[Biocompatibility of polyethylene terephthalate--PET--(Trevira strong)--an in vivo study of the sheep knee].

The anterior cruciate ligament was transected at the femoral origin in the right stifle joint of 25 sheep. The ligaments were re-inserted using the Marshall technique, and reinforced with a 3 mm band made of polyethylene terephthalate--PET--(Trevira hochfest) using the through-the-condyle (TTC) procedure, and re-attached--with a preload of 20 N--to the femoral and tibial condyle with two 4 mm staples. To assess the biocompatibility of the augmentation band, the synovial fluid was analysed for total protein and glucose concentration 2, 6, 24, and 56 weeks after implantation, and a total and differential cell count performed. No significant differences were found before and after implantation of the PET band. No pathological increase in the total protein concentration occurred after implantation (normal range: > 3.0 g/dl), and no significant differences vs. the preoperative analysis were found. No synovitis-signalling decrease in the glucose concentration (normal range: > 40 mg/dl) was observed. The preoperative glucose concentration of 87 +/- 12.84 mg/dl showed no significant difference from the postoperative concentration of 95 +/- 13.58 mg/dl. The cytological examination revealed no increase in the leucocyte counts (normal range: 3 leucocytes/HPF). Neither free nor phagocytosed wear particles were seen.