title: Correction of error in two-dimensional wear measurements of cemented hip arthroplasties.
abstract: The irregularity of individual wear patterns of total hip prostheses seen during patient followup may result partially from differences in radiographic projection of the components between radiographs. A method to adjust for this source of error would increase the value of individual wear curves. We developed and tested a method to correct for this source of error. The influence of patient position on validity of wear measurements was investigated with controlled manipulation of a cadaveric pelvis. Without correction, the error exceeded 0.2 mm if differences in cup projection were as small as 5 degrees. When using the described correction method, cup positioning differences could be greater than 20 degrees before introducing an error exceeding 0.2 mm. For followup of patients in clinical practice, we recommend using the correction method to enhance accuracy of the results.
authors.affiliation: Department of Orthopaedic Surgery, University Medical Center Groningen, Groningen, The Netherlands. b.the@orth.umcg.nl
authors.forename: Bertram
authors.initials: B
authors.lastname: The
authors.forename: Linda
authors.initials: L
authors.lastname: Mol
authors.forename: Ron L
authors.initials: RL
authors.lastname: Diercks
authors.forename: Peter M A
authors.initials: PM
authors.lastname: van Ooijen
authors.forename: Nico
authors.initials: N
authors.lastname: Verdonschot
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D001843:Bone Cements; D002102:Cadaver; D019245:Compressive Strength; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D016014:Linear Models; D020959:Polyethylene; D011187:Posture; D011475:Prosthesis Failure; D013314:Stress, Mechanical; D016896:Treatment Outcome
chemical_list: D001843:Bone Cements; D020959:Polyethylene