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Posts Tagged ‘Pelvis’

The information provided below is meant to educate the patient about the options available to hip replacement candidates. Your orthopedic surgeon should explain to you which hip replacement is best for you and why.

In a total hip replacement, both the thigh bone (femur) and the socket are replaced with implant materials and prostheses. Specifically, a metal stem is inserted into your thighbone. Attached to the neck of the stem is a hip ball, just over an inch in diameter. The hip ball fits into a liner. Together, the ball and liner create the new joint. The liner is inserted into a metal shell that in turn is anchored to your pelvis. But there are a number of different approaches a surgeon can take, depending on her analysis of your particular case.

Because of the advances in the last thirty years, several different types of implant materials have also been found useful in hip replacement procedures. Each material has its own advantages and disadvantages, but it is ultimately up to your surgeon which materials to use. Beyond the different types of materials, a surgeon must also decide whether to anchor the hip implant to the bone using cement fixation or something called “bone ingrowth.”

Fixation

For bone ingrowth, the surface of the prostheses simulates the bone with a special granular surface into which the bone grows, thereby locking the implant into place. Cement fixation holds the implant in the bone by acting as a filler between the bone and the implant. It is made of a substance that is mixed at the operation and hardens into a durable, long lasting polymer.

Modularity

You may also want to consult with your doctor about the design of the implant. Modular systems offer the ability to interface different sizes of femoral heads to fit over the stem; angles, sizes, and lengths of the implant are made to fit your anatomy. The advantage of a modular system is that it gives the patient more flexibility.

Choosing Hip Replacement Implant Material

The main issue that doctors and patients confront when choosing implant material revolves around the wear debris that is released into your body from any of the implant materials. Even the materials with the most wear debris (metal ball and polyethylene liners) show up only after many years (10-15). Nevertheless, it is important to educate yourself about the various options for hip replacement surgery.

Metal-on-Polyethylene

Because of its durability and performance, Metal-on-Polyethylene has been the leading artificial hip component material chosen by surgeons since FDA approval 30 years ago. The metal ball is cobalt chrome molybdenum alloy and the liner is polyethylene.

Metal-on-Polyethylene is the most understood and practiced of all the procedures. Using these materials, a surgeon has a range of options to obtain stability in the body while the operation is underway. This ability to adapt and customize during the surgical procedure is an important attribute of polyethylene. It is also the least expensive bearing.

The disadvantage of Metal-on-Polyethylene is shedding over time. After 10 to 15 years, patients who are extremely active may shed debris that results in joint inflammation and bone loss. However, new wear resistant polyethylene liners have been introduced, called “highly crosslinked polyethylene.” If you are a very active individual or a relatively young patient, your surgeon may prescribe an all-ceramic hip joint or all-metal hip joint.

Ceramic-on-Polyethylene

Your next option is a ceramic ball and polyethylene liner. Ceramic heads are harder than metal and are the most scratch resistant implant material. The hard, scratch resistant, ultra-smooth surface can greatly reduce the wear rate on the polyethylene bearing. The wear rate for this type of implant is less than Metal-on-Polyethylene.

One disadvantage found in Ceramic-on-Polyethylene are the incidents of fractures, but newer, stronger ceramics have resulted in fewer of these. Overall, the wear rate for Ceramic-on-Polyethylene is 50% less than that of Metal-on-Polyethylene.

In terms of cost, Ceramic-on-Polyethylene is more expensive than Metal-on-Polyethylene, but less than Ceramic-on-Ceramic.

Metal Ball and Metal Liner

Metal-on-Metal bearings were approved by the FDA in 1999, offering the potential for greatly reduced wear, with less inflammation and less bone loss.

One clear advantage of metal-on-metal implants is the variety of femoral head sizes and neck lengths available (modularity). Metal-on-metal components allow the largest heads throughout the entire range of implant sizes. Large ball heads provide increased range of motion and greater stability, which can significantly reduce the risk of hip dislocation, a crucial factor in the long-term success of an implant.

Although wear is reduced, the wear products (sub-microscopic particulates, soluble metal ions) are distributed throughout the body. This has raised concerns about long-term bio-compatibility. At present these are only concerns, for there have been no definitive clinical findings that these wear products are harmful.

Anatomic Size Metal-on-Metal Ball Heads

Because the human femoral (ball) head is naturally large, it makes sense to implant a large, anatomic replacement. This was not possible in the past because traditional polyethylene liners made smaller femoral heads necessary. However, with the introduction of metal-on-metal implant components, liners may be eliminated, allowing surgeons to use large femoral heads. Use of a larger ball head has been shown to increase the range of motion an individual may experience as well as decrease the possibility of dislocation.

