Well, without knowing the relevent clinical details or a detailed clinial evlauation it would be difficult to comment specifically on the situation. Hyaluronic acid is not recommended in any cause of knee pain. Knee pain could occur due to chondromalacia, tendonitis, bursitis, fractures, patellar dislocation, injuries to the internal knee ligaments/ menisci, infections/ inflammations, arthritis, cyst formation, bone growths/ tumours, nerve injuries etc; just to name a few; while hyaluronic acid may be used in advanced cases of osteoarthritis. I would suggest consulting an orthopedician for an evaluation and appropriate management.
Hope this helps.