Background: Biomechanically, the Ludloff osteotomy fixed with lag screw compression has been shown to be more rigid than proximal crescentic and other proximal first metatarsal osteotomies for correction of symptomatic hallux valgus with a moderate to severe increase in the first intermetatarsal angle. The Ludloff osteotomy may, therefore, have a lower incidence of dorsal malunion and transfer metatarsalgia than other proximal first metatarsal osteotomies, such as the crescentic or chevron. Methods: We reviewed the results of 82 consecutive cases of moderate to severe hallux valgus deformities corrected with the Ludloff oblique metaphyseal-diaphyseal osteotomy of the first metatarsal combined with a distal soft-tissue procedure and medial eminence resection. Results: Follow-up was possible in 70 cases (85%) at an average of 30 months (range, 18 to 42 months). Preoperatively, the mean hallux valgus and first intermetatarsal angles were 31 degrees and 16 degrees, respectively. Postoperatively, these values improved to an average of 11 degrees and 7 degrees. In the sagittal plane, the first metatarsal was plantarflexed by an average of 1 mm, and there were no symptomatic transfer lesions of the second metatarsal. The mean AOFAS hindfoot score improved from 54 to 91 points. Complications included prominent hardware requiring removal (5), hallux varus (4), delayed union (3), superficial infection (3), and neuralgia (3). Conclusions: The use of the Ludloff oblique first metatarsal osteotomy resulted in excellent correction of the first intermetatarsal angle in patients with moderate to severe hallux valgus. With the plane of the osteotomy and rigidity of fixation, immediate ambulation was possible with minimal risk of dorsiflexion malunion of the first metatarsal.
Static biomechanical studies have demonstrated that the Ludloff shaft metatarsal osteotomy is significantly more stable than other commonly used proximal (basilar) osteotomies, such as the proximal crescentic and the proximal chevron. High average static bending failure moments have been recorded for the screw fixation Ludloff osteotomy construct. The objective of the current study was to find a reasonable alternative method of fixation in cases where a short osteotomy may not be amenable to adequate screw fixation and in cases where an inadvertent intraoperative fracture of the metatarsal occurs and subsequent screw fixation is precarious due to inadequate bone stock. A Ludloff osteotomy was performed on 24 matched pairs of cadaveric specimens to compare the strength of fixation of three different types of Kirschner wires (smooth, threaded, and SOC threaded). Biomechanical testing with plantar force was carried out, and failure load and stiffness were measured for each specimen. The current results indicate that the threaded pin construct provides adequate strength for fixation of the Ludloff osteotomy in the clinical setting.