Patella Subluxation or Dislocation

A subluxing patella (kneecap) is a temporary, partial dislocation of the kneecap from its normal position in the groove in the end of the thigh bone (femur). This groove is located between two bumps at the end of the thigh bone called the femoral condyles.

How does it occur?

This temporary dislocation of the kneecap usually happens during forced leg straightening, with the kneecap moving out of the groove to the outer side of the knee. The cause is usually an abnormality in the way your legs are built. You may have an underdevelopment of the inner thigh muscle or an overdevelopment of the outer thigh muscle. Your kneecap may be higher in the leg than usual. You may be knock-kneed or have underdevelopment of the outer (lateral) femoral condyle.

Symptoms

You may feel the kneecap moving out of position. You may have swelling and pain behind the kneecap. You may have pain when you bend or straighten your leg.

Diagnosis

Your health care provider will ask about your symptoms and examine your knee. He or she may be able to feel the kneecap slipping to the outside as you bend and straighten your leg. An x-ray may show underdevelopment of the lateral femoral condyle.

Treatment

Initial treatment includes reduction of the patella back into place which may happen on its own or
at an emergency room or urgent care. After that, depending on how bad the injury was, you may
be asked to wear a knee immobilizer or special brace. Follow your provider’s instructions for the
brace, however most patients can take the brace off when not putting weight on their leg. It’s also
helpful to remember the following acronym:

Patella Dislocation Stage I Exercises

Straight Leg Stretch
Lay down in a bed or on the floor on your back and place a towel or pillow under your ankle or heel and sit for 3 to 5 minutes allowing for gravity to straighten your knee. You may also place a small weight over the knee.

Heel Slides
Lay down in a bed or on the floor on your back, drag your heel towards your buttocks on the bed or floor so your knee bends. Stop when you feel pain, a small stretch is normal. Hold for five seconds, repeat 10 times. Do three sets of 10.

Quadriceps Sets
Sit on the floor with your injured leg straight in front of you. Press the back of your knee down while tightening the muscles on the top of your thigh. Hold this position for five seconds. Complete three sets of 10.

Straight Leg Raise
Sit on the floor with the injured leg straight and the other leg bent, foot flat on the floor. Pull the toes of your injured leg toward you as far as you can, while pressing the back of your knee down and tightening the muscles on the top of your thigh. Raise your leg six to eight inches off the floor and hold for five seconds. Slowly lower it back to the floor. Complete three sets of 10.

Abduction
Lie on your uninjured side, leaning on the elbow of your uninjured side and using the arm of the injured side in front of you to stabilize your body. Slowly lift the injured leg up, hold for five seconds, then lower slowly. Be sure to keep your hips steady and don’t roll forwards or backwards. Complete three sets of 10.

Adduction
Lie on your injured side with your top leg bent and flat foot placed in front of the injured leg, which is kept straight. Raise your injured leg as far as you can comfortably and hold it there for five seconds. Keep your hips still while lifting your leg. Hold this position for five seconds, then slowly lower your leg. Complete three sets of 10.

Extension
Lie on your stomach. Raise your injured leg as far as you can comfortably and hold it there for five seconds. Keep your hips still while lifting your leg. Hold this position for five seconds, then slowly lower your leg. Complete three sets of 10.

Patella Dislocation Stage II Exercises

DO NOT PROGRESS WITH THESE EXERCISES UNTIL CLEARED TO DO SO

Standing Calf Stretch
Facing a wall, put your hands against the wall at about eye level. Keep the uninjured leg forward and your injured leg back about 12 to 18 inches behind your uninjured leg. Keep your injured leg straight and your heel on the floor and keep your toes pointed towards the wall. Next, do a slight lunge by bending the knee of the forward leg. Lean into the wall until you feel a stretch in your calf muscle. Hold this position for 30 to 60 seconds, and repeat three times.

Half Kneeling Ankle Mobility
Begin in a half-kneeling position with your forward foot a few inches away from the base of a wall. Shift your weight forward, pushing your knee toward the wall as far as you can. Hold, then relax and repeat. Make sure to maintain your balance and move only through a pain-free range of motion.

Hamstring Stretch
Lie on your back and bring the affected leg towards your chest. Grab the back of your thigh and try to extend your leg. Hold this position for 30 to 60 seconds, feeling a stretch in the back of your thigh. Repeat three times. You may also try this with a towel around your foot if it is more comfortable.

Quadriceps Stretch
Stand sideways to a wall, about an arm’s length away from the wall, with your injured leg towards the outside. Facing straight ahead, keep the hand nearest the wall against the wall for support. With your other hand, grasp the ankle of your injured leg and pull your heel up toward your buttocks. Do not arch or twist your back. Hold this position for 30 seconds. Repeat three times. This may also be done while lying on the opposite side and grasping the ankle of the affected leg. Do not arch or twist your back. Hold this position for 30 seconds. Repeat three times.

Clamshells
Lie on your side with your knees slightly bent, keeping your legs and ankles together. Open and close your knees like a clam by lifting your top knee up until it is parallel with your hip. Keep your feet together throughout the exercise, move slowly and controlled as if someone is pushing against your knee while you are pressing it up. Complete three sets of 10.

Treatment may also include:

  • Elevating your knee to help any swelling go away
  • Taking an anti-inflammatory medication
  • Wearing a brace prescribed by your health care provider to keep your
  • kneecap in place doing exercises to strengthen the inner side of the thigh muscle (quadriceps)
  • Some people need surgery to keep the kneecap from subluxing
  • putting ice packs on your knee for 20 to 30 minutes every 3 to 4 hours for the first 2 or 3 days or until the pain goes away

While you are recovering from your injury you will need to change your sport or activity to one that will not make your condition worse. For example, you may need to bicycle instead of run.

Prevention

  1. Stay in shape
  2. Stretch – Before doing any strenuous activity, do a 5 minute warm up and do stretching
    exercises. Remembering to stretch your knee will help keep the structures around the knee
    flexible and less likely to be irritated by activity
  3. Increase training gradually – Dramatic increases in activity over a short period of time can
    result in overuse injuries
  4. Use proper running gear – Make sure that your shoes fit properly and provide good support
  5. Use proper running form
  6. Strengthening of thigh, hip and trunk muscles – Helps to “off-load” stress on the
    patellofemoral joint using the above mentioned exercises

When can I return to my sport or activity?

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