Page 349 - Demo

General discussion 34713well below the threshold, but also did not differ significantly from the surface roughness of the pristine condyle, thus proving the value of the HadSat®-protocol.(95) Besides the wear analysis of the prosthesis, a histological evaluation of the peri-articular tissues was performed as well, which was then applied to the ‘synovial-like interface membrane’-classification (SLIM), to determine the presence of neo-synovitis (Type I), infection-induced synovitis (Type II) and adverse local tissue reactions to implant wear particles (Type VI). In addition, during the histological evaluation of the enthesis, the osseous integration was evaluated as well, thus evaluating a Type V-reaction (prosthesis-associated arthrofibrosis).(103–105)To be able to classify a reaction as a SLIM Type I reaction, a wearinduced neosynovitis, 20% of the tissue sample needs to be infiltrated with macrophages, containing wear debris usually smaller than 1 µm in diameter. In addition, multinucleated foreign-body giant cells can be found as well. These cells mostly contain wear debris particles larger than 5 µm.(103–105) Although an increased amount of macrophages was seen in both the coated TMJR tissues (22.15 ± 25.31) and uncoated tissues (17.76 ± 21.16) compared to the control samples (7.4 ± 10.36), the maximal amount of macrophagic surface infiltration remained well below the threshold with an average infiltration of 3.8% for the coated and 3.1% for the uncoated system tissues. A SLIM type II reaction, a synovitis due to infection, can either be low- or high-grade. Whereas in case of the first granulation tissue with fibroblasts, vascular proliferation, chronic edema and neutrophil granulocytes, plasma cells and lymphocytes are found, a high-grade infection boasts a larger amount of neutrophil granulocytes.(103–105) In none of evaluated samples were signs of an infectious synovitis, nor did any of the trail animals develop clinical signs of an infectious joint. A SLIM-type VI reaction is an adverse inflammatory tissue reaction, being caused by particle toxicity and/or host allergy, with three types of histological reactions having been described. A mainly macrophagic Nikolas de Meurechy NW.indd 347 10-06-2024 11:12