RT Journal Article SR Electronic T1 Insufficient evidence to recommend a specific bearing surface in implantable hip devices: comparative studies find little difference in outcomes JF Evidence Based Medicine JO Evid Based Med FD BMJ Publishing Group Ltd SP 22 OP 23 DO 10.1136/ebmed-2012-100678 VO 18 IS 1 A1 Haddad, Fares A1 Oussedik, Sam YR 2013 UL http://ebm.bmj.com/content/18/1/22.abstract AB