California ? Gov. Arnold Schwarzenegger underwent arthroscopic knee surgery Saturday night after a nagging injury prompted him to clear his schedule and cancel a weekend appearance in Lake Tahoe.

Schwarzenegger spokesman Aaron McLear said the surgery was needed after the governor tore the shock-absorbing cartilage in his knee a couple of weeks ago while working out.

Schwarzenegger, 61, was under general anesthesia during the hourlong procedure. Lt. Gov. John Garamendi temporarily took over the duties of governor for that hour.

McLear said the recovery process would not interfere with the governor’s job. Schwarzenegger will not require a wheelchair or crutches during his recovery.