INTRODUCTION
Most of us don’t think about our hips because they are generally pain free, stable and our legs are of the same lengths. These factors allow us to move about freely and lead fairly active lives.
The hip joint itself is a ball and socket joint covered with smooth cartilage. This cartilage may degenerate and breakdown due to a variety of reasons including age-related change, chronic steroid or alcohol use, trauma, infection and other less common reasons. The hip starts to hurt with normal movement, stiffness and loss of function sets it and patients often have an abnormal gait despite painkillers. Your orthopaedic surgeon would take a good medical history and perform a thorough medical examination before organising an xray for you. Often this process is adequate to diagnose hip arthritis. Occasionally an MRI scan of the hip may be required if the arthritis is in its early stages.
Non-surgical management of hip arthritis include the use of anti-inflammatory medication, physiotherapy and a change in daily activities. Occasionally an injection containing a local anaesthetic and a small dose of steroid or lubrication is given into the hip joint to help alleviate the pain temporarily.
At Orion Orthopaedic, if our patients return with persistent hip pain and loss of function despite these measures, we would then discuss surgery for their symptoms.
In young patients with hip pain and arthritis, hip preservation surgery would be desirable. Depending on the underlying cause of hip pain, we may perform arthroscopic labral repairs and microfractures for arthritis or core decompression surgery for early Avascular Necrosis of the hip. Where patients are older or if hip preservation surgery is not appropriate, a total hip replacement would be preferable.
Total Hip Replacement (THR) has been performed for decades in Singapore and worldwide. This surgery involves replacing the worn out parts of the hip causing the symptoms and replacing them with an implant. The majority of the implant is titanium while parts of it may be made of polyethelen (plastic) or Ceramic. This surgery has traditionally been performed through either a posterior or lateral approach to the hip. The worn out bones and cartilage are carefully removed and replaced with implants. The surgery normally takes about 2 hours and patients are allowed to talk a day or two after surgery. They are often admitted for several days till they are stable on their feet.
Risks
The total hip replacement surgery is safely done by a well trained and experienced hip surgeon. In order to perform the procedure, a skin incision is made which will leave a scar. There are also low risks of infection as antibiotics are given before, during and after surgery. Risk of nerve injury is avoided by careful dissection during the procedure. With both the posterior and lateral approaches to the hip, there are risks of limb length discrepancy (legs of different lengths). With the posterior approach, there is a risk of posterior hip dislocation. To avoid this, certain hip precautions are taken after surgery; patients are not allowed to squat, lie on their side or sit cross legged to prevent their hip from dislocating or popping out the back.
At Orion Orthopaedic Surgery, we performed the THR through a direct anterior approach (DAA). This is a new technique that has been practiced in the US, UK and Australia for several years and was learnt by Dr Mizan Marican during his fellowship at the prestigious Melbourne Orthopaedic Group in 2017. The benefits of this surgical approach are several fold;
- Muscles are not cut, they are merely pushed to the side and allowed to return to their original position after the implants have been inserted. This allows patients to start walking on the day of their surgery itself. As the posterior capsule is not violated, the risk of posterior dislocation of the hip is extremely remote.
- The risk of limb length discrepancy is low as we assess for leg lengths during surgery itself. We take accurate x-rays and clinically assess patients while they are lying on their backs. It is difficult to accurately assess leg lengths with patients lying on their sides.
- With routine use of x-rays during surgery, we ensure that the implants used are of the appropriate size and are placed in the optimal position. These factors will contribute to hip stability and longevity.
