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. .