Abstract
Research Type:
Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies
Introduction/Purpose:
Currently, the number of total ankle prosthesis performed is increasing. The literature describes that this procedure improves patients' related outcome measures compared to their preoperative baseline state. A minimum two-year follow-up is required for outcome publications. To date, there are no long-term, high-volume studies analyzing how patient-reported outcomes behave over time.
Methods:
This is a retrospective cohort study of all total ankle prosthesis implanted at a single tertiary center. Primary total ankle prosthesis performed between 2003 and 2023 were analyzed. The scores for the physical component of the SF36 (SF-36 PC), the mental component of the SF36 (SF-36 MC), the Ankle Arthritis Score (AAS), and the Ankle Osteoarthritis Scale (AOS) were analyzed at the time of enrollment, at 6 months, and annually, up to 15 years postoperatively if available. Scores were compared over time using the Friedman test. Subsequently, if any statistically significant differences were observed, the differences between each period were analyzed using the Wilcoxon test. Finally, the P values were adjusted according to the Bonferroni correction.
Results:
A total of 631 total ankle replacements were included in the study, with a mean follow-up of 9.9 years (SD 6.3). Statistically significant differences at all follow-ups were found in the AOS scores and the SF-36 PC (both P < 0.001) compared to baseline, whilst the AAS scores and the SF-36 MC did not show any significant differences. The AOS and SF-36 PC scores improved respectively by 89.2 % and by 91.3 % of their total improvement in the first year, and the next year, this increased to 92.6 % and 100 %. Afterwards, the PROMs showed minimal variation until 15 years, when both scores began to decline.
Conclusion:
This is one of the largest cohort studies with more than 15 years of follow-up after total ankle replacements. The tremendous improvement, especially in the first year, of patient-reported outcomes indicate that total ankle replacements provide significant advantages to patients with end-stage ankle disease. The minimal changes observed one year and longer after the surgery support the understanding that patients will experience the procedure's success within this timeframe. With this information, surgeons could advise patients before the procedure. This also suggests that follow-up for studies on patient-related outcomes could be set to a maximum of one year.
Patient reported outcomes after total ankle prosthesis