Hi,
I would suggest you to see knee surgeon.If you have ACL tear of grade >3, you may need to go through ACL repair surgery along with that Doctor will repair your meniscus and take out all loose cartilage tissue from the joint space. If loose pieces of cartilage tissue persist for long time, it might cause OA problem early to age. Meanwhile, you take physical therapy sessions, there are few exercises which are restricted in ACL injury specially Isotonic Quadriceps strengthening training and some movements like cross legged position etc. Once your healing start and you gain some strength in muscles, you can resume your all activities and movements. Quadricpes muscle is strengthened with closed chain exercises. This pain in tendon might be because of your gait pattern due to ACL injury, still if you provide more details, might be I will able to help you more. Thanks