What is Tendonitis of the Knee?

Tendonitis is a painful condition caused by inflammation, or irritation, of a tendon. A tendon is a thick, band-like cord that attaches a muscle to a bone. Tendonitis of the knee is common, especially in athletes. The patellar tendon is the most common tendon in the knee that suffers from tendonitis. It connects the kneecap (patella) to the shinbone (tibia) and helps you straighten your leg by way of the quadriceps muscle. Pain from patellar tendonitis is likely to be felt along the tendon, just below the patella in the front of the knee.

Causes of Tendonitis

Tendonitis is an overuse condition that is generally caused by repetitive running, jumping, plyometric workouts, and kicking. Pain will typically start with pain after stressful activities, progressing to pain during activities, and at its most advanced stage, pain at rest with little provocation. This pain comes from the repeated stress at the tendon where it connects to the patella and its severity will be determined by the duration and intensity of the activities causing the pain. Over time, this repetitive stress at the tendon can cause structural damage. Therefore, athletes of all ages who spend many hours a week doing repetitive activities are prone to developing tendonitis.

What are the Symptoms of Tendonitis of the Knee?

  • Pain along the tendon with or without activity.
  • Tenderness to the touch.
  • Localized swelling in the tendon.
  • Decreased range of motion.
  • Decreased flexibility.
  • Muscle weakness.

How is Tendonitis of the Knee Treated?

Physical therapy is often effective for tendonitis of the knee. Physical therapy will generally include a combination of range of motion, flexibility, and strength exercises along with activity modifications with the goal reducing pain with activity. Often rest, ice, or over-the-counter anti-inflammatory medicines are used. Occasionally, surgery is necessary in order to relieve chronic symptoms.

Non-Surgical Treatments for Tendonitis of The Knee

  • Self-care.
  • Physical therapy.


Often rest, ice, and over-the-counter anti-inflammatory medicines relieve pain and inflammation from tendinitis of the knee. Anti-inflammatory medicines include:

  • Ibuprofen (Advil/Motrin)
  • Naproxen (Aleve).

Physical therapy for tendonitis of the knee

Physical therapy can often relieve pain and inflammation from tendonitis of the knee.

- Initial treatment is to restrict activities causing tendon pain. The time and degree of activity restriction depends on the severity and length of time symptoms have been present.

- During the period of rest, ice and anti-inflammatory medication are recommended as well as physical therapy to improve joint range of motion and muscle flexibility.

- Once pain is reduced and range of motion/flexibility is restored, exercises to strengthen the tendon and muscles of the lower leg are started.

- Once range of motion/flexibility/strength are maximized and symmetric to the other side, education is given to gradually return to activities and manage symptoms.

Surgery for Tendonitis of The Knee

If non-surgical treatments do not help enough, you may need a surgery to relieve symptoms. Before going forward with a surgery, an MRI is obtained to assess the integrity of the tendon. After failing non-surgical treatment, it may be likely that the damage to the tendon is irreversible which will be seen on the MRI scan. If irreversible tendon damage is seen on the MRI scan, a patellar tendonectomy surgery would be recommended. During this procedure, a small incision is made to allow visual inspection of the damaged portion of the tendon where it is then removed. Along with the removal of the damaged tissue, the surgeon will surgically stimulate the remaining viable tendon to allow for tissue regeneration. A light dressing and Cryo/Cuff is applied after surgery to minimize swelling and reduce pain. Physical therapy starts soon after surgery done independently at home before following up in the clinic with a physical therapist 5-7 days post op

Physical Therapy After Surgery

After surgery, you will work with physical therapy to achieve:

  • Full joint range of motion and muscle flexibility, equal to the other side.
  • Return the tendon and quadriceps muscle to full strength, equal to the other side.
  • Return to a pain free prior level of function.

You will do most of your exercises at home, but will come back to the office for some physical therapy visits to assess and progress through the plan of care. You will continue to work with your personal physical therapist or athletic trainer until all goals are met.