Distraction Osteogenesis for the Shortened Metatarsal After Hallux Valgus Surgery

Background: Shortening of the first metatarsal is known to occur during hallux valgus surgeries. If the shortened first ray disrupts the normal weight transfer, then transfer metatarsalgia may result. After failed conservative treatment, a common operative option is an osteotomy of the lesser metatarsals. However, osteotomies of normal metatarsals further alter the normal anatomy and can significantly shorten the forefoot. Restoration of first metatarsal length using distraction osteogenesis may more closely restore normal foot anatomy and biomechanics and subsequently treat transfer metatarsalgia. Methods: Five patients had distraction osteogenesis for a shortened first metatarsal that resulted from a previous hallux valgus surgery. A four-pin single-plane external fixator was applied to the first metatarsal to lengthen the metatarsal under the principles of distraction osteogenesis. Lengthening was complete once the affected first metatarsal was equal to the length of the adjacent second metatarsal. Results: The mean consolidation period was 15.8 weeks. Preoperative and postoperative length of the first metatarsal was expressed as a percentage of the length of the ipsilateral second metatarsal. The preoperative mean was 77.1% and the postoperative mean was 93.8%. All osteotomies went on to consolidation, and no grafting or secondary procedures were needed. There were no postoperative infections, malrotation, or malalignment. All patients reported reduction in their forefoot pain and returned to a nonantalgic, full weightbearing gait. Conclusions: This small series depicts the potential success of distraction osteogenesis for the iatrogenically shortened first metatarsal and associated transfer metatarsalgia.