The accuracy and precision of acetabular implant measurements from CT imaging

Frontiers in Bioengineering and Biotechnology

Bioengineering and Biotechnology

Alister Hart¹  Robin Richards¹  Johann Henckel²  Anna Di Laura³  Angelika Ramesh³  Harry Hothi³ 

[1] Institute of Orthopaedics and Musculoskeletal Science, University College London, London, United Kingdom;Royal National Orthopaedic Hospital NHS Trust, Stanmore, United Kingdom;Royal National Orthopaedic Hospital NHS Trust, Stanmore, United Kingdom;Department of Mechanical Engineering, University College London, London, United Kingdom;

关键词: 3D-CT;    inclination;    version;    acetabular component position;    coordinate measuring arm;    cup orientation;   

DOI  :  10.3389/fbioe.2023.1150061

 received in 2023-01-23, accepted in 2023-04-17,  发布年份 2023

来源: Frontiers

【 摘 要 】

The placement of acetabular implant components determines the short- and long-term outcomes of total hip replacement (THR) and a number of tools have been developed to assist the surgeon in achieving cup orientation to match the surgical plan. However, the accuracy and precision of 3D-CT for the measurement of acetabular component position and orientation is yet to be established. To investigate this, we compared measurements of cobalt chrome acetabular components implanted into 2 different bony pelvic models between a coordinate measuring Faro arm and 3 different low dose CT images, including 3D-CT, 2D anterior pelvic plane (APP) referenced CT and 2D scanner referenced (SR) CT. Intra-observer differences were assessed using the Intraclass correlation coefficient (ICC). The effect of imaging the pelvis positioned in 3 different orientations within the CT scanner was also assessed. The measured parameters were the angles of inclination and version. 3D-CT measurements were found to closely match the “true values” of the component position measurements, compared with the 2D-CT methods. ICC analysis also showed good agreement between the coordinate measuring arm (CMA) and 3D-CT but poor agreement between the 2D SR method, in the results from two observers. When using the coordinate system of the CT scanner, the measurements consistently produced the greatest error; this method yielded values up to 34° different from the reference digitising arm. However, the difference between the true inclination and version angles and those measured from 3D APP CT was below half a degree in all cases. We concluded that low radiation dose 3D-CT is a validated reference standard for the measurement of acetabular cup orientation.

【 授权许可】

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Copyright © 2023 Henckel, Ramesh, Hothi, Richards, Di Laura and Hart.