HIP RESURFACING SURGERY 

Physiology of Human Hip

Before beginging to understand what hip resurfacing surgery is, it will help to understand the physiology of the human hip.

Anatomy of the Human Hip

The hip is a ball and socket joint that allows movement in the upper leg - front to back and side to side. The hip joint is the largest weight bearing joint in the body and is surrounded by strong ligaments and muscles.

The normal hip joint consists of a ball rotating inside a socket. The ball is called the head of the femur and the socket in the pelvis is called the acetabulum. The surface of the femoral head and the acetabulum (i.e. the ball and the socket) is covered by a protective layer of cartilage. This makes the joint smooth and reduces friction during movements. It covers and protects the bone like the rubber of a car tyre.

Any condition that damages the cartilage will lead to pain, dysfunction and eventually arthritis. Cartilage can get damaged due to a number of reasons including Injury, Infection, Ankylosing Spondylitis, Avascular Necrosis ( loss of blood supply to bone), Rheumatoid Arthritis, Osteoarthritis, Developmental problem like bone Dysplasias, slipped upper femoral epiphyses, etc.

What is Hip Resurfacing?
Hip resurfacing (also known as hip resurfacing surgery, Birmingham hip resurfacing, Birmingham hip resurfacing surgery, Articular Surface Replacement/ASR and surface replacement arthroplasty), an orthopedic procedure, is an approach to the treatment of hip pathology. It's a technology that replaces the worn surfaces of the hip joint with caps of high carbide cobalt chrome.

Hip Resurfacing Surgery is a bone-conserving alternative to conventional Total Hip Replacement (THR). Unlike THR, hip resurfacing does not involve the removal of the femoral head and neck or removal of bone from the femur. Rather, the head, neck and femur bone are preserved in an effort to facilitate future surgery should it be necessary and to enable the patient to take advantage of newer technology or treatments in the future.

Furthermore, the current generation of hip resurfacing devices utilizing metal bearings have demonstrated a much higher level of wear resistance as well as reduced bone loss and inflammatory tissue reaction about the hip joint as compared to metal-polyethylene bearings.

All these factors make hip resurfacing anatomically and biomechanically similar to the natural hip joint resulting in increased stability, flexibility and range of motion. Further, dislocation risk is virtually eliminated. Higher activity levels are typically achieved with less risk. These benefits are realized because the head diameter that results from resurfacing is very similar to the patient’s normal head diameter and these larger head sizes are typically much larger than the femoral balls utilized in conventional THR.

Why is hip resurfacing surgery performed?
Hip resurfacing surgery is an approach to the treatment of hip pathology. Some of the common illnesses requiring hip resurfacing are:
 
Osteoarthritis (OA)
The leading cause of hip pain is osteoarthritis, also commonly known as 'wear and tear' arthritis. It is a progressive disease that wears away the smooth cartilage lining of the hip’s ball-and-socket joint. As the cartilage gets damaged and wears, the pain from the rubbing of the two sides of the hip joint increases. The first OA symptom is usually hip joint pain or groin pain while walking or running. However, this pain may eventually get strong enough that surgical intervention may become necessary.

Developmental Dysplasia of the Hip
Developmental dysplasia of the hip (DDH), also called hip dysplasia, is a lifelong condition, which occurs in about one in 1,000 people. DDH sufferers are born with altered hip anatomy. Because the DDH hip is out of joint as it grows, it doesn’t develop properly, and it wears out faster. DDH leads to arthritis at an earlier age. Developmental dysplasia of the hip is often diagnosed in the first year of life. In infants with developmental dysplasia of the hip, a brace or harness is used to hold the hip joints in place during early growth. If bracing fails or if the child is diagnosed later, surgical reconstruction may be needed. DDH usually results in hip pain and hip arthritis through adulthood.

Avascular Necrosis (AVN)
Avascular necrosis of the hip or hip osteonecrosis results when reduced blood circulation starves the bones that form the hip joint. In time, the starved bone dies, and the hip joint can collapse. AVN is most prevalent in middle-aged adults. Hip pain, especially after standing or walking, is the most common symptom. Hip AVN most commonly afflicts the femoral head, where the femur (or thighbone) attaches to the pelvis. The femoral head may weaken and collapse.

Inflammatory Arthritis
Inflammatory arthritis (rheumatoid arthritis) is a chronic joint disease that usually develops in middle age, but may occur in young patients. Inflammatory arthritis of the hip causes swelling hip joints, hip pain and joint stiffness. First symptoms of inflammatory arthritis of the hip include hip pain, joint swelling, joint stiffness and a loss of motion.

How does hip resurfacing work?
The hip is a ball-and-socket joint where the ball-end of the thighbone (or femur) swivels smoothly in the socket (or acetabulum) of the pelvis. In an unhealthy hip, the femur and acetabulum may become rough and worn causing pain, swelling and stiffness as the bones of the joint rub together.

Using the Birmingham Hip Resurfacing implant, these worn ball-and-socket surfaces in the joint are replaced with smooth and durable high carbide cobalt chrome to give a resurfaced metal on metal hip joint that glides with a smooth, natural motion.

Who is a candidate for hip resurfacing?
Birmingham Hip Resurfacing (BHR) is an alternative to Total Hip Replacement (THR) in younger and more active patients. Typically, physically active patients, under 65 years of age who suffer from hip arthritis, hip dysplasia, avascular necrosis of the hip or inflammatory arthritis are candidates for BHR. Patients who are over 65 years of age can also benefit from BHR is their bone quality is strong enough to support the implant. You must discuss your suitability for hip resurfacing with an orthopedic surgeon. Log in or register now for a FREE quote and an assessment of your case.