Knee tendonitis is an injury that causes inflammation, irritation or swelling of the tendons of the knee. It’s the most common of possible knee injuries  and is usually an overuse injury occurring among athletes or active individuals as a result of overtraining or subjecting the knee to sharp movements or uneven surfaces. There are actually four types of knee tendonitis – pes anserinus tendonitis, popliteus tendonitis, semimembraneous tendonitis and (perhaps the most well known type) patellar tendonitis. Symptoms of all four types of tendonitis include tenderness, pain and stiffness in the knee area. Mild to moderate cases of this condition are usually treatable using conservative approaches that include rest, icing, physical therapy and (in some cases) cortisone injections.
Causes
Knee tendonitis can have different causes depending on the specific type under consideration.
As previously mentioned, patellar tendonitis (also called Jumper’s Knee) is usually brought on by intensive running or jumping, typically among teeenage athletes. The focus of this type of tendonitis is the patellar tendon that connects the kneecap to a point just beneath it and on the shinbone (tibia). This tendon plays a key role in knee extension (the pivotal action of the knee when running or jumping).
Pes anserinus tendonitis (which is actually the most common form of knee tendonitis) is usually the result of intensive running by middle aged individuals. This type of tendonitis usually involves the pesanserinus tendons that are situated just below below the kneecap and on the medial (inner) side of the knee. The role of these tendons is to prevent excessive outward twisting of the leg during the act of running. One of these tendons is the semi membraneous tendon and inflammation of this tendon causes a separate type of tendonitis known as semimembraneous tendonitis.
Popliteus tendonitis affects the popliteus tendons and is the result of excessive inward rolling of the feet (pronation) or of running downhill. This tendon sits behind the knee and towards the lateral (outer) side of the joint.
Symptoms Of Knee Tendonitis
The main symptoms of knee tendonitis include pain, swelling and stiffness of the knee. The patient may also experience more severe pain when climbing or descending stairs or rising from a seated position. In some cases. the pain may also increase at night.
However, the focus of these problems will be in different areas depending on the type of tendonitis that is present.
Patellar tendonitis causes pain, swelling and stiffness immediately below the knee cap on the anterior (frontal) side of the knee.
Pes anserine tendonits will result in these conditions appearing on the inside of the knee. Semi membraneous tendonitis usually causes them to appear on the inside and back of the joint. Popliteal tendonitis usually causes these problems to appear on the posterior (rear) of the knee.
Treatment
In most cases of knee tendonitis, rest (i.e. refraining from intensive physical activities and particularly those involving running or jumping) is sufficient to resolve the problem.
In addition to rest, doctors may prescribe:
Icing the painful area (or applying a cold pack) to reduce moderate pain and inflammation;
Taking non steroidal anti inflammatory medications if the pain and/or inflammation is especially severe;
Compressing the knee using a knee sleeve (for example) or a tensor bandage;
Keeping the knee elevated above heart level whenever possible (e.g. when lying or sitting down) ;
Cortisone injections to relieve high levels of inflammation. However, if taken for too long, these can actually result in further deterioration of the tendon and turn the problem into a chronic one.
Surgery
If the knee tendonitis is severe and resists the conservative approaches described above, surgery may be considered. However, the patient should be careful to thoroughly discuss the long term risks of this option with the surgeon before agreeing to it.