Patellar Dislocation and Subluxation

with Phase II Rehab

ExitCare ImageInjuries to the knee often include kneecap (patellar) dislocation or subluxation. The patella is a V-shaped bone that sits in a groove in the thigh bone (trochlea). A patellar dislocation occurs when the kneecap is displaced from the trochlea, and the joint surfaces are no longer touching. A subluxation is a similar injury, where the kneecap becomes displaced, but the joint surfaces are still touching. Patellar dislocations and subluxations are most common in adolescents and younger adults.


  • Severe pain in the front of the knee when attempting to move the knee.

  • A feeling of the knee giving way.

  • Tenderness, swelling, and bruising (contusion) of the knee.

  • Numbness or paralysis below the dislocation, from pinching, cutting, or pressure on the blood vessels or nerves (uncommon).

  • Visible deformity, especially if the dislocation of the kneecap occurs towards the outside of the knee.

  • Lump on the inner knee, which is the end of the inner part of the thigh bone (femur).


Patellar dislocations are caused by a force placed on the kneecap, that is strong enough to displace the bone from its proper alignment. Common causes of injury include:

  • Direct hit (trauma) to the knee.

  • Twisting or pivoting injury to the lower limb, when the foot is planted on the ground.

  • Powerful muscle contraction.

  • Birth defect (congenital abnormality), such as shallow or malformed joint surfaces.


  • Contact sports (football, rugby, soccer), sports that require jumping and landing (basketball, volleyball), or sports in which cleats are worn on shoes.

  • People with wide pelvis, knocked knees, shallow or malformed joint surfaces.

  • Previous knee injury.

  • Poor strength and flexibility.


  • Warm up and stretch properly before activity.

  • Maintain physical fitness:

  • Strength, flexibility, and endurance.

  • Cardiovascular fitness.

  • For jumping or contact sports, protect the kneecap with supportive devices (elastic bandages, tape, braces, knee sleeves with a hole for the patella and a built-up outer side, or straps to pull the patella inward, or knee pads).

  • Use cleats of proper length.


If treated properly, patellar dislocations and subluxations usually require at least 6 weeks to heal.


  • Associated fracture or joint cartilage injury.

  • Damage to nearby nerves or major blood vessels (rare).

  • Longer healing time or recurring dislocation, if activity is resumed too soon.

  • Excessive bleeding within the knee, due to dislocation.

  • Kneecap pain and giving way, often due to inadequate or incomplete rehabilitation.

  • Unstable or arthritic joint, following repeated injury or delayed treatment.


Patellar dislocations and subluxations require immediate realigning of the bones (reduction). Realigning is often completed by hand. However, surgery is sometimes needed. After realignment, treatment first involves the use of ice and medicine, to reduce pain and inflammation. Elevating the injured knee above the level of the heart will also help reduce inflammation. Restraining the knee is often needed, to allow for healing, for up to 6 weeks. After restraint, it is important to perform strengthening and stretching exercises to help regain strength and a full range of motion. These exercises may be completed at home or with a therapist.


  • If pain medicine is needed, nonsteroidal anti-inflammatory medicines (aspirin and ibuprofen), or other minor pain relievers (acetaminophen), are often advised.

  • Do not take pain medicine for 7 days before surgery.

  • Prescription pain relievers may be given, if your caregiver thinks they are needed. Use only as directed and only as much as you need.


  • Cold treatment (icing) should be applied for 10 to 15 minutes every 2 to 3 hours for inflammation and pain, and immediately after activity that aggravates your symptoms. Use ice packs or an ice massage.

  • Heat treatment may be used before performing stretching and strengthening activities prescribed by your caregiver, physical therapist, or athletic trainer. Use a heat pack or a warm water soak.


  • Pain, tenderness, or swelling gets worse, despite treatment.

  • You experience pain, numbness, or coldness in the foot.

  • Blue, gray, or dark color appears in the toenails.

  • Any of the following signs of infection occur after surgery: fever, increased pain, swelling, redness, drainage of fluids, or bleeding in the affected area.

  • New, unexplained symptoms develop. (Drugs used in treatment may produce side effects.)



RANGE OF MOTION (ROM) AND STRETCHING EXERCISES - Patellar Dislocation and Subluxation Phase II

Once your knee has healed well enough to bend (flex) at least 100 to 110 degrees, your caregiver may progress you to Phase II of your rehabilitation. This phase will help you gain even more flexibility in your knee to allow you to return to your previous daily and recreational activities. It is important that you do not force any exercise. Never continue an exercise that increases your pain or gives you the sensation that your knee is about to "pop out" or dislocate. Inform your physician, physical therapist or athletic trainer of any exercises that you need to discontinue, due to increasing either of these symptoms.

While completing these exercises, remember:

  • Restoring tissue flexibility helps normal motion to return to the joints. This allows healthier, less painful movement and activity.

  • An effective stretch should be held for at least 30 seconds.

  • A stretch should never be painful. You should only feel a gentle lengthening or release in the stretched tissue.

ExitCare Image STRETCH - Quadriceps, Prone

  • Lie on your stomach on a firm surface, such as a bed or padded floor.

  • Bend your right / left knee and grasp your ankle. If you are unable to reach your ankle or pant leg, use a belt around your foot to lengthen your reach.

  • Gently pull your heel toward your buttocks. Your knee should not slide out to the side. You should feel a stretch in the front of your thigh and knee.

  • Hold this position for __________ seconds.

Repeat __________ times. Complete this stretch __________ times per day.

