X-ray (Radiographic) Measurements
X-rays were reviewed at regular intervals after surgery to look for signs of possible device loosening, device movement, or accelerated wearing away of the components. At two years after surgery, all of the 185 Trident® cases evaluated were considered a radiographic success. No devices showed signs of device loosening, device movement, or accelerated wearing away of the components.
Patient Success Rates
A patient was considered a success within the study if, at two years after surgery, the hip implant system was still in place (had not been replaced), the Harris Hip Score was greater than 70 points, and there were no X-ray signs that might indicate loose or unstable hip implant components. The patient success rate for the control group was 94%. The patient success rate for the Trident® ceramic-on-ceramic group was 97%.
Use for Inflammatory Joint Disease
The study results presented above include only patients who had primary total hip replacement for severe, non-inflammatory degenerative joint disease. Eight additional cases of inflammatory joint disease were enrolled in the study, and received a ceramic-on-ceramic system (either ABC or Trident®). The eight cases have been followed for a mean duration of 16 months. As of the latest functional evaluations, the mean HHS is 94 (range 85-100). There have been no reoperations or revisions. There have been no operative hip-related complications. All components appear stable on X-ray.
The goals of artificial hip replacement include relief of pain, restoration of function, and correction of deformity. Ceramic-on-ceramic, however, demonstrates significantly lower wear versus conventional metal-on-plastic components in laboratory testing. Therefore, it is anticipated that these improved wear characteristics will result in a longer lasting implant.
Any artificial hip replacement may be associated with serious complications. These include dislocation, loosening, implant breakage, bone fracture, reaction to the implant’s materials, bone loss, change in the length of the treated leg, pain, hip stiffness, excessive bleeding, hip joint fusion, nerve damage, allergic reaction to medical and/or blood transfusion, infection, reactions to pain relieving drugs, blood clots in the legs and/or lungs, amputation, heart attack, pneumonia, excessive wear of the implant’s components, decrease of bone mass, and audible sounds during motion.
With this ceramic-on-ceramic system, sudden breakage of ceramic components resulting from excessive forces is possible; however, no ceramic component broke during the clinical study. Corrosion (eroding) between the insert and shell may be possible; however, this event was not demonstrated in the clinical study, and laboratory tests have shown the potential to be minimal.
Any of the above-cited complications may require medical intervention, including additional surgery. In rare instances, complications may lead to death. Please ask your surgeon to discuss with you any of these complications that are not familiar to you.
Call your doctor if you experience any of the following symptoms:
Consult your doctor regarding considerations before surgery, rehabilitation after surgery, and expectations for surgery. It is important to begin planning for your return home from the hospital before your surgical procedure. Your surgeon may suggest tips to prepare your home for after surgery. For example, get an apron or belt with pockets to carry things while you are on crutches, buy or borrow a cordless phone, remove scatter rugs and other obstacles to safe transport using crutches, have high chair and commode accessories available. Above all, during this time, treat yourself well, eat balanced meals, get plenty of rest, and if requested by your surgeon, donate your own blood so it can be transfused during and after surgery.
After surgery you will need to rest your hip to allow proper healing. Your activity will be restricted during this healing period. During the first weeks after surgery, you may be advised to put a pillow between your legs when turning over in bed, wear elastic stockings, use raised toilet seat, take showers rather than baths, restrict activities such as sudden twisting or turning, crossing legs, exposing the scar to sunlight, and driving. Follow carefully your doctor’s instructions regarding progression to normal weight bearing and resumption of normal physical activity. Individual results will vary and all patients will experience different activity levels post-surgery.
Even after the healing period, excessive loads placed on the implants through sudden trauma or high impact activities, such as running and jumping, can damage the artificial joint. While the expected life of an artificial hip replacement system is difficult to estimate, it is finite. The components are made of foreign materials that will not indefinitely withstand the activity level and loads of normal, healthy bone. The hip joint may have to be replaced at some time in the future.
Other options may include use of a conventional hip replacement system, other surgical procedures that do not replace the hip joint, or non-surgical treatments based on pain management and activity restriction. Your doctor can explain these alternatives, and help you decide which treatment is best for your condition.
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