Outcome of Medial Displacement Calcaneal Osteotomy for Correction of Adult-Acquired Flatfoot

Abstract

The results of medial displacement calcaneal osteotomy (MDCO) with flexor digitorum longus (FDL) tendon transfer were reviewed, as well as postoperative radiographic changes, to determine quantitative x-ray-based indications for MDCO with FDL tendon transfer in cases of adult-acquired flatfoot. Twenty-five patients, ages 42 to 71 years, underwent MDCO with FDL tendon transfer for stage II posterior tibial tendon dysfunction. Follow-up was 2.6 to 10.2 years. Preoperative and postoperative Japanese Society for Surgery of the Foot (JSSF), Foot Function Index, and SF-36 scores and physical and radiographic findings were compared. Eight measures of foot alignment were obtained from weight-bearing radiographs at 3, 6, 9, and 12 months after surgery and every 6 months thereafter. Differences in scores and values over time were analyzed statistically. Average JSSF scores improved from 59 preoperatively to 91.3 postoperatively (p < .001). The only x-ray parameters that improved significantly and showed maintenance of the surgical correction were the lateral talometatarsal (LTMT) and tibiocalcaneal (TBC) angles. With preoperative LTMT and TBC angles of >25° and >15°, respectively, correction was inadequate. It was concluded that indications for MDCO with FDL tendon transfer in cases of adult-acquired flatfoot are a preoperative LTMT angle of <25° and hindfoot coronal alignment (TBC angle) of <15°.