ObjectiveTo investigate the effectiveness of double arthrodesis to correct flatfoot deformity with pes valgus. MethodsBetween May 2009 and May 2012, 12 patients with flatfoot deformity and pes valgus were treated using subtalar and talonavicular joints arthrodesis through a single medial incision approach. There were 5 males and 7 females with an average age of 53.3 years (range, 21-78 years), including 5 left feet and 7 right feet. Of them, 11 cases had posterior tibial tendon dysfunctions; 6 cases were at Johnson-Strom stageⅢ, 5 cases at stageⅡ(c); and 1 case had tarsal coal ition. Preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analogue scale (VAS) score were 48.75±3.46 and 6.08±1.14, respectively. ResultsThe mean operation time was 85.6 minutes (range, 65-125 minutes). Eleven patients were followed up for 19.4 months on average (range, 13-30 months). All of the cases obtained primary healing of incision, with no complication of infection and nerve or blood vessel injury. X-ray film showed that the mean time of bone union was 9.8 weeks (range, 7-18 weeks); no bone nonunion occurred. No loosening or breakage of internal fixation was observed. Pain occurred at the calcaneal-cuboid joint (1 case) and at fixation site (1 case), and was relieved after symptomatic treatment. The mean AOFAS score and VAS score were significantly increased to 81.36±2.98 and 0.72±0.11 respectively, showing significant differences when compared with preoperative scores (t=19.946, P=0.000; t=16.288, P=0.000). ConclusionSubtalar and talonavicular joints arthrodesis by a single medial incision approach is a useful alternative to tri ple arthrodesis for the correction of flatfoot deformity with pes valgus