This study showed that surgical treatment for end-stage ankle OA resulted in satisfactory clinical outcomes in patients aged ≥75 years; improvements in scores were observed in patients undergoing both TAA and AA. Furthermore, the improvements were comparable to those observed in patients aged <75 years. Thus, the results of our study suggest that surgical treatment of end-stage ankle OA can be a viable treatment option, even in elderly patients.
We showed that the JSSF hindfoot scale score and all SAFE-Q subscale scores improved significantly for TAA patients in the older age group with a mean age of 78 years. Specifically, the improvement in the SAFE-Q subscale scores ranged from 13 to 38 points. Non-surgical treatment is the first-line treatment for ankle OA; however, insufficient data support its efficacy (23). Moreover, elderly patients, such as those aged >75 years, tend to undergo non-surgical management because of their limited physical functioning and concern for postoperative complications (7). The minimal clinically important differences in the SAFE-Q scores for TAA patients were not determined. However, the recorded improvements in the scores found in this study were comparable to those of previous reports (24–26) and were clinically significant.
This study showed that the recorded improvements in the outcomes of the older age group were comparable to those of the younger age group for TAA patients. Our results were in line with those of Tenenbaum et al. (14) in which patients aged >70 years and those aged 50-60 years demonstrated equivalent improvement in the American Orthopedic Foot and Ankle Society (AOFAS) ankle/hindfoot scale and visual analog scale (VAS) pain scores. Demetracopoulos et al. (15) also found that most of the clinical outcomes in patients aged >70 years were comparable to those aged ≤70 years, although the AOFAS function and SF-36 vitality subscale scores were lower in older patients than in younger patients. Other studies used a younger cut-off age of 50-65 years (8–13) and reported no difference in clinical outcomes depending on age. Thus, the results of our study suggest that TAA could be a treatment of choice even in patients aged ≥75 years. Furthermore, there was no difference in intraoperative and postoperative complications between the groups, which was a concern for the elderly.
Similar to TAA, all clinical outcomes improved postoperatively in AA patients in the older age group, with a mean age of 79 years. Only a few studies have reported postoperative results for AA in geriatric patients (16, 17). Strasser et al. (17) found that the postoperative foot and ankle ability measurement scores were 82 points in 22 patients with a mean age of 75 years. However, the authors (17) did not obtain the preoperative scores. Additionally, Yang et al. (16) assessed 41 patients (mean age, 71 years) who had arthroscopic AA and observed significant improvement in the AOFAS ankle/hindfoot scale and VAS pain scores. Although direct comparison would be difficult because of the different evaluation measures used, our results were consistent with those of previous studies (16, 17).
Post-AA, improvements in clinical scores were comparable between patients aged <75 years and those aged ≥75 years. Previous studies have shown that age at surgery was not associated with clinical outcomes (27–29). However, the patients in these studies were relatively young, with a mean age of 57-63 years. Therefore, the results of our study suggest that even older patients can expect a similar level of clinical improvement after undergoing AA. In contrast, Berlet et al. (30) reported that patients aged ≥60 years had a higher risk of nonunion after foot and ankle arthrodesis. However, we could not determine the effect of age on bone union because of the small study population. Furthermore, there was no difference in intraoperative and postoperative complications between the groups or within the TAA group.
This study has several limitations. First, the older age group may have consisted of selected patients with good health status; therefore, surgeons would have logically expected good postoperative outcomes. This limitation could be biased toward better results in the older age group. Second, several covariates that may affect the clinical outcomes, including comorbidities, mental status, and physical activity level, were not included in the multivariate analysis because of the retrospective nature of this study. Although our study can provide clinically meaningful information to patients and surgeons, further prospective studies are necessary to draw definitive conclusions on the association between age and clinical outcomes. Third, the follow-up period was relatively short, with a mean period of 18-26 months. However, considering both short-term results and long-term outcomes is important for elderly patients who may have a shorter life expectancy than younger patients. Fourth, despite collecting patient data from eight hospitals, the study population was relatively small, especially for comparing the incidence of revision surgery between the age groups.