Total Hip Joint Replacement
You Don’t Have to Live with Joint Pain
Your joints are involved in almost every activity you do. Simple movements such as walking, bending, and turning require the use of your hip and knee joints. Normally, all parts of these joints work together and the joint moves easily without pain. But when the joint becomes diseased or injured, the resulting pain can severely limit your ability to move and work. Osteoarthritis, one of the most common forms of degenerative joint disease, affects an estimated 43 million people in the United States.1 Whether you are considering a total joint replacement, or are just beginning to explore available treatments, this website is for you. It will help you understand the causes of joint pain and treatment options. Most importantly, it will give you hope that you may be able to return to your favorite activities.
Once you’re through reading this website, be sure to ask your doctor any questions you may have. Gaining as much knowledge as possible will help you choose the best course of treatment to relieve your joint pain — and get you back into the swing of things.
What is a Hip Joint?
Your hip joint is a ball-and-socket joint, formed by the ball, or femoral head, at the upper end of the thighbone, and the rounded socket, or acetabulum, in the pelvis. The bone ends of a joint are covered with a smooth, tough material called cartilage. Normal cartilage cushions the bones and allows nearly frictionless and pain-free movement. The rest of the surfaces of the joint are covered by a thin, smooth tissue lining called the synovium. The synovium produces fluid that acts as a lubricant to reduce friction and wear in the joint.
Common Causes of Joint Pain
Osteoarthritis (OA)
Sometimes called degenerative arthritis because it is a “wearing out” condition involving the breakdown of cartilage and bones. When cartilage wears away, the bones rub against each other, causing pain and stiffness. OA usually occurs in people aged 50 years and older, and frequently in individuals with a family history of arthritis.
Rheumatoid Arthritis (RA)
Causes the synovium to become thickened and inflamed. In turn, too much synovial fluid is produced within the joint space, which causes a chronic inflammation that damages the cartilage. This results in cartilage loss, pain, and stiffness. RA affects women about 3 times more often than men, and may affect other organs of the body.
Post-traumatic Arthritis
May develop after an injury to the joint in which the bone and cartilage do not heal properly. The joint is no longer smooth and these irregularities lead to more wear on the joint.
Avascular Necrosis
Can result when bone is deprived of its normal blood supply. Without proper nutrition from the blood, the bone’s structure weakens and may collapse and damage the cartilage.
Paget’s Disease
A bone disease that often affects the hip. Bone formation is sped up, causing the density and shape of the bone to change. Joint pain can also be caused by deformity or direct injury to the joint. In some cases, joint pain is made worse by the fact that a person will avoid using a painful joint, weakening the muscles and making the joint even more difficult to move.
Treatment Options
Following the orthopaedic evaluation, your orthopaedic surgeon will review and discuss the results with you. Based on his or her diagnosis, your treatment options may include:
- Medication
- Joint fluid supplements
- Physical therapy
- Joint replacement
Total Hip Replacement
Hip replacement is one of the most important surgical advances of this century. This surgery helps more than 300,000 Americans each year1 to relieve their pain, and get back to enjoying normal, everyday activities. Hip replacement involves the removal of arthritic bone ends and damaged cartilage and replacing them with prosthetic implants that replicate the hip joint.
Hip replacement surgery may be considered when arthritis limits your everyday activities such as walking and bending, when pain continues while resting, or stiffness in your hip limits your ability to move or lift your leg. Hip replacement may be recommended only after careful diagnosis of your joint problem. It is time to consider surgery if you have little pain relief from anti-inflammatory drugs or other treatments, such as physical therapy, do not relieve hip pain. Hip replacement can help relieve pain and get you back to enjoying normal, everyday activities.
Total hip replacement is often reserved for patients who:
- Have a painful, disabling joint disease of the hip resulting from a severe form of arthritis
- Are not likely to achieve satisfactory results from less invasive procedures, such as arthrodesis (artificial stiffening or fixation of the joint)
- Have bone stock that is of poor quality or inadequate for other reconstructive techniques
In a total hip replacement operation, the surgeon replaces the worn surfaces of the hip joint with an artificial hip joint. The worn head of the femur (thigh bone) is replaced with a metal or ceramic ball mounted on a stem; the stem is placed firmly into the canal of the thigh bone at its upper end. The acetabulum (hip socket) is prepared and implanted with a metal cup and plastic or ceramic insert. The ball and insert glide together to replicate the hip joint.
Total Hip Implants
The conventional arrangement of a metal ball into a special plastic (polyethylene) cup has been shown to have positive results over the years. How long it will last depends not only on age, but also on a patient’s activity level.
Another factor that may affect the durability of a total hip replacement is the bearing surface. The bearings are the two parts of the artificial hip that glide together throughout motion. These bearings can be metal-on-polyethylene, metal-on-metal, ceramic-on-polyethylene or ceramic-on-ceramic.
Technologies That May Impact Implant Performance
There have been significant advancements in improving the bearing surfaces in total hip replacement. Ceramic-on-ceramic bearings provide superior wear performance.1 Stryker’s ceramic-on-ceramic system has demonstrated significantly lower wear than metal-on-polyethylene systems in the laboratory; therefore, it is anticipated that these improved wear characteristics may extend the life of the implant.
There are also new, advanced polyethylene implants available that have demonstrated extremely low wear in the laboratory, and they are expected, over time, to have similar wear performance clinically.2
Your physician will discuss the exact type of prosthesis and surgical procedure with you.
Complications of Hip Replacement
As with any surgery, there is risk of complications after hip replacement surgery. However, they are relatively rare. Blood clots are the most common complication after surgery. Your orthopaedic specialist may prescribe one or more measures to prevent a clot from forming in your leg veins. These measures may include special support hose, inflatable leg coverings and blood thinners.
