Metal-on-metal hips frequently revised due to ion levels, lingering pain

ORLANDO, Fla. — Elevated metal-ion levels, loose cups either radiographically or clinically and psychological changes are among the indications orthopedic surgeons need to consider for the revision of metal-on-metal hip articulations, according to a presenter at a recent meeting.

“You do not have to worry much about the patient who has ions below 10 [parts per billion], no clinical symptoms and a good X-ray,” Lawrence D. Dorr, MD, said during his presentation. “If you have an X-ray that has evidence of radiolucent lines around the entire cup, then you have a patient who you have to worry about — with or without symptoms. They could get progressive loosening. You need to follow them at a 6-month interval.”

Dorr said elevated metal-ion levels, especially cobalt, mean increased wear so local osteolysis and bone destruction are risk factors with increased follow-up. For patients with metal-ion levels greater than 10 parts per billion (ppb) and clinical symptoms, he said surgeons need to decide whether to revise the patient’s metal-on-metal hip.

Click here to read the full story in the April issue of Orthopedics Today.