Biomechanics of implanted joints of the foot.

Joint implants in the foot have contributed much to reducing deformity and pain. They can act as spacers to improve cosmetic appearance; they can increase or decrease motion in joints, while adding stability; and they can replace arthritic or diseased joints and reduce their associated symptoms. They cannot produce normal function of the foot. There is a great need to know more about the long-range effects of implanted joints on foot function and the associated compensations that invariably occur. This knowledge will lead to improved criteria for the existing implants and new designs and materials for the implants yet to come.