Knee Injuries and Disorders

Knee ligament injuries

You have two sets of ligaments in your knee. The collateral ligaments and the cruciate ligaments.

Collateral ligament injuries

Your medial collateral ligament (MCL) is on the inner side of your knee and the lateral collateral ligament (LCL) is on the outer side. They limit how much your knee can move from side to side.

• You can sprain or tear your MCL if you get a direct blow to the outside of your knee, which stretches the inner side of your knee. This may happen when you’re skiing, for example.
• You’re less likely to injure your LCL but it can happen if your knee is pushed outwards (away from your other knee). This may happen if you get a blow to the inside of your leg – for example, during contact sports such as football. You can also injure your LCL by twisting on the side of your foot or extending your knee beyond its normal range of movement.

Cruciate ligament injuries

Cruciate means cross-shaped. Your anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) form a cross inside your knee. They help to keep your knee stable by controlling how much it moves backwards and forwards.

• An ACL injury can be one of the most serious types of knee injury. An ACL injury often happens when you twist your knee – for example, if you land on your leg then quickly turn. This might happen when you’re playing football or basketball, for example.
• Your PCL may get damaged if you fall on your knee while it’s bent. Another way of damaging your PCL is when your knees hit the dashboard during a car accident.

Grading ligament injuries

If one of your knee ligaments is damaged, a doctor may grade your injury to show how bad it is. This will help to work out what treatment you may need and how long your knee injury will take to heal.

• Grade 1 is a stretch of the ligament without tearing it.
• Grade 2 is a partial tear of the ligament.
• Grade 3 is a complete tear through the ligament.

Other soft tissue injuries

Your knee is surrounded by soft tissue that you can damage. Soft tissue means any tissue in your body that isn’t bone – for example, cartilage and tendons.

Cartilage injuries

One of the most common knee injuries is a meniscus tear (a meniscus is one of the wedge-shaped pieces of cartilage inside your knee). This can happen if you play a sport that involves twisting – for example, football or basketball. But it can also happen when you run, play tennis, and ski. As you get older, your menisci may become worn, which makes them more likely to tear during normal daily activities.

Your knee also has another type of cartilage called articular cartilage. This covers the ends of your bones inside the joint and it can get damaged too.

Tendon injuries

If you run regularly or play sports where you jump a lot, you may damage the tendons that attach muscles to your knee. You can irritate or tear the tendon that connects your kneecap (patella) to your thigh muscle. This tendon is called the quadriceps tendon. Or you may irritate soft tissue around your kneecap, including the patellar tendon just below your kneecap. This injury is sometimes called jumper’s knee.

Prepatellar bursitis

Housemaid’s knee is the common name for prepatellar bursitis. It’s often caused by the pressure of kneeling forwards for long periods. The bursa (a small fluid-filled sac that acts as a cushion in front of your kneecap) will swell up with fluid. Prepatellar bursitis can also be caused by a direct blow to your knee, by a fall, or by a bacterial infection.

You may injure your knee if:

• you bang your knee so it moves beyond its usual range of movement – knee injuries can happen from falling or if you land awkwardly
• you play a sport such as football that combines running, jumping, and stopping with quick changes of direction
• you twist your knee, especially in sports such as football or basketball
• your knees hit the dashboard in a car accident – this can damage your posterior cruciate ligament

You’re more likely to have a knee ligament injury if you:

• have knee osteoarthritis because this can weaken the muscles around your knee joint, which increases your risk of injury
• don’t take precautions when you exercise – for example, not warming up before you do anything active or not cooling down afterwards

Knee injury symptoms can vary depending on which part of your knee is affected.

If you have a torn knee ligament, symptoms may include:

• knee pain
• swelling
• instability – you may feel like your knee is giving way

You may also:

• feel or hear a pop or snap at the time you injure your ligament
• find you can’t put your full weight on your leg

If you injure a meniscus in your knee, you may:

• have severe pain and your knee may swell after a few hours
• have a ‘locked’ knee that you can’t move in the usual way
• still be able to walk a little on your leg

If you’ve torn your tendons, you may have some knee pain and swelling. You may also find that:

• your kneecap is lying higher or lower than it should be
• you can’t lift your knee

If you have prepatellar bursitis, you may have:

• swelling over the front of your kneecap
• knee pain that’s worse when you bend your knee
• difficulty kneeling and walking
• red skin over your knee

If you have an infection, your knee may look red, and feel hot and painful. You may also have a high temperature. Always see your GP if you have these symptoms.

