Surgical Treatment of Severe Idiopathic Flexible Flatfoot byEvans–Mosca Technique in Adolescent Patients: A Long-TermFollow-Up Study

Flexible idiopathic flatfoot is very common in growing age and rarely causes pain or disability. Surgery is indicated only in severesymptomatic cases that are resistant to conservative treatment, and numerous surgical procedures have been proposed. Lateralcolumn calcaneal lengthening as described by Evans and modified by Mosca is a widely used surgical technique for the correctionof severe symptomatic flexible flatfoot. In the present study, we report the long-term clinical and radiographic results in 14adolescent patients (mean age: 12.8 years) affected by severe symptomatic flexible flatfoot, surgically treated by Evans–Moscaprocedure, for a total of 26 treated feet (12 cases bilateral and 2 unilateral). In all cases, surgery was indicated for the presence ofsignificant symptoms resistant to nonsurgical management. Clinical evaluation was made according to the American OrthopedicFoot and Ankle Society (AOFAS) Ankle-Hindfoot Scale, the Foot and Ankle Disability Index (FADI) Score, and Yoo et al.’scriteria. Radiographic evaluation was made using anteroposterior and lateral weight-bearing radiographs of the feet to evaluateMeary’s angle and Costa–Bertani’s angle and to evaluate possible osteoarthritic changes in the midtarsal joints. At follow-up(mean: 7 years and 7 months), we observed a satisfactory result in all patients. *e mean average score of the AOFAS Ankle-Hindfoot Scale improved from 60.03 points to 95.26; the mean FADI score improved from 71.41 to 97.44; and according to Yooet al.’s criteria, the average clinical outcome score was 10.96. At radiographic examination, nonunio‎n of the calcaneal osteotomywas never observed. Meary’s angle improved from an average preoperative value of 25°to 1.38°at follow-up; Costa–Bertani’s angleimproved from an average preoperative value of 154.2°to 130.9°at follow-up. In no case, significant radiographic signs ofmidtarsal joint arthritis were observed. According to our results, we believe that Evans–Mosca technique is a valid option ofsurgical treatment for severe idiopathic flexible flatfoot and allows a satisfactory correction of the deformity with a low rateof complications.