title: THA Retrievals: The Need to Mark the Anatomic Orientation of the Femoral Head.
abstract: The hypothesis of this study was that the rotational orientation of femoral head damage would greatly affect the volumetric wear rate of the opposing polyethylene (PE) liner. Damage on twenty retrieved cobalt-chromium femoral heads was simulated in a validated damage-feature-based finite element model. For each individual retrieval, the anatomic orientation of the femoral head about the femoral neck axis was systematically varied, in 30° increments. The PE wear rate differential between the maximum- versus minimum-wear orientations was often sizable, as high as 7-fold. Knowing the correct femoral head anatomic orientation is therefore important when analyzing the effects of femoral head damage on PE liner wear. Surgeons retrieving modular femoral heads should routinely mark the anatomic orientation of those components.
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa.
authors: Anneliese D
authors: AD
authors: Heiner
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa.
authors: Karen M
authors: KM
authors: Kruger
authors: Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio.
authors: Nishant M
authors: NM
authors: Tikekar
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa; Orthopaedics Department, VA Medical Center, Iowa City, Iowa.
authors: John J
authors: JJ
authors: Callaghan
authors: Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio.
authors: John J
authors: JJ
authors: Lannutti
authors: Department of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa.
authors: Thomas D
authors: TD
authors: Brown
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D002857:Chromium / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D005270:Femur Head / Q000601:surgery*; D005272:Femur Neck / Q000601:surgery; D020342:Finite Element Analysis; D006622:Hip Prosthesis; D006801:Humans; D020959:Polyethylene / Q000737:chemistry; D011474:Prosthesis Design; D012399:Rotation; D013997:Time Factors
chemical_list: D002857:Chromium; D003035:Cobalt; D020959:Polyethylene
keywords: damage; femoral head; finite element analysis; retrieval analysis; total hip arthroplasty; wear