Sharp stabbing sensation in left knee. pain occurs when bending or lifting leg. no pain pushing or massaging knee. ideas?

Ideas, many: Knee pain is very frequent, as with other pains try to recall: onset of pain, radiation, alleviating or aggravating factors, severity of the pain. Possible causes: sprain, tendonitis, bursitis, osteoarthritis, etc. You need to see your primary doctor first and then maybe you need further referral if is not a simple diagnosis. If you had a trauma and then pain seek an orthopedist.