Treatment Outcomes of Total Ankle Arthroplasty Using an Artificial Talus

Abstract

Category: Ankle Arthritis Introduction/Purpose: Problems associated with mid- to long-term total ankle arthroplasty (TAA) include loosening and sinking of the talus implant. These problems arise due to a lack of stability compared with artificial joints such as knees and hips. In Japan, aluminum ceramic talus implants have been developed and are reported to result in good treatment outcomes. Here we investigated and report the treatment outcomes for combined TAA (cTAA), in which TAA is combined with a talus implant during the initial procedure. Methods: We assessed 15 cases involving 16 feet that underwent cTAA for which follow-up was available for at least 6 months. These cases comprised five feet with stage IIIb osteoarthritis and nine feet with stage IV osteoarthritis according to the Takakura classification as well as two feet with talus necrosis. The mean patient age was 73.5 years, and the mean follow-up period was 9.1 months. The talus implant was completely customized for all cases, and TNK Ankle (Kyocera, Japan) tibial components were used. Assessments were performed before and after surgery using the Japanese Society for Surgery of the Foot scale (JSSF scale) for physician-led objective evaluation and the Japanese Orthopaedic Association/Japanese Society for Surgery of the Foot and Self- Administered Foot Evaluation Questionnaire (SAFE-Q) subscales for patient-reported subjective evaluation. The validity and reliability of the JSSF scale and SAFE-Q have been verified by metering psychological verification. Scores were compared using paired t-tests. Results: The mean JSSF score improved significantly from 46.7 points preoperatively to 85.3 points postoperatively. For the SAFE-Q, pain and pain-related scores improved significantly from 40.5 points preoperatively to 75.8 points postoperatively (p < 0.001), physical function and daily lifestyle status improved significantly from 41.1 points preoperatively to 72.9 points postoperatively (p < 0.001), social lifestyle function improved significantly from 37.8 points preoperatively to 76.4 points postoperatively (p < 0.001), and overall sense of health improved significantly from 51.7 preoperatively to 80.7 postoperatively (p < 0.001). Shoe-related results improved from 50.0 points preoperatively to 69.4 points postoperatively (p = 0.038). Only one postoperative complication was noted, which was a case of deep wound infection. Conclusion: Short-term outcomes for cTAA were mostly good in our study population. The findings suggest that talus implants could be used as a treatment option for cases involving severe deformities, crushed talus injuries, and bone defects in which the use of TAA had previously been difficult, which can be handled with cTAA. These findings reveal new possibilities for expanded indications going forward. However, as these were short-term treatment outcomes, further follow-up is required in future studies.