Author/Editor     Milošev, I; Antolič, V; Minovič, A; Coer, A; Herman, S; Pavlovčič, V; Campbell, P
Title     Extensive metallosis and necrosis in failed prostheses with cemented titanium-alloy stems and caramic heads
Type     članek
Source     J Bone Joint Surg Br
Vol. and No.     Letnik 82-B, št. 3
Publication year     2000
Volume     str. 352-7
Language     eng
Abstract     We describe three prostheses with cemented titanium-alloy stems and Al203 ceramic femoral heads which had to be revised after a mean period of implantation of 78 months. In each case, the neck of the prosthesis had been so severely worn that the profile was elliptical rather than circular. There was severe metallosis of the periprosthetic tissues. Metal particles isolated from the tissues were approximately one nanometre in size and the ratios of titanium, aluminium and vanadium in the particles were the same as in the original alloy. Histologically, the high concentration of metal particles masked the presence of high-density polyethylene (HDP) debris, but again particles about one nanometre in size were isolated from the tissues. The severe necrobiosis and necrosis noted were consistent with other reports of the presence of extensive wear particles in periprosthetic tissues. Wear is presumed to have occurred as a result of mismatch between the shape or size of the taper cone and the femoral head, or to changes in the geometry of loading due to migration of the cup. To facilitate early intervention, patients with this design of prosthesis should be monitored radiologically.
Descriptors     HIP PROSTHESIS
PROSTHESIS FAILURE
INFLAMMATION
HIP JOINT
MICROSCOPY, ELECTRON
TITANIUM
VANADIUM
CERAMICS
CORROSION