Calder, S The compares a unipolar with a bipolar prosthesis of similar stem design. [electronic resource] - Clinical orthopaedics and related research Feb 1999 - 259 p. digital Publication Type: Clinical Trial; Comment; Letter; Randomized Controlled Trial ISSN: 0009-921X Subjects--Topical Terms: AgedAged, 80 and overHip Fractures--surgeryHip ProsthesisHumansProspective StudiesProsthesis Design