Direct Anterior
Total Hip Replacement

Dr. Chang performs the majority of hip replacements through the direct anterior approach. The direct anterior approach (DAA) has gained popularity recently due to faster recovery during the first 12 weeks of surgery compared to traditional approaches from the back (posterior) or the side (lateral). The direct anterior approach is a muscle sparing approach that eliminates the need to release major tendons and muscles, leading to less pain in the immediate post-operative period.

It is important to note that after 6-12 months research studies have not demonstrated any significant differences in functional outcomes between any of the approaches (direct anterior, posterior, or lateral). Surgeon experience and training is more important than a specific approach. Each approach has pros and cons that should be discussed with your surgeon during consultation.

Non-operative measures should be attempted prior to consideration of a hip replacement. These measures are often helpful in the early stages of arthritis.

Pain medication: Tylenol is typically recommended as the first-line pain medication. Some patients with liver disease may not be able to tolerate regular Tylenol. Anti-inflammatory medications are also helpful but are not suitable for all patients. Patients with cardiac disease, high blood pressure, kidney disease, and/or stomach ulcers may not be able to take regular anti-inflammatory medications. Regular opioid medications are not recommended due to risk of addiction and development of chronic pain. Patients should consult with their family doctor prior to starting any new medication.

Physiotherapy: Physiotherapy exercises to improve strength to your core, buttocks, quadriceps, hamstrings, and abductors are often helpful for reducing symptoms in early arthritis.

Injections: Local hip injections can be helpful in the early stages of arthritis. They are less effective in end-stage disease. Consult your surgeon to determine if an injection would be indicated for you.

Weight loss: Weight loss helps reduce the pain associated with arthritis by taking pressure off your hip joint. It is appreciated that regular exercise can be challenging due to persistent and severe hip pain. Your family doctor can often help with diet resources.

Walking aids: A cane or walker may help improve your comfort, stability, and confidence with walking.

The decision to proceed with a hip replacement is an individual one. It is important to have a formal discussion with your surgeon to determine if you are a good candidate for a hip replacement.

A hip replacement can be considered in a patient with end-stage arthritis and hip pain that restricts walking ability and other day-to-day activities that impact quality of life. In addition, patients should have good baseline health and have attempted non-operative measures (see above).

In a hip replacement, the damaged femoral head (ball) and acetabulum (socket) are replaced with an artificial joint (prosthesis). The femoral component is made out of an artificial ball (either cobalt-chrome or ceramic) and metal stem (typically a titanium alloy or stainless steel) which is inserted into the femur. The acetabular component is made out of a metal shell (typically a titanium alloy) and plastic liner (typically polyethylene).

Many countries, including Canada, mandate data collection on certain medical devices such as joint replacements; these are called national joint registries. Recent evidence derived from pooled joint registry data from multiple countries estimate survivorship of a total hip replacement is 89.4% at 15 years, 70.2% at 20 years, and 57.9% at 25 years. It is important to remember that these are estimates of survivorship. There is optimism that the newer generation of implants used today will last longer than what is reported today in the literature.

The majority of hip replacements done by Dr. Chang are performed as day surgery. After surgery you will be assessed by a physiotherapist to ensure that you can walk and climb the stairs safely. You will be given a prescription for pain medication and blood thinners prior to discharge.

Your first post-operative appointment will be approximately 2-weeks after surgery in the fracture clinic to check your wound and review your progress.

The second follow-up appointment will be approximately 6 weeks after surgery. A clinical review and x-ray will be performed at that time.

It is typical to require a walker or crutches for the first 1-3 weeks after surgery. It is often advisable to transition to a cane after you have stopped using a walker. Most patients are comfortable with normal day-to-day activities 6 weeks after surgery.

The average recovery time varies by patient but usually is 3-6 months. However, it can take up to 12-18 months after surgery to regain full strength.

All patients recover differently after surgery. The decision on when to return to work is variable and depends on you and your type of job. As a guide, most people with “desk” type jobs can resume work 4 weeks after surgery. People with more “physical” type jobs can resume work 12-16 weeks after surgery.

