Impact of forefoot width variation on clinical and functional outcomes following the Lapidus procedure

This study aimed to evaluate the effect of variations in bony and soft tissue foot widths on clinical and functional outcomes after hallux valgus correction with the Lapidus procedure.

Forty-three feet in 35 patients with a mean follow-up of 18.5 months undergoing the LP were reviewed. Clinical and functional data were assessed with the VAS for pain, AOFAS Scale, LEFS and SF-12 health survey, which is divided into physical and mental health composite scales (PCS-12 and MCS-12). Radiographic analysis of forefoot width was based on bony and soft tissue limits. Intermetatarsal-angle and HV-angle were also assessed.

Bony width changed significantly from 95.5 mm to 84.2 mm (11.8%) and soft tissue width from 107.12 mm to 100.84 mm (5.86%) (p < 0.001). IMA and HVA improved significantly. Significant clinical and functional improvements were observed, except in MCS-12. In simple linear regression, correlation was found between variations of bony width with Δ-AOFAS and Δ-PCS-12, meaning that as the forefoot narrows, their values increase (p = 0.02 and p = 0.005, respectively). It was also related to Δ-IMA, meaning that the forefoot narrows as these parameters improve (p < 0.001 and p < 0.001). Soft tissue width was related to Δ-PCS-12 and Δ-AIM. In multiple linear regression, the strongest correlation was between bony width variation and Δ-IMA (p = 0.029, r² = 0.22).

Forefoot narrowing was correlated with improved clinical and functional outcomes, as measured by AOFAS and PCS-12. In addition, correction of the radiographic parameters, mainly IMA, reflected on a significant decrease in the forefoot width.