Here we explain the different typres of knee injuries. Sudden onset or acute knee injuries are usually the result of twisting or a hard impact and will likely involve ligament, tendon or cartilage joint injury. Read our advice on immediate first aid as well as when you should see a doctor. Pain which comes on gradually can affect the front (anterior), back (posterior), inside (medial) or outside of the knee (lateral knee pain). If you are not sure what is causing your pain then why not try our sports injury symptom checker.
An acute knee injury usually occurs suddenly through either trauma or a twisting action. Pain in the knee can vary in severity from very mild to very severe and this depends on the injury mechanism (how the injury occurred) and the forces involved during the impact. It is strongly advised not to carry on playing if you have acute knee pain as this can easily progress to a chronic pain or to more complex knee injuries.
Anterior cruciate ligament sprains are common in contact sports and those involving a sudden change of direction. Often an ACL injury will occur in combination with injury to other structures in the knee joint and require immediate first aid. Read more on treatment for ACL Injury
Medial ligament sprain
Medial ligament sprain or MCL injury is a tear of the ligament on the inside of the knee, it is usually a result of direct impact or twisting motion. A medial ligament injury is common in contact sports such as football and rugby, as well as martial arts. They can also occur in daily life through falls and twists of the knee joint. Read more on the treatment and rehabilitation of medial ligament sprain.
Posterior cruciate ligament sprain
The posterior cruciate ligament is important for stabilizing the knee and preventing it from bending back the wrong way. Symptoms of pcl sprain include pain at the time of injury and there may be swelling. Instability of the joint is noticeable and associated with the feeling of the knee giving way. Pain is reproduced when the posterior cruciate ligament is stressed by attempting to bend the knee the wrong way. Read more on the treatment and rehabilitation of posterior cruciate ligament sprain.
Patella tendon rupture
Patella tendon ruptures are extremely painful and may be accompanied with an audible 'pop' at the time of injury. The patella tendon is prone to rupturing in individuals with a history of patella tendon injury such as jumpers knee or degeneration due to age. Symptoms include swelling of the knee, particularly at the bottom of the knee over the tendon. The athlete will be unable to put weight on the knee or hold the knee in a straightened position. Read more on the causes and treatment of patella tendon ruptures.
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Anterior knee pain is pain at the front of the knee including the patella or kneecap. If you are not sure what is causing your knee injury is why not try our symptom checker? The two most common causes of pain at the front of the kneecap are patellofemoral pain and patella tendinitis or Jumpers knee. Sometimes it can be difficult to tell the two apart and occasionally they can occur simultaneusly. Here we outline the causes of pain at the front of the knee as well as important conditions which can be missed.
Patellofemoral Pain Syndrome (PFPS) also known as runners knee, chondromalacia patellae, anterior knee pain and patellofemoral joint syndrome is a generic term used to describe patella pain at the front of the knee. it occurs when the patella (kneecap) rubs on the femur bone underneath. Symptoms include aching pain in the front of the knee around and under the patella. Tenderness along the inside border of the kneecap and swelling can occur after exercise. Patellofemoral pain is often worse when walking up and down hills or sitting for long periods of time. Read more on patellofemoral pain syndrome symptoms and treatment.
Jumpers knee or patellar tendonitis is an overuse injury that causes pain at the front of the knee. Repetitive strain from too much running or jumping causes inflammation or degeneration of the patella tendon. Symptoms include tenderness when pressing and it may appear larger or thicker than the unaffected side. Aching and stiffness after exercise is also common. In particular jumping activities are likely to cause most pain or discomfort. Jumpers knee is graded 1 to 4 depending on how bad the injury is with grade one being only mild pain after training and a grade four resulting in constant pain. Read more about the symptoms and treatment of Jumpers knee
Osgood Schlatters disease
Osgood Schlatters disease is a very common cause of knee pain in children between the ages of 10 and 15 years old. It is primarily an over use injury although certain factors can increase the likelihood of sustaining this condition. An early diagnosis and appropriate treatment is essential as this injury can be stubborn to treat if left. Tenderness and pain is worse during and after exercise but usually improves with rest. Read more on Osgood Schlatters disease treatment.
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Posterior knee pain is pain at the back of the knee. Below we outline the most common causes of pain at the back of the knee, less common causes as well as important conditions and injuries that should not be missed. Biceps femoris tendonitis (hamstring tendonitis) is probably the most common over use injury at the back of the knee although referred pain and various causes of swelling are also likely causes of pain at the back of the knee.
Medial knee pain is pain on the inside of the knee which usually comes on gradually as opposed to a sudden acute knee injury. If you are not sure what your injury is then why not try our symptom checker? Pain on the inside of the knee is usually an acute injury caused by a sudden trauma, however it can come on gradually over time with poor biomechanics and overuse. Below we outline the most common medial knee injuries as well as some of the less common causes and important conditions which should not be missed.
Medial ligament sprain
Medial ligament sprain or MCL injury is a tear of the ligament on the inside of the knee, it is usually a result of direct impact or twisting motion. A medial ligament injury is common in contact sports such as football and rugby, as well as martial arts. They can also occur in daily life through falls and twists of the knee joint. Symptoms of MCL are graded 1, 2 or 3 depend on the severity of the injury. Read more on how Medial ligament sprain is graded and how it is treated.
