Total Hip Replacement Surgery

What are the causes of hip pain?

The normal hip functions as a "ball-and-socket" joint. The femoral head (ball) articulates with the acetabulum (socket), allowing smooth range of motion in multiple planes. Any condition that affects either of these structures can lead to deterioration of the joint. This, in turn, can lead to deformity, pain, and loss of function. Hip pain has many causes. Osteoarthritis is the most common cause in the western world. Avascular necrosis, post-traumatic arthritis and rheumatoid arthritis are some of the causes of arthritic hip pain. Total Hip Replacement surgery may be an excellent solution to these conditions.

1. Osteoarthritis – wear and tear of the hip joint due to age-related degenerative change. It usually occurs in the older patient and may have a genetic cause. Over time the hip cartilage wears away causing hip pain and stiffness. Patients may find it difficult to walk long distance, climb stairs and perform simple activities of daily living such as putting on shoes and socks.
2. Avascular Necrosis - also known as AVN or ‘osteonecrosis’, this is when the blood supply to the femoral head in the femur is damaged. This may cause bone to die and the surface of the femoral head to collapse, leading to eventual degeneration of the joint and arthritis. Often the cause of AVN is unknown (idiopathic) although sometimes the cause may be due to excessive steroid intake, often unwittingly through TCM, or due to excessive alcohol intake, certain diseases and even deep sea diving.
3. Post-Traumatic Arthritis – This can follow a serious hip injury or fracture. The joint surface of the hip may become damaged and eventually arthritis may occur over time.
4. Rheumatoid Arthritis – this is an autoimmune disease and one of the common types of a group of conditions called ‘Inflammatory Arthropathies’. The synovial membrane may become inflamed and lead to joint destruction over time. Typically other joints of the body may involved, and other organ systems may be affected. Patients may present at a younger age with this disease. Special blood tests may be required to diagnose inflammatory joint disease, and an Orthopaedic Surgeon often works closely with Rheumatologists who may prescribe special drugs (DMARD’s) to control the diease before hip replacement surgery.
5. Childhood Hip Problems – such as Developmental Dysplasia of the Hip, congenital hip dislocation and Perthes Disease may lead to abnormal hip joint development and arthritis of the hip in later life.
6. Referred Spinal Pain – commonly spine pain is mistaken for hip pain. Spinal pain may involve back or buttock pain radiating down the back of the leg, sometimes associated with leg numbness or weakness. Hip pain often occurs in the anterior part of the groin and radiates down to the knee.

What are the solutions to hip pain?

Once the problem has been identified as coming from a worn out hip joint, physiotherapy, painkillers and even a steroid injection may be tried, to relieve the pain. Often though if the pain is severe, and the hip joint is very worn out then there may be no choice to replace the joint, and undergo a hip replacement.

What is a Hip Replacement?

Total hip replacement (THR) – also called total hip arthroplasty (THA), is one of the most successful orthopaedic procedures performed worldwide today. For patients with hip pain due to a variety of conditions, THR can relieve pain, can restore function, and can improve quality of life. It is estimated that over 300,000 total hip replacements are performed each year in the United States alone.

In general, over 90 percent of THAs are working successfully, are pain-free, and are without complication 10 to 15 years postoperatively. Some patients continue with their original implant even after 25 years of use.

What happens before a Hip Replacement Surgery?

Once you have decided to undergo a Total Hip Replacement, you are carefully screened for any pre-existing medical conditions that may need to be treated prior to surgery. Some further investigations such as blood tests, chest X-ray and Electrocardiogram (ECG) may be performed. Sometimes you will need to see another specialist to make sure everything is safe before we proceed.

The hip replacement operation is discussed in detail so that you and your family have realistic expectations regarding the risks as well as the benefits of the procedure, and understand the operation and recovery process.

You will be sent to a physiotherapist pre-operatively to learn what to expect from the surgery, how to walk with a stick or frame and what exercises to perform following the procedure.

You will be advised to stop most blood thinning medications and TCM herbs two weeks prior to the surgery.

Before the Hip Replacement procedure, the Anaesthetist may offer you either General Anaesthesia – where you go to sleep for the entire procedure, or a Spinal Anaesthetic – where an injection is given to your spine which numbs the legs for several hours. It is important not to eat or drink eight hours before the procedure, as this may interfere with the anaesthetic and your hip replacement operation postponed.

"In my practice, as an Arthroplasty Fellowship Trained Surgeon, I take the time to carefully plan the operation and determine what size implants are required and exactly where they will be placed during the procedure. I am also a MAKOPLASTY certified surgeon and can use a Surgical Robot Arm to guide my operation with an excellent and reproducible degree of accuracy." - Dr. Alan Cheung

Total Hip Replacement Surgery

In a Total Hip Replacement Surgery (also known as Total Hip Arthroplasty), the damaged cartilage and bone from the hip is removed and replaced with special implants:

The femoral head is removed and replaced with a metal stem that can be cemented into the shaft of the femur. For younger patients with good quality bone, sometimes an uncemented stem is impacted into the femoral shaft. A metal or ceramic ball is placed on the metal stem to replace the femoral head. The worn cartilage of the hip socket (acetabulum) is removed and replaced with a metal shell. A plastic or ceramic liner is placed with this shell. This allows a smooth, low friction articulation with the new femoral head. "During the Hip Replacement operation itself, I aim to use the smallest possible incision (minimally invasive surgery) to perform the surgery. This is not always possible in complex or revision surgery or when the patient is very large. I aim to handle the tissues with care and minimise blood loss, to reduce post-operative pain and allow a swift recovery." - Dr. Alan Cheung"

Recovery Following Total Hip Replacement

Typically Hip Replacement surgery takes an hour, with several more hours of observation in the Recovery ward before the patient is discharged to the General Ward.

"In my practice I aim to stand the patient up immediately following surgery and have them walking as soon as possible. This is possible because I use modern techniques of ‘enhanced recovery’ and ‘multimodal analgesia’ as well as a local anaesthesia infiltration (LIA) technique during surgery to minimise pain. I also work closely with my anaesthetic and physiotherapy team to assess each individual patient in order to achieve good pain relief and a smooth recovery." - Dr. Alan Cheung

Typically a patient is discharged either home, or to a rehabilitation unit for more physiotherapy, on or before Day 3 of surgery.

It is important that the physiotherapy instructions are followed carefully and exercises are performed, in order to get the best out of the Hip Replacement surgery.

Normally you may drive 6 weeks following a total hip replacement. You are advised not to fly long distances until at least 6 weeks following surgery.

Depending upon their occupation, most patients can return to work between 6-12 weeks following Hip Replacement surgery.

In summary, Total Hip Replacement can be an excellent solution to hip pain and vastly improve the quality of life of a patient with a worn out hip joint.