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Anterior Cruciate Ligament (ACL) Injury: Repair & Reconstruction


This article is useful for anyone who wants to look to learn more about or is suffering from an anterior cruciate ligament (ACL) injury. We are keen to help advise and prevent further deterioration of the knee joint by ensuring a good evidence-based approach to understanding and learning about anterior cruciate ligament (ACL) injury.

Anyone suffering from a ruptured anterior cruciate ligament (ACL) injury will benefit from reading this article and speaking to our team about how to progress things forwards and to accompany any rehabilitation program directed by a therapist.

What is the anterior cruciate ligament (ACL) injury?

In an anterior cruciate ligament (ACL) injury the ACL plays an important role in the stabilising of the knee. It also helps guide your shin bone through its normal, as well as a stable, range of natural motion. This makes it very important not just for the stability of the knee but also allows the full range of motion when kicking, pivoting, weaving, etc.

Roughly as thick as an index finger, the ligament is made up of strands of collagen that have been wound together. A healthy ACL can withstand upwards of 500lbs of force. In anterior cruciate ligament (ACL) injury this mechanism can be severely affected leaving the knee weak and vulnerable to future injuries.

What is a ruptured anterior cruciate ligament (ACL) injury?

A ruptured anterior cruciate ligament (ACL) injury is one that has become torn in some way, usually due to a sudden change in direction, falling awkwardly, or even slowing down too rapidly from a run. When the ligament tears it unravels like a rope and it cannot heal without help. With the ACL injured, the knee will usually become quite unstable and can buckle when an attempt to stop or turn is made.

How can an Anterior Cruciate Ligament become ruptured?

An ACL can become torn or otherwise injured in a variety of different ways during anterior cruciate ligament (ACL) injury. Athletes and sportsmen are particularly susceptible since they put more strain and pressure on various joints and ligaments than most other people.

Quickly changing direction to go around an opposing player, for example, can tear the ligament and cause anterior cruciate ligament (ACL) injury. This happens most frequently when the foot is firmly planted on the ground when the pivot occurs, even at low speed.

Anterior Cruciate Ligament (ACL) injury can also be caused when the knee is struck from the front, as might happen in a contact sport such as rugby or American football.

How common is anterior cruciate ligament (ACL) injury?

An anterior cruciate ligament (ACL) injury is the most common knee injury and accounts for around 40% of all sports-related injuries. Taken in that context, ACL injuries are fairly common. Those that are physically active are of course more at risk than those that are not, but that said is not easy to injure yourself this way unless you regularly take part in sporting activities.

Symptoms of anterior cruciate ligament (ACL) injury

Patients will often describe hearing a loud pop followed by pain in the affected knee. This pain will make walking, or putting weight on the knee, difficult. After a few hours, the knee will begin to swell due to bleeding in the joint. The swelling, while protecting from further damage, will make straightening the knee that much is harder to straighten the leg/knee.

Diagnosing an anterior cruciate ligament (ACL) injury

An anterior cruciate ligament (ACL) injury can be diagnosed through a physical examination. An orthopedic surgeon, for example, will be able to make a diagnosis after they have:

  • Taken your medical history. This includes asking how you hurt your knee, symptoms, history of knee injuries, and general inquiries regarding your health.
  • Knee examination. The range of movement tests, stability tests, tenderness, and swelling examinations
  • Taken an X-ray. If you cannot put weight on the leg or the swelling is such that a regular examination is not practical, then the doctor may have X-rays taken. This will show if any bones are broken and where fragments are.

For a case study on an ACL injury – click here

What are your treatment options for anterior cruciate ligament (ACL) injury?

There are two methods of treatment available – surgical and non-surgical. The non-surgical option is preferred where the patient does not have a lifestyle that requires a lot of physical activity such as running, jumping, etc. The doctor will take into consideration the level of activity prior to the injury to determine the better course of action. Patients sometimes prefer the non-surgery option and opt for rehabilitation and physical therapy instead.

If surgery is planned then it will occur several weeks after injury, usually within 5 months:

  • To allow swelling to recede
  • Allows rehabilitation take place which can help strengthen muscles that surround the knee
  • Reduces the risk of excess scar tissue

There are three main options for the reconstruction of a torn anterior cruciate ligament (ACL) injury and each involves grafts from different sources:

Kneecap tendon repair for anterior cruciate ligament (ACL) injury

The middle portion of the patella tendon can be used to create a new ligament. Called a patella graft, this new ligament is placed into the knee and provides a secure graft. A disadvantage of this is a pain in the knee afterward which can last sometimes up to 2 years is not uncommon.

Donor repair for anterior cruciate ligament (ACL) injury

Similar to the above, a patella tendon is taken from a deceased donor rather than the patient. There is much less pain following the surgery but it is also not as reliable as using the patient patella tendon – this is because the sterilisation process kills the living cells in the graft which means it takes longer to heal.

Hamstring repair for anterior cruciate ligament (ACL) injury

The hamstring is a large, strong muscle group located at the back of the thigh. A portion of the tendon is removed from the hamstring and is used to make a new ACL. The hamstring is very resilient and returns to full strength inside of just 6 months.

With either option, surgery, or non-surgery, there are things to keep in mind:

Rest for anterior cruciate ligament (ACL) injury

Take it easy on your knee. Work on the range of motion, moving the knee within comfortable limits to avoid stiffness, but otherwise, keep the weight off it as much as possible.

Painkillers for anterior cruciate ligament (ACL) injury

You should plan to take painkillers and anti-inflammatory drugs that you have been prescribed around 30 minutes before you exercise the knee. This will help combat soreness and discomfort.

Ice Packs for anterior cruciate ligament (ACL) injury

Ice packs should be used between 3 and 5 times a day but for no longer than 20 minutes each time. The time limit is important as any longer and the nerve endings in the knee can become damaged.

Rehabilitation for anterior cruciate ligament (ACL) injury

With the help of some post-injury/surgery exercises, there is no reason why your Anterior Cruciate Ligament cannot be returned to its pre-injury condition and the patient can resume their past lifestyle.

Below you will find the 3 stages of rehabilitation for anterior cruciate ligament (ACL) injury

Stage 1 rehabilitation for anterior cruciate ligament reconstruction following (ACL) Injury

Stage 2 rehabilitation for anterior cruciate ligament rehabilitation for (ACL) Injury

Stage 3 rehabilitation for anterior cruciate ligament exercises (ACL) Injury

For more information about anterior cruciate ligament (ACL) Injury

If you would like additional information about anterior cruciate ligament (ACL) Injury or to discuss how we may be able to help you with your rehabilitation, please contact us using the form below and we will get back to you as soon as possible.

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