Mini-Incision Minimally Invasive Hip Replacement Surgical Procedure

If your doctor recommended you as a candidate for mini-incision minimally invasive hip replacement, it is important for you to understand the details of this procedure.

A mini-incision is usually three inches to four inches long, compared to the traditional 12-inch to 18-inch opening. Because surgeons don’t cut as much skin, muscle, tendons and ligaments, patients can potentially recover quicker and return to an active lifestyle in weeks instead of months.

The mini-incision technique can be performed through either the anterolateral (front of the hip) or posterolateral (back side of hip) approach. In both techniques the patient is laying on his/her side. The approach selected is based on surgeon training and preference.

The Operation

Before you are admitted to the hospital, a medical evaluation will be conducted by your physician, which will include an X-Ray of your hip.

On the day of your surgery, you will be taken to the operating room. An anesthesiologist will administer anesthesia to prevent pain while the surgery is performed. Depending on what your surgeon and the anesthesiologist decide is best, the anesthesia will either put you completely to sleep or just numb the lower part of your body including the hips.

After the anesthesia begins to work, you will be placed on the operating table lying on your side. This makes it easier for the surgical team to see and work on your hip. The team will put supports at your chest and hips to make sure you don’t move during the operation.

The surgeon will then feel along the outer side of your body just below the waist, looking for the greater trochanter (the top of the leg) where it attaches to the pelvic bone.

The surgeon will then make a single incision about three to four inches in length over the hip joint. The length of the incision depends on the size of the patient, but it is kept as small as possible while still giving the surgeon room to work. It also gives the surgeon the option to approach the area from either the front or the back.

"By precisely positioning the incision and going between muscles instead of cutting through them, damage to the tissues surrounding the hip is minimized," said C. Kent Boese, MD, a surgeon at Miller Orthopaedic Affiliates in Council Bluffs, IA. "Minimizing muscle damage means less pain and quicker return of strength; the key to a faster return to normal activities."

First, your surgeon will need to prepare the socket in the acetabulum for the new hip. The diseased area will be removed and a special metal cup (or socket) will be implanted. A liner made of special medical grade plastic, metal or ceramic is inserted into the metal cup. The femoral head will then be placed into the liner.

Using special instruments, the doctor will move the muscles and other tissues in the area out of the way. This is a considerable change from traditional hip replacement where more of the muscles are cut.

This instrumentation is then used to expose and remove the femoral head removing the diseased area.

Using special instrumentation, the surgeon will remove some of the inner bone from the femoral canal (thigh bone). This is done so a hip stem can be implanted to support a new femoral head (ball of your hip).

In order to ensure the stem fits properly, one or more trial stems may be put in the hollowed out femur. The surgeon will then check to make sure the leg can be moved through its entire range of motion and that there are no major differences in the length of your legs.

Once the surgeon sees the joint is ready and the proper stem has been selected, the trial is removed and the actual stem is inserted. The use of cement to secure it in place is up to the individual surgeon and often depends on the shape and strength of the remaining thighbone.

When the doctor is satisfied with the position and movement of your new hip joint, the incision will be closed.

"Using minimally invasive surgery techniques, we have found that patients have a shorter duration of acute surgical pain, a reduction in surgical time, and less swelling," said Wayne Goldstein, MD, from the Illinois Bone and Joint Institute in Des Plaines. "The shorter incision now needs only a simple skin closure with an adhesive. This no longer requires skin staples or sutures, which can be uncomfortable to remove later."

The Recovery Room

When the procedure is finished, you will be taken to the recovery room where specially trained nurses and technicians will watch you closely until the anesthesia wears off. When the surgical team determines that you are alert and your heart rate, blood pressure and breathing are all normal, you will be transferred to your hospital room.

"The average length of stay in the hospital is 3.4 days in our practice," said Tad Vail, MD, Associate Professor of Orthopaedic Surgery at the Duke University School of Medicine in Durham, NC. "The real changes have come about when it is time to discharge these patients from the hospital. In our minimally invasive hip replacement patients, 80% are sent directly home compared to 80% going to rehabilitation hospitals for more treatment (rehabilitation and physical therapy) when other surgical methods are used."

Recovery takes time and hard work. The life of a new joint depends on weight, activity level, age and other factors. Each patient responds differently. While uncommon, adverse events can occur including loosening, deformation or wear of one or more components, osteolysis, infection, fracture of the components or bone, change in position of the components, dislocation and tissue reaction. Also, a mini-incision may need to be converted into a traditional incision during surgery.

Many surgeons may still prefer to perform traditional hip replacement surgery. Only an orthopaedic surgeon can determine whether you are a candidate for the minimally invasive hip replacement procedure. As with any surgery, there are risks including blood clots, infections, pneumonia, dislocation, prosthesis loosening, and nerve damage. You should discuss these risks with your orthopaedic surgeon.