PT - JOURNAL ARTICLE AU - Harvi F. Hart AU - Tuhina Neogi AU - Michael LaValley AU - Daniel White AU - Yuqing Zhang AU - Michael C. Nevitt AU - James Torner AU - Cora E. Lewis AU - Joshua J. Stefanik TI - Relationship of Patellofemoral Osteoarthritis to Changes in Performance-based Physical Function Over 7 Years: The Multicenter Osteoarthritis Study AID - 10.3899/jrheum.210270 DP - 2022 Jan 01 TA - The Journal of Rheumatology PG - 98--103 VI - 49 IP - 1 4099 - http://www.jrheum.org/content/49/1/98.short 4100 - http://www.jrheum.org/content/49/1/98.full SO - J Rheumatol2022 Jan 01; 49 AB - Objective To determine the relationship of patellofemoral osteoarthritis (PFOA) to changes in performance-based function over 7 years.Methods There were 2666 participants (62.2 ± 8.0 yrs, BMI 30.6 ± 5.9 kg/m2, 60% female) from the Multicenter Osteoarthritis Study with knee radiographs at baseline who completed repeated chair stands and a 20-meter walk test (20MWT) at baseline, 2.5, 5, and 7 years. Generalized linear models assessed the relation of radiographic PFOA and radiographic PFOA with frequent knee pain to longitudinal changes in performance-based function. Analyses were adjusted for age, sex, BMI, tibiofemoral OA, and injury/surgery.Results Linear models demonstrated a significant group-by-time interaction for the repeated chair stands (P = 0.04) and the 20MWT (P < 0.0001). Those with radiographic PFOA took 1.01 seconds longer on the repeated chair stands (P = 0.02) and 1.69 seconds longer on the 20MWT (P < 0.0001) at 7 years compared with baseline. When examining the relation of radiographic PFOA with frequent knee pain to performance-based function, there was a significant group-by-time interaction for repeated chair stands (P = 0.05) and the 20MWT (P < 0.0001). Those with radiographic PFOA with frequent knee pain increased their time on the repeated chair stands by 1.12 seconds (P = 0.04) and on the 20MWT by 1.91 seconds (P < 0.0001) over 7 years.Conclusion Individuals with radiographic PFOA and those with radiographic PFOA with frequent knee pain have worsening of performance-based function over time. This knowledge may present opportunities to plan for early treatment strategies for PFOA to limit functional decline over time.