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Metal on Metal

This is the original McKee-Farrar total hip.

Total hips in which a metal ball is placed into a metal socket have been used for over 60 years. However, early designs were made of poor materials and were not well made. They also did not have bone ingrowth technology. Despite this, there are cases in which these hips lasted 40 or more years.

Modern metals of chrome-cobalt-molybdenum and modern manufacturing techniques have led to the production of extremely durable implants. Dr. Clyburn has been using metal on metal implants for over 12 years. He has not had a single patient who has worn out the metal on metal articulation. In fact, in polyethylene hips, a gradual wearing away of the plastic can be seen on x-ray. With metal on metal, no evidence of wear has been seen in several thousand patients. The metal ball can be made in large diameters which are very similar to the natural femoral head. This results in increased range of motion and a reduced risk of dislocation. Many patients report a very natural feel of the hip. The metal on metal ball and socket in use today attaches to an uncemented, porous coated stem. Dr. Clyburn usually uses stems which are proven to have good results over many years. He tends not to choose the "latest and greatest" designs.

This is a close up picture of a total hip stem showing how the bone has grown into the porous metal of the implant. The implant has become part of the patient.

Over his 23 years in practice, he has seen many examples of the latest and greatest technology which actually led to catastrophic failures. Both the Unispacer Knee and the Sulzer Total Hip were widely advertised and touted to be the latest and greatest boon to patients. However, they failed and the company no longer exists.

Read the article on Metal On Metal on the University Health Science Center at Houston's website.