this difference (p = 0.15).
- The method was precise for versions < 20° (p = 0.054).
Conclusions:
- Wan's goniometer method is precise for acetabular radiographic versions under 20°.
- Mathematical correction is essential for accurate measurements of larger acetabular versions in total hip arthroplasty.
