Does Hallux Valgus Correction Reduce the Width of the Forefoot?
University of Texas Medical Branch
Background: Hallux valgus has been associated with a widened forefoot. Success after hallux valgus surgery is correlated with relief of toe pain in conventional shoes and improvement in the appearance of the foot. Therefore, reduction in forefoot width referred to as metatarsal span, likely correlates with both criteria and may be a reliable radiographic indicator of success after hallux valgus surgery. Women’s shoes differ on average 9.5mm and men’s shoes differ approximately 4.8mm in width size measurements. Methods: Pre- and postoperative radiographs of 52 patients who underwent correction of hallux valgus with a distal chevron osteotomy and Akin osteotomy were evaluated by four observers. The observers measured the hallux valgus angle (HVA), the intermetatarsal 1st and 2nd metatarsal angle (IMA), and the metatarsal span (MS). The data were assessed with analysis of variance to establish interobserver reliability. Results: Interobserver reliability was 0.95 for the HVA (CI 0.92-0.97), 0.9 for the IMA (CI 0.85-0.94), and 0.98 for the MS (CI 0.97–0.99). Preoperative HVA ranged from 14 degrees to 48 degrees, IMA ranged from 6 degrees to 25 degrees, and MS ranged from 74.2mm to 110.6mm. The average HVA improvement was 19.4 degrees, IMA improvement was 6.7 degrees, and MS reduction was 8.7mm. No correlation was identified with regards to correction of the HVA or IMA to MS. Conclusion: Digital radiographic linear measurements were easily and reliably made. Therefore, linear measurements as described in this article can be used as a tool to evaluate if clinical outcomes correlate with reduction of metatarsal span. Hallux valgus correction reduces the forefoot width and may play a part in helping patients to fit more comfortably into shoe wear. Keywords: Hallux valgus; Radiography; Metatarsal Span; Reliability; Shoe Width