How to avoid ligament injuries in children

Seeing children running about a sports pitch, or enjoying ski school is a great sight, and one we all actively encourage, both as parents, teachers or one of the army of volunteer coaches. However, increasing numbers of children are sustaining serious knee injuries, which could have long term consequences on their future activity levels. Whilst several sports bodies around the world have introduced simple injury prevention exercises to try and mitigate this problem, here in the UK we are behind the curve and need to do more.

In this article, Specialist Orthopaedic Knee Surgeon, Professor Adrian Wilson, who has treated serious complex ligament injuries in both adults and children, gives his views on how we can all help to ensure our young people enjoy a lifelong relationship with sport and exercise. His own daughter suffered an anterior cruciate ligament (ACL) rupture whilst on a family ski holiday a number of years ago. Whilst she is now able to participate in many activities, she unfortunately no longer skies, due to the risk of further damage.

Our children in the UK are incredibly active, with 88% of 5-15 year olds taking part in sport at least once a month₁. However, it is the increasingly competitive nature of school and local sports teams and the enthusiasm post 2012 for growing the next generation of Olympic medal winners, which I believe could be having an impact on children’s bodies and leading to injury.

A greater understanding of the impact on their knees of specific activities and the application of simple warm up exercises could make a real difference, as it is starting to do in other parts of the world.

Damage to the anterior cruciate ligament (ACL) is the most frequently seen injury and is increasingly common in young people. The ACL is the largest ligament in the knee and controls the back and forth motion of your knee, along with the less commonly injured posterior cruciate ligament (PCL), which is the largest ligament in the knee and helps give stability.

If the ACL is torn or ruptured, the knee becomes unstable when it is twisted and can give way, as well as losing its full range of movement. As the knee gives way, the delicate structures inside it, as well as the joint surface and meniscal cartilages, may also be damaged.

A study in the US found that the number of ACL injuries in 6-18 year olds has increased by over 2% a year for the last 20 years². Whilst I don’t have exact figures for the number of children being affected in the UK, I would estimate it to be growing at around 15% a year. The US study found that just under half of pre-teens and 65% of adolescents being seen for a swollen knee had suffered an ACL rupture.

As well as children playing more sport and competing at a younger age, better detection via MRI scans and greater patient awareness have meant that more children and young people are being diagnosed with ligament damage, hence greater numbers being referred on to knee specialists.

As children’s bones and ligaments are not yet fully developed, they are at greater risk of damage.

An ACL injury is most likely to occur when children are taking part in sports involving twisting and pivoting and jumping, such as football, netball, tennis and rugby, which are all played regularly in UK schools. Skiing, due to the pressure on the knee, whilst the ankle is kept in a fixed position, is also one of the sports with a higher than average occurrence of ACL tears.

It can also occur with certain movements, such as a child jumping and landing hard on their feet. If the quadriceps muscles aren’t strong enough, a movement can suddenly put too much pressure on the knee joint, causing the ACL, a rope-like band of tissue, to tear or rupture.

Teenage girls are between two and ten times more likely than boys to tear an ACL, due to their body shape, limb alignment, neuromuscular control, and the presence of hormones which might loosen the ligament.

Usually with an ACL injury, there will be a popping sound. The child may also use their hands to demonstrate a severe twist of their knee or describe it as feeling wobbly or loose.

They will definitely feel pain when the ACL tear happens, however afterwards, they might have symptoms, depending on the severity of the injury. Often there is pain, which can be intense, and swelling of the knee joint, which can happen within 24 hours of the injury occurring.

Most will have no problems walking. But if they try to go back to sport, they may have some instability, or be unable to bear weight on the affected knee.

For any knee injury or following a ski fall or collision on the football or netball field, it is important to stop activity straight away. If the knee is swollen, ice should be applied for at least 20 minutes at a time, and the knee should be kept elevated.

A trip to A & E or a local minor injuries clinic is the first port of call, or to your GP, whichever is available soonest. If weight bearing is painful, your child should be kept off their feet until you can get them assessed.

If your child has any of the symptoms of a ligament injury mentioned above, you must insist on getting a referral to a knee specialist, who is an expert in ligament injuries. Your consultant will need an MRI scan to confirm the diagnosis, so request that your child is referred for a scan at the same time.

While an X-ray might be taken at A & E, this will only show bone damage, so will be used to rule out a fracture or break. An MRI scan, which assesses ligaments and muscles can confirm a partial or complete ACL tear so you really need one to confirm diagnosis.

I cannot stress enough how important it is to see a knee specialist early. The average time from knee ligament injury to fixing the problem is four weeks in Australia, the US and many European countries. Unfortunately, it can take 18 months in the UK by which time there is usually significant secondary damage to the joint surface and meniscus shock absorbers which is bad news. This is why our outcomes are less than ideal and lagging behind the rest of the world.

Once your child has had an MRI scan and been referred to a consultant orthopaedic knee surgeon and ideally a specialist in ligament repair and reconstruction, they will review the MRI scan and carry out a full assessment.

The consultant will discuss your child’s symptoms and examine the knee to check for tenderness, stiffness, swelling and any other problems. They may also ask them to move their knee into different positions to assess the range of movement and the function of the joint. Depending on your child’s age and the severity of the injury, there are two treatment routes for a torn ACL.

Non-surgical treatment: involves physiotherapy and additional support – such as a knee brace – when playing sport.
Surgery: if the knee regularly gives way during normal everyday activities, or prevents your child taking part in sport, they may require ACL surgery. Traditionally, this surgery involved a long recovery period of around a year; however, new procedures for treating ACL injuries, which I have pioneered, have reduced this to around four months.

If an adult is injured and damages their anterior cruciate ligament, the tear usually occurs in the upper or middle part of the ligament. However, in children and young people, the attachment of the ligament to the bone is a weak point and the ligament can become completely separated from the bone, possibly with a fragment of bone still attached.

In some cases, it may be possible to re-attach the bone fragment along with the ligament using keyhole surgery. However, ligament re-attachment can only be carried out in the first few weeks after an injury. In some cases, I might also advise carrying out the All-Inside reconstruction technique and anterolateral ligament (ALL) reconstruction alongside ACL surgery to improve the outcome.