Incidence, prevalence, natural course and prognosis of patellofemoral osteoarthritis: the Cohort Hip and Cohort Knee study

• Published in: Osteoarthritis and cartilage Vol. 25; no. 5; pp. 647 - 653
• Main Authors: Lankhorst, N.E, Damen, J, Oei, E.H, Verhaar, J.A.N, Kloppenburg, M, Bierma-Zeinstra, S.M.A, van Middelkoop, M., PhD
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2017
• Subjects: Aged; Cohort; Cohort Studies; Disease Progression; Female; Humans; Incidence; Knee; Logistic Models; Male; Middle Aged; Multivariate Analysis; Netherlands - epidemiology; Osteoarthritis; Osteoarthritis, Knee - diagnostic imaging; Osteoarthritis, Knee - epidemiology; Osteoarthritis, Knee - physiopathology; Pain Measurement; Patellofemoral joint; Patellofemoral Joint - physiopathology; Physical Examination - methods; Prevalence; Prognosis; Radiography - methods; Range of Motion, Articular - physiology; Rheumatology; Risk Assessment; Severity of Illness Index; Surveys and Questionnaires; Tibiofemoral joint; knee; tibiofemoral joint; cohort; patellofemoral joint; osteoarthritis; Knee; Patellofemoral joint; Cohort; Osteoarthritis; Tibiofemoral joint
• ISSN: 1063-4584; 1522-9653
• DOI: 10.1016/j.joca.2016.12.006

Summary Objective To examine the proportion of isolated patellofemoral osteoarthritis (PFOA) compared to tibiofemoral OA (TFOA) in middle-aged participants with early OA symptoms of the knee; to describe the natural course of PFOA compared with that of TFOA and to identify whether patients with PFOA have a different phenotype compared to patients with TFOA, or with combined PFOA and TFOA (COA). Design Participants with early OA symptoms of the knee were selected, completed questionnaires, underwent physical examination, and had knee radiographs at baseline, and at 2 and 5 years follow-up. Based on radiographs, participants were classified as having isolated TFOA, isolated PFOA, COA, or no radiographic OA. Multivariate logistic regression was used to identify participant characteristics associated with a specific group of OA at 2 years follow-up. Results The cohort comprised 845 participants (mean age 55.9 years). At baseline, 116 had PFOA, none had TFOA or COA. Of these 116 participants, 66.3% had developed COA at 5 years follow-up. At 2 years follow-up, PFOA, TFOA and COA were present in 77 (10.8%), 39 (5.5%) and 83 (11.6%) participants, respectively. Multivariate regression analyses at 2 years follow-up showed that participants with radiographic PFOA or TFOA were not significantly different from each other with respect to signs and symptoms. Conclusions These results suggest that OA is more likely to start in the patellofemoral joint and then progress to COA in individuals with symptoms of early knee OA. No differences in TFOA and PFOA phenotypes were determined with respect to signs and symptoms.