Total ankle arthroplasty incorporating a total talar prosthesis

Aims

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.

Patients and Methods

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 (61 to 82) and 75 years (62 to 82), respectively. The mean follow-up was 58 months (43 to 81) and 64 months (48 to 88), respectively. The outcome was assessed using the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale, the Ankle Osteoarthritis Scale (AOS), and the Self-Administered Foot Evaluation Questionnaire (SAFE-Q).

Results

The mean preoperative JSSF score of the combined TAA and standard TAA groups was 44 (sd 11) and 49 (sd 10), respectively. The mean postoperative JSSF scores were 89 (sd 6.1) and 72 (sd 15), respectively. The mean postoperative JSSF score of the combined TAA group was significantly higher (p = 0.0034). The mean preoperative AOS scores for pain and function in the combined TAA and standard TAA groups were 5.8 (sd 3.3) and 5.5 (sd 3.1), and 8.6 (sd 1.3), and 7.1 (sd 2.9), respectively. The mean postoperative AOS scores of pain and function were 2.5 (sd 2.5) and 2.2 (sd 1.9), and 2.5 (sd 3.3) and 3.4 (sd 2.9), respectively. There were no significant differences between the two groups in terms of postoperative AOS scores. The mean postoperative SAFE-Q scores were: for pain, 76 (sd 23) and 70 (sd 23); for physical function, 66 (sd 25) and 55 (sd 27); for social function, 73 (sd 35) and 62 (sd 34); for shoe-related, 73 (sd 19) and 65 (sd 26); and for general health, 78 (sd 28) and 67 (sd 29), respectively. There were no significant differences between the two groups in terms of postoperative SAFE-Q scores.

Conclusion

Combined TAA resulted in better clinical results than standard TAA.