Understanding Hip Replacement Surgery and its complications

Hip replacement joint surgery is a surgical procedure whereby the damaged parts of hip joint are replaced with prosthetic implants (artificial parts). The hip replacement surgery is categorised into two: Total replacement also referred to as total hip arthroplasty and the hemi or half replacement also referred to as hemiarthroplasty. The total hip replacement involves replacement of both the femoral joint and the acetabulum (hip bone) while the hemiarthroplasty consists of replacing only the femoral head. Nowadays, hip replacement surgery is the most popular orthopaedic operation, although the patient's short term and long term satisfaction varies widely.

When is the right time for a hip replacement surgery?

Hip replacement procedure should be carried out when the hip joint is experiencing painful symptoms that can no longer be controlled through medicinal treatment. Depending on the severity of the hip damage, your surgeon will recommend a total hip replacement or a hemiarthroplasty.

What leads to hip replacement surgery?

Joint failure is the reason why hip replacement is performed. Joint failure can be as a result of osteoarthritis, rheumatoid arthritis, traumatic arthritis, avascular necrosis, hip fractures, protrusion acetabuli, bone tumours, malignant and benign.

Complications during a hip replacement surgery

• Nerve damage: The sciatic nerve is at risk of being accidentally surgically cut due to its close proximity to the capsule of the hip joint. This same nerve may also become over-stretched during hip manipulation during surgery. Depending on the extent of the nerve damage, temporary or permanent damage may result. There may be loss of muscle power and feeling in parts of the leg. It may take up to 6 months or more for recovery. Most patients have some numbness around their incision site which may be permanent.
• Vascular damage: The damage involves direct trauma to the blood vessels in the area of the surgery. The damaged blood vessel can be repaired by a vascular surgeon if it is caught in time.
• Femur fracture: Force is applied during the surgical procedure. This can result in a femoral shaft fracture, especially in older or osteoporotic patients. Again, the problem is addressed during surgery, but may lead to extended rehabilitation. The surgeon may place weight bearing restrictions while you are walking.
• Leg length discrepancy: In some cases, it may be difficult to get the exact same leg lengths. The result is usually a longer leg on the surgical hip. It may be unavoidable and deliberate in order to improve muscle function or stabilise the hip. If there is more than a quarter of an inch difference, a shoe lift may be necessary. In some patients, both legs are the exact same length but they think their surgery leg "feels" longer. In most cases this "feeling" goes away as the patient adjusts to their new hip. Rarely does shortening of the leg occur. If the leg is significantly shortened after surgery, it may have dislocated.
• Anaesthetic complications: Complications can occur, and in rare cases even death. Your anaesthesiologist will explain the risks involved prior to your surgery.

Complications after hip replacement surgery

• Blood Clots: This is one of the most common complications after hip replacement. The most common area is in the calf. Increased leg pain is usually the most obvious symptom. Redness around the area of the clots may also occur. It's a minor problem if the clots stay in the leg. But if they dislodge, they can reach the lungs (pulmonary embolism) and can possibly result in death (very rarely). If your surgeon suspects blood clots, he will immediately order an ultrasound to confirm or rule out clots. Most surgeons will order bed rest until the test results come back positive or negative for blood clots. He will prescribe a blood thinner. Compression boots and ankle/leg exercises help reduce the chance of blood clots.
• Infection: Infection can occur during surgery or develop afterwards. It is one of the most serious risks to the joint replacement. If the infection settles deep into the joint and surrounding tissues, the new joint often has to be removed until the infection clears with treatment. If the patient develops an infection elsewhere in the body (bladder, teeth, chest), it must be controlled to prevent the possibility of it spreading through the blood to the new joint. If you have rheumatoid arthritis or diabetes, or have been taking cortisone for a long time, you are more prone to infection in the weeks following your surgery. Infection can occur many years after the surgery. Bacteria can travel through the bloodstream from an infection in other parts of your body (bladder infection, infected wound, kidney infection). Oral antibiotics may need to be taken before and after routine dental work years after your hip replacement operation.
• Hip dislocation: The first six weeks after hip replacement is the most vulnerable time for your new hip. During this period, muscle tension is the only thing holding the metal ball in the socket. If the metal ball slips out of the socket, it's dislocated. As the hip muscles regain their strength and scar tissue forms around the ball, the risk of hip dislocation diminishes.
• Bowel complications: Constipation frequently occurs for the first week or so after surgery. This can be caused by medication, immobility, loss of appetite, not drinking enough fluids. Stool softeners or enemas may be needed.
• Loosening of the prosthesis: The harder your bones are, the longer your hip replacement will last. Hard bones create a stronger bond. People with rheumatoid arthritis and osteoporosis are more at risk. Running and heavy impact activities can also loosen the bond of the implant. Keep your weight down, as this will put more stress on the hip joint. Every pound you gain adds three pounds of force on your hip. Choose a surgeon who has performed many hip replacements. Talk to some of his previous patients to see how they are doing after their hip replacement.

Most people who undergo hip replacement surgery will never need to replace their artificial joint. But because more and more people are having hip replacements at a younger age, the wearing away of the joint surface can create problems. After 15-20 years of wear and tear, replacement (revision surgery) of the artificial joint is becoming more common. Revision surgery does not have as good an outcome as the initial surgery. Remember to consider all the hip replacement complications before you decide on surgery.