Minimally-Invasive Total Hip Replacement Surgery

Last updated Friday, August 10, 2007

Summary

Overview

• The key to minimally-invasive hip surgery is protecting the muscle and other tissues around the joint.
• In minimally-invasive total hip replacement surgery, a surgeon makes two small incisions – one in front of the hip and one in the back.
• With traditional hip replacement surgery a 5 to 10-inch incision in the side of the hip is needed, whereas with the minimally-invasive approach, incisions are about 1.5 inches and two inches in length, though this can vary with the size of the patient.
• Using x-ray guidance, the surgeon pushes aside the hip muscle, rather than cutting it to remove the arthritic hip and replace the hip’s “ball” and “socket” with titanium implants.
• A patient spends one to two days in the hospital, versus three or four days with traditional surgery.
• Total recovery time is about four weeks, rather than eight weeks with the traditional approach.

Characteristics of minimally-invasive total hip replacement surgery - degenerative joint disease

• Osteoarthritis damages the cartilage, the soft material between the leg bone and the socket, which helps the joint move easily.
• Patients with osteoarthritis of the hip frequently experience joint pain and discomfort, stiffness and swelling, which inhibit their movements, such as walking, stair climbing and prolonged sitting.

Types

The most common condition leading a person to seek a hip replacement is osteoarthritis.

• Rheumatoid arthritis – a chronic disorder that inflames the joints and causes erosion to the cartilage.
• Injuries ‑ such as those experienced in car accidents, may contribute to one’s likelihood of developing degenerative joint disease and thus he or she may need a hip replacement
• Autoimmune diseases – such as lupus, where the immune system attacks the joint cartilage
• Avascular necrosis – a condition where the bone dies, leading to destruction of cartilage

Similar conditions

• Back problems
• Muscle strains or bursitis

Physicians can distinguish hip osteoarthritis from other conditions by performing a careful examination, gathering a complete patient medical history, and having x-ray(s) taken. A magnetic resonance image (MRI) or other tests may be needed to confirm diagnosis.

Incidence and risk factors

Hip arthritis is very common. An estimated 40 million Americans report having been diagnosed with osteoarthritis; a significant portion of these people has arthritis in the hip. This statistic has led to more than 250,000 total hip replacements performed in the United States each year. About two-thirds of patients with hip arthritis may be eligible for the minimally-invasive hip replacement operation.

People who have a higher risk for hip arthritis or degenerative joint disease include:

• People who are obese
• Those with a family history of hip problems
• People who have experienced severe hip trauma
• Those with inflammatory conditions or autoimmune diseases, such as rheumatoid arthritis or lupus

Diagnosis

Medications

Exercises

Possible benefits of hip osteoarthritis

Hip replacement surgery is a surgical technique to treat arthritis pain in the hip. The traditional replacement procedure has been performed for 40 years, but recent advances have made a less-invasive approach available.

In both surgical approaches, the ball and socket of the hip joint are replaced. After recovery, most patients report a vast improvement in their overall quality of life as they are able to resume their activities of daily life. Many patients are able to regain an active life, enjoy increased mobility and frequently are free from pain, stiffness and swelling. Some people report their sleep quality is improved due to a lack pain and discomfort.

Types of surgery recommended

Hip replacement surgery should be considered when other, non-surgical, methods of treating hip arthritis have been attempted without success.

Traditional hip replacement surgery requires a large incision over the hip bone and the separation of muscle from the joint. By contrast, surgeons using the newer minimally-invasive technique make two smaller incisions – a 2 inch one in front of the hip and a 1.5 inch one in back (though incision length can vary with the size of the patient). Using x-ray guidance and special tools, the surgeon pushes aside muscle instead of cutting through it. The socket portion of the hip joint is replaced through the front incision and the ball portion of the hip joint (on top of the thigh bone) through the back incision.

What happens without surgery?

Surgical options

There are two approaches available for total hip replacement surgery. Which approach to use depends upon the patient’s specific condition, a number of medical issues, and the surgeon’s comfort with each of the various available options.

Hip resurfacing surgery – Surface replacement initially was introduced in the 1970s. However, durability was poor and most surgeons abandoned the procedure. There has been a resurgence of interest in surface placement over the past decade because of improvements in design, bearing surface, and instrumentation.

The potential advantages of resurfacing include: preservation of femoral bone use of a bigger femoral head component, which may be more stable; also, it has been theorized that subsequent revisions may be easier.

However, disadvantages include the inability to adjust for leg length differences, and a relatively high risk of femoral neck fracture. Also, there are concerns about disruption of blood supply to femoral head with this operation. Potential risks such including metal allergies and systemic effects (corrosion products from metals going to other organs) have been raised as concerns with this approach. Patients potentially eligible for hip resurfacing are younger, active patients (<60), with good bone stock, who understand that the risks may be greater and that less is known about the long-term results with this approach than with total hip replacement.

