Patients with persistent midfoot pain, but no radiological evidence of osteoarthritis, might have under-recognized disease in the second and third cuneiform metatarsal joints, according to data published in Arthritis Care and Research.
“We hypothesized that people with midfoot OA and those with persistent midfoot pain without radiographic OA would exhibit a greater prevalence of MRI structural abnormalities compared to asymptomatic controls,” John B. Arnold, PhD, of the Leeds Institute of Rheumatic and Musculoskeletal Medicine at the University of Leeds, in the United Kingdom, and co-authors wrote. “The first aim of this study was, therefore, to compare assessed structural abnormalities in people with symptomatic midfoot osteoarthritis (OA), those with persistent midfoot pain but confirmed absence of radiographic OA, and asymptomatic adults.”
To investigate the connection between MRI imaging and foot-related disability, researchers conducted a cross-sectional study involving three groups of patients. Group one included patients with symptomatic and radiographically confirmed midfoot osteoarthritis. Group two consisted of patients with persistent midfoot pain but an absence of radiographic evidence. Group three consisted of asymptomatic adults with no foot symptoms, used as the control. Patients were recruited between June 2009 and February 2011, as well as between December 2017 and August 2018.
Participants with symptomatic OA were aged older than 40 years and demonstrated midfoot pain for more than 3 months. The study included participants whose pain was an average of three or higher on an 11-point scale following weight-bearing activities, the authors wrote. Standard radiographic imaging showed no evidence of OA. Exclusion criteria for these patients included the presence of more than 30 minutes of early morning stiffness in the feet, the presence of inflammatory arthritis, muscle or other connective tissue diseases and neurological conditions including diabetes.
The researchers examined the midfoot joints of each participant’ most painful feet using a 3T MR system. Pain over the previous 24 hours was documented using a 100 mm visual analog scale. Disability relating to the foot was measured using the Manchester Foot Pain and Disability Index, a 19-question survey assessing pain and disability in the impacted foot.
In total, 50 patients were included following eligibility for midfoot OA; 22 were eligible and included in the midfoot pain group, and 35 healthy control patients were included. Bone marrow lesion severity sum-scores were greater in people who noted midfoot pain and had no signs of OA in X-ray imaging (P = .007), according to the researchers. Single-variable models demonstrated that bone marrow lesions, joint space narrowing and subchondral cysts were associated with higher levels of pain (P < .01). MRI anomalies did not associate with pain in multivariable analyses.
“This study found that structural abnormalities of OA not visible on plain-film X-ray, such as [bone marrow lesions (BMLs)], were associated with persistent midfoot pain in people without radiographic OA, as well as symptomatic, radiographic OA,” Arnold and colleagues wrote. “The location and pattern of BML involvement was consistent with elevated mechanical loading, highlighting the potential role for treatments that reduce midfoot bone stress in the treatment of midfoot pain and OA.”