Tissue damage could be behind pain in hip implants

Dr Mark Figgie and Dr Timothy Wright discuss a hip implant model

  The cause of unexplained pain in people who have had metal-on-metal hip implants is more likely to be tissue damage than the wear of the implant. A team from the Hospital for Special Surgery in the US wanted to find the causes of unexplained pain in people who had metal-on-metal hip implants who had come to their hospital for revision surgery.

They compared 50 people who needed surgery because of unexplained pain to a control group of 48 people who needed surgery because of loosening, malalignment, infection or fracture.

Results showed that 60% of the unexplained pain group had moderate to high adverse tissue reactions and 12% had some build-up of metal deposits in their soft tissue. Ten times as many people in the unexplained pain group had high-grade tissue damage scores compared to the control group.

Dr Timothy Wright who was involved in the research highlights that metal-on-metal implants have potential advantages but they do fail due to unexplained pain.

“We found that some patients had a significant amount of tissue damage but not a lot of wear, suggesting that factors other than wear are contributing to the problem regardless of whether the patients have pain,” he says. “We have used the information from our study to develop guidelines for patients and surgeons.”

Hip implant patients with unexplained pain should be followed closely by their surgeon as early identification of patients with unexplained pain is vital to avoid significant tissue damage.