Review Question - QID 6780

A 48-year-old woman with a history of a spinal cord injury as a teenager, has unilateral weakness in the left lower extremity. She has used an ankle-foot orthosis for many years without difficulty but recently has had a recurrent painful callus beneath the great toe that has been recalcitrant to nonsurgical management. Examination reveals intact sensation with an intractable plantar keratosis (IPK) beneath the first metatarsal head. Motor examination reveals no active ankle or great toe dorsiflexion, and 4/5 plantar flexion strength at the ankle and great toe. Passive ankle dorsiflexion is 10 degrees, whereas passive plantar flexion is 40 degrees. Passive great toe dorsiflexion is 30 degrees and plantar flexion is 10 degrees. Foot alignment on standing is normal. Radiographs are shown in Figures 47a and 47b with a marker beneath the IPK. Based on her request for surgical treatment, what is the most appropriate procedure?