Recovery
Generally, after hip replacement surgery, you may spend approximately 3 to 5 days in the hospital. Most hip replacement patients begin standing and walking with the help of a walker and a physical therapist the day after surgery.
Recovery varies with each person. It is essential that you follow your orthopaedic surgeon’s instructions regarding home care during the first few weeks after surgery; especially the exercise program you are prescribed. You should be able to resume many normal light activities of daily living within 3 to 6 weeks following surgery. Some discomfort with activity, and at night, is common for several weeks. Complete recovery can take from about 3 to 6 months.
While most people will gradually increase their activities and play golf, doubles tennis, shuffleboard or bowling, you will be advised to avoid more active sports, such as jogging, singles tennis and other high impact activities.
You Don’t Have to Live with Severe Hip Pain
You don’t have to live with severe hip pain and the limitations it puts on your activities. If you haven’t experienced adequate relief with medication and other conservative treatments, Hip Joint Replacement may provide the pain relief you long for and enable you to return to your favorite activities. Remember, even if your doctor recommends hip replacement for you, it is still up to you to make the final decision.
For more information contact your doctor.
The Trident® Ceramic Acetabular System
System Description
The Trident® Ceramic Acetabular System is an artificial hip replacement device that features a new, state-of-the-art ceramic-on-ceramic bearing couple. The artificial hip replacement device consists of four basic components: an alumina ceramic insert (socket liner), an alumina ceramic femoral head (ball), a metal acetabular shell (socket), and a metal femoral stem (hip stem).
The hip stem is inserted into the top of the thighbone. The ball fits onto the top of the hip stem. The socket liner and mating socket are fixed to the hip joint. The ball and socket articulate together.
The Trident® implant has bearing surfaces (the ball and socket) made of alumina ceramic. Laboratory testing of alumina ceramic has shown it to have less wear than the metal and plastic materials that are currently used in total hip surgery. Alumina ceramic is extremely hard — in fact, its hardness is second only to diamond — and provides excellent lubrication between the ball and socket. Because of its material characteristics, alumina ceramic-on-ceramic demonstrates significantly lower wear versus conventional metal-on-plastic components in laboratory testing. Therefore, it is anticipated that these improved wear characteristics will extend the life of the implants.
Purpose of the Device
This total hip replacement is indicated for patients with painful, disabling hip joint disease caused by a severe form of arthritis. This total hip replacement should not be used for patients:
- Who may have an infection in or near the hip joint
- Who are unable to comply with the instructions for preparing for and recovering from the surgery
- Who do not have enough healthy bone to support fixation of the implants
- Whose bones are not fully grown
Clinical Experience
Howmedica Osteonics Corp. (hereafter referred to as Stryker Orthopaedics) conducted a clinical study in the United States for its ceramic-on-ceramic hip system, which was conducted under a study protocol approved by the United States Food and Drug Administration. The study was performed at 16 orthopaedic centers of excellence across the United States. The clinical study was conducted for Stryker Orthopaedics’ first generation ceramic-on-ceramic design (called the ABC System), and second generation ceramic-on-ceramic design (called the Trident® System). In all, the data from 558 hip replacement surgeries (cases) with these ceramic-on-ceramic bearings were evaluated.
The prospective, randomized, clinical study began in 1996, with 349 cases with the first-generation ceramic-on-ceramic systems, and 165 cases with a control device (conventional, metal-on-polyethylene). The clinical data on these cases were evaluated out to 24 months (2 years) after surgery. In 1999, the patented Trident® Ceramic System was then entered into the study. This patented design offers a stronger, easier-to-use ceramic liner design. Two hundred nine (209) Trident® inserts were implanted in the study. The clinical data from these cases has also been evaluated out to 24 months (2 years) after surgery.
The Trident® System features the identical ceramic-on-ceramic articulating bearing surface as the ABC System; however, the Trident® System features an outer titanium sleeve. The titanium sleeve offers the following unique advantages over other first generation ceramic-on-ceramic designs:
- Increases the strength of the ceramic insert by 50%: The Trident® Alumina Insert is the strongest ceramic insert on the U.S. market today.
- Protects the insert rim from chipping during implant assembly: Occasional chipping of the insert rim during surgery was reported during clinical studies of first-generation designs. No Trident® ceramic implants chipped or fractured in the study.
- Allows reassembly of the acetabular shell to the insert: First generation designs prohibit reassembly of a ceramic insert to its shell, making insert adjustment or replacement more difficult.
Safety Data
Safety of the ceramic-on-ceramic hip systems was established by studying the adverse (unfavorable) events within the clinical study. The adverse events experienced by patients who received the ceramic-on-ceramic hip systems (test group) were comparable to the adverse events experienced by patients who received a conventional, metal-on-polyethylene hip system (control group). There were no deaths in the test or control study groups. Additional surgery to replace or remove components occurred 4 times in the Trident® ceramic-on-ceramic group, as compared to 5 times in the metal-on-poly (control group). Analysis of the adverse event data demonstrated that there was no significant difference between the adverse events experienced in the test and control groups.
Effectiveness Data
The effectiveness of the Trident® ceramic-on-ceramic systems was established by comparing the Harris Hip Scores (HHS) and the radiographic (X-ray) measurements of patients who received the ceramic-on-ceramic systems to those of patients who received the metal-on-polyethylene (control) hip system.
Pain and Function Improvement
The Harris Hip Score is a scale from 1-100 that assesses a patient’s level of pain and function. The highest possible score (100) indicates pain relief and normal functional ability. The lowest possible score (0) indicates severe pain and disability. A score of 90-100 is considered excellent. At two years after surgery, the average Harris Hip Scores for the ceramic-on-ceramic group and for the control group were both in the excellent range.
