Replying to Creaky Knees

So I came off my mountain bike a few months ago and broke my wrist and grazed up my knees (mostly my left), a couple weeks later I noticed that my knees (predominantly left) are creaking/grinding whenever I squat under anything from a moderate to heavy load, creaking is probably the best word I can describe it with and I can feel it creaking but I get no pain from it at all. Anyone else had this? Will it eventually stop or is it worth seeing physio about? Cheers