Total Hip Replacement

Ian has vast experience in total hip replacement surgery. He was recently invited to give the introductory speech at the 30th anniversary lecture programme for the Furlong Hip in Barcelona.

Total hip replacement is a surgical technique where the severely damaged cartilage and bone of hip joint is removed and substituted with an artificial prosthesis which is bio-compatible and functions similar like a normal hip. It is one of the most common joint replacement procedures, subsequent to knee replacements. The main aim of surgery is to restore function to the joint and relieve pain.

Hip joint is one among the largest joints of the body. It is a ball and socket joint in which the head of the femur forms the ball while the socket is formed by the acetabulum, a part of the pelvis bone.  Articular cartilage forms a smooth covering on the bony surfaces of the ball and socket and provides a cushioning effect to the bone ends that aids in their easy movement. A thin tissue surrounds the hip joint known as synovial membrane that produces synovial fluid which lubricates the cartilage and reduces friction during several movements of the hip. Ligaments are a group of tissues that provide stability to the joint by connecting the ball to the socket.

Damage to the hip joint can be caused by a number of diseases such as arthritis, fracture or other conditions.  These can result in pain, decrease motion and effect daily activities leading to disability.

Causes of hip pain:

Arthritis is a condition in which pain, swelling, stiffness, and limited movement results due to inflammation of joints. The most common cause of chronic hip pain and disability is hip arthritis. The types of arthritis which usually affects the hip joints are:

• Osteoarthritis: It is characterized by gradual wearing away of cartilage of the hip joint. Due to severe erosion of the cartilage, the bones rub together within the joint. During movements of the joint, the ball tends to grind into the socket, causing the bone surfaces rough and irregular, altogether leading to pain and stiffness. Commonly seen in geriatric individuals and has a tendency to run in families.
• Rheumatoid arthritis: It is an autoimmune disease in which lining of the joint (synovium) becomes inflamed. Hip pain and stiffness is caused due to inflammation of the cartilage.
• Traumatic arthritis: This type of arthritis results from hip injury or fracture. Cartilage is damaged as a result of these injuries leading to severe pain and stiffness over a period of time.
• Avascular necrosis is a condition in which there is a lack of blood supply to the femoral head due to injury to the hip. This usually results in arthritis.

Symptoms of hip arthritis:

The most symptom of hip arthritis is joint pain and stiffness leading to limited range of motion. Daily activities can be painful and you may be restless. Joint stiffness may cause limping while walking.

Diagnosis:

Your surgeon may perform physical examination followed by medical history evaluation. Few investigations will be carried out such as blood and urine samples, x-rays or occasionally MRI.

Treatment:

Hip replacement surgery is one among the last treatment options considered to treat severe hip damage which results in severe/intolerable pain. Other non-surgical treatment options include:

• Losing weight: Weight has a direct impact on the hip joint. The lesser the weight, the healthier the joint helps to delay joint replacement and also improves the surgical result post-operatively if you have undergone replacement surgery.
• NSAIDs are prescribed to treat pain and swelling
• Physical therapy such as muscle (around the hip joint) strengthening exercises
• Appropriate modification of patient activities like specific exercises regularly, water aerobics, swimming with a pull-buoy, cycling, walking can be helpful to maintain a healthy hip joint
• Intake of joint supplements
• Use walking aids such as canes or crutches to reduce the excessive stress placed on the joint until six weeks post-operatively.

Procedure:

Prior to the surgery, your surgeon will discuss with the anaesthetist and decide which appropriate anaesthetic, either local or general anaesthetic to be used for undergoing surgery.

The hip joint prosthesis comprises of two components: Ball and stem is the femoral part and a socket that acts as acetabulum. Various metals (for example: ceramics, plastic, stainless steel, chrome or fusion of these) are used to make different types of prosthesis. Special acrylic bone cement is used to anchor certain prosthesis into place while others depend on the bone surrounding the artificial joint to fix them in place.

An incision is placed along the side of the affected hip joint. Muscles supporting the hip joint are excised and the diseased fragment of the hip joint is removed from the femoral head. The femur accommodates the femoral part of the prosthesis and the acetabular part of the prosthesis is positioned into the prepared socket area in the pelvic bone. The ball and socket of the artificial hip joint are articulated together and the muscles are re-approximated to the femoral head. Prior to the incision closure, any fluid or blood may be drained by inserting drainage tubes. To prevent possible infection in the new joint, antibiotics are given during and after the surgery.

Post-operative care:

An artificial hip joint has a limited range of motion when compared to a natural hip. Additional care has to be taken until the soft tissues have completely healed surrounding the new joint to prevent any dislocation.

Recovery depends how well you follow the home care instructions advised by your hip surgeon. Some of the guidelines to be followed are:

• Crossing your legs should be avoided
• Avoid lifting of heavy objects
• Avoid bending and twisting your hip instead use grabbers to pick the things
• Always use a pillow placed between your legs while sleeping
• Avoid standing for long hours
• Use elevated toilet seat
• Avoid sitting on low chairs
• Start a graduated walking program that slowly increases your walking ability
• Appropriate exercises to be performed to restore movement and strengthen the hip muscles
• Start physical therapy as advised by your doctor

Risks:

Like any other major operations, there are certain risks and complications involved with total hip replacement surgery. The possible complications after total hip replacement include:

• Infection
• Dislocation
• Fracture of the femur or pelvis
• Injury to nerves or blood vessels
• Blood clot formation in the leg veins
• Leg length inequality
• Hip prosthesis may loosen or wear out
• Failure to relieve pain
• Scar formation and pressure sores or ulcers (also known as decubitus ulcers)