title: Comparison of Head Center Position and Screw Fixation Options Between a Jumbo Cup and an Offset Center of Rotation Cup in Revision Total Hip Arthroplasty: A Computer Simulation Study.
abstract: Jumbo acetabular cups are commonly used in revision total hip arthroplasty (THA). A straightforward reaming technique is used which is similar to primary THA. However, jumbo cups may also be associated with hip center elevation, limited screw fixation options, and anterior soft tissue impingement. A partially truncated hemispherical shell was designed with an offset center of rotation, thick superior rim, and beveled anterior and superior rims as an alternative to a conventional jumbo cup. A three dimensional computer simulation was used to assess head center position and safe screw trajectories. Results of this in vitro study indicate that a modified hemispherical implant geometry can reduce head center elevation while permitting favorable screw fixation trajectories into the pelvis in comparison to a conventional jumbo cup.
authors.affiliation: Stryker Orthopaedics, Mahwah, New Jersey.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Faizan
authors.affiliation: Stryker Orthopaedics, Mahwah, New Jersey.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Black
authors.affiliation: Stryker Orthopaedics, Mahwah, New Jersey.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Fay
authors.affiliation: Stryker Orthopaedics, Mahwah, New Jersey.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Heffernan
authors.affiliation: University of California, San Francisco, California.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Ries
mesh_terms: D000077:Acetabulum / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D001863:Bone Screws; D003198:Computer Simulation; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis; D011474:Prosthesis Design; D012086:Reoperation / Q000379:methods; D012399:Rotation
keywords: CT based shell design; acetabular shell; offset center of rotation shell; revision hip arthroplasty; simulation