What is Hip Replacement ?

The normal hip joint is a ball and socket joint. The socket is a "cup-shaped" component of the pelvis called the acetabulum. The ball is the head of the thighbone (femur).Hip replacement, or arthroplasty, is a surgical procedure in which the diseased parts of the hip joint are removed and replaced with new, artificial parts. These artificial parts are called the prosthesis

 

Types: Hip replacement surgery can be performed as a:

1. Total replacement   .
2.  Hemi (half) replacement.

Total hip joint replacement involves surgical removal of the diseased ball and socket and replacing them with a metal (or ceramic) ball and stem inserted into the femur bone and an artificial plastic (or ceramic) cup socket. .In other words, Total Hip Replacement (Total Hip Arthroplasty) consists of replacing both the acetabulum and the femoral head while Hemiarthroplasty generally only replaces the femoral head.

CAUSES:

Osteoarthritis. Commonly known as wear-and-tear arthritis, osteoarthritis damages the slick cartilage that covers the ends of bones and helps joints move smoothly.

Rheumatoid arthritis. Caused by an overactive immune system, rheumatoid arthritis produces a type of inflammation that can erode cartilage and occasionally underlying bone, resulting in damaged and deformed joints.

Osteonecrosis. If there is inadequate blood supply to the ball portion of the hip joint, the bone may collapse and deform.

Post-traumatic arthritis. This can follow a serious hip injury or fracture. The cartilage may become damaged and lead to hip pain and stiffness over time.

 

Avascular necrosis. An injury to the hip, such as a dislocation or fracture, may limit the blood supply to the femoral head. This is called avascular necrosis (also commonly referred to as "osteonecrosis"). The lack of blood may cause the surface of the bone to collapse, and arthritis will result. Some diseases can also cause avascular necrosis.

Childhood hip disease. Some infants and children have hip problems. Even though the problems are successfully treated during childhood, they may still cause arthritis later on

Prolong use of drugs:  Fracture of the hip can happen because of  prolong uses of some drugs which weaken bones and systemic diseases (such as systemic lupus erythematosus).

WHEN SURGERY IS RECOMMENDED?

You might consider hip replacement if you're experiencing

• Hip pain that limits everyday activities, such as walking even with a cane or walker or bending
• Hip pain that continues while resting, either day or night
• Stiffness in a hip that limits the ability to move or lift the leg
• Inadequate pain relief from anti-inflammatory drugs, physical therapy, or walking supports
• Makes it difficult to rise from a seated position
• Interferes with your sleep
• Affects your ability to climb stairs.

HOW HIP REPLACEMENT HELP?

• Relieve pain
• Help your hip joint work better by increasing mobility
• Improve walking and other movements.
• Improved quality of life

WHAT ARE THE ALTERNATIVES FOR HIP REPLACEMENT?

Conservative management

The first line approach as an alternative to hip replacement is conservative management which involves a multimodal approach of medication, activity modification and physical therapy.Conservative management can prevent or delay the need for hip replacement.

Preoperative care

Preoperative education is currently an important part of patient care. There is some evidence that it may slightly reduce anxiety before hip or knee replacement, with low risk of negative effects.[

Hemiarthroplasty

Hemiarthroplasty : is a surgical procedure which replaces one half of the joint with an artificial surface and leaves the other part in its natural (pre-operative) state. This class of procedure is most commonly performed on the hip after a subcapital (just below the head) fracture of the neck of the femur (a hip fracture). The procedure is performed by removing the head of the femur and replacing it with a metal or composite prosthesis. The procedure is recommended only for elderly and frail patients, due to their lower life expectancy and activity level. With the passage of time the prosthesis tends to loosen or to erode the acetabulum.

Hip resurfacing: Hip resurfacing is an alternative to hip replacement surgery. Health-related quality of life measures are markedly improved and patient satisfaction is favorable after hip resurfacing arthroplasty.

Viscosupplementation: Current alternatives also include viscosupplementation, or the injection of artificial lubricants into the joint.

 

DIAGNOSIS:

• Medical history. Your orthopaedic surgeon will gather information about your general health and ask questions about the extent of your hip pain and how it affects your ability to perform everyday activities.
• Physical examination. This will assess hip mobility, strength, and alignment.
• X-rays. These images help to determine the extent of damage or deformity in your hip.

Other tests. Occasionally other testsan electrocardiogram (ECG), chest x-ray and Magnetic resonance imaging (MRI) scan may be needed to determine the condition of the bone and soft tissues of your hip.

Be sure to find out which medications you should avoid or continue to take in the week before surgery.

 

IS A CEMENTED OR UNCEMENTED PROSTHESIS BETTER?

The answer to this question is different for different people. Because each person’s condition is unique, the doctor and you must weigh the advantages and disadvantages.

Cemented replacements are more frequently used for older, less active people and people with weak bones, such as those who have osteoporosis, while uncemented replacements are more frequently used for younger, more active people.

Studies show that cemented and uncemented prostheses have comparable rates of success. Studies also indicate that if you need an additional hip replacement, or revision, the rates of success for cemented and uncemented prostheses are comparable.

• Blood clots.
• Infection
• Fracture.
• Dislocation: Certain positions can cause the ball of your new joint to become dislodged, particularly in the first few months after surgery. If the hip dislocates, your doctor may fit you with a brace to keep the hip in the correct position. If your hip keeps dislocating, surgery is often required to stabilize it.
• Change in leg length: Your surgeon takes steps to avoid the problem, but occasionally a new hip makes one leg longer or shorter than the other. Sometimes this is caused by a contracture of muscles surrounding the hip. In this case, progressively strengthening and stretching those muscles may help.
• Loosening of implant: Although this complication is rare with newer implants, your new joint may not become solidly fixed to your bone or may loosen over time, causing pain in your hip. Surgery might be needed to fix the problem.