Quality shoes should last at least two years, or more, with attention paid to wear patterns caused by orthopedic foot, ankle, and knee conditions. Shoes that wear more on the edges and in isolated areas of the heel or sole indicate a balance or medical problem and lessen the time before shoe replacement is required. But, special inserts or shoe modifications can improve the time your shoes will last and you will normally have more foot comfort as well. Once shoes start to deform, unless repaired or modified, shoes will wear out much more quickly.