Total ankle arthroplasty (TAA) has become the most reliable surgical solution for patients with end-stage arthritis of the ankle. Aseptic loosening of the talar component is the most common complication. A custom-made artificial talus can be used as the talar component in a combined TAA for patients with poor bone stock of the talus. The purpose of this study was to investigate the functional and clinical outcomes of combined TAA. Ten patients (two men, eight women; ten ankles) treated using a combined TAA between 2009 and 2013 were matched for age, gender, and length of follow-up with 12 patients (one man, 11 women; 12 ankles) who underwent a standard TAA. All had end-stage arthritis of the ankle. The combined TAA features a tibial component of the TNK ankle (Kyocera, Kyoto, Japan) and an alumina ceramic artificial talus (Kyocera), designed using individualized CT data. The mean age at the time of surgery in the combined TAA and standard TAA groups was 71 years (Aims
Patients and Methods
Between 2002 and 2008, 130 consecutive ankles were replaced with an hydroxyapatite (HA) and titanium-HA-coated Ankle Evolutive System total ankle prosthesis. Plain radiographs were analysed by two independent observers. Osteolytic lesions were classified by their size and location, with cavities >
10 mm in diameter considered to be ‘marked’. CT scanning was undertaken in all patients with marked osteolysis seen on the plain radiographs. Osteolytic lesions were seen on the plain films in 48 (37%) and marked lesions in 27 (21%) ankles. The risk for osteolysis was found to be 3.1 (95% confidence interval 1.6 to 5.9) times higher with implants with Ti-HA porous coating. Care should be taken with ankle arthroplasty until more is known about the reasons for these severe osteolyses.
We describe the early results of a prospective study of 100 total ankle replacements (96 patients) at a single centre using the Mobility Total Ankle Replacement. At final review, six patients had died and five ankles (5%) had been revised, two by fusion and three by exchange of components. All remaining patients were reviewed at a minimum of three years. The mean follow-up was 43 months (4 to 63). The three-year survival was 97% (95% confidence interval (CI) 91 to 99). The four-year survival was 93.6% (95% CI 84.7 to 97.4). The portion of bony interface that was visible on plain radiograph was divided into 15 zones and a radiolucent line or osteolytic cavity was seen in one zone in 14 ankles. It was not seen in more than one zone. In five ankles it was >
10 mm in width. This study suggests that the early outcome of ankle replacement is comparable to that of other total joint replacements.
