Pain is common immediately after anterior cruciate ligament, or ACL, reconstruction surgery. With time and active rehabilitation, this pain should decrease and eventually disappear. There are several causes of pain that starts days to years after surgery.
Arthroscopic surgery is done to replace a torn ACL. Using a small camera and shaving instruments, the torn ACL is removed. Holes are drilled into the thigh bone and lower leg. The patella tendon with pieces of your kneecap and lower leg bone attached, hamstring tendons, or a cadaver graft is used to replace the ACL. The graft is held in place with screws. In some procedures the screws are inside the bone, while other techniques use metal hardware outside the bone.
Infection is a serious potential complication of ACL surgery. It presents as increasing pain, swelling and redness. There may be drainage from the surgical incisions. The treatment of an ACL surgery infection includes repeat arthroscopic surgeries to clean out infected areas, and up to six weeks of intravenous antibiotics. Removal of the graft may be required to treat the infection. Infection is rare -- the American Academy of Orthopaedic Surgeons reports that this occurs after less than 1 percent of ACL surgeries. Infection is most common in the first 90 days after surgery.
In the first month after surgery, blood clots can develop in the leg. This causes painful swelling in the lower leg. Blood clots are more common in people with a family history of blood clotting disorders. Clots that travel to your lungs can be fatal. Seek immediate medical attention if you suspect you may have a clot. Early after surgery, you may also experience pain at the surgical scar sites.
New injuries can occur as you become more active after ACL surgery. However, according to the American Academy of Orthopaedic Surgeons, this risk of injury is equal for both knees. If you experience a sudden, new pain while recovering from ACL surgery, see your surgeon.
Tearing an ACL requires significant force. In the first years after ACL surgery you may experience pain behind your kneecap. This pain originates from damaged cartilage on the kneecap, or improper movement of your kneecap as you move you leg. Bracing and therapy often relieve patella pain.