title: Unilateral hallux valgus: is it true unilaterality, or does it progress to bilateral deformity?
abstract: BACKGROUND
  This study was undertaken to determine whether unilateral hallux valgus progresses unilaterally and to evaluate the demographics, etiologies, and radiographic findings associated with symptomatic unilateral hallux valgus deformities.
  
  
  METHODS
  Patients treated for hallux valgus between January 2004 and December 2008 were identified, and of these, 33 patients with unilateral deformities were enrolled. Progression of deformities in normal feet were evaluated at last follow-up visit, and the clinical information and radiographic measurements of those with a deformed normal foot or an unchanged normal foot were compared.
  
  
  RESULTS
  Thirty-three patients (3.4%) had a unilateral hallux valgus deformity on preoperative radiographs. The mean length of follow up was 4.7 years (range, 2.4-11). Twenty-four cases had no deformity of the normal foot at last follow-up (the unchanged group), but 15 cases had developed hallux valgus deformity (the deformed group). No significant intergroup differences were found in terms of metatarsus adductus angle (P = .412), Meary angle (P = .771), talocalcaneal angle (P = 1.000), or calcaneal pitch angle (P = .267). However, members of the deformed group were significantly younger at disease onset (P = .045), exhibited a curved first metatarsal head (P = .046), and had a larger initial hallux valgus angle (P < .001).
  
  
  CONCLUSIONS
  The frequency of bilateral symptomatic hallux valgus was found to be over 97.3%, and significant differences were found between the deformed and unchanged groups in terms of age of onset, metatarsal head shape, and hallux valgus angle.
authors.affiliation: Foot and Ankle Clinic, Department of Orthopedic Surgery, Eulji Medical Center, Eulji University School of Medicine, Seoul, Korea.
authors.forename: Ki Won
authors.initials: KW
authors.lastname: Young
authors.forename: Young Uk
authors.initials: YU
authors.lastname: Park
authors.forename: Jin Su
authors.initials: JS
authors.lastname: Kim
authors.forename: Hyuk
authors.initials: H
authors.lastname: Jegal
authors.forename: Kyung Tai
authors.initials: KT
authors.lastname: Lee
mesh_terms: D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006214:Hallux / Q000473:pathology*; D006215:Hallux Valgus / Q000473:pathology*; D006801:Humans; D008297:Male