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FAQ

How safe are Zimmer’s hip systems?

1. Information on the approval process in Europe

2. Information on the approval process in the Asian-Pacific Region

1. Information on the approval process in Europe

Hip replacement is one of the most successful clinical treatment methods[i]. It can enormously improve the quality of life of patients who are in the late stages of osteoarthritis. Before an implant is put into clinical use in Europe, it undergoes a multiple-year development cycle and many tests. These tests are subject to internationally recognised standards and guidelines. Only then can a product receive a CE mark. The product launch process can vary per country. Different than with medicinal products, the doctor has a lot more influence on the final treatment result. Just like all manufacturers, Zimmer ensures correct handling of its implants by means of comprehensive surgical instructions and training.

[i] Lancet 2007; 370: 1508–19; Published Online March 29, 2007 DOI:10.1016/S0140- 6736(07)60457-7

2. Information on the approval process in the Asian-Pacific Region

Hip replacement is one of the most successful clinical treatment methods[i]. It can enormously improve the quality of life of patients who are in the late stages of osteoarthritis. Before an implant is put into clinical use in Asia Pacific, it undergoes a multiple-year development cycle and many tests. These tests are subject to internationally recognised standards and guidelines. In addition, these implants are subjected to the necessary approval processes prior to their supply in the respective Asia Pacific countries/region. Different than with medicinal products, the doctor has a lot more influence on the final treatment result. Just like all manufacturers, Zimmer ensures correct handling of its implants by means of comprehensive surgical instructions and training.

[i] Lancet 2007; 370: 1508–19; Published Online March 29, 2007 DOI:10.1016/S0140- 6736(07)60457-7
How are incidents with implants reported?

Zimmer, as well as its local distributors are obliged to report incidents with their implants . Depending on country, not every notification  is made public, sometimes only if corrective measure become necessary.

How long will an artificial hip joint last?
Normally, an endoprosthesis will last many years before it has to be replaced due to regular deterioration. It is difficult to give a precise number because the durability of a prosthesis depends on many factors. These factors include the prosthesis design, the surgical technique, the patient’s clinical picture and other individual patient factors (lifestyle, activity level, gender and bone quality)[i]. For example, studies have shown a survival rate for hip prostheses of 95% after at least 10 years in patients implanted older than 75 years of age. This means that only 5% of the hip stems investigated in the study had to be replaced before 10 years were up[ii],[iii]. However, these findings and figures cannot be applied across the board to all prostheses and to all individual cases.

[i] Int Orthop. 2008 October; 32(5): 597–604. Published online 2007 April 19. doi:  10.1007/s00264-007-0364-3
[ii] Furnes O, Lie SA, Espehaug B, et al. Hip disease and the prognosis of total hip replacements. A review of 53,698 primary total hip replacements reported to the Norwegian Arthroplasty Register 1987–99. J Bone Jnt Surg Br. 2001;83(4):579–586. doi: 10.1302/0301-620X.83B4.11223.
[iii] Older J. Charnley low-friction arthroplasty: a worldwide retrospective review at 15 to 20 years. J Arthroplasty. 2002;17(6):675–680. doi: 10.1054/arth.2002.31973.
Which complications can occur during a hip joint implantation?

As with all medical interventions, complications cannot be entirely ruled out with hip replacement. Complications such as haematomas, swelling, loosening, pain, inflammation or bone fractures can always occur, regardless of the prosthesis used. They are very well-known and well-researched. Many factors can cause complications as these[i]: Among other things, the prosthesis design, the surgical technique, the indication and individual patient factors such as advancement of the underlying disease (most severe osteoarthritis at an advanced age).


[i] Older J. Charnley low-friction arthroplasty: a worldwide retrospective review at 15 to 20 years. J Arthroplasty. 2002;17(6):675–680. doi: 10.1054/arth.2002.31973.
What are Zimmer’s artificial hip joints made of?

For hip stems anchored with cement, high quality cobalt-chrome alloys are used and titanium alloys are used for cementless implants. The following combinations are available for the articulations (ball head and socket insert): Metal or ceramic head with polyethylene socket insert (inlay), ceramic head with ceramic inlay and metal head with metal inlay.

In principle, materials that are very well tolerated by the human body and resistant to deterioration are used in order to contribute to the longest prosthesis service life possible. 

What are metal-on-metal hip systems and how often are they used?

