Cytori Therapeutics (CYTX) shares have surged in pre-market trading today after the company announced that the Cytori Cell Therapy was approved for clinical use to treat knee osteoarthritis at the Tokyo Osteoarthritis Clinic under the Japanese 'Act on the Safety of Regenerative Medicine�. Tokyo Osteoarthritis Clinic will begin to treat patients with Cytori Cell Therapy immediately. The approval is limited to facilities under the clinic�s umbrella but does not restrict the number of patients that can be treated.