Knee
Tendinitis of the Knee
The knee joint is supported by several important tendons, which play a crucial role in stabilizing and facilitating the movement of the knee. The patellar tendon connects the patella (kneecap) to the tibia (shinbone). It plays a central role in straightening the knee and is essential for activities like standing, walking, and running. The quadriceps tendon is located just above the patella and connects the quadriceps muscles in the front of the thigh to the patella. This tendon assists in extending the knee and is integral for movements such as jumping and climbing.
What is tendinitis of the knee?
Tendinitis of the knee, also known as patellar or quadriceps tendinitis, is a condition characterized by inflammation and irritation of the patellar or quadriceps tendon. It is the most common cause of knee pain, especially in elite athletes such as volleyball players, basketball players, and weightlifters. It is a common condition in teen athletes and people in their 20s and 30s.
What causes tendinitis of the knee?
Tendinitis of the knee is caused by repetitive mechanical stress that causes micro-trauma which creates microscopic tears in the tendon and leads to tendon degeneration. Knee tendinitis often results from overuse or repetitive strain on the knee, particularly in activities like running, jumping, or sports that involve frequent knee movements. Additionally, poor biomechanics, muscle imbalances, and improper footwear can contribute to the development of patellar tendinitis or quadriceps tendinitis.
Who is at risk of developing knee tendinitis?
- Recreational athletes who engage in activities that require strenuous and repetitive jumping, running, or playing sports such as soccer without proper conditioning.
- Elite athletes who play jumping sports like basketball or volleyball, or any sport that involves jumping, landing, and abrupt changes in directions.
- People who are taller and heavier
- Older age and prior injuries
- Misalignment of the foot, heel, or shin bone (tibia), differences in leg length or foot arch height
- Some metabolic diseases, such as Diabetes
- Athletes who train excessively and/or train/play on hard ground
- Men are affected more often than women.
What are the symptoms of tendinitis of the knee?
- Aching pain in the front of the knee
- Pain around the kneecap, usually felt below the kneecap if patellar tendinitis but can be felt above if quadriceps tendinitis.
- Pain that goes away with rest. The pain resolves with rest because the tendon can heal microscopic tears.
- Swelling
- Pain that recurs with prolonged sitting, squatting, and climbing stairs.
- Pain that becomes chronic with repetitive stress and can interfere with daily functions and sleep.
How is tendinitis of the knee diagnosed?
Knee tendinitis is a clinical diagnosis based on medical history, physical examination, and symptoms. Ultrasound can often facilitate diagnosis while MRI can sometimes confirm the presence of chronic irritation of the patellar or quadriceps tendon. Imaging studies can help to identify the severity of the degeneration.
Tendinitis of the Knee Non-Surgical Treatment
Can tendinitis of the knee be treated without surgery?
Knee tendinitis can be difficult to treat because symptoms tend to resolve and recur. Non-operative treatment of knee tendinitis involves a change in activities to avoid movements that cause knee pain (i.e. jumping, running, etc.). Additionally, using over-the-counter anti-inflammatory medications to reduce pain and inflammation, and physical therapy can help diminish symptoms. When it comes to physical therapy, eccentric squat-based training is a mainstay of treatment and is preferred for the treatment of athletes. In some cases, a knee strap or compression sleeve brace can be beneficial in managing inflammation and pain. A knee strap can help “unload” the insertion of the patellar tendon in cases of patellar tendinitis.
Typically, symptoms will resolve within 2-3 months of conservative, non-surgical treatment. However, when symptoms persist, a platelet rich plasma (PRP) injection directly to the affected tendon can also help relieve knee pain and promote healing of the micro-tearing of the tendon. PRP therapy for chronic knee tendinopathy has been shown to provide improved clinical outcomes in almost 77% of patients and allowed them to return to their pre-symptom activity levels in 86% of cases. Moreover, extracorporeal shock wave treatments have also been shown to produce good outcomes in cases of persistent knee tendinopathy.
If your knee pain is resolved with non-operative treatment and you can return to your desired level of activity, then no surgery for knee tendinitis is needed. However, conservative treatment approaches fail in about 10% of athletes and up to 27% of professional athletes choose surgery to relieve chronic symptoms.
Tendinitis of the Knee Surgical Treatment
What are the surgical options for tendinitis of the knee?
Surgery is usually reserved for patients whose symptoms persist after conservative management, and therefore, their overall function remains limited. Physical therapy is important for optimizing improvements after surgery. The gold standard treatment is arthroscopic debridement, removal of the diseased part of the patellar tendon, and bone drilling to stimulate a healing response. In some cases, a tendon repair, reconstruction, or augmentation with a graft is required if the tissue quality of the native tendon is compromised.
How long is the recovery after surgery for tendinitis of the knee?
Return to play rates following surgery for tendinitis of the knee are high, but the timeline is variable. The range for return to sport following surgery for chronic tendinitis of the knee is 3-12 months.
Effects of Untreated Tendinitis of the Knee
What are the long-term effects of untreated tendinitis of the knee?
Tendon injuries are very common, and because tendons have limited blood supply, injuries are difficult to heal. If left untreated, knee tendonitis can lead to chronic pain and reduced mobility. In some cases, it may progress to more severe conditions like tendinopathy or tendon rupture.