The HOOS, JR. (Hip Disability and Osteoarthritis Outcome Score, Joint Replacement) and KOOS, JR. (Knee Disability and Osteoarthritis Outcome Score, Joint Replacement) questionnaires were used to assess patient-reported outcomes pre-operative score within 90 days of surgery and post-operative score 300-425 days after surgery.
Calculations were performed using the same approach described in the 2025 American Joint Replacement Registry (AJRR) Annual Report. Only patients who completed questionnaires at both time points were included in the analysis. These results reflect outcomes across Sutter Health acute care hospitals following elective primary hip and knee replacement surgery.
Meaningful improvement was calculated by minimal clinical important difference (MCID). MCID was determined to be a positive change score of half the pooled standard deviation. Cases statistically incapable of achieving MCID due to a high preoperative score were excluded.