If you injure your knee and the pain is mild or moderate or has come on gradually, you can visit your GP or a physiotherapist. If your pain is very bad or your knee is badly swollen, go to your nearest A&E department.

Your doctor or physiotherapist will ask about your symptoms and examine you. They may feel for fluid in your knee joint by pressing gently around your kneecap. They’ll also ask you to describe how you hurt yourself, where your pain is, and what type of pain it is.

Your doctor may ask you to walk, sit, or lie down so they can test for any injury to your knee ligaments or soft tissues. They’ll bend and straighten your knee and move your leg into different positions while diagnosing knee injuries.

If your doctor thinks you need surgery, they’ll refer you an orthopaedic surgeon (a doctor who specialises in bone, tendon, and ligament surgery).

You may need to have some other tests to help diagnose knee injuries.

• An X-ray or CT scan – this can check for a broken bone (fracture) or arthritis.
• An MRI scan – this may help to show up damage to the cartilage or soft tissues of your knee after an injury.
• Knee aspiration – your doctor may remove a sample of fluid from your knee.
• Knee arthroscopy – your surgeon may look inside your knee using a telescope attached to a tiny camera. This can help to show if there’s damage to a meniscus, cartilage, or ligament. Your surgeon may treat your damaged knee at the same time.

There’s a lot you can do to help yourself if you have a knee injury. It’s a good idea to follow the POLICE procedure.

Protect. Protect your injury from further damage. Rest immediately after the injury but not for long. Consider using some form of support or crutches.

Optimal Loading. Get active sooner rather than later. Start to put weight on your knee and build up your range of movement. Do this gradually – be guided by what feels right for you.

Ice. Place a cold compress such as a bag of ice or frozen peas wrapped in a towel onto your knee. Do this for around 20 minutes every couple of hours for the first two to three days.

Compression. Compress your knee using a bandage to help reduce swelling.

Elevation. Elevate your knee above the level of your heart to reduce swelling. Sit or lie on a chair and use a cushion to raise your leg.

• Your doctor or physiotherapist may suggest different knee injury treatments, depending on what you’ve done to your knee and how bad the damage is. It’s frustrating, but it’s important to be patient while you recover – your injury may take time to fully repair itself. You may not be able to do all the things you’re used to doing for some time.

  Medicines for knee injuries

  Over-the-counter painkillers such as paracetamol and ibuprofen can help with the pain if you injure your knee. You can also use anti-inflammatory gels and creams to help with pain relief.

  Your doctor may prescribe stronger painkillers that contain codeine if your pain is very bad.

  Always read the patient information that comes with your medicine and if you have questions, ask your pharmacist or doctor for advice.

  Physiotherapy for knee injuries

  If your injury is more severe, or it doesn’t get better over time, your GP may refer you to a physiotherapist. You can also choose to see a physiotherapist privately.

  A physiotherapist will create a programme of exercises to gradually strengthen your knee so you can move it normally again. The exact exercises will depend on how you’ve injured yourself, and how badly. But your physiotherapist will probably give you exercises to do every day at home, as well as at your follow-up appointments.

  You may need to use a brace to support your knee while it recovers, usually if your injury was severe.

  Surgery for knee injuries

  Your doctor or physiotherapist may refer you to an orthopaedic surgeon for some knee injuries. You may need surgery to repair the damage to your knee – especially if other treatments haven’t worked.

  Your surgeon may suggest you have an operation if you have one of the following injuries and non-surgical treatments haven’t worked.

  • You’ve torn your anterior cruciate ligament (ACL), especially if you do a lot of sport or have also a meniscus tear. In ACL reconstruction, your surgeon will take a piece of tendon (usually from your patella tendon or thigh) to replace the damaged ligament.
  • Your knee is still painful or locks after an injury to your meniscus. Your surgeon may repair or partially remove your damaged meniscus.
  • You’ve injured your medial collateral ligament (MCL) and it hasn’t healed after three months of other treatments. Your surgeon may repair or reconstruct your MCL.

  You may be able to have keyhole surgery called a knee arthroscopy to get to the damaged area of your knee.