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Anterior Cruciate Ligament Reconstruction


Where there has been an injury to the Anterior Cruciate Ligament (ACL), reconstruction surgery may be recommended. The procedure is very common and is successful for around 95% of patients.

When people speak of having “a knee reconstruction” (e.g. Football players), this is generally what they are referring to.



This procedure is specifically recommended for...

  • Younger patients keen to have an active lifestyle.
  • Patients wishing to participate in sports such as soccer, netball and football where the knee must be able to twist.
  • Patients with physically demanding jobs, such as jobs in the fire and police service, roofers and scaffolders.
  • Anyone else who has tried to live with a torn ACL and finds it intolerable.

Preoperative Instructions

You will be given a full briefing of how to prepare for your procedure well in advance of the day of surgery. In very general terms you will need to...

  • Let our team know what other medication you are taking and follow our guidelines on taking these medications in the days/weeks before surgery.
  • Let our team know if you develop symptoms of any illness (including a cold or fever) or if you believe you may be pregnant.
  • If you smoke, stop smoking ideally several days or weeks ahead of the procedure, but at the very least not smoke after midnight the night before surgery.
  • Not eat or drink anything past midnight on the night before surgery.
  • Bring all available and relevant imaging with you to hospital.
  • Ensure you are pre-organised at home with meals, mobility aids, and people to help over the first few days once you get home.
  • If you don’t already have a physiotherapist, it is a good idea to book to see one early after surgery.


In most cases this procedure is performed using minimally invasive (‘keyhole’ or ‘arthroscopic’) surgery techniques and is conducted under a general anaesthetic.

Surgery involves the following steps…

  1. Once the patient is under general anaesthesia, the surgeon checks to see if the ACL has been damaged and assesses and treat any damage to other parts of the knee via arthroscopy.
  2. Next, the torn remnants of the ACL are excised, and a new ligament is fashioned using 2 of the 3 hamstrings tendons, folded over to form a “4 strand autologous hamstrings” graft.
  3. Holes are drilled onto the bones of the femur and tibia either side of the knee and the replacement ACL graft is fixed in place to the bone.
  4. The surgeon checks the tension and stability of the replacement ACL and then checks the range of motion of the knee with the new ACL.
  5. Once the surgeon has determined everything is working properly, all incisions are closed and covered with dressings.

Postoperative Instructions

The patient will need to stay in bed for the remainder of the day of surgery and pain medication will be supplied either as tablets or intravenously. Ice packs or a 'Cryo-Cuff' are used to reduce swelling (on returning home it is important to continue to use ice on the knee for 20 minutes at a time, as often as possible).

Blood thinning injections are use in hospital to reduce the possibility of blood clots ('DVT') occurring and for the same reason patients are advised to take half an aspirin (150mg) every day after being discharged from hospital.

Over the 2-3 days after surgery, any pain and swelling should diminish. From day one your knee should be able to take your full weight.  You will be shown some simple exercises by a physiotherapist for when you return home, and you will be provided with a pair of crutches. A postoperative review is generally held 7-10 days after surgery.

In the event of any redness or swelling on or around the wound, or any pain, or if you have a fever or feel unwell, you should get in contact with your surgeon immediately.

After this procedure there will be an extensive period of rehabilitation before the knee approaches its original strength and range of motion - 4-6 months is the norm, when following the prescribed exercise regime. The new ligament will take around 12 months to regain full strength. The following activities can generally be taken up at these points...

  • Cycling 4-6 weeks post surgery.
  • Jogging 3-4 months post surgery.
  • Sport specific training 9 months after surgery.

For full details on the exercises to be performed and the prescribed rehabilitation protocol please refer to ACL Surgery Rehabilitation.


All surgery carries with it some form of risk. Common risks that apply to all surgery, including ACL reconstructive surgery, are...

  • Bleeding.
  • Formation of a blood clot (“DVT” or deep vein thrombosis).
  • Infection.
  • Nerve damage.
  • Difficulty getting the wound(s) to heal.
  • Abnormal pain reactions or nerve hypersensitisation known as complex regional pain syndrome (CRPS).

Risks that are related to this specific procedure include...

  • Problems related to the replacement ACL, such as scarring or loosening of the new ligament.
  • Scarring or generalised stiffness of the whole joint known as arthrofibrosis.
  • Where screws or other hardware have been used to fix the new ligament in place, these may need to be removed if problems develop.
  • There is a higher risk of hamstring strains after harvesting the graft.
  • It is common to develop a numb patch of skin next to the area where the graft is harvested from.

Mr Callahan will be able to discuss all of the details relating to risks and benefits of the procedure at your initial meeting.

Related Information

Anterior Cruciate Ligament (ACL) Injury