In this post I will discuss the two primary hip replacement surgery approaches: the direct anterior approach and the minimally invasive posterior approach. I will go over the similarities, differences, advantages and disadvantages to each approach.
What is a Hip Replacement Approach?
First, we should understand what is a hip replacement approach. Simply, it is the surgical procedure where an orthopedic surgeon determines where to make the incision and the path he or she takes to reach the damaged hip tissue and bones in a patient requiring a hip replacement.
The surgeon will determine which approach is best for you after examining you. He or she will make this decision based on your age, strength, anatomy and health status. Only a professionally trained surgeon should advise you on the approach which is right for you. The guidelines I present here are only meant to inform you about the different options available to you so you can make an informed decision.
Surgeon Recommends – But You Have a Choice
As I have written before, I made a decision to move forward with the direct anterior approach, the procedure my referred orthopedic surgeon recommended. I admit, I was not adequately educated on the approach and surgery and only knew the basics of the approach before my surgery. It worked out well for me.
You can alleviate fear by becoming knowledgeable and informed about your options regarding hip replacement surgery.
I sometimes think the orthopedic surgeon is biased to the hip replacement approach he or she is good at. I know that is a strong statement, but an orthopedic surgeon builds his or her practice around forte. Most surgeons know more than one approach, but most of their training and experience is built around one approach.
When talking with your orthopedic surgeon, ask the surgeon what options you have for your hip replacement surgery. If you are a candidate for a type of hip replacement approach the surgeon doesn’t perform, or you expressed strong desire to have another approach performed, he or she may refer you to a surgeon who specializes in that approach.
Ask the surgeon:
- What is his or her hip replacement surgery approach expertise?
- How many hip replacements has he or she performed?
- What is his or her success rate?
- Is there anyone who will recommended him or her?
Comparisons of Direct Anterior Approach and Minimally Invasive Posterior Approach
Before I compare the Direct Anterior and Minimally Invasive Posterior hip replacement approach, you must understand one thing. There is not one clinically-proven “best” hip replacement approach. There are risks and benefits to each approach.
Each approach has the overall risk of:
- Blood clots, DVT, PE
- Complications from anesthesia
Minimally Invasive Posterior Approach
The minimally invasive posterior approach is performed while the patient is on his or her side. The approach is also known as the Moore or Southern approach. It is considered to be the traditional hip transplant approach. The approach is from the rear or behind the hip joint and gives very good access to the joint.
Be careful, as the older method of this approach did not use minimally invasive methods which included larger incisions and longer hospital recovery times. If the surgeon wants to perform this approach, please verify the minimally invasive posterior approach is being used.
Incisions – For the Minimally Invasive Posterior Approach, the incision is 4-6 inches. Someone with previous hip surgery or abnormal anatomy may require larger incisions.
Muscles Removal – the piriformis and superior gemeli hip rotator muscles are detached from the ball and socket of the hip joint and reattached near the end of the operation. These muscles heal within 4 to 6 weeks after the surgery.
Nerve Risk – very minimal for the approach. There is no risk to the femoral cutaneous nerve, which provides feeling to the outside of the thigh. There is less than one percent risk to the sciatic nerve, due to retraction of the of tissue during the surgery.
Fracture Risk – low for the approach. The torque or press on the femur is small.
Surgeon’s Intraoperative Visualization – is very good as the approach provides full visualization of all part of the hip joint. Since it is high, no interoperative x-rays are required. The Minimally Invasive Posterior Approach is a simple approach and is not technically challenging for the surgeon.
Risk of Location – Is higher than the Direct Anterior Approach, although it is as low as 9%. Posterior dislocations may occur when the patient bends more than 90 degrees at the hip/waist after surgery. The risk is much lower for dislocation two months after surgery.
