Structure, Function and Pain of the Hip
The hip is best described as a ball and socket where the head of the femur (thigh bone) rests within the socket (acetabulum) on the pelvis to form the joint. In a normal, healthy hip joint, the bony surfaces of the acetabulum and femoral head are covered in a smooth, shiny, elastic type tissue called cartilage. This cartilage protects each bony surface and allows the hip to move smoothly without pain.
The primary function of your hip is to bear your body weight when standing and transmit this weight to your leg. Your hip joint also provides you with a degree of movement, allowing you to turn your leg in and out, move it forwards and backwards as well as side to side.
In an arthritic or damaged hip, often times the cartilage is destroyed and the smooth, bony surfaces become rough and irregular. These changes in the hip joint often cause pain, especially with walking and frequently results in loss of movement of the hip. This is often felt as aching or even sharp pain in the groin and/or knee. You may also find muscles around the hip begin to weaken and the hip, when moving, feels stiff.
For more information about arthritis, please visit The Arthritis Society.
Hip replacement is often considered when the pain in the hip becomes so severe that it begins to interfere with your sleep and your ability to carry out your activities such as walking, working or sports. The goals of the surgery are:
- To end or reduce your pain
- To improve your hip movement and overall function
- To improve your quality of life
Hip replacement involves removing the damaged bone in the hip and selecting a new joint according to your individual size. The head and neck of the femur are cut away and the inside of the femur is reshaped. A metal head and stem are inserted inside the reshaped femur to replace the old hip. A metal shell with a plastic liner is placed into the acetabulum to complete the new hip joint.
Risks and Benefits of Hip Replacement
With your decision to proceed with hip replacement, you will discuss with your surgeon the risks and benefits of this surgery. Since 1994, more than 200,000 hip replacements have been performed in Canada and millions worldwide. They have proven to be extremely durable. Ninety to ninety-five percent success rates at ten to twenty year check-ups are common.
As with any operation, hip replacement has a number of potential risks. These include:
- Anesthetic complication
- Deep vein thrombosis (DVT) and pulmonary embolism (PE) (blood clots in your leg or lung)
- Death (0.7%)
- Infection (approximately 0.5%)
- Slow healing
- Technical complications ie. damage to skin, muscle, bone, nerve or blood vessel
- Post-operative dislocation (0.4%)
- Leg length discrepancy (occasional occurrence)
- Late wear and loosening of the implant needing revision (between 0.5 and 1% per year)
- Thigh pain
Your surgeon will review these with you before your surgery and answer any of your questions.
Revision Hip Replacement
In patients over the age of 60 years, it is hoped that a hip replacement will last the lifetime of the patient. Occasionally, the parts fail for a variety of reasons such as wearing out, loosening, dislocation or deep infection. A revision hip replacement often involves removing the parts put in previously and replacing these with new total hip parts.
Revision hip replacement is a more difficult and lengthy operation than the initial hip replacement, but can offer extremely good results in terms of pain relief and return of function.
For more information regarding revision hip replacement, please consult with your orthopaedic surgeon.