Radiographic Evaluation of Minimally Invasive Distal Metatarsal Osteotomy for Hallux Valgus

Background: The use of minimally invasive surgical technique for hallux valgus is controversial. The purpose of this study was to retrospectively evaluate the radiographic results of a minimally invasive distal metatarsal osteotomy for correction of hallux valgus. Materials and Methods: From September 2005 to March 2008, a minimally invasive distal metatarsal osteotomy was performed in 82 patients (125 feet) for hallux valgus. The average age was 40.8 (range, 13 to 71) years. The mean followup period was 18.3 (range, 9 to 38) months. These patients were categorized into groups based on their gender, age, preoperative hallux valgus angle, and preoperative 1-2 intermetatarsal angle. The radiographs were reviewed for preoperative and final followup hallux valgus angle, 1-2 intermetatarsal angle, and malunion or nonunion. A final followup hallux valgus angle greater than 20 degrees was defined as "recurrence of deformity" and represented a poor radiographic result. Results: There were no nonunions but one case of plantarflexion malunion. One case had skin irritation due to prominent bone. A poor radiographic result occurred in 29 feet (23.2%). Of those 36 feet whose preoperative hallux valgus angle was equal or greater than 30 degrees, 23 feet had a poor radiographic result (63.9%). Of those 89 feet whose preoperative hallux valgus angle was less than 30 degrees, only six feet had a poor radiographic result (6.7%) (p = 0.0001). The preoperative 1-2 intermetatarsal angle was found to have no statistically significant influence on poor radiographic results (p = 0.0539). Both the age and sex of the patients had no statistically significant influence (p = 0.8048 and 0.8604, respectively). Conclusion: Based on our results, we do not recommend use of this technique to treat moderate to severe hallux valgus (hallux valgus angle, 30) degrees. We believe a traditional open osteotomy with formal capsulorrhaphy would be a better choice of treatment.