The course of foot OA
During 18 months of prospective follow-up in CASF, subjects with isolated first MTP joint or polyarticular foot OA showed no clinically meaningful change in symptoms (Arthritis Care Res [Hoboken]. 2018 Jul;70[7]:1107-12).
But that finding may have been a function of the relatively brief follow-up, as the Chingford 1000 Women Study, with its 19 years of prospective follow-up, told a different story. Dr. Gates, of the University of Southampton (England), reported that among the 193 patients with foot x-rays at both baseline and follow-up, by which point they averaged nearly 76 years in age, 33.2% had OA of the first MTP joint of either foot at baseline as defined by at least a grade 2 score on the LaTrobe foot atlas, and 13% had prevalent involvement of both feet. During 19 years of follow-up of the women from Chingford, an area in northeast London, the incidence of new-onset radiographic first MTP joint OA was 7% in the left foot and 17% in the right. Meanwhile, progression to grade 3 radiographic OA occurred in the left foot of 28% of those with grade 2 disease at baseline and in 35% of those with baseline first MTP joint OA of the right foot. Twenty-eight percent of patients with unilateral first MTP joint OA at baseline progressed to bilateral involvement within 19 years.
Dr. Gates reported having no financial conflicts regarding the Chingford study, funded primarily by Arthritis Research UK, which merged with Arthritis Care in 2018 to form Versus Arthritis.
Similarly, Dr. Marshall reported no financial conflicts regarding CASF, also funded by Arthritis Research UK.
SOURCES: Marshall M. Osteoarthritis Cartilage. 2019 Apr;27[suppl 1]:S16, Abstract I-8 and Magnusson K et al. Osteoarthritis Cartilage. 2019 Apr;27[suppl 1]:S260-S261, Abstract 367.