Knee injuries Wharanga ā-turi

Bones

Three bones meet at your knee joint:

• the thighbone (femur)
• the shinbone (tibia)
• the kneecap (patella).  

Cartilage

Articular cartilage

The ends of the bones and the back of the kneecap are covered with this slippery substance. It helps your knee bones glide smoothly across each other as you bend or straighten your leg.

Meniscus

There are 2 of these strong rubbery discs of cartilage. They help to cushion and stabilise your knee joint. 

Ligaments

Bones are connected to other bones by ligaments. There are 4 main ligaments in your knee. They act like strong ropes to hold the bones together and keep your knee stable.

Collateral ligaments

These are on the sides of your knee. The medial collateral ligament is on the inside of your knee. The lateral collateral ligament is on the outside. They control the side-to-side motion of your knee.

Cruciate ligaments

These are on the inside of your knee joint. They cross each other to form an 'X'. The anterior cruciate ligament (ACL) is in front and the posterior cruciate ligament at the back. The cruciate ligaments control the front and back motion of your knee.  

Tendons

Muscles are connected to bones by tendons. The quadriceps tendon connects the muscles in the front of your thigh to your kneecap. The patellar tendon runs from your kneecap to your shinbone.

Bursae

A bursa is a small sac of fluid that helps to reduce friction and lets everything move smoothly. There are several bursae in the knee, between surfaces such as bones and tendons. 

Fat pad

A fat pad is a cushion of fat tissue behind and below your kneecap that helps to absorb shock.

There are many causes of knee injury. They often happen after:

• a sudden impact
• a fast, twisting movement
• an awkward fall.  

Injuries can happen to the soft tissues including the:

• menisci
• tendons
• ligaments
• surrounding muscles
• bursae
• fat pads.

Injury can also include the bones.

Often, more than one of these parts of the knee may be involved.

Knee pain can also develop more slowly, over time, for example from overuse of the kneecap tendon, which anchors your thigh muscle to your leg. Sometimes the fat pad can become irritated and get pinched when you move your knee.

Knee injuries can go on to cause other problems such as osteoarthritis.

Osteoarthritis

Pain and swelling are the most common symptoms of knee injury. Depending on your injury:

• the pain may be mild or severe
• the swelling may be immediate or delayed
• the swelling may be a small or very large amount. 

It might also feel like your knee is:

• catching or locking up
• unstable, like your knee is giving way.

Immediate self care 

• If you have injured your knee, stop the activity you were doing.
• Apply first aid for soft tissue injuries.
• Keep any wounds clean, dry and covered.
• Take simple pain relief, such as paracetamol. Anti-inflammatories can also help with pain and inflammation. Take these medicines as directed and be aware of side effects.  

Soft tissue injuries and treatment

Pain relief medicines for adults

A physiotherapist or doctor can assess your knee problem.

Your healthcare provider will ask you questions like:

• how the injury happened
• when you first started feeling pain in your knee
• what symptoms you have.

They will check your knee joint, including the soft tissues in your knee like your ligaments and menisci. They will also check your movement, strength and function. 

Often a diagnosis can be made from your description of what happened and a physical examination. If your knee is very swollen after an injury this can make it difficult to properly examine your knee. You may be asked to come back when it is less swollen.

Sometimes, you might need an x-ray or MRI scan to find the exact problem. If it is likely you need surgery to fix the problem, you may be referred to an orthopaedic surgeon.

Scans and x-rays

ACL (anterior cruciate ligament) injury

If your knee pain has developed slowly over time, your physiotherapist or healthcare provider can assess what the problem is. Some knee pain problems are quite common.

Patellofemoral or anterior knee pain

This pain is felt in the front of your knee and around your kneecap. It is sometimes called runner's or jumper's knee because it is common in people who do sports. Non-athletes can also get it. It particularly affects women and young adults.

This painful condition also causes stiffness. It makes it painful to climb stairs, kneel, sit for long periods and do other normal activities.

Iliotibial band syndrome 

Your iliotibial band (ITB) runs from your hip to the outside of your knee. ITB syndrome happens when the iliotibial band rubs against the outside of your knee joint. It is a common condition in runners. 

Symptoms include pain over the outside of your knee, which comes on gradually and gets worse until you have to stop.

A naturally tight or wide iliotibial band may make you more likely to get ITB syndrome. Weak hip muscles are also a common cause.

Treatment depends on which part of your knee is sore and how significant the injury or pain is. 

A physiotherapist can help you recover. They can provide you with exercises and advice to help you get back to doing the things you enjoy.   

If your knee is very swollen and painful, you may be given:

• a compression stocking (a Tubigrip) to reduce swelling
• crutches to help you walk.

Using a pair of crutches

It may be helpful to check that your running shoes are suitable. A podiatrist can advise which sort of shoes will be best and whether inserts (orthotics) could help.

If you smoke, stopping can give you the best chance of healing.

Allied health (physiotherapy) — Healthpoint

Find a physio — Physiotherapy New Zealand

You may need time off work or to adapt your current work tasks while you recover.