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ACL Surgery

What is the ACL?

The anterior cruciate ligament (ACL) is the main stabilising ligament inside of the knee. Its main function is to prevent the tibia (shin bone) from sliding forward and rotating on the femur (thigh bone). Tears/ruptures of the ligament can result in knee instability.

How is the ACL commonly injured?

ACL tears are typically caused by pivoting or twisting non-contact injuries.

Patients often describe four features related to the injury (LIMP):

  • Leg giving way at the time of injury.

  • Inability to continue activity immediately following injury.

  • Marked swelling immediately or very soon after the injury.

  • Pop heard at the time of the injury.

What are the Symptoms of an ACL injury?

After the initial swelling and pain has settled patients describe “giving way” or instability of the knee. This is particularly apparent when returning to pivoting or twisting activities.


ACL Tear
Diagnosis & Treatment

ACL Injury Diagnosis & Treatment

How is a tear diagnosed?

Mr Sethi would take a thorough history about the injury and how your knee feels. Mr Sethi would then examine your knee and perform special tests which give a very good indication whether the ACL has been injured.

A MRI scan of the knee is helpful to confirm the diagnosis and also assess whether there are any other associated injuries to the knee. Where possible Mr Sethi will arrange for you to have a state of the art 3T MRI Scanner.


What are the treatment options?

A torn ACL will not heal by itself. After assessing you Mr Sethi will discuss different treatment options with you.


Not all ACL injuries require surgery and can be managed conservatively with a supervised physiotherapy led rehabilitation programme.


However patients who continue to experience instability of the knee or wish to participate in pivoting sports, such as in playing football, skiing, rugby, netball and basketball will often require an ACL reconstruction to provide stability to their knee.

It is important that treatment plans are individualised for each patient and Mr Sethi will help guide you to the right treatment plan for you.

ACL Surgery

ACL Surgery

Description of ACL Reconstruction

ACL surgery requires precise knowledge of the anatomy of the knee, attachment sites of the ACL and knowledge on the other ligaments and structures of the knee. If one fails to replace an anterior cruciate ligament at its correct attachment sites or if other concurrent injuries are not treated, there is a much higher risk of failure of the ACL graft.

What does surgery involve?

The majority of ACL injuries require a complete reconstruction and cannot be repaired. There are various grafts that can be used to reconstruct the ACL and Mr Sethi can discuss these with you. Mr Sethi often uses a hamstring, patellar tendon or quadriceps tendon graft. Each graft have advantages and disadvantages. For the majority of patients a hamstring is the most suitable option. Mr Sethi avoids using allograft (tissue from another person) and prefers to use autograft (using your own tissue) where possible; ACL reconstruction performed using allograft have shown to have a higher failure rate

A small number of patients may be suitable to have an ACL repair, a novel technique which may result in a faster return to sport. Mr Sethi is one of a few surgeons in the UK performing ACL repair surgery.

The technique of ACL reconstructions has changed dramatically over the last decade in orthopaedics. ACL reconstruction grafts performed prior to 5-10 years ago were usually placed more centrally on both the tibia and femur and many of these patients have continued problems with rotation instability. This problem became recognised through extensive clinical and biomechanical research and the surgical technique has currently changed dramatically to where the reconstruction tunnels are now placed more anatomically to provide better stability to the knee.


Mr Sethi primary surgical reconstruction technique involves using an autograft (from the patient’s own tissues) during ACL surgery. The reconstruction tunnel is drilled at the anatomic attachment site of the ACL on the tibia and a tunnel is drilled at the ACL attachment site on the femur. The graft is pulled into the joint and fixed in place.

ACL Surgery

ACL Reconstruction

ACL Reconstruction

Mr Sethi performs the majority of the procedure arthroscopically (key-hole surgery) and a small 2.5 - 5 cm incision is made  for taking the graft.


Arthroscopic (key-hole) techniques allow for less pain post-operatively for the patient and a faster recovery. Most patients return home on the day of surgery with no overnight stay in hospital.

What is the recovery period following surgery?

The majority of patients have their surgery as a day case and can go home the same day as their operation. Patients will require crutches for approximately the first 10 days after surgery. Within the first couple of weeks patients will begin their physiotherapy rehab programme. Initial physiotherapy will focus on regaining the range of motion of the knee, controlling swelling and advice on pain control. Each rehab programme is individualised according to each patients condition and needs. In general it takes between 9 and 12 months before the knee and new ACL graft is strong enough for the patient to return to pivoting sports.

What are the risks of surgery?

Surgical techniques continue to improve, however risks of surgery remain.

Risks include:

  • Numbness around the knee (especially around the graft harvest site)

  • Swelling

  • Stiffness

  • Re-injury of the ACL graft

  • Blood clots (Leg/lung)

  • Infection


Some patients will be at greater risk of certain complications than others and Mr Sethi will be able explain this to you.



It is absolutely essential for a well supervised physical therapy protocol following ACL reconstruction surgery.


Reactivation of the muscles, restoring range of motion, and reducing swelling are absolutely essential to obtaining optimal post-operative outcomes.


Mr Sethi strongly believes that a well structured rehabilitation programme following an ACL reconstruction is just as important as the surgery itself!


It is also important for patients to understand that the rehabilitation following an ACL reconstruction is a lengthy process and it can take up to a year before you can return to pivoting sports - there are no short cuts, when it comes to rehabilitation following ACL surgery it is a marathon rather than a 100m sprint !

ACL Repair

ACL Repair

In recent years there has been a renewed interest in repairing a torn ACL rather than reconstructing it with graft tissue.

There are many theoretical advantages in repairing the ACL rather than reconstructing it. The natural nerve and blood supply to the ACL is preserved and the healing time is shorter than an ACL reconstruction.

Patients who have an ACL repair often experience a faster recovery and faster return to sport than those who have an ACL reconstruction. They also often report a more "natural" feeling knee after an ACL repair.

It is important to appreciate that not all patients are suitable for an ACL repair. In addition, ACL repair is a newer technique and we do not have long term data on the outcomes of repair. Mr Sethi would be able to discuss this technique in more detail and see if particular patients are suitable for an ACL repair. Mr Sethi is one of few surgeons in the UK performing ACL repair.

ACL repair
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