title: Metal-on-metal hip resurfacing: the effect of cup position and component size on range of motion to impingement.
abstract: The aim of this dry bone study was to determine the range of hip motion to impingement for different hip resurfacing cup positions and component sizes. The maximum angles of hip flexion, extension, abduction, and adduction were calculated from 3-dimensional coordinates for: 1. Cup inclination of 30 degrees , 40 degrees , 50 degrees , 60 degrees , and 70 degrees with fixed anteversion; 2. Cup anteversion of 0 degrees , 10 degrees , 25 degrees , 35 degrees , and 45 degrees with fixed inclination; and 3. 3 different component sizes on the same size dry bones. An acetabular component inclination of 50 degrees and an anteversion of 25 degrees allowed the most physiologic range of hip motion. A larger-diameter femoral component relative to the native femoral neck diameter resulted in a greater range of hip motion to impingement.
authors.affiliation: Department of Trauma and Orthopaedic Surgery, Royal Cornwall Hospital, Cornwall, United Kingdom.
authors.forename: Dan
authors.initials: D
authors.lastname: Williams
authors.forename: Matt
authors.initials: M
authors.lastname: Royle
authors.forename: Mark
authors.initials: M
authors.lastname: Norton
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation; D001696:Biomechanical Phenomena; D002858:Chromium Alloys; D006621:Hip Joint / Q000502:physiology*; D006622:Hip Prosthesis; D006801:Humans; D008670:Metals; D008954:Models, Biological; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*
chemical_list: D002858:Chromium Alloys; D008670:Metals