title: Effect of femoral component head size on movement of the two-component hemi-arthroplasty.
abstract: The movement of 75 two-component hemi-arthroplasties, implanted following displaced subcapital fracture of the femoral neck, were examined radiologically in equal numbers of Hastings hips (22 mm), 22-mm Bi-articular hips and 32-mm Bi-articular hips. A classification of the movement of the two-component hemi-arthroplasty was devised. The 22-mm Bi-articular hips showed predominantly intraprosthetic movement compared with the 32-mm Bi-articular hips, where movement was mainly extraprosthetic, thus confirming in vivo the Charnley low friction principle. True bipolar movement was found predominantly in the Hastings hips. In selecting a two-component hemi-arthroplasty, the prosthesis of choice is therefore one with a 22-mm rather than a 32-mm femoral head.
authors.affiliation: Royal East Sussex Hospital, Hastings, UK.
authors.forename: R N
authors.initials: RN
authors.lastname: Brueton
authors.forename: J S
authors.initials: JS
authors.lastname: Craig
authors.forename: B L
authors.initials: BL
authors.lastname: Hinves
authors.forename: F W
authors.initials: FW
authors.lastname: Heatley
mesh_terms: D000368:Aged; D005260:Female; D005265:Femoral Neck Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging; D006622:Hip Prosthesis / Q000295:instrumentation* / Q000592:standards; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography