Anterior Cruciate Ligament Tear: Reconstructive Surgery

The goal of ACL reconstruction surgery is for the patient to regain full function of the knee joint which will allow him or her to return to sports. ACL grafts undergo a degeneration process (the graft is usually at its weakest 6 weeks after the surgery) followed by a regeneration process, which may take up to 10 years.

Surgery is typically performed 3 or more weeks after the date of injury, when the knee has a full range of motion and the individual has control of the thigh muscle. ACL surgery usually requires replacing (reconstruction) of the injured ligament because ACLs usually cannot be sewn back together (repaired).

Indications for Surgery

  • Individuals who regularly need to pivot, cut, jump or land on knee
  • Patients with recurrent giving way or knee instability, despite 3 to 6 months of participation
  • in a conservative (non-surgical) rehabilitation program
  • Patients with an anterior cruciate ligament (ACL) tear and a reparable meniscus tear
  • Patients with an ACL tear and other ligament injuries in the same knee

Reasons not to Operate

  • Individuals who do not regularly need to pivot, cut, jump, or land
  • Individuals who exercise by jogging, cycling, or swimming only
  • Inability or unwillingness to complete the postoperative rehabilitation program
  • Infection of the knee, current or previous, is a concern but not an absolute contraindication
  • If the patient is not yet fully grown (skeletal immaturity), surgery may not be recommended until the patient is fully grown, but this is not an absolute contraindication
  • Persons with severe knee arthritis should not have surgery

Risks and Complications of Surgery

  • Risks of surgery
  • Infection
  • Bleeding
  • Nerve damage (numbness, weakness, paralysis) of the knee, leg, or foot, although it is not uncommon to have some numbness, temporary or permanent, on the outer part of the upper leg
  • Stretching or tearing of the reconstructed ligament, causing recurrent instability
  • Knee stiffness or loss of knee motion
  • Rupture of the patellar tendon or patellar fracture (both are uncommon)
  • Pain from screw used to hold the graft (rare)
  • Clot in the veins of the calf or thigh (deep venous thrombosis, phlebitis) that may break off in the bloodstream and go to the lungs (pulmonary embolus) or brain (causing a stroke)


Most ACL reconstruction surgeries are performed with the assistance of an arthroscope to help the surgeon view the knee joint without needing a large incision. These procedures may be completed and you can go home the same day (outpatient basis), or you may need to stay in the hospital overnight. The torn ACL is removed and replaced by a graft. There are many different graft options for ACL reconstructions:

  • The central third of the patellar tendon, from the same or opposite knee
  • The hamstring tendon
  • The quadriceps tendon
  • Transplant from a cadaver (allograft) patellar tendon or Achilles tendon

The different types of grafts each have their own advantages and disadvantages. The type of graft used should be discussed with your surgeon.

After the torn ACL is removed, the surgeon will shave part of the bone in order for the graft to fit well in the joint. The surgeon will also look at the other structures of the knee that may have been damaged during the injury, and these may be fixed. In order for the new graft to be placed in the joint, two tunnels are drilled in the bones of the knee. The graft is then secured into the tunnels with screws, heavy stitches (sutures), spiked washers, or posts. The devices used to hold the graft in place usually do not need to be removed.

Return to Sports

You may return to sports when your therapist gives you permission to do so. Return to sports is usually allowed when the knee has a full range of motion, muscle strength is regained, and functional use has been restored. This usually requires 4 to 6 months following ACL reconstruction.

Seek Medical Care If

  • You experience pain, numbness, or coldness in the foot and ankle
  • Blue, gray, or dark color appears in the toenails
  • You experience increased pain, swelling, redness, drainage, or bleeding in the surgical area
  • You have signs of infection (headache, muscle aches, dizziness, or a general ill feeling with fever)
  • New, unexplained symptoms develop (drugs used in treatment may produce side effects)

To learn more about reconstructive surgery of anterior cruciate ligament (ACL) tears, please call (918) 494-AOOK (2665).