I would say NO...while it may be good to work it into your routine to simply keep cardio going it will in no way improve running.....Just as actually doing a TTwill improve your TT ya gotta run baby,,,,I say do fewer miles at a higher intensity....Sprint more, track work longer rest time recovery between running. If you knees are that bad just do less more work harder...Much research has demonstrated that Higher INTENSITY but shorter time is beneficial.
Good luck ..