[The TNK ankle: short- and mid-term results].

Total ankle replacement has been introduced in the last 30 years. The TNK ankle is build from ceramics, and it was continuously improved. This prosthesis has the longest fellow-up times. Seventy ankle prostheses of the newest generation has been implanted between 1991 and 2001. Of these, 67 prostheses were assessed clinically and radiographically after 62 months (range, 24 to 132 months). Three ankles have been revised. The clinical score improved for the patients with primary or posttraumatic arthritis from 34 to 86, and for the patients with rheumatoid arthritis from 45 to 74. Loosening was found in 4 ankles with non-rheumatoid arthritis, and in 17 ankles with rheumatoid ankles. Total ankle replacement has emerged to a valuable alternative to ankle arthrodesis, and satisfactory results have been achieved with the current implants. The bone-implant interphase might play a most important factor for success. There is evidence that the biologic advantages of ceramics may help to improve long-lasting success in total ankle replacement.