Abstract
Background
An increased incidence of periprosthetic osteolysis, resulting in loss of biologic fixation, has been recently reported in contemporary THAs with low-carbide metal-on-metal compared to metal-on-polyethylene couple bearings. A hypersensitivity reaction due to Co and Cr debris is reported as a potential cause for failure of THAs with high-carbide bearings, but there are no evidence-based data for this reaction in low-carbide metal-on-metal bearings.
Questions/purposes
We investigated whether there were differences in immunologic hypersensitivity reactions in retrievals from revised THAs with COP versus MOM bearing couples.
Patients and Methods
We compared newly formed capsule and periprosthetic interface membranes retrieved from revision surgery due to aseptic failure in 20 patients with low-carbide bearings and 13 patients with ceramic-on-polyethylene bearings. For control tissue we obtained samples from the hip capsule during the primary THA implantation in 13 patients with low-carbide bearings and seven with ceramic-on-polyethylene. We examined the tissues with conventional histologic and immunohistochemical methods.
Results
Compared to the controls and the tissue from patients with ceramic-on-polyethylene bearings, the tissues from patients with low-carbide metal-on-metal bearings were associated with (1) extensive necrosis and fibrin exudation in the newly formed hip capsule and (2) diffuse and perivascular lymphocytic infiltration of a higher degree than in the ceramic-on-polyethylene hips in conventional histologic examination and (3) more T than B cells.
Conclusions
The conventional histologic and immunohistochemical findings in tissues retrieved from failed THAs with low-carbide metal-on-metal bearings are consistent with a link between hypersensitivity and osteolysis with low-carbide bearing couple THA
