The reliability of measuring acetabular component position on radiographs using everyday diagnostic imaging software

Area of Science:

• Orthopaedic Surgery
• Medical Imaging
• Biomedical Engineering

Background:

• Post-operative imaging is crucial for assessing acetabular component position in total hip arthroplasty (THA).
• Accurate acetabular component placement is vital for successful THA outcomes.
• While CT is definitive, plain radiographs are commonly used, but measuring component position is challenging.

Purpose of the Study:

• To evaluate the reliability of Lewinnek's method for measuring acetabular component position on digital radiographs.
• To assess the feasibility of using readily available diagnostic imaging software for this measurement.

Main Methods:

• Lewinnek's method was applied to 69 post-operative anteroposterior (AP) digital radiographs from primary THA patients.
• Measurements were performed using the InteleViewer Picture Archiving and Communication System (PACS) software.
• Intra-observer and inter-observer reliability were calculated using the intraclass correlation coefficient (ICC).

Main Results:

• Excellent intra-observer reliability was found for both inclination (ICC=0.99) and anteversion (ICC=0.99) measurements.
• Excellent inter-observer reliability was also demonstrated for inclination (ICC=0.97) and anteversion (ICC=0.93).
• Confidence intervals for all measurements were narrow, indicating high precision.

Conclusions:

• Lewinnek's method is a reliable technique for measuring acetabular component position on post-operative AP digital radiographs.
• The use of basic, readily available PACS software enhances the practicality of this method for orthopaedic surgeons.
• This approach provides a dependable tool for evaluating acetabular component positioning in routine clinical practice.