Surgery delayed for more than two weeks has less of a chance of having a satisfactory outcome. Surgery is only half the battle for this problem. Therapy is a necessary and essential treatment for most people recovering from a flexor tendon injury. Special hand therapy usually involves making one or more custom splints, performing and supervising special exercises, and making the hand feel better in general. Confirm that this is the problem, and check for nerve injury or other problems which can occur at the same time.
Treatment really depends on the type of injury.
Moving the fingers and doing exercises right away. A splint or a cast, along with special exercises. Performing surgery to repair the damage. Sewing a cut flexor tendon together is something like sewing two small ropes together, end to end. Special stitches are used on both the inside and the outside - but even with the best stitches, the repair can still be pulled apart if it is not protected by a special splint.