year ten science:please help:"What type of joint is the hip joint"?

Question

i need some info for some research:
What type of joint is the hip joint?
Two reasons why plastic is used to make artificial hip joints
why is a high calcium diet essential after a hip replacement operation?
THANK YOU

Answer 1

its a ball and socket joint
plastic is noncorrosive and low coeffeciant of friction
whent he surgery is done the socket is ground out so the new ball fits in perfectly this increases the risk of fracture so calcium is a must for preventative measures

Answer 2

The hip joint is a ball-and-socket joint.

Plastic (actually high-density polyethylene) has been used for the socket in hip replacements for many years. It wears away at the rate of about one mm per year against a metal ball (either cobalt-chromium or titanium), giving such an implant a lifespan of 10-15 yrs. New developments in socket design use "cross-linked" poly that may have a slower wear rate. The wear particles produced move from the implant to the bone. The body sees these particles as "foreign bodies" and produces enzymes which can slowly dissolve bone which may result in loosening of the implant. In a very active individual, loosening may take place sooner than it would in a more sedentary older person. Loosened joint implants require a second surgery, called a "revision", in which the prosthesis is removed and replaced.

New bearing materials have been developed that may reduce the amount of wear debris generated and may extend the life of the fake joint. These materials include ceramic/ceramic and metal/metal bearings.

Hip joint implants may be cemented in place or press-fit in place allowing bone ingrowth to attach the implant to the bone. In some cases, cement is used on the femoral stem and ingrowth is used on the acetabular cup in the pelvis.

Good general nutrition, including adequate calcium and other minerals, is needed for healthy bone development, whether one has a hip replacement or not.

Answer 3

In a total hip replacement, part of the thigh bone (femur) including the ball (head) is removed and a new, smaller artificial ball is securely fixed to the rest of the thigh bone. The surface of the existing socket in the pelvis (the acetabulum) is roughened to accept a new artificial socket that will join up (articulate) with the new ball.

Most artificial joints (prostheses) are fixed into the bone with acrylic cement. However, in more active patients one part (usually the socket) or both parts may be inserted without cement. If cement is not used, the surface of the implants is roughened or specially treated to encourage bone to grow onto them. Where only one part is fixed with cement, this is known as a 'hybrid' hip replacement. Where neither part is fixed with cement this is called a cementless hip replacement.

The replacement parts can be plastic (polyethylene), metal or ceramic. The most widely used combination is a metal ball with a plastic socket (metal-on-plastic). Younger, more active patients may be given joints with a ceramic ball and a plastic socket (ceramic-on-plastic), or joints where both parts are made of the harder materials, which wear less (metal-on-metal or ceramic-on-ceramic).


Be sure to get enough iron, calcium and fiber in your diet.

Iron can make a big difference in how well you work, play and learn. It is part of the hemoglobin molecule in your blood that carries oxygen to your body’s cells.
Calcium is a mineral needed for healthy, strong bones so it is important that you consume enough calcium each day.
Fiber helps prevent constipation caused by inactivity and use of pain medicines during your hospital stay and recovery period.

Answer 4

it is a ball and socket joint

plastic is used probably because it is lightweight and durable and it will lessen the friction as the joint moves. i would imagine it would be quite strong too.

I don't know why a high calcium diet would be essential - maybe to ensure that the rest of your bones are strong.