Optimal Position of the Heel Following Reconstruction of the Stage II Adult-Acquired Flatfoot Deformity

Background: While previous work has demonstrated a linear relationship between the amount of medializing calcaneal osteotomy (MCO) and the change in radiographic hindfoot alignment following reconstruction, an ideal postoperative hindfoot alignment has yet to be reported. The aim of this study was to identify an optimal postoperative hindfoot alignment by correlating radiographic alignment with patient outcomes. Methods: Fifty-five feet in 55 patients underwent flatfoot reconstruction for stage II adult-acquired flatfoot deformity (AAFD) by 2 fellowship-trained foot and ankle orthopedic surgeons. Hindfoot alignment was determined as previously described by Saltzman and el-Khoury.(23) Changes in pre- and postoperative scores in each Foot and Ankle Outcome Score (FAOS) subscale were calculated for patients in postoperative hindfoot valgus (0 mm valgus, n = 18), mild varus (>0 to 5 mm varus, n = 17), and moderate varus (>5 mm varus, n = 20). Analysis of variance and post hoc Tukey's tests were used to compare the change in FAOS results between these 3 groups. Results: At 22 months or more postoperatively, patients corrected to mild hindfoot varus showed a significantly greater improvement in the FAOS Pain subscale compared with patients in valgus (P = .04) and the Symptoms subscale compared with patients in moderate varus (P = .03). Although mild hindfoot varus did not differ significantly from moderate varus or valgus in the other subscales, mild hindfoot varus did not perform worse than these alignments in any FAOS subscale. No statistically significant correlations between intraoperative MCO slide distances and FAOS subscales were found. Conclusions: Our study indicates that correction of hindfoot alignment to between 0 and 5 mm of varus on the hindfoot alignment view (clinically a straight heel) following stage II flatfoot reconstruction was associated with the greatest improvement in clinical outcomes following hindfoot reconstruction in stage II AAFD. Level of Evidence: Level III, comparative series.