Hip arthroscopic surgery – Hip arthroscopy allows evaluation of hip pain in patients with nonspecific x-ray and MRI findings and reproducible, functionally-limiting physical signs and symptoms. It can also be used for treatment of synovitis (where the hip capsule lining becomes inflamed), removal of loose bodies, and treatment of labral tears. It is not effective for treating osteoarthritis for most patients.

Effectiveness

Urgency

Risks

The possible risks involved in hip replacement surgery include:

• Infection in the soft tissue or bone of the hip
• Limb-length difference requiring use of a shoe lift
• Nerve injury or vascular damage
• Blood clot 
• Restricted movement or stiffness of the hip joint
• Need for a blood transfusion
• Dislocation of the hip or fracture of the bone during surgery

For most patients, the likelihood of having a major complication – defined as a complication that could leave the patient worse off after the procedure than (s)he was before it – is extremely low.

Managing risk

• If an infection occurs around the implant, this frequently requires further surgery.
• With nerve damage, physical therapy may be prescribed to provide desensitization. Sometimes medications are used to manage nerve pain, should this be necessary.
• With restricted movement or stiffness, physical therapy may be prescribed to help mobilize the joint. Very rarely (a small fraction of one percent of the time), surgery can be used to help patients with severe stiffness.
• If bleeding occurs, blood transfusions are sometimes given; some patients elect to pre-donate their own blood in advance of surgery.
• If a blood clot occurs, blood thinners may be prescribed, along with use of special stockings, leg pumps. Hip dislocations are treated by manually repositioning the ball into the socket. If the dislocation recurs, surgery may need to be performed again.

Who should consider Minimally-Invasive Total Hip Replacement Surgery?

About two-thirds of patients who undergo hip replacement are eligible for the minimally-invasive approach. Candidates include:

• People who are fit and motivated enough to handle the accelerated rehabilitation process
• Those who have adequate social support at home to assist them immediately following surgery. Minimally-invasive surgery patients return home after only two days in the hospital and will require assistance around the house for at least one to two weeks
• People who do not have other significant medical problems, and those whose medical issues (e.g. diabetes or high blood pressure)are well managed

Patients, who are obese, have severe osteoporosis (low bone density) or who have had previous hip surgery generally need to undergo the traditional hip replacement operation.

Preparation

Patients may be required to discontinue certain prescriptions that may increase likelihood of bleeding. Some patients also donate blood in advance of surgery. In addition, patients are also asked to:

• Have a pre-surgery check up with their primary care physician or a medicine consultant to ensure they are medically able to handle the procedure and recovery
• Have a pre-operative visit with the orthopaedic nurse to receive instruction on the procedure itself, what to expect before, during and after the surgery, and sometimes an advance visit with the physical therapist to provide a brief description of the rehabilitation they will need to start in the hospital and continue at home.
• Make arrangements for someone to assist them with cooking, cleaning and driving after surgery. It is best to prepare food ahead of time and put meals in the freezer as food preparation will not be possible for several weeks during recovery. The patient should make other advance household preparations as well.

Timing

Costs

The patient’s insurance company should provide a reasonable estimate of:

• The surgeon’s fee,
• The hospital fee, and
• The degree to which these should be covered by the patient’s insurance.

Surgical team

Hip replacement surgery should be performed by a board certified or board eligible orthopaedic surgeon, who specializes in the procedure, has received special training and performs them on a regular basis. Studies suggest that surgeons who perform many procedures each year (so-called “high-volume surgeons”) have fewer complications than surgeons who perform joint replacements only occasionally. 

Finding an experienced surgeon

There is good evidence that the experience of the surgeon performing total hip replacement affects the outcome. It is important that your surgeon not only is an experienced orthopaedic surgeon; (s)he also should have a high level of skill and experience with total hip replacements.

• Are you board-certified in orthopaedic surgery?
• Have you done a fellowship (a year of additional training, beyond the five years required to become an orthopaedic surgeon) in joint replacement surgery?
• Do you do more than 50 hip replacements each year?
• Does your practice focus on joint replacement surgery, and the problems of joint replacement patients?

You may also visit the American Association of Orthopaedic Surgeons web site at www.aaos.org and click on the “Find a Physician” page.

Facilities

Technical details

In both traditional and minimally-invasive hip replacement surgery, the old, arthritic hip joint must be removed and replaced with new ball and socket titanium implants.

In a traditional approach, the surgeon makes an 5 to 10-inch incision in the side of a patient’s hip that requires the surgeon to cut through or detach muscle. At the end of the surgery, the surgeon must repair the divided muscle and tissues.

