Would a large weight loss help or cure severe knee or hip pain?

I don’t have pain. But two friends of mine have hip or knee pain that is so bad that one is on prescribed Hydrocodone. He thought a large loss of weight (he was not overweight) would help him but, as he lost quite a bit like two sizes his pain progressed and now he uses a cane. The other friend has hip and knee pain , is a little overweight and wants to lose fifteen pounds to help stop her pain.
Do you think weight loss alone can cure hip or knee pain?