ACL injury: Anterior cruciate ligament injury and treatment

A full or partial tear of the anterior cruciate ligament (ACL) can stop you from doing some of your favourite sports, exercise or hobbies. HCA UK’s knee specialists can accurately diagnose a torn or ruptured ACL and suggest the best way to manage your injury. 

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HCA UK’s knee specialists can accurately diagnose a torn or ruptured ACL and suggest the best way to manage your injury. We offer:

  • Knee specialist appointments available the next working day
  • Appointments and imaging on the same day to minimise disruption to your schedule
  • Accurate ACL injury diagnosis using the latest technology
  • Quality care: 97% of orthopaedic patients rate our care as ‘very good’ or ‘excellent’

What is the anterior cruciate ligament?

The anterior cruciate ligament (ACL) is a strong band of cord-like tissue that runs across and inside your knee to keep it stable. The ligament attaches the thigh bone (femur) to the top of your shin bone (tibia).

Your ACL sits in front of your posterior cruciate ligament. They form a cross inside the knee – hence the term 'cruciate' in their names. The ACL serves three key functions:

  • It allows your knee to twist with stability. This is especially useful in sports such as football, rugby and skiing
  • It protects other structures in the knee from damage, such as the meniscus
  • It acts as a shock absorber to limit damage that can result in arthritis

What is an ACL injury?

ACL injuries happen when the ligament is stretched beyond its normal range of motion and are categorised from Grade 1 to Grade 3. At the point of injury, a torn ACL can often be described as sounding like a 'snap' or 'pop', and the amount of pain experienced can vary depending on the severity of the injury. In some instances, people may only suffer slight discomfort, while a tear of the anterior cruciate ligament can be incredibly painful for others. 

Grade 1: An ACL sprain that occurs when ligament fibres remain mostly unbroken. This injury can generally be treated with rest and pain relief. In most cases, an injury like this can heal in anywhere between two and four weeks

Grade 2: A partial ACL tear where some fibres of the ligament break as a result of a sudden impact or twisting movement to your knee. Partial tears of the ACL are less common than complete tears. Physical therapy can help improve the knee’s stability, with recovery often taking up to three months

Grade 3: A full tear – also known as an ACL rupture – is when the ligament snaps completely or becomes detached from the bone. This is a significant injury that is more common among athletes and often results in damage to other areas of the knee, such as the meniscus or other ligaments, at the same time. The tear is highly unlikely to heal without surgical intervention. A full recovery typically takes up to a year.

Causes of ACL injury

A torn ACL can happen during everyday activity but is also a common sports injury that may happen during an awkward landing, impact or sudden change of direction that results in a twisting motion at the knee. Common causes include:

  • Getting your feet stuck while twisting – for example, a football boot getting caught on turf
  • Landing awkwardly from jumping, perhaps after a gymnastics manoeuvre or when dancing
  • Direct impact to the area, such as a bad tackle in football or rugby

Our specialist knee consultants can assess your injury and advise on the best way to treat it.

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What are the symptoms of an ACL injury?

When you tear your ACL, you may experience some or all of the following:

  • A popping or snapping sensation and sound at the time of injury 
  • Pain that increases as you try to move your knee or put weight on it
  • Rapid onset of swelling
  • Feeling unstable or unsteady when weight-bearing after the injury
  • A feeling of stiffness in your knee, or feeling as though the joint is moving or buckling
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When to see a specialist for ACL pain

If you’re experiencing a combination of symptoms and efforts to manage them yourself are not working, you'll likely require urgent care. ACL injuries are significant and can result in further complications if left untreated because extra pressure is put on other areas of the knee joint.

Our urgent care centres provide swift treatment to anyone over 18 with a non-life-threatening condition. Based in three of our London hospitals, they see 94% of people within 15 minutes of arrival.

Wherever you seek treatment, your medical team will likely take measures to reduce any swelling in the first instance. They’ll then diagnose the extent of your injury and decide on the best course of action. 

How are ACL injuries diagnosed?