In a minimally-invasive surgery, the surgeon uses a two-inch incision on the front of the hip and a two-inch incision on the back of the hip. It is thought that this approach may cause less injury to the muscles around the hip. As a result, the recuperation period is less painful and the recovery more rapid than with the conventional approach. Through the small incision on the front of the hip, the surgeon places a cup, about the size of half a peach and is made of plastic. The cup is covered with a layer of titanium with a web pattern that will allow the bone of the pelvis to grow into it, keeping the cup in place. Through the other small incision on the back of the hip the surgeon places a titanium ball and stem into the femur, or thighbone. The bone grows into the stem over the six weeks following surgery, holding it securely in place. The components are placed using x-ray guidance to help insure accuracy. Once the ball and cup are in place, the surgeon puts the new ball into the new socket, and closes the surgical incisions.

Anesthetic

Anesthesia for hip replacement surgery can either be general or regional (spinal nerve block). The type of anesthetic is determined by an anesthesiologist based on the patient’s needs.

Anesthesia is administered by an anesthesiologist intravenously or through injection.

It is advisable that patients discuss the anesthesia with an anesthesiologist before surgery to ensure their comfort and safety.

Length of hip osteoarthritis

Pain and pain management

It is thought that minimally-invasive hip replacement surgery is less painful than the traditional approach primarily because muscles and tissue are not disrupted to the same degree. The hospital stay with minimally-invasive surgery is usually one to two days, versus three to four days with traditional surgery.

Use of medications

If a patient has a nerve block, he or she can often go straight to oral medications and no IV pain medication is needed. If the patient has general anesthesia, he or she may be on pain medication administered through IV for one day. Most receive the narcotic either through IV or orally for the first day and then for about a week thereafter they will be prescribed a narcotic pain medication, such as Percocet or Vicodin. Typically patients then transition to Tylenol as needed.

In addition, patients will be prescribed a blood thinning medication following surgery to prevent blood clots. They will usually be required to take this medication every 12 hours for two weeks.

Effectiveness of medications

Important side effects

As with any pain medication, if a patient takes too much or combines it with alcohol, they could experience the common side effect of drowsiness, nausea or possibly itching.

Taking the specified amount without alcohol may still cause side effects, such as a sedative effect, nausea, vomiting, constipation and even temporary depression.

Nausea can be alleviated by taking medication with food and/or avoiding alcohol when taking pain medication. Itching can be addressed by taking an antihistamine or patients may try using a skin cream or lotion for relief.

Patients should contact their physician if they experience any side effects to determine the best course of action.

Hospital stay

With minimally-invasive hip replacement, patients are usually hospitalized for about two days. With a traditional operation, hospitalization is usually three to four days.

Patients are assisted with getting up and out of bed as soon after surgery as possible. They are instructed on the use of crutches or a walker, how to navigate their way to the restroom and to go up and down stairs. Before discharge, patients must be able to walk with crutches or walker to the restroom and get in and out of bed on their own.

Recovery and rehabilitation in the hospital

Hospital discharge

Convalescent assistance

Following hip replacement surgery, patients typically recover at home. They will need help cooking and cleaning while they are on crutches. They will not be able to drive for at least two weeks. Patients may choose to have washcloth baths or to receive help getting in and out of the shower or tub.

A convalescent facility is not usually needed. In fact, patients requiring intensive rehabilitation are encouraged to have a traditional surgical approach.

Physical therapy

Rehabilitation options

Can rehabilitation be done at home?

Usual response

After hip replacement surgery and adequate rehabilitation, patients usually experience decreased stiffness and improved mobility if they perform the prescribed stretching and strengthening exercises and range of motion movements.

Risks

Following hip replacement surgery, the potential risks with rehabilitation are:

• Doing too much exercise or range of motion movements, thus causing pain and muscle soreness
• Not targeting the appropriate muscles, thus potentially causing persistent weakness and a delay in full recovery
• Failing to avoid vulnerable positions of the hip and leg, which could cause a risk of hip dislocation.

Duration of rehabilitation

Returning to ordinary daily activities

Long-term patient limitations

Costs

The patient’s insurance company can provide a reasonable estimate of:

• The rehabilitation cost and
• The degree to which these should be covered by the patient’s insurance.

Summary of hip osteoarthritis for Minimally-Invasive Total Hip Replacement Surgery - degenerative joint disease

• Hip replacement surgery may be considered when other, non-surgical methods of treating hip arthritis have been attempted without success.
• Whatever the approach to the operation, the goal of hip replacement surgery is long-term function restoration and pain reduction.
• It is best for hip replacement surgery to be performed by a surgeon who performs many hip replacements every year (a “high-volume surgeon”), and who has had special (fellowship) training in joint replacement surgery.
• Hip replacement surgery is an advanced technique to treat arthritis pain in the hip. Recent advances have made a less-invasive approach available to a wide range of patients.
• Minimally-invasive hip replacement can be performed with much smaller incisions that spare muscle and tissue. This helps patients to recover from surgery much faster.

Surgery for Minimally-Invasive Total Hip Replacement Surgery - degenerative joint disease at the University of Washington