The Agility total ankle arthroplasty. Seven to sixteen-year follow-up.

BACKGROUND: We previously reported the intermediate-term results with the early version of the Agility total ankle replacement, a unique design that takes advantage of arthrodesis of the tibiofibular syndesmosis for tibial component support. The purpose of this study was to report longer-term results of this procedure in the treatment of disabling ankle arthritis. METHODS: We conducted an independent review of all Agility total ankle replacements performed by a single surgeon between 1984 and 1994. Follow-up evaluation consisted of completion of a validated ankle osteoarthritis scale and a short questionnaire and a review of the radiographs. All radiographs were evaluated for evidence of the development of progressive hindfoot arthritis, nonunion of the tibiofibular syndesmosis, progressive radiolucent lines, osteolysis, and component subsidence. RESULTS: One hundred and thirty-two arthroplasties were performed in 126 patients. After a mean follow-up period of nine years, thirty-three patients (thirty-six implants) had died, fourteen patients (11%) had a revision of the implant or an ankle arthrodesis, and one had the leg amputated because of an unrelated cause. Of the remaining seventy-eight patients (eighty-one ankles), sixty-seven (sixty-nine ankles) were followed clinically. More than 90% of them reported that they had decreased pain and were satisfied with the outcome of the surgery. We found modest differences in a comparison of the pain and disability scores with those of age-matched controls. Of the 117 ankles that had been followed radiographically for a minimum of two years, twenty-two (19%) had progressive subtalar arthritis, seventeen (15%) had progressive talonavicular arthritis, and nine (8%) had a syndesmosis nonunion. Eighty-nine (76%) of the 117 ankles had some evidence of peri-implant radiolucency. CONCLUSIONS: Arthrodesis of the tibiofibular syndesmosis impacts the radiographic and clinical outcomes with the Agility total ankle replacement. The relatively low rates of radiographic hindfoot arthritis and revision procedures at an average of nine years after the arthroplasty are encouraging. Agility total ankle replacement is a viable and durable option for the treatment of ankle arthritis in selected patients.

The Agility total ankle replacement.

The Agility Total Ankle System can be used in most arthritic conditions that involve the ankle joint, including many angular deformities that result from trauma or degenerative wear. The surgeon must be prepared to realign the ankle and to achieve soft-tissue balancing at the time of the surgery to avoid late failures. Proper patient selection is very important, and certain conditions, including diabetes with peripheral neuropathy, poor skin quality or poor circulation, and deficient bone stock, must be avoided to achieve a successful outcome. The surgical procedure must be done in a precise manner, with selection of the proper size of prosthesis and accurate insertion of the components in all directions. Proper tensioning of the joint is also paramount to achieve long-term stability. The precise degree of tensioning is still somewhat controversial, although with experience the deltoid end point can be readily determined in most patients. The follow-up care of these patients is very important, not only from the standpoint of compliance but also because any long-term problems must be recognized and treated before the implant is lost.