Knee pain can be caused by a number of different conditions. Outlined below are the most common causes of pain in the knee joint:
Patello-femoral pain syndrome (PFPS)
Patello-femoral pain syndrome causes pain at the front of the knee, around the knee cap area. Pain is often worse when the knee is in the same position for a long time and on going up and down stairs. People with PFPS often notice cracks and grinding sensations in the knee. Although this can sound unpleasant, it is not harmful and you should continue to use the knee normally.
Patello-femoral pain syndrome is caused by the joint where the kneecap (patella) meets the thigh bone (femur) becoming irritated. There are usually a number of causes for this, but the most common reasons are weakness in the muscles around the knee, tight muscles and changes in foot alignment (e.g. flat feet). Stretching and strengthening the muscles around the knee usually improves pain caused by PFPS and your physiotherapist will advise you on the best exercises for you to perform (click here to see videos of your exercises). Special insoles to wear in your shoes can also be helpful and sometimes you may be referred to see a podiatrist to provide you with these.
Osteoarthritis (arthritis) is caused by the gradual thinning of the smooth cartilage that lines all of our joints. This is a normal process that happens as we get older, however, it can cause joint pain and stiffness. Using the affected joint will not cause more wear and in-fact too much rest will cause more pain and stiffness in the joint and weakness in the surrounding muscles.
Although arthritis cannot be cured, symptoms can be improved by keeping active and performing regular exercise. Exercising keeps the muscles around the joint strong and flexible which can help to reduce pain and maximise your functional ability. Losing weight can also help with pain from arthritis. If you would like advice about diet and weight loss, community health trainers can give practical advice and support with this. Further information about arthritis can be found here on the Arthritis Research UK website.
Meniscal (cartilage) injuries
The bones in your knee are separated by two large, semi-circular sections of cartilage called menisci. Sometimes these can be injured and develop small tears, causing pain around the knee joint. Meniscal tears can also cause “locking” of the knee, where the knee becomes stuck and has to be passively moved to “unlock” it (this is different to stiffness is the knee, which can be caused by a number of different conditions).
Not all meniscal injuries require surgery. Many people will do just as well with physiotherapy and can return to normal after two to three months. However, a small proportion of people may not recover fully with physiotherapy and may need keyhole surgery to repair or trim the meniscus. Your physiotherapist will assess you and prescribe an appropriate exercise programme to help you return to normal. If you are not improving they will then discuss whether you need to be referred on to see an orthopaedic surgeon to help to resolve the problem.
Ligament injuries to the knee
The knee is supported by four main ligaments, the medial and lateral collateral ligaments and the anterior and posterior cruciate ligaments. Ligaments fasten bones together and provide the stability to joints. The ligaments of the knee can be injured in falls and sports injuries, causing pain and limited movement in the knee. Injuries to the cruciate ligaments can also causing “giving way” of the knee, particularly when twisting and turning.
More severe ligament injuries sometimes require a short period of immobilisation to allow them to heal, however, for most injuries it is better to get the knee moving from shortly after the injury to prevent long term stiffness and weakness. Many ligament problems in the knee can be resolved with physiotherapy alone, allowing you to return to all your normal activities. Your physiotherapist will teach you an exercise programme to restore the movement to your knee, improve strength and balance and return to sport and exercise. However, if the knee is continuing to give way or cause other problems, your physiotherapist will recommend whether referral on to orthopaedics may be helpful.
Lower limb fractures (broken bones in the leg)
Fractures are breaks or cracks in bones. They can be treated conservatively by immobilising the limb in a cast or may be surgically repaired. Your orthopaedic surgeon will decide which option is best for you, based on your x-ray or scan findings. Once the surgeons are happy with how the fracture is healing you will usually be referred to physiotherapy to help you get the movement, strength and mobility back into your leg.
Because broken bones have to be immobilised in order to heal, it is usual for the joints around the fracture to become stiff and the muscles to become weak. This can cause pain in around the joint initially, however this usually improves once you get things moving. Once your fracture has healed you should try and walk as normally as possible, however, you may have to gradually re-introduce more difficult activities (e.g. jogging). If you have any concerns about specific activities, discuss this with your physiotherapist. Occasionally, broken bones can cause a condition called Complex Regional Pain Syndrome (CRPS).