Our knee specialist will assess you in detail. This will involve asking you a series of questions, examining your knee and typically undergoing an MRI scan. Your scan will be conducted by a consultant musculoskeletal radiologist that specialises in performing scans and passing on key information to your consultant.

The MRI scan helps to confirm the diagnosis and uncover any damage to other parts of the joint. After assessing the severity of your injury, you and your consultant can start planning your onward care.

Potential treatment options

Resting your knee is a key part of the recovery. Your consultant will discuss any further treatment options with you. These may depend on how stable your knee feels, your day-to-day function and your sporting profile. 

Non-surgical ACL treatment

  • RICE: Rest, ice, elevation and compression will help your joint recover. It’ll also likely be recommended after any surgery you undergo
  • Pain relief: Medication such as paracetamol and ibuprofen will help manage discomfort and may allow you to get back to everyday activities quicker if your ACL injury is mild
  • Knee supports: Braces and similar products provide compression to manage inflammation and also support the joint as you bear weight, easing any feelings of weakness or buckling
  • Modifying activity: You’ll likely need to change your activities for a period after suffering an ACL injury. Footballers, rugby players and dancers may need to take it easy for many months while recovering.

You may choose not to have surgery on a torn ACL if your joint feels stable and you’re not aiming to return to activities such as sport. Many people can live comfortably after experiencing low-grade tears without surgical repair.

Opting against surgery after experiencing a grade three tear may leave you more vulnerable to damaging your knee further down the line. Most people who suffer serious ACL tears choose surgery to benefit their quality of life.

ACL injuries are also often associated with other injuries like meniscal tears or damage to other ligaments– if the knee has sustained injury to more than one structure, it can be even harder to recover without surgery.

Surgical ACL treatment

In cases of a torn or ruptured ACL, you may need to consider surgery to restore the ligament (ACL restoration). This involves reforming the ACL with other tissue — usually from your hamstrings or patellar tendon. Your consultant will talk this through with you.

Surgery to repair your ACL may be recommended if conservative treatment does not help your symptoms, you’ve suffered a serious ACL tear, or your job is physically strenuous. An operation might also be required if you’ve also damaged other ligaments, cartilage or bone.

Can I prevent an ACL injury?

It’s difficult to fully prevent ACL injuries as they often occur because of unexpected impacts or movements. You can take measures to reduce the chances of them happening in the first place:

  • Protective equipment: Knee braces can add support and protection to your knees, potentially limiting the damage done or preventing an ACL tear in some instances
  • Resting: Take time to fully recuperate after exercising or playing sport. Pushing your body to its limits can exacerbate smaller injuries and result in being at increased risk of suffering an ACL injury
  • Reduce risks: You could suffer a torn ACL by falling at home or work. Clear away tripping hazards and use proper equipment - for example, use a ladder securely if working at heights.
  • ACL prevention programmes: if you undertaking high risk sports or have a history of a partial tear, you might consider an ACL prevention programme: these involve exercises designed to reduce the strain on the ACL and have been proven to reduce rates of injury.
The London Hip Unit, July 2021

How to book a consultant appointment about your ACL injury 

If you're experiencing pain or suspect you've injured your knee, we have the experience and facilities to accurately diagnose and treat ACL injuries of all kinds. Here's how to make an appointment to see one of our specialists.

  1. Fill in our online form.
  2. If you've been referred to us by a GP or hospital, keep any letters you've received to hand so we can take as much detail as possible.
  3. We'll either schedule your appointment immediately or get in touch within 24 hours to confirm a time and place. We can also discuss your payment options with you if necessary. 

FAQs about ACL injuries

It's unlikely that you'd be able to walk unaided straight away after suffering a complete ACL rupture. It may well become easier to walk on over time, but your knee could feel unstable or like it's 'locking' due to the joint's instability.  In the event of a partial tear or strain, you’d experience pain and discomfort when walking on the injured knee and doing so could increase your risk of exacerbating the injury.
It typically takes over six months to return to physical activities after surgery for an ACL tear. Professional athletes are typically out of action for around 8 to 10 months after suffering an ACL injury.  Recovery times may be shorter in instances of partial ACL tears, while sprains to the ligament may heal in a matter of weeks with rest and a knee brace being used.
Partially torn ACLs may heal naturally, but a lack of blood flow to the area generally means the process is slow and complete tears almost never heal.
These terms are sometimes used interchangeably but can have subtly different meanings. A ruptured ACL is when the ligament is completely torn or pulled away from the bone. Ligament tears can be partial when some of the ligament remains intact. A full ACL tear is the same as an ACL rupture.

