Patient acceptable symptom state for European Foot & Ankle Society Score After Hallux Valgus Surgery

BACKGROUND: The European Foot & Ankle Society (EFAS) Score is a validated patient-reported outcome measure for the evaluation of postoperative foot and ankle outcomes. Yet, unlike the AOFAS, there is a dearth of literature defining the patient acceptable symptom state (PASS) for EFAS after hallux valgus surgery. This study aimed to determine the PASS for EFAS after hallux valgus surgery. METHODS: This was a retrospective cohort study using prospectively collected data of patients who underwent hallux valgus surgery between May 2017 and September 2023 in the authors' institution. Patients were evaluated preoperatively and at 6 months and 2 years postoperatively, using functional outcomes such as EFAS and American Orthopaedic Foot & Ankle Society (AOFAS) Hallux Metatarsophalangeal-Interphalangeal Rating System. PASS thresholds were determined with the Youden Index on receiver operating characteristic curves, with responses to an anchor question as the external criterion. RESULTS: A total of 361 patients were followed up for 2 years. This included 324 (89.8%) female and 37 (10.2%) male patients. The mean age and body mass index (BMI) was 56.0 ± 14.0 years and 24.1 ± 4.6, respectively. Patients underwent various procedures including scarf-Akin osteotomy (n = 220, 60.9%), minimally invasive chevron-Akin osteotomy (n = 102, 28.3%), arthrodesis of first metatarsophalangeal joint (n = 15, 4.2%), scarf osteotomy (n = 14, 3.9%), Lapidus procedure (n = 7, 1.9%), and Bosch osteotomy (n = 3, 0.8%). The PASS for EFAS was determined to be 20.5 at 6 months (sensitivity 86.8%, specificity 70.4%) and 23.5 at 2 years (sensitivity 87.2%, specificity 72.0%). However, the PASS for AOFAS was determined to be 84.5 at 6 months (sensitivity 72.6%, specificity 75.0%) and 82.5 at 2 years (sensitivity 90.9%, specificity 63.4%). CONCLUSION: The PASS for EFAS established in this study can be used for the clinical interpretation of future hallux valgus studies. A potential ceiling effect of the EFAS was identified, and the revised AOFAS PASS thresholds may warrant consideration.