What is knee tendonitis?
The knee joint comprises of the bones of the thigh and the leg along with several muscles and tendons (ends of the muscle that connects the muscle to the bone). The term tendonitis refers to inflammation of the tendons. The tendons and the other structures in the knee joint are regularly exposed to various ranges of wear and tear.
The amount of regular usage is generally higher in individuals involved in athletics and certain other sports such as rugby, football or rowing. The tendons of the knee may often become inflamed owing to overuse of the knee or trauma involving the knee joint. Such knee injuries are commonly noted in individuals who are involved in different kinds of sports or older people. 
Types of knee tendonitis
Some of the specific types of knee tendonitis include patellar tendonitis (also called ‘jumper’s knee’), quadriceps tendonitis and iliotibial band friction syndrome.
The patellar tendonitis is the commonest type of tendonitis of the knee and is hence also referred to as knee tendonitis in some cases. Other common name used to denote patellar tendonitis is jumper’s knee. Athletes involved in sports such as running, jumping and other movements of the legs that put high pressure on the knees or result in extensive usage of the knee joint are more prone to knee tendonitis. Such pressures commonly result in microscopic tears which tend to increase over time and finally resulting in inflammation of the tendons. Knee tendonitis may also be noticed in conditions such as rheumatoid arthritis which is characterized by inflammation of multiple joints in the body. 
Aging, in general, affects the functioning of different parts of the body and may also have a role in the occurrence of knee tendonitis. It has also been noted that knee tendonitis is commonly noted in individuals and athletes in whom the muscles of the knee have been matured to the maximum extent. Trauma or injury to the knee due to a fall or awkward extension of the knee joint may also result in knee tendonitis in certain instances.
What are the signs, symptoms and treatment of knee tendonitis?
The severity and the specificity of the signs and symptoms associated with knee tendonitis may vary with the amount of inflammation in the tendons and the specific tendon involved. Pain is the most common symptom associated with knee tendonitis. The severity of pain is based on the amount of injury to the tendons. In mild cases, pain is noted after participating in sports activities or brisk walking. In moderate to severe cases, the pain is noted while performing any activities involving the knee joint such as running. While in severe cases the pain may be severe enough to restrict the affected individual from moving the affected knee. The affected knee joint is also painful to touch and some amount of swelling may also be noted in a few cases. Pain may be noticed in older individuals while climbing stairs up or down.[1,2]
How is knee tendonitis treated?
Knee tendonitis involves a wide number of treatment options that range from medications to surgery of the knee joints. The treatment is selected based on the amount and severity of the injury to the tendons of the knee.
Doctors usually perform tests such as physical examination based on the signs and symptoms noticed. This is often sufficient to diagnose knee tendonitis. Further tests such as MRI scans, ultrasonography, and other advanced imaging techniques may be advised if a severe injury is suspected or to rule out the presence of any other associated conditions of the knee.
- Mild cases of knee tendonitis often recover with adequate rest to the knee and consumption of pain-relieving and anti-inflammatory medications.
- In some cases, intermittent application of ice to the affected knee joint may also relieve the pain and inflammation of the tendons. However, be careful: when you're first injured, ice is a better choice than heat — especially for about the first three days or so, because applying ice will numb pain and cause blood vessels to constrict which will help reduce swelling. However, after the first three days, you will benefit more from heat application in a case of chronic tendinitis pain, because heat increases blood flow to an injury, which may help promote healing. Heat also relaxes muscles, which promotes pain relief.
- Physiotherapy which involves specific exercises to strengthen the muscles and tendons of the knee are also advised.
- Stretching exercises and squatting exercises (following the reduction in the symptoms) are advised to improve the knee function and also strengthen it to prevent further injuries.
- Young adults with knee tendonitis are often advised exercises such as lunges, squats and leg presses to strengthen the knee joints.
Mild to moderate
- Mild to moderate cases may require additional treatment such as splinting the knee joint to restrict the movement of the knee joint and thereby prevent undue stress on the knee joint.
- Injection of steroid medications near the affected knee joint may be required if the symptoms persist even after following the above mentioned simple approaches.
Severe cases which do not respond to any other approaches may require surgery to repair the ruptured or torn tendon.
Following the surgery of the tendons, the individuals are generally advised a few weeks of rest during which they should restrict the movement of the knee. After a few weeks of the surgery, physiotherapy is started to enable the affected individual to return to normal activities in a gradually phased manner.
In case of athletes complete recovery and return to sports may require more than 3 months time following surgery.
How can you prevent knee tendonitis?
As processes such as increasing age cannot be changed, following certain preventive measures can be helpful in preventing knee tendonitis. The participation in sports is also quite important for the athletes and they cannot avoid it in many instances. However, following proper physiotherapy techniques and warm up procedures can prevent the incidence of knee tendonitis.
Early identification of knee tendonitis and prompt treatment can prevent it from becoming severe enough to restrict day to day activities.
The muscles, tendons and other parts of the body need to be warmed up before beginning any activity that involves the continuous use of the joints. Simple warming and stretching exercises are necessary before getting involved in any kind of sport activities. This helps in improved blood circulation and enables the muscles to get ready for the higher stresses.
Stretching and squatting exercises are often beneficial in strengthening the knee joints and thereby preventing knee tendonitis.
Continuous sitting or standing for prolonged periods may also put undue pressures on the knee making them prone to knee tendonitis. Intermittent walking or stretching the knee joint and the legs can be beneficial in improving the muscle health.