Twice I've Had Sudden Onset Of Sharp Stabbing Pain In

Twice I've had sudden onset of sharp stabbing pain in left hip and buttock that radiates down thigh. Most severe on standing and stairs. Sometimes lessen with walking but not always. I have bursitis in both hips but this is a sudden onset stabbing pain. Had orthoscopic right knee surgery 6 weeks ago. Did well for first three weeks, then hip acted up again, so knee is more stiff because of the hip. Difficult to sleep because of the discomfort. Also have had an increase in hands and elbows with what I'm assuming is arthritis. Not exercising much because of the pain.
Thank you for your ideas