Foot functions in ankylosing spondylitis

Abtract: AIM: Because of the wide diversity of developmental stages in spondyloarthropathies (SpA), clinical and radiographic weak correlations are often found in the development of enthesopathies. In this study, foot functions of ankylosing spondylitis (AS) patients were analyzed with clinical and radiological features.

Method: Sixty-two AS patients and 39 age-matched, gender-matched, and body mass index (BMI)-matched healthy volunteers were included in this study. Acute-phase reactant levels of participants were recorded. The disease activity and functionality were assessed using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI). Foot functional index (FFI) and timed up and go test (TUG) were performed by the same educated nurse. Radiographically, the SpA-tarsal radiographic index (TRI) and the calcaneal inclination angle (CIA) were measured by the same physician to assess midfoot and arches.

Results: FFI subscores and total, TUG results, and CIA measurements were found to be significantly higher in the AS group (p < 0.05). FFI-pain, FFI-disability, and FFI-activity limitation subscores were significantly and positively correlated with BASDAI and BASFI scores (p < 0.05). Radiological changes ranging from grade 1 to grade 4 were detected in 68% of the AS paients according to TRI. Nineteen AS patients had pes planus and 26 AS patients had pes cavus deformity.

Conclusion: The foot and ankle are frequently affected during the course of AS. Foot involvement and its functional impacts should be assessed regardless of the disease activity parameters in AS patients.