Hyaluronic acid will not repair cartilage injuries but it may help with your pain symptoms. Manufacturers report that this is due to the substance reducing friction, but we know that while its effect lasts about 8-12 months, it really only lasts in the joint for about 3 months. So we aren’t really 100% sure how it has a lasting effect.
More important is why you have developed the injury and looking at how to overcome this and limit further issues. Also, some postulate that PRP injection, short for platelet-rich plasma, can help - not with the restoration of cartilage but, again, with pain symptoms.