EVALUATION OF VITAMIN E ADDED ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE IN TOTAL KNEE ARTHROPLASTY – JOINT FLUID CONCENTRATIONS OF TOCOPHEROL AND MATRIX METALLOPROTEINASE 9

Abstract

The aim of this study was to report a 3 year follow up of vitamin E add polyethylene in total knee arthroplasty. UHMWPE powder (GUR1050) was mixed with 0.3% of vitamin E before consolidation by direct compression molding. The vitamin E added UHMWPE was applied to the articular surface and patella in 65 patients (mean age, 69.6 years). Joint fluid concentrations of tocopherol and matrix metalloproteinase 9 were measured in vitamin E added UHMWPE cases one year after surgery, and were compared to those of conventional UHMWPE cases and osteoarthritis patients. Concentrations of α-tocopherol and γ-tocopherol were measured by using HPLC with ultraviolet-visible wavelength detection. Concentrations of matrix metalloproteinase 9 were detected by using enzyme immunoassay.

The Average Knee Society score were 91.7(clinical) and 76.7(functional). There were three failures (1 supracondylar fracture, and 2 skin necrosis). The average concentrations of α-tocopherol were 281.8μg/dL (10 cases) in the vitamin E group, 371.8μg/dL (15 cases) in the conventional group, and 317.8μg/dL (46 cases) in the osteoarthritis group. There were no significant differences among three groups. The average concentrations of γ-tocopherol were 43.4μg/dL in the vitamin E group, 52.3μg/dL in the conventional group, and 49.8μg/dL in the osteoarthritis group. There were no significant differences among three groups. The average concentrations of matrix metalloproteinase 9 were 83.2 ng/mL in the vitamin E group, 78.4 ng/mL in the conventional group, and 17.4 ng/mL in the osteoarthritis group. There was no significant difference between the vitamin E group and the conventional group. However, The matrix metalloproteinase 9 concentrations of the osteoarthritis group were significantly lower than others.

No cases exhibited measurable polyethylene wear or osteolysis and also no abnormal values relating to vitamin E on joint fluid examinations. At three year follow-up, vitamin E added polyethylene demonstrated the safe use for the human body.