Short-term radiographic analysis of operative correction of adult acquired flatfoot deformity

Background: Multiple procedures have been described to treat stage II (flexible) deformities driven by the clinical presence of "mild" versus "severe" deformity. The purpose of this study was to identify the radiographic correction after bony realignment procedures and to compare preoperative measures with postoperative measures to better understand the clinical application of these procedures. Methods: Seventy-two feet in 68 patients treated for stage II deformity between January 1999 and December 2010 were available for retrospective chart review. The average age of the patients was 55 years, and final radiographs were evaluated at an average of 9 months postoperatively. All patients had a flexor digitorum longus transfer to the navicular and bony realignment. Radiographic parameters measured included lateral talus-first metatarsal angle, medial cuneiform-floor distance, calcaneal pitch, anteroposterior talus-second metatarsal angle, and talonavicular coverage angle. Differences in pre- and postoperative measurements and between group comparisons were analyzed. Results: Three patient groups were identified: medial displacement calcaneal osteotomy (group 1), lateral column lengthening (group 2), and both medial displacement calcaneal osteotomy and lateral column lengthening (group 3). The lateral talus-first metatarsal angle mean difference was 5.1 degrees in group 1, 16.2 degrees in group 2, and 16.5 degrees in group 3. The talonavicular coverage angle mean difference was 5.7 degrees in group 1, 24.2 degrees in group 2, and 19.4 degrees in group 3. Changes in pre- to postoperative measures were statistically significant for all groups for the parameters measured. The pairwise group comparison revealed a statistically significant difference in the correction obtained in group 3 compared with that of group 1. Conclusion: Clinical and radiographic parameters are a consideration when choosing bony realignment procedures to reconstruct a flexible flatfoot deformity. In the treatment of more severe deformities, lateral column lengthening resulted in a greater radiographic improvement in alignment. A medial displacement osteotomy alone is also a valuable tool to correct these deformities although it provided a different level of correction compared with the lateral column lengthening.