The procedure typically lasts between one and two hours and is performed under general anaesthetic. Surgery to fix a torn ACL is typically done via arthroscopy (keyhole surgery). Small incisions will be made in your knee so that your surgeon can use a camera and specialised tools to operate within the knee joint. As this type of surgery does not ‘open’ your knee, you can benefit from a faster recovery and less post-operative pain. 

Your surgeon will create a new ligament using tissue known as a graft. Tissue from the patellar tendon or hamstring tendon is most used in ACL restoration, although in some cases an artificial graft may be required. The graft will be held in place permanently by screws, buttons or staples that will remain in the joint.

Once your surgeon is happy that the repair is complete, your incisions will be closed with stitches or surgical tape and your knee will be bandaged.

You won't experience pain during the surgery as you'll be under anaesthetic, but the surgery site may feel sore when you come around and your knee will likely feel stiff. This is usually manageable with standard pain-relief medication.
Your costs will depend on your circumstances, including what diagnostic tests you require and the particulars of your surgery. Find out more about how you can pay for your treatment.
You’ll typically be sent home with crutches to use for a few weeks after undergoing surgery. Physiotherapy exercises will help strengthen the muscles around your knee. People are generally able to walk unaided around a month after surgery.
You’ll typically be sent home with crutches to use for a few weeks after undergoing surgery. Physiotherapy exercises will help strengthen the muscles around your knee. People are generally able to walk unaided around a month after surgery.

You may be able to return to light duties or a sedentary job within a few weeks of surgery. However, if your job involves a lot of physical labour, it may be months before your knee is strong enough to support you at work.

Professional athletes often require a much longer period undergoing a rehabilitation programme to return to full strength. ACL injuries typically keep sportsmen and women out of action for up to a year. 

Why choose HCA UK

Why choose HCA for ACL injury treatment?

Swift appointments: We offer consultant appointments and diagnostic scans on the same day and we will confirm your appointment within 24 hours of you getting in touch with us

Leading experts in ACL injuries: Our knee consultants have helped all manner of people recover from a torn or ruptured ACL and know exactly how to manage symptoms

Rated 'Outstanding': We have a higher proportion of leading ratings from the Care Quality Commission (CQC) than any other private hospital group in the UK

Advanced technology: Our diagnostic centres have the very latest equipment to provide a clear picture of your ACL injury

Satisfied patients: We're proud to report that 97% of orthopaedic patients said they received very good or excellent care from HCA UK (2022 patient surveys)

Official recognition: Our ACL injury consultants are members of the British Orthopaedic Association (BOA) and follow the body's strict code of standards. 

Hana's story

A torn ACL threatened Hana's dreams of playing professional football. And once she'd recovered, another serious knee injury struck. Hana met with one of our consultants in trauma and orthopaedic Surgery at The Lister Hospital in Chelsea, Hana got back to full fitness and made it back on the pitch. 

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Hana's recovery: Roaring back from a serious knee injury

Hana was a fearsome player on the pitch, but her commitment came at a price. 
How to book an appointment

Book an appointment with an ACL injury specialist

ACL injuries may need swift care to prevent further damage or long-term effects. Contact us today to get an appointment with a consultant who can give you answers about your ACL pain.

Our locations

Institute of Sport Exercise and Health (ISEH)

170 Tottenham Court Road W1T 7HA London
The Harley Street Clinic

The Harley Street Clinic

35 Weymouth Street W1G 8BJ London
The Portland Hospital

The Portland Hospital

205-209 Great Portland Street W1W 5AH London

This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.