Skip to content

Knee Pain Health Center

Font Size

Patellar Dislocation - Topic Overview

The kneecap (patella) is normally positioned over the front of the knee joint at the base of the thighbone (femur). A kneecap can be dislocated, or moved out of its normal position, when:

  • The inner edge of the kneecap is hit, pushing it toward the outer side of the leg. This can happen more easily if there is patellar tracking disorder (the kneecap is already slightly out of place).
  • The foot is firmly planted pointing outward, and the knee is bent with the thigh turned inward. This kind of injury is common during many sports activities.

Symptoms of a dislocated kneecap may include:

Recommended Related to Knee Pain

Why You Must Protect Your Knees

By Jeannette Moninger Women are the weaker-kneed sex - really! Ease the pain with these tips. Years of stooping, kneeling, and running around really takes a toll on your knees, and women have it especially bad: Studies show we're up to six times more likely than men to suffer from knee injuries like ACL tears. Got an achy, creaky, or weak knee? We'll help you find the cause — plus, we've got ways to fix your bad knees for good.

Read the Why You Must Protect Your Knees article > >

  • Severe pain.
  • A misshapen knee that looks like a bone is out of position.
  • A popping sensation, followed by a feeling that something is out of place.
  • Inability to bend or straighten the knee.
  • Knee swelling.
  • Cool, pale skin or numbness and tingling in or below the affected knee.

A dislocation can cause other problems even if the bone pops back into place.

  • If the dislocation was due to weak thigh muscles or a problem with the alignment or structure of the knee bones, the knee may dislocate again.
  • Ligaments, tendons, muscles, and cartilage in or around the joint may stretch or tear.
  • A piece of bone may break off somewhere in the knee joint.

    WebMD Medical Reference from Healthwise

    Last Updated: November 18, 2013
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    1
    Next Article:

    Today on WebMD

    knee exercise
    If you're living with knee pain, try these.
    knee in brace
    Everything you wanted to know about it.
     
    nurse helping woman on crutches
    When it comes to knee pain.
    man with knee pain
    Read this first.
     
    man biting a bullet
    Article
    6 Ways To Ruin Your Knees
    Article
     
    Keep Joints Healthy
    SLIDESHOW
    Knee exercises
    SLIDESHOW