You are exactly right and thank you for the warning. All patients should be aware that the risk of osteolysis (bone loss) increases over time after hip (and knee) joint replacements. The main reason for this is wear and tear as a result of an active lifestyle. Men tend to be affected more often than women.
One other risk factor is the type of implant used. Certain types of implants are more likely to shed metal debris with use. The first ultra-high molecular-weight polyethylene (UHMWPE) implant components (parts) used tend to wear out faster than the newer highly cross-linked UHMWPE implants. So anyone with the conventional UHMWPE should be assessed for sure.
Not everyone with osteolysis has symptoms (pain, swelling, loss of motion), especially early on. The only way to know for sure if there is any bone loss is to take an X-ray. Osteolytic lesions look like someone took a bite out of the bone. But X-rays are only a two-dimensional view of a three-dimensional object. So although they show there is a problem, X-rays aren’t enough to tell the surgeon the full extent of the defect.
That’s where CT scans and MRIs come in. Sometimes both types of imaging studies are needed. That’s because they show different structures: CTs scan the bones whereas MRIs are better at showing changes in the surrounding soft tissues.
But does everyone need all of these tests? Not really. The timeline (beginning five years after the patient gets the hip) is the first criteria for testing. Other risk factors mentioned (age, gender, activity level) must be taken into consideration as well.
Anyone who is concerned about this problem and/or who may be at increased risk should talk with their surgeon about their need for follow-up X-rays. Since these kinds of complications don’t develop until five years or more after the joint replacement surgery, earlier screening is not likely necessary.