Hip Anatomy and Terminology

The hip is the largest “ball-and-socket” joint in the body. It is held together by ligaments, tendons, and a joint capsule.

The ball is called the “femoral [fem-er-uhl] head,” which is the top of the femur or thigh bone.

The socket is called the “acetabulum” [as-i-tab-yuh-luhm] and is a part of the pelvis.

The femoral head fits into the acetabulum forming the hip joint. They fit together so the ball can rotate freely in the socket.

Articular cartilage is a very smooth surface that covers the femoral head and the acetabulum so that the hip joint glides easily during motion.

The labrum is a soft rim that lines the edge of the acetabulum. The labrum creates a seal of the hip joint. This seal helps keep an oily fluid called synovial fluid inside the hip joint. The labrum also helps stabilize the hip. The hip is also stabilized by the surrounding muscles, ligaments, tendons and joint capsule.

Doctors use a number of different terms for hip dysplasia depending on severity and time of occurrence. These names include:

  • Hip Dysplasia
  • Developmental Dislocation of the Hip (DDH)
  • Hip Dislocation
  • Developmental Dysplasia of the Hip (DDH)
  • Acetabular Dysplasia
  • Congenital Dislocation of the Hip (CDH)
  • Call to Action Buttons

  • Email Sign Up

    Email Sign Up
  • Social Media Links

  • Translate Link

    Para ver en Español Click Aquí

  • SubNav Menu

  • Latest News

    Latest News

    Submit a Story

    Should you wait to have a PAO until your arthritis...

    May 30

    There is often a question of how long it’s safe to postpone PAO surg...

    Book Review V2

    May 29

    Hip Dysplasia Books and Resources Betsy Miller IHDI Advisory C...

    W-Sitting and Hip Development

    May 29

    Contrary to popular belief, this W-sitting posture is normal for m...

  • Latest Stories

    Latest Stories

    Submit a Story

    Miles

    Jun 12

    About two years ago, my 17 year old son started experiencing moderate ...

    Michele

    Jun 10

    I was born with bilateral hip dysplasia. My left hip is worse then my ...

    Jacob

    Jun 10

    Jacob was born early on February 9, 2019 at 37 weeks gestation. His bi...