IDENTIFICATION AND DISTRIBUTION OF SYNTHETIC LIGAMENT WEAR PARTICLES IN SHEEP

After one year, wear of medial collateral ligament replacements in she ep resulted in the presence of large numbers of wear particles and fib ers in the joint space. This study examined the frequency of transport of these particles to the regional lymph nodes and to the liver and s pleen. Inguinal, iliac, and paraaortic nodes were examined with regula r and polarized light for the presence of particles presumably origina ting from polyethylene, aramid, polytetrafluoroethylene, polyestertere phthalate, polylacticacid, and carbon ligaments. Lymph nodes from shee p that had received tendon autograft replacements were also evaluated. Particles were observed in 33% of all nodes and in at least one node in 84% of all sheep. Particles were found in contralateral nodes, but not in the spleen or liver. Particles were observed usually as intrace llular in foamy histiocytes, although extracellular carbon fibers and extracellular aramid fibers were also seen. Giant cells were occasiona lly detected in the polytetrafluoroethylene, polyethylene, and aramid nodes. In the polytetrafluoroethylene nodes and in the autograft nodes particles containing Mg, Si, and Fe were identified by elemental anal ysis. The morphological similarities between various birefringent part icles and the particles indirectly identified as talc have led us to q uestion the identification of wear debris solely on the basis of biref ringence. (C) 1996 John Wiley & Sons, Inc.