ExitCare Image STRETCH – Hamstrings, Supine

  • Lie on your back. Loop a belt or towel over the ball of your right / left foot.

  • Straighten your right / left knee and slowly pull on the belt to raise your leg. Do not allow the right / left knee to bend. Keep your opposite leg flat on the floor.

  • Raise the leg until you feel a gentle stretch behind your right / left knee or thigh. Hold this position for __________ seconds.

Repeat __________ times. Complete this stretch __________ times per day.

ExitCare Image STRETCH - Hamstrings, Doorway

  • Lie on your back with your right / left leg extended and resting on the wall and the opposite leg flat on the ground through the door. At first, position your bottom farther away from the wall.

  • Keep your right / left knee straight. If you feel a stretch behind your knee or thigh, hold this position for __________ seconds.

  • If you do not feel a stretch, scoot your bottom closer to the door, and hold __________ seconds.

Repeat __________ times. Complete this stretch __________ times per day.

ExitCare Image STRETCH – Iliotibial Band

  • On the floor or bed, lie on your side so your right / left leg is on top. Bend your knee and grab your ankle.

  • Slowly bring your knee back so that your thigh is in line with your trunk. Keep your heel at your buttocks and gently arch your back so your head, shoulders and hips line up.

  • Slowly lower your leg so that your knee approaches the floor, until you feel a gentle stretch on the outside of your right / left thigh. If you do not feel a stretch and your knee will not fall farther, place the heel of your opposite foot on top of your knee and pull your thigh down farther.

  • Hold this stretch for __________ seconds.

Repeat __________ times. Complete this stretch __________ times per day.

ExitCare Image STRETCH – Lateral Patellar Mobilizations, Seated

  • While sitting, bend your knee 90 degrees or a little less. Place your foot flat on the floor.

  • Place the inside of your palm at the base of your thumb, on the inside border of your kneecap.

  • Press down on the inside border, so that the outside border lifts up slightly.

  • You should feel a slight stretch on the outside edge of your kneecap. Hold this position for __________ seconds.

Repeat __________ times. Complete this stretch __________ times per day.

STRENGTHENING EXERCISES - Patellar Dislocation and Subluxation Phase II

These are some of the exercises you may progress to in your rehabilitation program. It is critical that you follow the instructions of your caregiver and not progress to these Phase II exercises until directed. You may continue with all Phase I strengthening exercises. Remember:

  • Strong muscles with good endurance tolerate stress better.

  • Do the exercises as initially prescribed by your caregiver. Progress slowly with each exercise, gradually increasing the number of repetitions and weight used under his or her guidance.

ExitCare Image STRENGTH - Quadriceps, Short Arcs

  • Lie on your back. Place a __________ inch towel roll under your right / left knee, so that the knee bends slightly.

  • Raise only your lower leg by tightening the muscles in the front of your thigh. Do not allow your thigh to rise.

  • Hold this position for __________ seconds.

Repeat __________ times. Complete this exercise __________ times per day.

OPTIONAL ANKLE WEIGHTS: Begin with ____________________, but DO NOT exceed ____________________. Increase in 1 lb/0.5 kg increments.

ExitCare Image STRENGTH - Hip Extensors, Bridge

  • Lie on your back on a firm surface. Bend your knees and place your feet flat on the floor.

  • Tighten your buttocks muscles and lift your bottom off the floor until your trunk is level with your thighs. You should feel the muscles in your buttocks and back of your thighs working. If you do not feel these muscles, slide your feet 1-2 inches further away from your buttocks.

  • Hold this position for __________ seconds.

  • Slowly lower your hips to the starting position and allow your buttock muscles to relax completely before beginning the next repetition.

  • If this exercise is too easy, you may cross your arms over your chest.

Repeat __________ times. Complete this exercise __________ times per day.

ExitCare Image STRENGTH - Quadriceps, Step-Ups

  • Use a thick book, step or step stool that is __________ inches tall.

  • Hold a wall or counter for balance only, not support.

  • Slowly step up with your right / left foot, keeping your knee in line with your hip and foot. Do not allow your knee to bend so far that you cannot see your toes.

  • Slowly unlock your knee and lower yourself to the starting position. Your muscles, not gravity, should lower you.

Repeat __________ times. Complete this exercise __________ times per day.

ExitCare Image STRENGTH - Quadriceps, Wall Slides

Follow guidelines for form closely. Increased knee pain often results from poorly placed feet or knees.

  • Lean against a smooth wall or door and walk your feet out 18-24 inches. Place your feet hip width apart.

  • Slowly slide down the wall or door until your knees bend __________ degrees.* Keep your knees over your heels, not your toes, and in line with your hips, not falling to either side.

  • Hold for __________ seconds. Stand up to rest for __________ seconds between each repetition.

Repeat __________ times. Complete this exercise __________ times per day.

* Your physician, physical therapist or athletic trainer will alter this angle based on your symptoms and progress.

ExitCare Image STRENGTH - Quad/VMO, Isometric

  • Sit in a chair with your right / left knee slightly bent. With your fingertips, feel the VMO muscle just above the inside of your knee. The VMO is important in controlling the position of your kneecap.

  • Keeping your fingertips on this muscle. Without actually moving your leg, attempt to drive your knee down as if straightening your leg. You should feel your VMO tense. If you have a difficult time, you may wish to try the same exercise on your healthy knee first.

  • Tense this muscle as hard as you can without increasing any knee pain.

  • Hold for __________ seconds. Relax the muscles slowly and completely between each repetition.

Repeat __________ times. Complete exercise __________ times per day.