Midterm and Long-term Follow-up After Surgical Reconstruction for Lateral Polydactyly of the Foot With Mosaic-like Alignment of the Phalanx Bones.

Background: The phalanx bones in several cases of lateral polydactyly of foot revealed complicated alignment with radiographic findings revealing medial-protrusion and lateral deviation of the middle phalanx. We previously defined such cases as showing "mosaic-like alignment" and demonstrated favorable postoperative outcomes using our surgical procedure. The aim of this study was to evaluate the midterm and long-term postoperative outcomes in such cases. Methods: The study included 17 feet from 16 patients; 5 male and 11 female, with one bilateral case. The radiographic findings in all cases revealed a mosaic-like alignment of phalanges. Average age of the patients at the initial surgery was 12 months and average duration of post-operative follow-up was 89 months (60 to 132 mo). The surgical procedures were focused on the alignment between the distal and proximal phalanges independent of the middle phalanx alignment. Ligamentous joint stability was restored using collateral ligament reconstruction. We retrospectively evaluated post-operative outcomes, and subjective evaluation by the patients and parents was carried out. Results: No cases revealed either varus or valgus deformities, pigmentation of the grafted skin, or functional disturbance. As for postoperative complications, we observed visible thickening in 7 toes, 3 of which further underwent partial resection of the middle phalanx. Subjective evaluation of the postoperative results by the patients and parents was "very satisfied" or "satisfied" in 15 of 16 cases. Conclusion: On the basis of our midterm to long-term postoperative outcomes, we believe that our method of surgical reconstruction provides a new option for the treatment of lateral polydactyly of the foot with mosaic-like alignment of the phalanx bones.