Every day of every week of every month, according to the Centers for Disease Control, almost 900 total hip replacement procedures are performed in this country.
That number is likely to rise exponentially over the next several years as more and more members of the 76 million-strong baby boom generation become Medicare-eligible.
The most common reasons for hip replacements, according to the National Institutes of Health are age and osteoarthritis. Osteoarthritis damages both the ball and the socket of the hip joint, severely restricting movement.
While millions of Americans may need hip replacements, many don’t really know what’s involved in the lengthy, complex operation. Dr. Robert Hill of Vero Orthopedics and Dr. Kirk Maes of Coastal Joint & Sports Medicine agreed to talk about the nuts and bolts of hip replacement surgeries.
First the surgeon has to get to the hip. That means making an incision on the front, back or side of the hip. That incision can be as short as four inches or as long as ten.
“We get down through the skin,” explains Hill, “and get down to the muscles and we release some of the muscles [from their tendon attachments] and we split some of them and that frees up the tissue and allows exposure to the hip joint.”
Hill, who served dual fellowships at the Cleveland Clinic in total joint replacement and adult reconstructive surgery continues, “We divide or split the muscles to expose the bone.”
After clearing space by manipulating the muscles, tendons, cartilage and tissues that surround the joint, the surgeon can begin work on the hip.
The bones involved are the femur, (thigh bone), and the pelvis, (hip bone), as well as the ball-like tip of the femur which is called the femoral head and the socket into which that ball section fits known as the acetabulum.
Briefly stated, the goal in any hip replacement procedure is to dislocate and pop the femoral head out of its socket in the pelvis and saw it off. The surgeon then scoops, scrapes and reams clean the interior surface of that socket as well as the now-exposed interior of the femur. A metallic or ceramic replacement for the femoral head that is attached to a metal rod is inserted into the femur and a metallic cup is placed inside the acetabulum socket in the pelvis along with a high-tech plastic spacer so metal-on-metal or metal-on-ceramic contact is avoided.
The new parts create the free-gliding motion that osteoarthritis had taken away.
“I use an anterolateral approach,” explains Hill. “I find that allows me the best exposure (to the hip joint) and allows me to do the surgery in the least amount of time.” That, Hill claims, is important because he says some other procedures can take three or four times longer, exposing the skin and subcutaneous tissues to the environment (and possible infection) for much longer periods of time while also increasing the risk of complications from anesthesia.
Dr. Maes takes a different route: “I’ve done hip replacements with all of the different surgical approaches that are available and I’ve settled on the standard posterior approach. I think it really offers the simplest recovery with the minimum amount of pain and inconvenience for the patient and the most efficient surgical experience possible.”
Maes, who served his internship at the U. S. Naval Medical Center in Portsmouth, VA and his residency at Hahnemann University Hospital, adds that his approach, “Only takes about an hour to do. It has the minimum of blood loss. It has the minimum of pain afterwards. People can get it done on Monday and 80 to 90 percent of them can go home on Wednesday comfortable and without ever taking narcotic pain killers, awake and alert.”
As to those nuts and bolts mentioned earlier, the truth is there aren’t any. In some cases, small screws may be used to secure the new metallic cup to the socket in the pelvis and sometimes bone cement, which is chemically identical to Plexiglas, is employed but otherwise the shelves at Home Depot or Lowes are pretty much devoid of anything useful for hip replacement surgery.
Your kitchen drawers, however, are a different story. “I use something like a big spoon,” explains Hill, “to scrape out the acetabulum.”
Once the new metallic cup is secured, attention turns back to the femur. “We have these reamers that are like long drill bits,” according to Hill, “that we put down the canal in the femur and take out the cancellous bone on the inside,” to make room for that flange-like stem on the new metal or ceramic ball.
Maes points out that there are, “a dozen different sizes of stems and at least 20 different manufacturers. The stems have a rough sandpaper-like surface that natural bone will attach to.”
Once the components of the new hip joint have been assembled, they are “dry fitted” to make certain all is as it should be and then put into place. Muscles and tendons are sutured and the incision is closed so the healing process can begin.
According to Maes, the muscle tension, “has a bungee cord effect” that holds the hip together which, in most cases, makes bone cement unnecessary.
Maes is also a huge proponent of post-operative physical therapy. He’s one of the founders of the Sebastian Medical Center’s Orthopedic Joint Camp.
The American Academy of Orthopedic Surgeons claims hip replacement surgeries are, “one of the most successful operations in all of medicine.”
Still, would-be hip replacement patients might be wise to double check their medical coverage. Blue Cross-Blue Shield says, “The cost (for hip replacements) can vary by as much as 313%, depending on where the surgeries are performed.”
Medicare and most insurers have set the prices they will pay but knowing in advance what the out-of-pocket expenses will be might make the recovery process that much easier.
Dr. Robert Hill is with Vero Orthopedics at 1155 35th Lane, Vero Beach. The phone number is 772-569-2330. Dr. Kirk Maes is with Coastal Joint & Sports Medicine at 13000 U.S. Hwy. One, Suite 5, in Sebastian. The phone number is 772-581-5881.