With metal-on-metal systems, a metallic femoral head slides into a socket insert made of the same material. Metal-on-metal combinations are also used for resurfacing. Metal-on-metal systems make up a relatively small percentage of all hip replacements worldwide; at Zimmer they constitute less than 3% of all Zimmer hip systems.

Are there material combinations that don’t produce any wear?
Just like in a natural joint, all implant systems will experience a certain amount of deterioration, and hence wear, depending on the material used. Some combinations are known for being particularly resistant to friction but may possibly have other properties that make them less suitable for certain patient groups[i]. However, the degree to which a joint deteriorates is also influenced by factors that have nothing to do with material. These factors include precise implant placement and how carefully the patient treats his implant. Essentially, decreasing deterioration and wear is the focus of Zimmer’s Research and Development department. The goal is to continue developing increasingly low-deterioration materials that can contribute to a longer and longer service life for the prosthesis.

[i] Kuntz M, Validation of a New High Performance Alumina Matrix Composite for use in Total Joint Replacement. Seminars in Arthroplasty, 2006; 17: 141-145
When does an implant need to be replaced?

The most frequent reason for replacing an implant is when it becomes loose in the bone. This is called aseptic loosening and it generally occurs after many years in the normal life cycle of the prosthesis[i]. When a prosthesis needs to be replaced earlier than expected, this is most often due to inflammations or recurring dislocations of the femoral head from the hip socket (also called luxation)[i]. For the patient, this can make itself known through pain or new limitations in mobility, for example. In this case, the patient should contact their physician. It is also important to attend regular check-ups, even if there are no problems. The treating doctor can then assess the healing progress and detect any possible complications early on.


[i] Older J. Charnley low-friction arthroplasty: a worldwide retrospective review at 15 to 20 years. J Arthroplasty. 2002;17(6):675–680. doi: 10.1054/arth.2002.31973.
Which implant is suitable for which patients?

The surgeon decides which system and which material composition is best suited for the patient based on many factors, such as the patient’s general state of health, gender, age, weight, mobility, physical activity and bone quality. The same applies to the surgical technique used – not every surgical technique and not every implant is equally well-suited for all patients.

How do I know which implant I received?

You will discuss which implant you will receive with your doctor before the surgery. After the operation, every patient will receive an endoprosthesis pass, which states which prosthetic components the patient received, when and where. Patients should always carry this document with them, if possible, so that doctors and physical therapists can be informed of the patient’s condition. This document can also be important during airport security checks in some circumstances. You can find out more by clicking on the image on the right hand side of this page.

Can implants cause allergies?
Allergies against the metal alloys of an artificial joint are rather rare[i]. Nevertheless, you should inform your doctor in plenty of time before the operation if you have a known allergy to certain materials and substances such as chrome or nickel, because hip and knee prostheses made of metal alloys can contain nickel. More information on this subject can be obtained from the Workgroup for Allergological-Immunological Aspects of Implant Material Tolerance (AllergoMat) of the Clinic and Polyclinic for Dermatology and Allergology of the Ludwig-Maximilian University in Munich.

[i] Silva M, et al: Metal-on-Metal Total Hip Replacement. Clin Orthop Rel Res 430, 2005, 53–61
What is known about elevated metal ion levels in the blood?

The effects of elevated blood metal ion levels are currently the subject of scientific discussion. Conclusive recommendations and conclusion are not yet available at this time. Here you can find more information about a recently published study on the topic.

Are there alternatives to joint replacement?
Advanced osteoarthritis, the pathological deterioration of articular cartilage, often causes pain and limited mobility. Of course, this diagnosis does not always necessitate an artificial joint. However, if conservative measures are no longer able to adequately alleviate pain and limitations in mobility and the patient is experiencing a deterioration of his entire quality of life, then an artificial joint can be an option. It is important to obtain comprehensive medical advice in order to decide whether joint replacement is a possibility. Osteoarthritis is not curable with the treatment methods we have available today.
When is the right time for an artificial hip?
This question cannot be answered across the board. Because every hip prosthesis has a limited service life and will have to be replaced eventually, joint replacement is usually considered to be the last option for cases of severe osteoarthritis. The decision as to when the right time has come can only be made by the patient in close consultation with his treating doctor. One factor that plays a role is the adverse effect on the quality of life experienced by the patient caused by the disease.