Most patients are candidates for the Minimally Invasive Posterior Approach
Hospital Stay – 2 – 3 days, the same as Direct Anterior Approach
Return to Sedentary Work – 2 weeks
Return to Physical Work – 3 months
Return to sports – 6 weeks – 3 months
Benefits of Minimally Invasive Posterior Approach
- Versatile approach
- Good access to the acetabulum
- Preserves the hip abductor muscles – gluteus medius and gluteus minimus muscles
- Minimizes the risk of post-operative abductor dysfunction
- Best when dealing with complex deformities
- Cemented or uncemented fixation of prosthesis can be chosen during the operation
- Surgeries are normally shorter
- No limit to the type of implant which can be used
Drawbacks of Minimally Invasive Posterior Approach
- More risks to dislocations
- More precautions need to be made over procedure
- sit in higher chair
- raised toilet seat
- Pain sitting on the incision site
- First four weeks of rehabilitation slower
- Limit driving in a car – suggested not driving within first four weeks after surgery
Direct Anterior Approach
The Direct Anterior Approach or Anterior Approach is performed while the patient is on his or her back and approaches the joint from the front of the hip. This surgery approach was first performed by Dr. Marion Smith-Peterson in 1939. The operation is often performed with use of a special table called the Hana®. The table positions the patient and leg using boots which are placed on the patient and secured to the table. This assists in dislocating the hip and aids in the surgeon’s visualization.
Incisions – are 4 – 6 inches, usually made at the very front of the hip.
Muscle Removal – The Direct Anterior Approach is sometimes referred to as a muscle sparing operation as muscles are not cut and reconnected. However the top external rotator muscle (piriformis) is ‘released’ and cannot be reattached during the procedure. Since there are other redundant rotator muscles, this does not create a large issue during recovery. One procedure to reduce the risk of damaging the latera femoral cutaneous nerve moves the incision more to the side. Here the incision cuts through the Tensore Fascia Latae and Sartorius muscles.
Nerve Risk – much higher risk of damaging the lateral femoral cutaneous nerve using the Direct Anterior Approach due to the retraction of the muscles during the surgery. This nerve provides sensitivity or feeling to the side of the thigh. There is a much smaller risk to the sciatic nerve using the approach.
Note: Lateral femoral cutaneous nerve was damaged during my surgery which used the Direct Anterior Approach. Shortly after surgery I had no feeling in the side of my thigh, and I could lean on something using my thigh and feel nothing. I could not feel if I had something in my pants pocket. Over a year later, I still have some numbness in the thigh. I was warned of this risk before surgery, and signed a document which said I understood the surgery risk. I don’t feel this was a huge side effect or complication of the surgery and it is something i live with.
Fracture Risk – is much higher for the Direct Anterior Approach. Femur and ankle fracture is greater due to table positioning. Fracture risks are increased in patients with osteoporosis .
Surgeon’s Intraoperative Visualization – The Direct Anterior Approach is technically challenging and surgeon visualization is impaired due to muscle interference. As noted, a special table called the Hana® allows the surgeon to easily access the front of the hip. A curved femoral implant is used as a straight implant is hard to place without injuring the abductor muscle. X-rays are used to improve the surgeon’s visualization, placement of the implant and help increase the accuracy of leg length.
Risk of Dislocation – is very low compared to the Minimally Invasive Posterior Approach and normally occurs at the front of the hip. Dislocation can occur due to external rotation of the leg during activity. Very few hip precautions are require.
Candidates for the Direct Anterior Approach include – Patients without hip deformities and flexion contractures. Good candidates aren’t significantly overweight and aren’t overly muscular in the leg.
Hospital Stay – 2-3 days, same as Minimally Invasive Posterior Approach
Return to Sedentary Work – 1 – 2 Weeks
Return to Physical Work – 1 -3 Months
On a personal note, I had just started a new job a few months before, and relocated to a different area of the country. I felt it looked very bad to be out so soon for a major operation being in a new job for so little time. I had a sedentary desk job, and my doctor allowed me to resume my work duties two weeks after surgery, as long as I worked from home.
