A joint is a point where multiple bones meet and work together so that you can perform daily tasks like sit, climb stairs, walk comfortably, etc. The hip joint is described as being a “ball and socket” joint due to the joint’s appearance of a ball (femoral head) fitting snugly in a cup-like socket (acetabulum). The ball (femoral head) is located at the top of the thigh bone (femur) and the socket (acetabulum) is part of the pelvis. The area where the bones meet is covered by slick but firm tissue called cartilage, allowing the joint to move smoothly.
Arthritis of the Hip
Arthritis is a general term used to describe inflammation of a joint. This is a normal reaction of the body to injury or disease that results in swelling, stiffness and pain. There are few types of arthritis.
- Osteoarthritis is the most common type of arthritis. This is also called degenerative joint disease and can occur as a patient gets older. Osteoarthritis affects the cartilage that covers the ends of the bones. The smooth cartilage cushion wears away. This leaves the ends of the bone rough. When the rough ends of the bone rub together, it causes pain.
- Rheumatoid Arthritis is a disease of the tissue that lines the inside of the joints. The joint lining is abnormal and produces poor-quality fluid with a chemical substance that destroys the joint surface. The joint becomes stiff, painful and deformed. The cause of rheumatoid arthritis is not known.
- Traumatic Arthritis can be caused by a fracture or injury to the hip joint. The injury may damage the cartilage in the hip. If the injury does not heal properly, the joint surfaces may become rough and lead to early “wearing out” of the joint, similar to osteoarthritis.
- Avascular Necrosis (AVN) or Osteonecrosis is a condition that happens when there is loss of blood to the bone. Because bone is living tissue that requires blood, an interruption to the blood supply causes bone to die. If not stopped, AVN can cause the bone to collapse. It most often affects your hip.
As joint disease progresses the bones begin to rub together causing a rough misshapen surface, sometimes resulting in bone-on-bone contact, producing pain and stiffness. Painful hip conditions can be treated in several ways including physiotherapy, exercise and medications. When a patient’s symptoms do not respond to these treatments, an orthopaedic surgeon may recommend hip replacement surgery with the aim of restoring mobility and relieving pain.
Painful hip conditions can be treated in several ways including physiotherapy, exercise and medications. When a patient’s symptoms do not respond to these treatments, an orthopaedic surgeon may recommend hip replacement surgery with the aim of restoring mobility and relieving pain.
Hip Joint Replacement - The Procedure
When the surgical team is ready, you’ll be taken to the operating room. There you’ll be given anesthesia. The anesthesia will help you sleep through surgery, or it will make you numb from the waist down. Then an incision is made, giving the surgeon access to your hip joint. The ball is cut from the thighbone, and the surface of the old socket is smoothed. Then the new socket is put into the pelvis. The socket is usually press-fit and may be held in place with screws or cement. A press-fit prosthesis has tiny pores on its surface that your bone will grow into.
The new hip stem is inserted into the head of your thighbone. After the stem is secure in the thighbone, the new ball and socket are joined. The stem of the prosthesis may be held with cement or press-fit. Your surgeon will choose the method that is best for you. After the new joint is in place, the incision is closed with staples or stitches.
Today, many patients who have hip replacement surgery can move their joint more easily, have less pain and are able to walk more comfortably for up to 20 years after surgery.
Revision (Repeat) Hip Joint Replacement Surgery
If for any reason hip replacement surgery fails, revision surgery may be necessary. In revision surgery, the original hip joint replacement components are removed and replaced with new ones. Revision surgeries are more complex and the implants may not last as long as first time or primary joint replacements. Failure can occur for a variety of reasons including:
- Repeated dislocations
- Loosening and wear of the new joint
- Bone loss
- Infection
Sometimes the joint fails when too much stress is placed on it over time. It is extremely important to follow the long term precautions to protect your joint.