Hydroxyapatite: Catalyst or conjuror?

A prospective, randomized, intermediate-term study of 174 patients (199 hips) comparing proximally hydroxyapatite (HA)-coated and non-HA-coated surfaces of identical stem design is presented. Clinical and radiographic data from 152 patients (174 hips) confirmed comparable outcomes in both groups according to the Hospital for Special Surgery modification of the Postel–d’Aubigne Hip Rating System. The non-HA group showed significantly higher (P=.03) activity-related thigh pain, however. There were no significant radiographic differences, with all stems showing bone ongrowth. The use of HA-coated stems resulted in early recovery of function and reduced activity-related trochanteric and thigh pain. A possible explanation for the difference is most likely early superior osseointegration. HA as a biologic adjuvant should gain widespread acceptance because of rapid recovery of function and lesser trochanteric and thigh pain. Copyright 2002, Elsevier Science (USA). All rights reserved.