Definition and Overview

An anterior cruciate ligament (ACL) reconstruction is a surgical procedure that involves the use of a tissue graft to replace a torn or injured ACL. The tissue graft can come from the patient, or from a deceased donor. The surgery is performed by an orthopaedic surgeon on an outpatient basis.

The ACL is one of the cruciate ligaments located in the knee, the other one being the posterior cruciate ligament (PCL). This is one of the major ligaments of the knee and is crucial to the flexion and production of restraining force to the joint.

The tearing of the ACL is one of the most common injuries that affect the knee. In the United States alone, around 100,000 individuals are affected with this condition every year. Athletes are particularly at a higher risk of ACL injuries, which are commonly caused by activities involving cutting, planting, landing, or pivoting, which are necessary for sports such as basketball, tennis, football, rugby, soccer, skiing, gymnastics, and volleyball.

Research shows that around 30% of ACL injuries occur when the individual comes into direct contact with another player or an object.

Women are more likely to suffer from ACL injuries than men because the ligament is smaller in female bodies. Women are also less likely to activate their hamstring muscles when performing cutting movements, which can result in reduced stability of the knee joint.

Who Should Undergo and Expected Results

Patients with serious ACL injuries can undergo the surgery. It can also be prescribed to patients with the following knee issues:

  • Knee joints that feel unstable during normal daily activities, such as standing and walking
  • Significant knee pain
  • Issues in the knee joint that prevent an individual from playing sports and performing certain athletic activities
  • Injuries to other ligaments in the knee joints
  • Torn meniscus, or the crescent-shaped fibrocartilaginous structure in the knee joint

How is the Procedure performed?

An ACL reconstruction procedure is performed with the following steps:

  • The patient will be asked to stop taking blood-thinning medication, including ibuprofen, aspirin, naproxen, and other similar drugs. The doctor will also advise the patient to refrain from alcohol consumption and smoking.
  • The patient will have to fast for six to 12 hours before the procedure.
  • The patient will be placed under general anaesthesia, which means that he or she will be asleep and unable to feel any pain during the entirety of the procedure. However, some patients and doctors might opt for a regional anaesthesia.
  • The tissue to be used in the graft will be harvested. There are two general types of tissue grafts for an ACL reconstruction procedure: an autograft and an allograft. An autograft involves tissue taken from the patient’s body, typically from the tendons in the hamstring or the kneecap. An allograft, on the other hand, comes from the tissues of a donor—including the recently deceased.
  • Small incisions around the knee joint will be made by the surgeon.
  • A tiny camera will be inserted through the incisions. This surgical technique is known as knee arthroscopy. The tiny camera is connected to a bigger video monitor that allows the surgeon to see the ligaments and other tissues of the knee without making bigger incisions that can prolong the recovery period.
  • Other medical instruments will also be inserted through the small incisions. Any other damage in the area will be repaired before replacing the ACL.
  • The surgeon will use a shaver and other instruments to remove the torn ligament.
  • If using an autograft, the surgeon will make another incision to harvest the tissues.
  • Tunnels will be made into the bones around the knee joint, which will be used to bring the new tissue through.
  • The new ligament will be attached to the bone with screws to keep it in place. The bone tunnels will fill in as the patient heals, which will then keep the ligament permanently in place.
  • The incisions will be sutured up and covered with a sterile dressing.
  • The patient will need to wear post-surgical knee brace up to a month after the surgery. Physical therapy will be recommended up to half a year after the ACL reconstruction.

Possible Risks and Complications

Risks and complications of an ACL reconstruction surgery include:

  • Excessive bleeding
  • Infection
  • Formation of blood clots in the lower leg
  • Slow healing of the ligament
  • Blood vessel injury
  • Stiffness of the knee joint
  • Limited motion range
  • Weakness of the knee joint and ligaments


  • Griffin L. The female athlete. In: Miller MD, Thopmson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 32.

  • Niska JA, Petrigliano FA, McAllister DR. Anterior cruciate ligament injuries: 1. Anterior cruciate ligament injuries in the adult. In: Miller MD, Thopmson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 98.

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