- The patient qualifies for primary Total Ankle Replacement (TAR) per the surgeon and has a diagnosis of one of the following: Primary Arthritis (e.g. Degenerative Disease), Secondary Arthritis (e.g. Post-Traumatic, Avascular Necrosis, if minimally 2/3 of the talus is preserved), or Systemic Arthritis of the ankle (e.g. Rheumatoid Arthritis, Hemochromatosis).