The Latest in Total Hip Replacement

Several major advances have occurred in the field of total hip replacement in the last few years. The primary concern of the patient who requires a total hip replacement should be how well it works, and the length of time the implant will function and provide satisfactory results.

When total hip replacement was first developed, the implants were cemented on both the pelvis side and the femoral side. Cement has been shown to last about 10 to 15 years. For this reason, bio-ingrowth hip replacement was developed. Bio-ingrowth hip replacements have a rough metallic surface with pores on the metal to allow the patients own bone to grow into the prosthesis. This type of metal fixation to bone without cement has the potential to last a lifetime. Dr. Likover performs almost exclusively bio-ingrowth total hip replacement for this reason on both femoral side and pelvis side.

The other issue, which is the factor in the length of survival of the implant, is the junction between the ball and the socket known as the "Interface". Originally, total hip replacement was developed with a metal ball and a polyethylene (plastic) socket. It has been shown over time that polyethylene without a metal backing deforms and wears out. Metal-backed polyethylene sockets have been used in America for many years, and still are in many cases. The newest interfaces now available are either metal-on-metal with a solid metal socket, or ceramic on ceramic with a metal backed socket. The stem in all cases is bio-ingrowth metal. Both metal-on-metal and ceramic on ceramic interfaces have the potential to last a lifetime. There have been some problems with ceramic heads breaking and thus Dr. Likover uses only metal on metal "big ball" implants. Head breakage is not a factor with this implant.

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One of the more common complications of hip replacement is hip dislocation, if the patient inadvertently assumes a squatting position or trips and falls, these abnormal positions might cause the ball to dislocate from the socket after it is implanted. A dislocation of the ball from the socket usually requires to patient to come to the hospital and be placed under anesthesia to allow the doctor to pull the implant back into place. By using a big ball and a big socket, the chance of dislocation is greatly reduced because it is very difficult for a large ball to come out from the socket. The original hip replacement had a very small ball (22mm) and dislocation of the ball was a very common problem, especially in the early postoperative period. A big ball implant uses an implant as large as the patient's bone will accept. Sometimes the ball is 55 mm across which is almost triple the size of the ball of the original hip replacements.

A last consideration in hip replacement is the type of incision used. In the last few years, "minimally invasive" hip replacement has been promoted by various orthopedic surgeons as a "major breakthrough." This has turned out to be a lot of "hype."

Dr. Likover performs a total hip replacement with as small an incision as possible. It has been shown now that some of the various minimally invasive procedures with tiny incisions carry increased risk of the implant being placed in a poor position, which can cause an early surgical failure or poor function of the implant. It is far more important to get the implant positioned correctly for a successful outcome than to be overly focused on the size of the skin incision.

Dr. Likover allows his patients to discontinue crutches as soon as possible and switch to a single crutch or cane at the patient's own rate. Usually by three to four weeks following the surgery, the patient is walking quite nicely without support. Total hip replacement patients usually improve their gait pattern for several months, and by four to six months, it is difficult in many cases to detect that the person had any surgery, let alone hip disease. Many patients walk normally without the slightest limp.

If you have any further questions, please contact me and I will be happy to answer them. Send me a message.