COMPLICATIONS WITH HYDROXYAPATITE PARTICULATE SEPARATION IN TOTAL HIP-ARTHROPLASTY

This study reports on the results of the implant and tissue analysis o f clinically retrieved hydroxyapatite (HA)-coated implants. Five of th e patients with fixed HA-coated stems had been clinically diagnosed wi th osteolysis. The semiquantitative histologic grading in these patien ts showed I-FA, polyethylene, and metal particles were all present (Gr ade 3+) in the osteolytic regions of the periprosthetic tissue. Additi onally, inflammatory cells (Grade 3+) were present in these regions. B ackscattered electron (BSE) and correlated elemental analysis showed H A particulate was present in the polyethylene inserts. The HA could be distinguished from bone chips in the polyethylene based on morphology and anatomic number gray level differences. This study was limited in that no clinical results of particular HA-coated implant series were reported. Careful follow-up care in patients with coated devices is re commended.