Second ray syndrome is due to degenerative changes of the plantar plate frequently associated to hallux valgus that may require dedicated surgical correction. An US classification is proposed and its impact on patient management is assessed. A total of 52 patients with hallux valgus and associated metatarsal pain scheduled for surgery were imaged. US resulted in modification of the treatment plan in 32% of patients. The surgical procedure was modified due to a plantar plate lesion not suspected on clinical and routine imaging findings. US improves the surgical management of patients with hallux valgus and second ray syndrome.