Electromagnetic fields for treating osteoarthritis.

This is an update of a Cochrane review first published in 2002. Osteoarthritis is a disease that affects the synovial joints, causing degeneration and destruction of hyaline cartilage and subchondral bone. Electromagnetic field therapy is currently used by physiotherapists and may promote growth and repair of bone and cartilage. It is based on principles of physics which include Wolff's law, the piezoelectric effect and the concept of streaming potentials.