title: The Effect of Taper Angle and Spline Geometry on the Initial Stability of Tapered, Splined Modular Titanium Stems.
abstract: Design parameters affecting initial mechanical stability of tapered, splined modular titanium stems (TSMTSs) are not well understood. Furthermore, there is considerable variability in contemporary designs. We asked if spline geometry and stem taper angle could be optimized in TSMTS to improve mechanical stability to resist axial subsidence and increase torsional stability. Initial stability was quantified with stems of varied taper angle and spline geometry implanted in a foam model replicating 2cm diaphyseal engagement. Increased taper angle and a broad spline geometry exhibited significantly greater axial stability (+21%-269%) than other design combinations. Neither taper angle nor spline geometry significantly altered initial torsional stability.
authors.affiliation: Joint Replacement Surgeons of Indiana Foundation, Inc., Mooresville, Indiana.
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Pierson
authors.affiliation: Joint Replacement Surgeons of Indiana Foundation, Inc., Mooresville, Indiana.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Small
authors.affiliation: Lenox Hill Hospital, New York, New York.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Rodriguez
authors.affiliation: Insall-Scott-Kelly Institute for Orthopedics and Sports Medicine, New York, New York.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Kang
authors.affiliation: Department of Orthopaedic Surgery, The Ohio State University, Columbus, Ohio.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Glassman
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D018483:Diaphyses; D005269:Femur / Q000601:surgery; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D011474:Prosthesis Design; D012086:Reoperation; D014025:Titanium / Q000737:chemistry*
chemical_list: D014025:Titanium
keywords: basic science; modular stem; revision; subsidence; total hip arthroplasty