Functional Outcomes After Total Ankle Replacement: A Forgotten Joint Score-12 Analysis With Up to 10-Year Follow-up

BackgroundTotal ankle replacement (TAR) offers pain relief and preservation of motion in patients with end-stage ankle arthritis. The Forgotten Joint Score-12 (FJS-12) is a validated patient-reported outcome measure (PROM) designed to assess joint awareness, but data in TAR remain limited.MethodsA retrospective study of all TARs performed at our institution between 2014 and 2023 was conducted. Patients with a minimum of 2 years of follow-up were contacted by telephone, and the FJS-12 was administered. Mean follow-up was 4.83 ± 2.48 years (range 2-10). Demographics, surgical details, and complications were recorded. Statistical analyses explored factors associated with FJS-12 scores. At the end of FJS-12 administration, patients graded their satisfaction on a 4-point Likert scale.ResultsOf 102 ankles screened, 81 patients were eligible (mean age 69.7 years; mean body mass index [BMI] 31.3). Female sex (P = .008), right-sided TAR (P = .004), and additional tendo-Achilles lengthening (P = .004) were associated with lower FJS-12 scores. Scores declined at 3 years post-surgery (P = .011). Other factors, including BMI, smoking, and hypertension, had no significant impact. Based on the score distribution and satisfaction analysis, the Patient Acceptable Symptom State (PASS) threshold corresponded to an FJS-12 of 43, and the forgotten-joint threshold to 85.ConclusionTotal ankle replacement provided favorable short- to mid-term functional outcomes, as measured by the FJS-12. The FJS-12 is a sensitive PROM that detects subtle differences in patient-reported outcomes and may be a useful adjunct in routine TAR follow-up. We propose preliminary TAR-specific PASS and forgotten-joint thresholds that closely match those reported for knee replacement and are lower than those for hip replacement. These thresholds provide clinically meaningful benchmarks for patient satisfaction and should be validated in larger, prospective, multicentre cohorts.Level of Evidence:Level III, retrospective cohort study.