The Direct Anterior Approach was appealing, as I was able to work remotely from my condo, and to return to work in four weeks. The Minimally Invasive Posterior Approach would have taken two weeks longer in recovery, or more.
Return to Sports – 1 – 3 months
Drawbacks of Minimally Invasive Posterior Approach – some report blood transfusion risk is lower, although some say it is increased.
According to my surgeon, I nearly required a blood transfusion. During my hospital recovery, I nearly passed out the day after surgery. I got up from the bed in my hospital to use the bathroom, with the aid of my cane. I dropped my cane and bent down to pick it up. The room started spinning and I felt like I was going to throw up. Luckily, a nurse spotted me and soon I had a team of nurses and an on-call physician working on me. Doctors referred to it as Vasovagal Syncope: a sudden drop in heart rate and blood pressure leading to fainting. The surgeon later said it was due to having lost a lot of blood in surgery. I was on the edge of requiring a transfusion. Due to this event, I had to stay in the hospital an extra day.
- The top external rotator muscle (piriformis) is ‘released’ (see muscles).
- X-rays are used due to lack of surgeon visualization (this is also listed as a benefit).
- Access to the femur is limited.
The Direct Anterior Approach is more technically demanding for the orthopedic surgeon and surgical team and requires more experience in order to perform. The orthopedic surgeon needs to be trained on the approach which requires more training than other approaches. Many experts note the steep learning curve is the major drawback to Direct Anterior Approach.
The approach is not good for morbidly obese patients and those who are very muscular.
Surgeries – 2-3 hours, longer than other methods, which increases surgery risk under anesthesia.
Benefits of Direct Anterior Approach – The approach provides good visualization of the acetabulum. It is
less invasive than other approaches, however this is sometimes debated too. With the newest Minimally Invasive Posterior approach the invasiveness is about the same.
Restrictions After Surgery – less restrictions after surgery. Immediately after surgery using the Direct Anterior Approach, patients may:
- Move their hip freely
- Cross legs
- Sit comfortably
- Walk up and down stairs
- Get in and out of cars
With other methods, the detached muscles are reattached to tendons, leaving a looser tension. This results in an increased risk of dislocation immediately after surgery. Limitations or precautions of hip movement to 90 degrees while bending at the waist (as with other methods) do not apply with the Direct Anterior Approach. The surgeon works between most muscles without detaching them. This helps prevent dislocations after the prosthesis are placed. Therefore fewer precautions are required for Direct Anterior Approach.
With Direct Anterior Approach there are reduced post-surgery dislocations and rehabilitation is accelerated. After 2 months the rehab progress is about the same.
There is greater stability after surgery using Direct Anterior Approach. Patients can place full weight on implant due to lack of muscle disconnect / reconnect.
The Direct Anterior Approach is not good for morbidly obese patients and very muscular patients. Recent news however suggests morbidly obese patients should receive bariatric surgery to reduce health risks before and after surgery (see link).
Concerns – the use of shorter stem implants for the Direct Anterior Approach and if these implants will hold up in the femur over time.
Conclusion and Engagement:
Direct Anterior Approach and Minimally Invasive Posterior Approach
What are your thoughts about what approach is best and best for you? Do you think an orthopedic surgeon can be biased in the approach he or she recommends?
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As always, thanks for reading my blog and this post.
Resources Used In This Post
Bonesmart.org: Hip Replacement Approaches
Dr Boettner: Posterior Approach Total Hip Replacement Surgery
Jay Kruse, M.D.: Hip Surgery: Posterior vs. Anterior Total Hip Replacement
The Leone Center for Orthopedic Care: Anterior Approach for Hip Replacement: Advantages and Disadvantages –
The Leone Center for Orthopedic Care: Why I No Longer Use the Anterior Approach for Primary Total Hip Replacement Surgery
The Leone Center for Orthopedic Care: Blog Update: Mini-Posterior and Direct Anterior Approaches to Total Hip Replacement