Ceramic Ball and Ceramic Liner

Ceramic is the hardest implant material used in the body, and has the lowest wear rate of all, to almost immeasurable amounts (1000 times less than Metal-on-polyethylene). These implants have been used in Europe for more than 30 years, and since 2003 in the United States.

Consequently, there is usually no inflammation or bone loss, nor systemic distribution of wear products in the body. New ceramics offer improved strength and more versatile sizing options. However, there has been a very few incidents reported of noises from such implants.

Hip-Resurfacing Option

For younger patients, a total hip replacement may not be the best solution for their hip pain because it can mean difficult and numerous revisions later in life. Hip resurfacing, however, leaves more of the bone in place, giving these patients more time before a total hip replacement becomes necessary.

Conclusion

If you are a candidate for hip replacement surgery, fixation, modularity, and implant materials are all topics that factor into making the right decision. Your doctor should explain to you which procedure and materials are best for you.

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The procedure and technology associated with hip replacement surgery is continually being refined and updated so as to meet the needs of the patients more effectively.

The hip joint is that part of the body where the thigh bone or femur meets the hip bone or pelvis. The head of the femur is shaped like a ball and this fits into a socket called the acetabulum on the hip bone. The ball moves within the socket allowing the person to perform a wide range of activities. When the hip joint is affected by injury or disease, it becomes stiff and painful and the person’s activities are curtailed.

During hip replacement surgery the damaged parts of the hip are removed and man made implants are put in their place. The new artificial hip thus created is expected to function in the same manner as the natural hip it has replaced.

In traditional hip replacement a long incision is made on the hip cutting through the muscle to expose the hip joint. Through this opening the damaged hip joint along with diseased bone and cartilage is removed. A metal cup is then fixed to the pelvis and a metal stem attached to the femur or thigh bone. A ball is placed on top of this stem and anti friction material is used to line all the exposed parts. The hip is then reassembled and finally the incision is closed.

A newer technique called minimally invasive hip replacement proceeds differently. One or two small incisions are made instead of a large one and the operation is performed with specialized instruments through these openings. The hip joint is not exposed fully and x-ray guidance is used instead.

The implants used in either method however are the same. The implants are made of materials that permit the natural gliding motion of the hip joint. Metal, plastic and ceramics are some of the materials used.

The implants can be fixed to the body in different ways. In some cases the parts are attached to the healthy bones using bone cement. In others biological fixation is used. Called the uncemented procedure, this involves parts which have a porous surface through which the natural bone is encouraged to grow and hold the part in place. Hybrid replacements use a combination of these two methods.

Preparation for hip replacement surgery starts a few weeks before the surgery is performed. The patient uses this time to clarify doubts, arrange finances and ready the home for life during rehabilitation. The patient is advised to avoid aspirin and non-steroidal anti-inflammatory medicines as these may interfere with the surgery. Pre-operative laboratory tests and x-rays are also undertaken and the patient is put on antibiotics to counter post operative infections.

Hip replacement surgery is a major operation. The patient thus has to be prepared that recovery will not be immediate and dramatic. Instead time, coupled with medication and exercise will heal and a normal active life can be regained gradually. The time taken to recover completely for the surgery differs from person to person. However a positive attitude can do wonders and hasten the recovery process considerably.

Hip replacements surgery costs have fallen dramatically in recent years, due to the emergence of medical tourism. Medical tourism combines the best treatment, with the advantage of vastly reduced costs. Here we will look at hip replacement surgery and the costs involved.

Reducing Hip Replacement Costs

Today, you can have the best surgery, and also benefit from vastly reduced costs by having your treatment done overseas.

By having your hip replacement operation abroad, you can use the cost savings to enjoy a relaxing holiday and maybe even have some money left over!

Let’s look at the hip replacement operation in more detail first and then look at costs and the best destinations for medical tourism.

Hip Replacement Procedure

Recent developments in hip replacement surgery have seen the operation become a safe and reliable method to treat severe and crippling hip arthritis pain.

Hip replacement surgery (known as arthroplasty) is usually carried when osteoarthritis has resulted in the wearing down of and erosion of the hip joint.

In a hip replacement operation, the worn out and arthritic parts of the hip joint are removed and a new artificial (prosthesis) hip joint is inserted as a replacement.

Successful hip replacement surgery aim is to:

Improve mobility, by improving the function of the hip joint and reducing the pain and discomfort felt by the patient.
How Hip Replacement Surgery is performed

Hip replacement surgery involves removing the ball and socket of the arthritic hip joint.

The surgeon must remove the top part of the thighbone (known as the femur), and an implant is then placed within the central canal of the thighbone.

The surgeon then removes excess cartilage and bone from the socket part of the joint (within the pelvis), and a new socket is fitted.

This then allows free movement at the new joint.

Hop Replacement costs

The cost of hip replacement in the UK is around