Causes:
Overuse of the tendon is the main cause of patellar tendinitis. As it is used every time a person straightens their leg, the tendon is at risk of injury through excessive repetition of particular movements, such as jumping. Basketball and volleyball players, as well as runners and soccer players, are particularly at risk of developing what is often called ‘jumper’s knee’.

Sometimes the condition may be triggered by a trauma to the front of the knee, but this is less common than injury due to overuse.

Repeated stress on the tendon can cause microscopic tears in the fibers. These heal with time but, if activity is continued without allowing adequate healing time, the inflammation will persist and worsen.

Certain factors increase the risk of developing the condition. Some of these are:

• Sudden increase in intensity or frequency of physical activity
• Being overweight, which increases stress on the tendon
• Overly tight quadriceps or hamstrings
• A kneecap naturally positioned slightly higher than usual, which places the tendon under increased stress

Symptoms:

• Pain which begins as a twinge but becomes more severe with time and activity
• Pain felt over the patellar tendon, between the kneecap and shinbone
• Pain, often sharp, worse with jumping or kneeling
• Aching pain, persisting after activity
• Occasionally there is swelling of the area around the tendon

Diagnosis:
Your doctor will make a diagnosis based primarily on your reported symptoms and the results of a physical examination of the knee.

You may have an x-ray to rule out possible bone fractures or a bone spur. Ultrasound can reveal tiny tears in the tendon, and an MRI (magnetic resonance imaging) clearly shows all the soft tissues and any damage sustained by them.

Many other conditions produce similar symptoms to patellar tendinitis, so your doctor may use a combination of procedures to arrive at a positive diagnosis.

Treatment:
Conservative, or non-surgical, treatment usually resolves the problem. However, if symptoms persist for over a year, surgery may be necessary to repair tears in the tendon or remove damaged parts.

Initially, any activity that makes the condition worse must be avoided. Refrain from doing anything that causes pain in the tendon. Recovery from patellar tendinitis is a slow process, ranging from a few weeks to several months, depending on the severity of the injury. It is very important to allow adequate time for healing. ‘Pushing through’ the pain will only cause more damage and delay healing.

Use ice packs on the front of the knee to reduce swelling of the tendon. Crush ice in a bag then cover the bag with a towel and place on the painful area for as long as possible without excessive discomfort, several times a day. This is especially effective during the first few days.

Do not use any kind of heat on the area for the first three days as this will increase swelling and pain.

You may find that an infrapatellar (or Chopat) strap helps to relieve pain. This is a strap that is worn around the leg, just under the kneecap. It applies pressure on the tendon, which directs force away from it and through the strap instead. Your doctor may recommend a particular knee brace for you.

Amongst other techniques such as massage and ultrasound, a physiotherapist may use an anti-inflammatory and pain-relieving technique called iontophoresis. A corticosteroid ointment is applied to the skin over the painful area then a gentle electric charge delivers the medication deep into the tissues of the tendon. Sometimes your doctor may inject the patellar tendon sheath with a corticosteroid, usually combined with an anesthetic.

Your physiotherapist will also develop an exercise program aimed at stretching and strengthening the leg muscles, particularly the quadriceps. A relatively new system known as eccentric exercise is proving to be highly beneficial, but a professional must teach you how to perform these exercises properly.

Exercise:
The following exercises should not be done without prior approval from your doctor or physiotherapist. Try to do them twice each day.
Hamstring stretch:
Keeping the knee straight, place the heel of your foot on the seat of a chair. Lean forward from the hips, making sure you do not bend at the waist. When you feel a gentle stretch in the back of the thigh, hold the position for 15-30 seconds. Repeat 3 times. Switch legs and repeat exercise.
Quad stretch:
Place the left hand on a wall for support. Hold the right foot with your right hand and gently pull the foot up and behind you towards the buttocks, stopping when you feel a stretch. Keep the knees together. Hold the stretch for 15-30 seconds. Repeat 3 times then switch legs and repeat exercise.
Leg extension:
Lie down on the floor with your legs straight out in front of you. Raise one leg (keeping it straight) about 6 inches off the ground. You can use a rolled towel under one thigh for support. Hold the position for 5-10 seconds then slowly bend your knee to lower the foot to the floor. Repeat 10 times. Switch legs and repeat exercise.
Straight leg raise:
Lying on your back on the floor, bend your unaffected knee and rest the foot on the floor. Keeping the knee of the injured leg straight, contract the thigh muscles and lift the leg up until the heel is about 6 inches off the ground. Hold for 5-10 seconds then slowly lower. Repeat 10 times. Switch legs and repeat exercise.
Quad sets:
Sit on the floor with your injured leg straight out in front of you and the unaffected leg bent with the foot on the floor. Contract the thigh muscles of the injured leg by pressing the knee towards the floor. Hold the position for 5-10 seconds then relax. Repeat 10 times. Switch legs and repeat exercise.

Prevention:

• Stretch and strengthen your leg muscles.
• Ensure that you use proper technique when exercising.