title: Large diameter heads: is bigger always better?
abstract: Large femoral heads have been used with increasing   frequency over the last decade. The prime reason is likely the effect   of large heads on stability. The larger head neck ratio, combined   with the increased jump distance of larger heads result in a greater   arc of impingement free motion, and greater resistance to dislocation   in a provocative position. Multiple studies have demonstrated clear   clinical efficacy in diminishing dislocation rates with the use   of large femoral heads. With crosslinked polyethylene, wear has   been shown to be equivalent between larger and smaller heads. However,   the stability advantages of increasing diameter beyond 38 mm have   not been clearly demonstrated. More importantly, recent data implicates   large heads in the increasing prevalence of groin pain and psoas impingement.   There are clear benefits with larger femoral head diameters, but   the advantages of diameters beyond 38 mm have not yet been demonstrated   clinically.
authors.affiliation: Center For joint Preservation & Reconstruction, North Shore LIJ/Lenox Hill Hospital, 130 E 77th street, 11th floor, New York, NY-10075, USA. josermd@aol.com
authors.forename: J A
authors.initials: JA
authors.lastname: Rodriguez
authors.forename: P A
authors.initials: PA
authors.lastname: Rathod
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D006617:Hip Dislocation / Q000209:etiology / Q000517:prevention & control*; D006621:Hip Joint / Q000502:physiology; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000517:prevention & control*; D010149:Postoperative Pain / Q000209:etiology; D011183:Postoperative Complications / Q000517:prevention & control*; D011475:Prosthesis Failure / Q000209:etiology; D016059:Range of Motion, Articular