Surgically treated adult acquired flatfoot deformity: Register-based study of patient characteristics, health-related quality of life and type of surgery according to severity.

BACKGROUND:Population-level data describing patient characteristics and interventions used in surgical treatment of adult acquired flatfoot deformity (AAFD) is lacking. METHODS:We analyzed baseline patient-reported data including PROMs and surgical interventions for patients with AAFD reported to the Swedish Quality Register for Foot and Ankle Surgery (Swefoot) 2014-2021. RESULTS:625 feet with primary AAFD surgery were registered. Median age was 60 (range 16-83) years and 64% were women. Mean preoperative EQ-5D index and Self-Reported Foot and Ankle Score (SEFAS) were low. In stage IIa (n = 319) 78% had medial displacement calcaneal osteotomy and 59% had flexor digitorium longus transfer, with some regional variations. Spring ligament reconstruction was less common. In stage IIb (n = 225), 52% had lateral column lengthening, and in stage III (n = 66), 83% had hind-foot arthrodesis. CONCLUSIONS:Patients with AAFD have low health-related quality of life before surgery. Treatment in Sweden follows best-available evidence but regional variations exist. LEVEL OF EVIDENCE:III.