Everything You Need To Know About Hip Replacements In Singapore
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It is a surgical procedure to replace a worn out hip joint which has made patients live with chronic pain, experience loss of function and poor quality of life. It enables patients to regain their independence and mobility with significant improvement in their hip pain. |
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Patients who are generally fit and well but suffer persistent and severe hip pain will benefit the most. We encourage our patients to return to their active lifestyles after surgery in order to maintain good muscle tone and self-confidence. We often offer this surgery to patients who have failed conservative management to deal with their hip pain. |
All our patients undergo robust pre-operative assessments and investigations to ensure a safe surgical journey for them. Patients are asked to lie flat on their back for the direct anterior approach (DAA) total hip replacement. After the anaesthetic has been given, an oblique or bikini skin incision is made over their groin. Muscles in the front of their hip are merely pushed to the side to enable us to enter the hip joint itself. The worn out hip joint is removed with specialised orthopaedic equipment. In the acetabulum (cup side), the worn out cartilage is removed and a titanium cup is put in its place. This is done under x-ray guidance to ensure the position and size of the cup are appropriate. The femur stem is inserted into the femur bone itself and the hip is reduced into position. An x-ray is performed again to ensure all implants are of the appropriate size and are well positioned. We manoeuvre the hip in various directions to ensure the hip is stable. This mimics the movements of the hip when our patients go about their daily activities such as walking up stairs, sitting on chairs , sleeping and even kneeling. Once we are satisfied that the hip is stable, the trial implants are removed and the actual implants are inserted. The wound is washed with antiseptic solution and the wound is closed with suture. Our patients are often only on paracetamol after surgery as no muscles are cut. They are also asked to start walking with the assistance of a physiotherapist on the same day as their surgery. This helps maintain muscle strength and improve their personal confidence. After a second physiotherapy the morning after, our patients often leave hospital after just one nights’ stay. |
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There are many reasons why one might develop arthritis of the hip. While genetic, congenital and developmental causes of hip arthritis cannot be avoided, we can avoid high alcohol and steroid consumption to prevent avascular necrosis (AVN) of the hip. Patients with hip AVN often require a hip replacement in their forties or fifties. Patients are also advised to maintain a healthy lifestyle and avoid being overweight. |
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Most patients with hip arthritis experience constant and significant hip pain with minimal physical activity. They may experience pain in the front, size or back of their hip depending on how bad the arthritis is. Some will walk with a limp or stooped posture. Often it is their friends or family members who notice these changes in gait the most. As the hip arthritis gets worse, there might be stiffness of the joint and patients will not be able to wear their socks or cut their toe nails. Some might notice their affected leg becoming shorter and their back becoming more deformed (scoliosis) due to the difference in their leg lengths. |
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Total hip replacements have been performed successfully for many decades throughout the world despite the different approaches to get into the actual hip joint itself. It is important that the surgeon performing the surgery is familiar with the approach to ensure a safe operation and successful outcome for their patients. While the posterior approach is very common, patients are subjected to long-term hip precautions after their surgery. They are not allowed to squat, kneel or sit on low chairs due to the risk of posterior dislocation of their hip. They also have to be cautions when lying on their side. The lateral approach to the hip has a lower risk of dislocation but patients are known to walk with an abnormal (Trendelenberg) gait after surgery. This is because the muscles at the side of the hip (abductor muscles) are detached at the beginning of the surgery and have to heal and recover after they are reattached. The direct anterior approach however is associated with only a remote risk of posterior dislocation as the posterior capsule of the hip is left untouched. The anterior capsule which was opened at the beginning of the surgery is closed with robust sutures. Patients do not have a Trendelenberg gait as the abductor muscles are left untouched. Patients are also not subjected to any hip precautions in their daily life and are allowed to kneel, squat and sit in low chairs if they choose. |
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In all hip replacement surgeries, the scar will take about 2 weeks to heal. Patients undergoing the direct anterior approach (DAA) total hip replacement are allowed to walk on the day of their operation and encouraged to keep walking to promote muscle strength. And self-confidence. In most cases they are allowed to drive about 2 weeks after their surgery as long as they have minimal pain, are walking without any aids and are not on an opioid medication (eg codeine, tramadol, morphine). |
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Total Hip Replacements are one of the most successful surgeries in orthopaedic surgery. Patients can expect significant improvement in the deep hip pain they used to experience before their surgery. We expect them to have a better quality of life and independence after they have undergone some rehabilitation and recovered. Patients with long standing muscle weakness may continue to need a walking aid but should still experience improvement in their hip pain after they have recovered from their surgery. |
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Patients are encouraged to maintain an active and healthy lifestyle before and after their surgery. We do encourage our patients to undergo some physiotherapy both before and after their operation to maintain good muscle strength and confidence. The well-trained physiotherapists will assess each patient individually and prescribe a customised physiotherapy program to target weak muscles and accelerate their recovery. Through the direct anterior approach (DAA) total hip replacement, patients can look forward to a robust physiotherapy program and recover with confidence. |
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The skin incision for the surgery will be about 9 to 10cm long and obliquely placed in the groin. It is called a bikini skin incision as the scar will be covered when the patient is wearing their undergarment. The surgical dressings will not have to be changed for 5 to 7 days and are expected to heal after 2 weeks. It is important to keep the wound clean and dry during this time. Patients may require a walking aid such as a walking stick or crutches for the first week or two if they have some aches in their thigh. Most patients will not need any walking aid after 2 weeks. Physiotherapy sessions will be arranged after surgery to ensure our patients continue to develop their muscle strength and rehabilitate successfully. |