Medial cartilage meniscus injury
A torn meniscus is a tear to the semi circular cartilage in the knee joint causing pain on the inside of the knee. This injury is usually by a direct impact in contact sports or twisting but can also occur in older athletes through gradual degeneration. Treatment depends on how bad the injury is and may require surgery. Symptoms include pain on the inside of the knee which may be of sudden onset but can also occur gradually. The patient will usually experience pain when fully bending the knee or squatting down. There may be swelling present but not always and the patient may also complain of the knee locking or giving way. Read more on causes and treatment of medial meniscus tear.
Osteoarthritis or wear and tear on the knee joint is a common cause of knee pain. Symptoms include a deep aching pain in the inner knee that is worse after exercise with stiffness in the joint and some swelling. Sometimes a clicking or cracking noise when moving the knee is heard. Read more on Osteoarthritis treatment.
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Lateral knee pain is that which occurs on the outside of the knee has come on gradually as opposed to an acute knee joint or ligament injury. If you are not sure what is causing your pain then why not check out our symptom checker? The most common causes of pain on the outside of the knee are Iliotibial band friction syndrome and Lateral cartilage injuries. Here we explain the most widely seen causes, less common causes of lateral knee pain as well as important injuries that should not be missed.
Iliotibial band syndrome
IT band syndrome or runners knee as it is sometimes called is a gradual onset injury causing pain on the outside of the knee. Over time the pain gets progressively worse until the player must stop. Typically the they will rest for a period of time until symptoms go only for it to return again as soon as they go back to playing tennis or running. Treatment is based around reducing the pain and inflammation along with stretching, foam roller use and strengthening exercises. Read more about IT band syndrome.
Lateral cartilage injury
Lateral meniscus tear is an injury to the semi circular cartilage on the outside of the knee joint. Symptoms include tenderness and pain around the outside surface of the knee. Each knee joint has two crescent shaped cartilage menisci which cushion and support the knee. They can be injured by twisting or traumatic injury as well as degenerating over time. Read more on the treatment and rehabilitation of lateral meniscus tears.
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Common knee symptoms
Click on the links below to view all injuries with that particular symptom:
Aching knee / Audible snap in the knee / Bruising / Burning pain / Gradual onset knee pain / Impact to the knee / Knee instability / Knee joint pain / Pain kneeling / Pain running / Pain sitting / Kneecap pain / Local swelling / Rapid swelling / Swollen knee / Twisted knee /
Immediate first aid for knee injuries
What should I do for a knee injury and when should I see a doctor? All acute and chronic knee injuries should be treated using the P.R.I.C.E. principle (protection, rest, ice, compression & elevation). This should be applied at home for at least the first 2 - 3 days. First, protect the knee injury from further damage. Stop training or playing immediately and apply a cold therapy and compression wrap. Where applicable, use a knee support or brace.
Rest - Refrain from exercise and try to reduce the demands of your daily activity to encourage recovery. It does not only refer to the prolonged period of time that the athlete will be out of action but also to the immediate period after the injury. An athlete must know when to stop training and allow the injured area to heal otherwise repetitive minor injuries can often result in a more severe injury that keeps the athlete out for much longer.
Ice - The topical application of ice or cold therapy to the area of the knee injury / swelling can assist in reducing the symptoms of pain and inflammation.
Compression - The use of a compression support or compression bandages to the knee can can help reduce swelling.
Elevation - Keeping the knee elevated above heart level whenever possible to help reduce swelling due to the effects of gravity.
Read more on PRICE principles >>>
When should I see a doctor?
The majority of knee injuries, especially the minor ones can be treated at home. However, if you have any of the following symptoms including severe pain, sever swelling, a pop or crack, locking and altered sensation you should seek further medical assistance.
- Severe pain in or around the knee, especially during walking.
- Severe swelling (oedema) in the knee.
- An audible “pop” or “crack” in the knee joint that is painful.
- A “giving way” feeling in the knee during walking or going up/down stairs.
- A feeling when the knee “locks” whilst bending or straightening it.
- Altered sensation in the foot – such as a feeling of “pins and needles” (paresthesia) or a “loss of feeling” (anaesthesia) in the lower leg.
- Unable to complete your normal daily activities after the initial 72 hours.
Further medical assistance can be sought through either your local Doctor or a private clinician such as a physiotherapist, sports therapist, osteopath or chiropractor.
In the first instance, if you have followed the P.R.I.C.E. principles (see above) and are still unable to walk after 72 hours or still have severe pain that is not subsiding after the first 72 hours you should visit your local A&E department for further assessment. Also, if your knee gives way whilst walking, feels loose (“unstable”) or locks (unable to move the knee due to pain) then you should consult your doctor or visit A&E.
Secondly, if you have applied for P.R.I.C.E. principles and still have weakness or knww pain that lasts a long time (more than 2 weeks) or have ongoing discomfort in your knee, you are highly recommended to seek advice from a specialist expert - such as a physiotherapist, sports therapist, osteopath, or chiropractor - who can provide you with advice and an appropriate and effective recovery and rehabilitation program.
Knee assessment and diagnosis
In order to properly assess the knee joint a good knowledge of its anatomy is needed. Within the knee joint lie numerous structures that are prone to injury, some more so than others. Hence a systematic and thorough examination is needed to ascertain which structures have been damaged.
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