What happens to the other knee or hip in osteoarthritis patients after their first knee or hip replacement

In a follow-up of 5,352 patients with idiopathic osteoarthritis, the mean follow-up duration was 17.8 years.

• After a total knee arthroplasty (TKA), 46.0% of patients underwent a contralateral TKA.
• Only 2.3% of patients had an ipsilateral total hip arthroplasty (THA) following a TKA.
• 1.3% of patients received a contralateral THA after an initial TKA.
• Following an initial THA, 30.5% of patients had a contralateral THA.
• 6.8% of patients underwent an ipsilateral TKA after an initial THA.
• Cox regression analysis indicated that a higher body mass index (BMI) was the only risk factor for a second THA.

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