Musculoskeletal system of our body includes bones, muscles, tendons and ligaments that attach the first two to each other. Tendons are made of fibrous tissue and are required to provide the attachment of muscles to the bones. The patellar tendon connects the kneecap (on the bottom side) and the shinbone (in the area of tibial tuberosity). The patellar tendon plays a huge role in the straightening of the leg. The quadriceps muscle is one of the strongest muscles in the body and the force created during the bending of the knee is absorbed by the patellar tendon.
The excessive pressure over the tendon gradually damages it. Initially the injury is tiny and no symptoms are present. As the lesion worsens the tendon loses the ability to resist the pressure and the affected person suffers from pain.
The condition is common for the athletes.
Causes and risk factors
Patellar tendonitis is also called the jumper’s knee. This name is not accidental – it refers to the main cause of the disorder – frequent jumping and therefore the condition is common for professional sportsmen. Jumper’s knee in characterized by the tendon lesion, although often there is no inflammation in the damaged area.
The athletes who are involved in basketball and volleyball, high and long jumping, tennis and gymnastics are more likely to develop the tendinopathy. However, sometimes the disorder affects also not athletes.
Degeneration of the tendon due to the microdamage results in the pattelar tendinitis in elderly.
An acute tendon trauma and inadequate treatment contribute to the development of the traumatic patellar tendonitis.
Typically the teens at the age between 10 and 16 years get affected.
Depending on the severity and duration, jumper’s knee has 4 stages:
- Stage 1 – Pain solely after activity, functional impairment isn’t seen;
- Stage 2 – Pain during and after activity, although the person remains able to perform in his/her sport;
- Stage 3 – Prolonged pain during and after activity, the person gradually loses the ability to perform as desirable;
- Stage 4 – Complete tendon tear, surgical repair is obligatory;
See also: Knee effusion
The major symptom of the patellar tendinitis is the pain in the area where the tendon is attached. Initially the pain is present only after the intense workout and jumping, later it becomes persistent.
Other symptoms include the following:
- Pain worsens with jumping, landing or running, sometimes with prolonged sitting;
- Pain usually occurs gradually and relates to an increased load on the knee;
- Bruising and cramping;
- Localized sensitivity over the tendon;
- Hamstring tightness;
- The tendon is very stiff early in the morning;
- The tendon may appear thickened when compared with the healthy side;
In the late stages the pain interferes with everyday activities.
Typically, tendon injuries occur in three areas:
- musculotendinous junction (where the tendon joins the muscle);
- mid-tendon (non-insertional tendinopathy) caused by a cumulative microtrauma from repetitive overloading (overuse, overtraining);
- tendon insertion (into bone);
The diagnosis is based on the history of the disorder, physical examination. To estimate the pain the VISA pain questionnaire is used. X-ray examination of the knee is necessary if the other causes of the knee pain should be excluded. Ultrasound examination and MRI are highly sensitive methods of examination used to verify the diagnosis and evaluate the damage to the tendon.
To relieve the pain RICE therapy may be used:
R – Rest the knee from the painful activity;
I – Ice over the affected area for 20 minutes every 2-4 hours, especially during the first 24-48 hours after any exercises;
C – Compress the painful area with an elastic bandage;
E – Elevate the leg.
Physical therapy is aimed to improve the strength of the quadriceps, hamstring and gastrocnemius muscles and includes straight leg raises, short-arc quadriceps exercises and wall slides.
Autologous blood injection, or platelet-rich plasma injection may be performed, such treatment is typically successful. Ultrasound or phonophoresis (ultrasound delivered medication) is helpful to decrease pain symptoms. Arch supports or orthotics are used to improve foot and leg stability and prevent future injury.
Surgery is indicated when the conservative therapy after 6-13 months fails to reduce the symptoms of tendinitis. A longitudinal or transverse incision is made over the patella tendon and abnormal tissue is then removed.
NSAIDs (nonsteroidal anti-inflammatory drugs) are commonly used to alleviate the pain and lessen the inflammation. Ibuprofen and Naproxen are usually used in the treatment of patellar tendonitis.
The prolonged intake of NSAIDs may cause the stomach ulcers, abdominal pain, nausea, heartburn, and indigestion.