Symmetry of bilateral hallux valgus deformity: A radiographic study

Hallux valgus (HV) is a common anatomical deformity leading to pain and difficulty with footwear and mobility. Bilateral HV deformity is much more common than unilateral although it remains unclear whether the severity of deformity is equal between feet. The objective was to investigate the severity and symmetry of HV in patients with bilateral symptomatic deformity presenting for surgery. Weight-bearing radiographs of patients presenting with symptomatic bilateral HV were reviewed. The hallux valgus angle (HVA) and intermetatarsal angle (IMA) were measured and classified as mild, moderate, or severe. Left-to-right comparison was undertaken to assess whether the degree of deformity was similar for each foot. The relationship between age, HVA, and IMA was also assessed. Between July 2014 and June 2020, 322 ft (161 patients with bilateral deformity) underwent corrective HV surgery. Of those, 6.8%, 64.6%, and 28.4% were classified as mild, moderate, and severe, respectively on the left side, and on the right 6.2%, 67.7%, and 26.1% were classified as mild, moderate, and severe respectively. There was no statistically significant difference between feet for either IMA (p = 0.06) or HVA (p = 0.85). There was a moderate correlation (R = 0.41, p ≤ 0.001) between HVA and IMA. There was only a 'weak' or 'very weak' correlation between age and HVA or IMA. Patients presenting for surgery with symptomatic bilateral HV have symmetrical moderate radiographic deformity at the time they present for consideration of surgical intervention.