Long term complications of ACL injury include early onset arthritis of the knee and/or re-tearing the ligament. Factors that increase risk of arthritis include severity of the initial injury, injury to other structures in the knee, and level of activity following treatment. Not repairing tears to the ACL can sometimes cause damage to the cartilage inside the knee because with the torn ACL, the tibia and femur bone are more likely to rub against each other. Nevertheless, ACL tears alone increase inflammatory markers in the knee which can have influence on the development of osteoarthritis.