In general, you can drive once you regain full power and function in your leg to safely perform an emergency brake. In addition, you must have finished taking any opioid medication. This typically takes 4-6 weeks after surgery.

One of the goals of a total hip replacement is to allow you to return to all the recreational activities that you enjoy. Many patients return to walking, hiking, cycling, skiing, skating, golf, tennis, and working out. Regular high impact activities, such as running and jumping, are generally not advised as they may lead to earlier implant failure.

Travel should be delayed for 6 weeks after surgery. Long distance travel and flying increases the risk of developing a blood clot early in the post-operative period.

If flying is essential prior to 6 weeks, it is recommended that you get up and move every hour on the plane. You will also require a prescription blood thinner.

You do not require any antibiotics before a routine dental procedure.

The Canadian Orthopaedic Association (COA), Canadian Dental Association (CDA), and the Association of Medical Microbiology and Infectious Disease (AMMI) have reviewed the best available research and have provided clear guidance on this.

The risk of a (deep) prosthetic joint infection is approximately 1% following primary (first-time) total hip replacements and up to 5-10% of revision (re-do) hip replacements. You will receive a dose of IV antibiotics before and after surgery to decrease the risk of infection. Prolonged antibiotics after surgery have not been shown to provide additional benefit and are usually not required.

Symptoms of a prosthetic joint infection include swelling, redness, wound drainage and increasing pain. Patients can also experience systemic symptoms such as a fever. Please contact your surgeon and/or go to the emergency department if you believe you are developing an infection.

Deep prosthetic joint infections may require IV antibiotics and multiple operations in order to eradicate the infection. Some or all of the components may need to be removed or exchanged.

Superficial skin infections are more common and can be usually treated with a course of oral antibiotics.

A dislocation occurs when the femoral head (ball) comes out of the acetabulum (socket). The risk of dislocation is approximately 1-2% following a primary (first-time) total hip replacement and up to 10% following a revision (re-do) hip replacement.

Most dislocations occur in the first 6-12 weeks after surgery. Recurrent dislocations may require revision surgery to stabilise the hip joint.

One of the goals of hip replacement surgery is to restore equal leg lengths after surgery. Dr. Chang uses various surgical techniques including intra-operative x-rays to make your leg lengths as equal as possible. However, it is occasionally necessary to make your leg slightly longer in order to optimise stability of your hip and prevent dislocation.

Most patients undergoing hip replacement through the direct anterior approach experience a patch of numbness on the outside of their thigh. This is due to a palsy of the lateral femoral cutaneous nerve, which crosses in close proximity to the operative field. This numbness tends to resolve slowly over time but may become permanent in some patients. Importantly, this has not be shown to affect the function or strength of your hip.

A periprosthetic fracture is a broken bone that occurs around the implants of a hip replacement. It can occur at the time of surgery or shortly after. The risk of a periprosthetic fracture is <1%.

Management depends on the location and severity of the fracture. Some periprosthetic fractures can be treated non-operatively. Other periprosthetic fractures require surgery to fix the fracture +/- revision (re-do) hip replacement.

The most common indications for revision (re-do) surgery are infection, recurrent dislocation, periprosthetic fracture, and loosening of the components. Implants can “wear” out over time and may require revision surgery to replace either the femoral component, acetabular component, or both.

Revision total hip replacement is associated with increased risk of complications and prolonged recovery compared to a primary (first-time) total hip replacement. However, patients typically do well after revision surgery.

A deep vein thrombosis (DVT) is a blood clot that can develop in the leg veins after surgery. DVTs that occur above the knee can be dangerous as they can dislodge and form a blood clot in the lungs called a pulmonary embolism (PE). This is a rare but serious condition which can be life threatening.

All patients receive medication to reduce the risk of a blood clot after surgery. The type of medication varies depending on the individual risk factors of each patient. If you have had a blood clot in the past it is important to inform your surgeon prior to surgery.

Damage to major nerves, such as the femoral nerve or sciatic nerve, is extremely rare following surgery. This can lead to a partial paralysis such as a “foot drop” where there is inability to lift the front part of the foot. Recovery can be prolonged and incomplete.

Major blood vessel damage is also extremely rare but can necessitate emergency blood transfusion and vascular repair in some cases.