New Mayo Study: 30% of THA Patients Will Need 2nd THA

“So if I have this hip replaced, what are the chances I will need the other hip done later on?” That is one of the questions that a team of Mayo Clinic researchers wanted to answer. Their study, “Subsequent Total Joint Arthroplasty After Primary Total Knee or Hip Arthroplasty: A 40-Year Population-Based Study,” was published in the March 1, 2017 edition of The Journal of Bone and Joint Surgery.

Daniel Berry, M.D. is the L.Z. Gund Professor of Orthopedic Surgery at Mayo Clinic. A co-author on the study, Dr. Berry told OTW, “Patients routinely want to know their chances of having to have their other knee or hip replaced someday. We wanted to be able to provide them with definitive answers.”

The study consisted of patients who underwent primary total hip arthroplasty (THA – 1,933) or total knee arthroplasty (TKA – 2,139) between 1969 and 2008.

Dr. Berry, a past president of the American Academy of Orthopaedic Surgeons, stated, “It is not necessarily intuitive that if someone has a hip replacement on one side then there is a modest chance of needing a knee replacement on the same or the opposite. We found that 30% of patients undergoing THA will need their opposite hip to be replaced later. For those undergoing TKA, 45% will likely need the other knee replaced at a later date. We also found that if someone has a hip replaced on one side the chances of needing a contralateral knee replacement were twice as high as needing an ipsilateral knee replacement. The reasons for this are not necessarily intuitive, but may relate to gait changes before or after the THA.”

“We also found that younger patients were more likely to have THA on both sides; but younger age at a first TKA was not associated with a different risk of subsequent contralateral TKA. Regarding the bilateral hip findings, this may be due to bilateral disease processes that selectively affect the young hip, such as osteonecrosis, or structural hip problems, such as acetabular dysplasia or femoroacetabular impingement.”

Asked what most orthopedic surgeons have been telling patients to date, Dr. Berry noted, “We have been taking our best educated guesses based on personal experience and the available literature. This study, however, provides longer-term data that was captured via the National Institutes of Health-funded Rochester Epidemiology Project. Now, we have more concrete longer term information for patients.”