RA patients are more likely to be re-admitted to hospital after joint replacement than OA patients. The large registry study showed a rise in 90-day readmissions in RA patients over three years at 5.8%, 8.9% and 10.6% for 2009, 2010 and 2011. For OA patients’ admissions remained similar at 6.7%, 6.7% and 6.8%. Medications and pre and postoperative rehabilitation programs could be to blame, said the Chinese and US researchers.