Immediate weight bearing following modified lapidus arthrodesis.

First metatarsocuneiform arthrodesis (Lapidus procedure) can provide powerful correction of mild to moderate hypermobile or severe hallux valgus, although a period of non-weight bearing may be necessary. The purpose of this retrospective investigation was to compare patients who underwent a modified Lapidus arthrodesis with 2 screws plus an additional "neutralization" Kirschner-wire with immediate partial weight-bearing in a removable boot, with a control group without the Kirschner-wire who were non-weight bearing for 6 weeks in a short leg cast. A total of 41 consecutive patients from January 2004 to January 2007 were included in this comparative cohort study. There were no significant radiographic changes between immediate and final 6-month postoperative radiographs in regard to first intermetatarsal angle (degree) and first ray elevation measurements (first to second metatarsal head elevation [mm] and Seiberg index [mm]) within groups (P = .49, .47, and .54, and 95% confidence intervals of [-2.1, 1.2], [-0.32, 2.03], and [-0.82, 0.44], respectively) or between groups (P = .259, .67, and .083, and 95% confidence intervals of [-4.2, 1.2], [-1.39, 0.91], and [-1.77, 0.12], respectively), as computed with paired 2-sample t tests. Stratified Mantel-Haenszel analyses revealed both groups to be comparable relative to severity of deformity, gender, age, smoking history, perioperative immunosuppressant use, and other comorbidities. No nonunions or malunions where observed in either group. The use of a temporary Kirschner-wire as a third point of fixation may enable immediate protected weight bearing, by minimizing load placed on the crossed lag screw construct, in patients undergoing modified Lapidus arthrodesis.