Direct Two-Incision Minimally Invasive Hip Replacement Surgical Procedure

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

The two-incision minimally invasive hip replacement technique allows the surgeon to replace the hip’s ball and socket joint through two 2-inch incisions. Because surgeons don’t cut as much skin, muscle, tendons, and ligaments patients can potentially recover quicker and return to an active lifestyle sooner than with traditional hip replacement surgery.

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 surgery, you will be taken to the operating room. An anesthesiologist will administer anesthesia to help 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 working, you will be placed on your side so the surgeon can operate on your bad hip. Padding and other special restraints will be placed so you don’t change position on the table.

The surgeon will then make two cuts or incisions in the area around your hip. One incision is made on the front of the hip, at the top of the pelvis. Another incision is made behind it. Although the lengths of the cuts will vary depending on the height and size of the patient, they will most likely only be two to three inches long. This is significantly smaller than the 12-inch or more incision needed for traditional hip replacement surgery.

After making the front incision, the surgeon will gently separate two major muscles to expose the socket. This is a considerable change from the traditional hip replacement where the muscles had to be cut apart. Separating the muscles out of the way rather than cutting them can potentially speed up the recovery time. From the back, the gluteus maximus muscle and fibers are separated rather than cut. This allows the surgeon to prepare the thigh bone without damaging the major muscles at the hip.

"By precisely positioning the incision and by going between muscles instead of cutting through them, damage to the tissues around the hip is minimized," said Jack Irving, MD, a surgeon with The Orthopaedic Group in New Haven, CT. "Minimal muscle damage means less pain and quicker return of strength, two keys to faster rehabilitation."

The surgeon will begin work on the socket by removing the diseased bone and other tissues in your hip. The area will then be reshaped to accept a new cup that replaces the original socket. A cup will be placed in the reshaped socket.

After moving the muscle, the surgeon will be able to see the ball of your hip, also called the femoral head. Using special instrumentation, the femoral head is then removed.

The surgeon will move your leg to get better access to the shaft of your femur (thigh bone) through the back incision. Using special instrumentation, the surgeon will remove some of the soft inner bone. This is done so a hip stem can be implanted to support your new femoral head (ball of the hip). To ensure the prosthesis fits properly, one or more trial stems may be inserted into the hollowed out femur. The surgeon will 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 your surgeon sees that the joint is ready and the proper stem size has been selected, the trial stem is replaced by the final implant. Like the socket, the use of cement to fasten the stem in place is up to the individual surgeon and often depends on the shape and strength of the remaining thighbone.

Finally, the surgeon will select the right size femoral head to fit on the stem. After it is placed correctly, the new ball and stem combination is placed into the socket cup. The joint will then be tested to make sure it moves freely and any needed adjustments will be made.

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

"The two incisions permit the parts of the hip to be inserted more accurately which helps to insure more normal function of the hip replacement earlier," Irving said. "Using minimally invasive surgery techniques, we have found that patients have a shorter duration of acute surgical pain."

The incisions are closed with dissolvable sutures and adhesive strips.

The Recovery Room

After the procedure is finished, you will then 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 three days in our practice," said Irving. "Patients are usually encouraged to go right to a cane on the second day after surgery. Progression from a walker to a cane and then to no assistive devices is related to the length of time a patient has had arthritis, which weakens muscles before surgery."

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. The most common adverse events include 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. Only an orthopaedic surgeon can determine whether you are a candidate for the minimally invasive two-incision hip replacement procedure.