Fusion Rate of First Tarsometatarsal Arthrodesis in the Modified Lapidus Procedure and Flatfoot Reconstruction

Abstract

Background: The purpose of this study was to determine the overall first tarsometatarsal joint (TMTJ) union rate in patients after they had a modified Lapidus procedure or a TMTJ arthrodesis as part of a flatfoot reconstruction. Methods: We retrospectively reviewed the charts of 182 patients (201 feet) who had a modified Lapidus procedure or a TMTJ arthrodesis as part of a flatfoot reconstruction between May, 1997, and May, 2001; all had at least a 6-month followup. The data collected included age, gender, tobacco use, diabetic status, complications, and radiographic evidence of union. There were 167 women and 15 men. The right foot was operated on in 106 patients and the left foot in 95. The average age was 53 (range 11 to 87) years. Results: First TMTJ arthrodesis healed uneventfully in 193 (96%), and eight (4%) had nonunions. Of those eight patients with nonunions, five had previous bunion surgeries, two were smokers, and one had diabetes. There were 25 (12%) patients with previous bunion surgeries and five of these (20%) had nonunions. Four patients (2%) had symptomatic nonunions resulting in revision. Of the 21 patients undergoing flatfoot reconstruction, none had a nonunion. Conclusion: One criticism of the modified Lapidus procedure is the unacceptable nonunion rate (10 to 12%). Out of the 201 feet, we had a 4% nonunion rate and a 2% revision rate, which is well below the reported nonunion rates. We also have found that patients with previous bunion surgery and recurrent deformity were at a higher risk for a nonunion. Clinical Relevance: We believe that the modified Lapidus procedure and first TMTJ arthrodesis can achieve acceptable union rates and be successful for correcting hallux valgus with a hypermobile first ray and can also be applied to certain patients undergoing flatfoot reconstruction.