The goal of ankle replacement is to resurface the ankle joint with mechanical parts that allow continued ankle motion and function without pain. The models used by the Service include the Agility Ankle and the Scandinavian Total Ankle Replacement (STAR).

The Agility is FDA approved, and the STAR is only available at the 10 select Services in the United States, including UI Hospitals and Clinics. Like hip and knee replacements, these devices are constructed of metal and plastic, and, as such, are mechanical parts that can wear out.

Currently, patients who are best served by an ankle replacement are those who will put low mechanical demands on their artificial joints. These include average or lightweight patients who would like to stand and walk with limited or no pain.

Experience indicates that several patient groups are less likely to have good and long-lasting results from ankle replacements, including patients with previous deep ankle infection, lower limb neuropathy, osteoporosis, high physical demands, obesity, poor skin, or vascular problems. After ankle replacement, patients are admitted to the hospital for a few days. They remain in a cast or boot with limited weight put on the foot for two to six weeks. A walker or crutches are used until the bone heals to the new implant.

References

Iowa Orthop J. 2002;22:99-102.

Forty-year outcome of ankle "cup" arthroplasty for post-traumatic arthritis.

Muir DC, Amendola A, Saltzman CL.

Ankle arthroplasty for post-traumatic tibiotalar arthritis remains controversial. The current literature strongly recommends arthrodesis, especially in those patients who will overload the joint: the young, the active and the overweight patients. The case described here is a 40-year follow up. A 31-year old man underwent talar dome resurfacing with a custom Vitallium implant for post-traumatic arthritis in 1962. He continued to work as a heavy laborer until retirement in 1987 and presently remains virtually asymptomatic with regard to his foot and ankle. The longevity of this individual implant has been remarkable. The unique design, minimal resection, surgical approach and remarkable success merit discussion in the light of publication of predominantly bleak reports of arthroplasty in this patient population.

Instr Course Lect. 2002;51:129-33.

The Agility total ankle replacement.

Saltzman CL, Alvine FG.

Department of Orthopaedic Surgery, Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA.

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.

Foot Ankle Clin. 2000 Dec;5(4):761-75.

Perspective on total ankle replacement.

Saltzman CL.

Departments of Orthopaedic Surgery and Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA.

Total ankle arthroplasty has become a viable alternative to ankle arthrodesis. Modern implant designs involve a syndesmosis fusion and resurfacing of the medial and lateral recesses of the ankle joint or the use of a three-component, mobile bearing implant. In limited clinical series, the early results of both these prosthetic design approaches are encouraging. In selected patients, ankle arthroplasty is an effective approach to relieving pain and improving function. Selected patients can be offered a total ankle replacement as an alternative option to arthrodesis in the treatment of end-stage ankle arthritis. Further development of prosthetic designs, which minimize bone resection and restore normal ankle motion, is needed.

J Orthop Sports Phys Ther. 2000 Feb;30(2):56-67.

Total ankle replacement revisited.

Saltzman CL, McIff TE, Buckwalter JA, Brown TD.

Department of Orthopaedic Surgery, University of Iowa, Iowa City 52242-1088, USA. charles-saltzman@uiowa.edu

The surgical treatment of painful, end-stage ankle arthritis includes ankle arthrodesis and total ankle replacement. In the past decade, total ankle replacement has become a viable alternative to ankle arthrodesis. Modern implant designs either involve a syndesmosis fusion and resurfacing of the medial and lateral recesses of the ankle joint or the use of a 3-component, mobile bearing implant. In limited clinical series, the early results of both these prosthetic design approaches are encouraging. In selected patients, ankle arthroplasty is an effective approach to relieving pain and improving function. The purposes of this paper are to review the clinical results from total ankle replacement and ankle arthrodesis; discuss indications, contraindications, design features, postoperative rehabilitation, and initial results for the major current total ankle designs; and present concepts for future total ankle development. In particular, this article explores the advantages and concerns with 2 prevalent but different design approaches. It also discusses future directions for total ankle replacement.

Instr Course Lect. 1999;48:263-8.

Total ankle arthroplasty: state of the art.

Saltzman CL.

Department of Orthopaedic Surgery, University of Iowa, Iowa City, USA.

Total ankle arthroplasty results from the 1970s and 1980s were comparatively poor. The outcomes of these surgeries deteriorated rather dramatically with time. Causes of failure were multifactorial, but the 2 features that seemed central to implant failure were constrained designs and cement fixation. Total ankle operations are considered technically demanding procedures, with relatively high early postoperative complication rates. As yet, the ideal total ankle patient remains to be defined. With the current implant results as a guide, the optimal patient is an older person who is low demand and has multiple joint problems involving either the ipsilateral foot or knee or contralateral ankle. Good alignment and ligamentous stability are essential. Osteonecrosis and profound osteoporosis are associated with poor results due to problems with bony fixation. Patients should be advised that the implant may fail, and that this may require further surgery, including the potential need for an ankle fusion or below-knee amputation. The results of ankle fusions, although usually initially good, seem to deteriorate with time (Table 2). Not uncommonly, patients develop either transverse tarsal or subtalar degenerative joint disease several years after an ankle arthrodesis. Because of the associated pain and functional limitations that can follow ankle fusion, efforts to develop a workable total ankle replacement continue. At present, the long-term results of most new designs are unknown. Today, total ankle arthroplasty probably should be limited to centers where surgeons have the volume of patients to master the demanding techniques needed for these operations and conduct prospective clinical trials to determine what factors lead to successful and unsuccessful outcomes.

J Bone Joint Surg Am. 1998 Oct;80(10):1410-20.

Comment in:

• J Bone Joint Surg Am. 2000 Aug;82-A(8):1205.

Total ankle arthroplasty: a unique design. Two to twelve-year follow-up.

Pyevich MT, Saltzman CL, Callaghan JJ, Alvine FG.

Department of Orthopaedic Surgery, University of Iowa, Iowa City 52246, USA.

We evaluated the intermediate-term results of a novel total ankle arthroplasty that includes insertion of the components without cement and arthrodesis of the tibiofibular syndesmosis as part of the operative procedure. One hundred consecutive Agility ankle replacements were performed in ninety-five patients between 1984 and 1993. At the time of follow-up, eighty-three patients (eighty-six ankles) were alive and twelve patients (fourteen ankles) had died. Five (6 per cent) of the eighty-six ankles in the living patients had been revised. Including the components that had been revised for loosening, twenty-one (twelve tibial and nine talar) components had migrated. Delayed union of the syndesmosis (twenty-eight ankles) and non-union of the syndesmosis (nine ankles) were associated with the development of lysis around the tibial component. Non-union of the syndesmosis was also associated with migration of the tibial component and circumferential radiolucency around that component. In addition to the patients who died, one patient had a resection of the implant with subsequent arthrodesis. The remaining eighty-two patients (eighty-five ankles) were the basis for the clinical evaluation in the study. The average age at the time of the procedure was sixty-three years (range, twenty-seven to eighty-one years). At the time of the most recent follow-up (range, 2.8 to 12.3 years; average, 4.8 years), forty-seven (55 per cent) of the remaining eighty-five ankles were not painful and twenty-four (28 per cent) were only mildly painful. The range of motion of the fifty-six ankles that were examined at the time of follow-up averaged 36 degrees (range, 10 to 64 degrees), and the results for seventy-nine (93 per cent) of the eighty-five ankles were satisfactory to the patients.