A new technique for measuring wear in total hip arthroplasty using computed tomography.
Accurately estimating polyethylene wear in 3 dimensions, without the need for additional procedures or equipment, is of significant interest. We investigated the use of a high-resolution clinical computed tomographic (CT) scanner to estimate femoral head displacement relative to the cup as an indirect method of estimating polyethylene wear. A hip phantom was used to simulate the 3-dimensional displacement of a femoral head. The phantom was imaged in a high-resolution CT scanner. The mean difference between the true phantom displacement as positioned by micrometers and the calculated displacement based on the CT images was as follows: for the x-axis, 0 mm (SD, 0.213; SE, 0.058); y-axis, 0.039 mm (SD, 0.035; SE, 0.026); and z-axis, 0.039 mm (SD, 0.051; SE, 0.020).
Massachusetts General Hospital, Boston, Massachusetts, USA.
Dov
D
Goldvasser
Marilyn E
ME
Noz
G Q
GQ
Maguire
Henrik
H
Olivecrona
Charles R
CR
Bragdon
Henrik
H
Malchau
D001696:Biomechanical Phenomena; D019544:Equipment Failure Analysis; D005270:Femur Head / Q000000981:diagnostic imaging*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D021621:Imaging, Three-Dimensional; D019047:Phantoms, Imaging; D020959:Polyethylene; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D013314:Stress, Mechanical; D013499:Surface Properties; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*
D020959:Polyethylene