Accuracy of Measurement of Polyethylene Wear with Use of Radiographs of Total Hip Replacements

• Published in: Journal of bone and joint surgery. American volume 2003-12, Vol.85 (12), p.2378-2384
• Main Authors: Ebramzadeh, Edward, Sangiorgio, Sophia N, Lattuada, Federico, Kang, Joon-Soon, Chiesa, Roberto, McKellop, Harry A, Dorr, Lawrence D
• Format: Article
• Language: English
• Subjects: Arthroplasty, Replacement, Hip - adverse effects; Arthroplasty, Replacement, Hip - methods; Biological and medical sciences; Compressive Strength; Equipment Failure Analysis - instrumentation; Equipment Failure Analysis - methods; Hip Prosthesis; Humans; Investigative techniques, diagnostic techniques (general aspects); Materials Testing; Medical sciences; Orthopedic surgery; Osteoarticular system. Muscles; Patient Simulation; Polyethylene - chemistry; Probability; Prosthesis Failure; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Sensitivity and Specificity; Statistics, Nonparametric; Stress, Mechanical; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/00004623-200312000-00016

BackgroundAlthough a number of methods are used to estimate polyethylene liner wear from radiographs of total hip replacements, there is no consensus with regard to the accuracy of these methods. The purpose of this study was to compare the accuracy of several such measurement methods with use of both laboratory radiographs and routine clinical radiographs.MethodsA phantom apparatus was designed to simulate random values of three-dimensional wear, with varying degrees of cup abduction and anteversion, and to obtain anteroposterior and cross-table lateral radiographs with each value. Wear was measured with use of the Charnley duoradiographic method, the Livermore method, and the method described by Dorr and Wan, as well as with use of PolyWare and Hip32 software packages, both with and without three-dimensional measurements. Clinical wear was measured from conventional radiographs made prior to revision surgery in fourteen patients and was compared with wear measured directly from the retrieved liners with use of a coordinate measuring machine.ResultsWith laboratory radiographs, median errors were 0.1 mm with the Livermore method and both computerized methods, 0.23 mm with the Charnley method, and 1.7 mm with the method of Dorr and Wan. Maximum errors were between 0.6 mm (Livermore) and 4.3 mm (Dorr and Wan). In contrast, with use of clinical radiographs, median errors ranged between 0.2 mm (Hip32) and 0.6 mm (Dorr and Wan). Maximum errors ranged between 1.8 mm (Dorr and Wan) and 2.5 mm (Livermore).Conclusions and Clinical RelevanceWith laboratory radiographs, computerized methods of polyethylene wear measurement offered distinctly greater accuracy than did manual methods; however, with clinical radiographs, they offered only slightly better accuracy. Although the increased accuracy of computerized methods may be necessary in research settings, manual methods provided sufficient accuracy for routine clinical assessment of wear.