A Reliability Study of Measurement Tools Available on Standard Picture Archiving and Communication System Workstations for the Evaluation of Hip Radiographs Following Arthroplasty

Abstract

Conventional radiography is the primary imaging tool for routine follow-up of total hip replacements, but the reliability of this method has been questioned. The aim of this study was to assess the reliability of commonly used measurements of the position of hip prostheses on postoperative radiographs with use of tools available on all standard picture archiving and communication system workstations. Fifty anteroposterior pelvic and lateral hip radiographs that were made after a unilateral total hip arthroplasty were included in this study. Acetabular inclination, lateral offset, lower-limb length, center of rotation, and femoral stem angle were independently assessed by two observers. Intraclass correlation coefficients were calculated for each measurement. The results demonstrated excellent reliability for acetabular angle (r = 0.95), lower-limb length (r = 0.91), and lateral offset (r = 0.95) measurements and good reliability for center of rotation (r = 0.73) and lateral femoral stem angle (r = 0.68) measurements. The position of total hip replacements can be reliably assessed with use of simple electronic tools and standard radiology workstations.