Innovative digital approaches to characterize core factors of patients with late-stage knee osteoarthritis: a cross-sectional study

Background: This study aimed to investigate in knee osteoarthritis patients the feasibility of a digital anthropometric approach for body size and composition assessment in combination with assessments of physical and pain characteristics. Methods: A convenience sample of 56 patients (34 females) was recruited. Clinical and radiographic evaluation, digital pain drawing and anthropometric assessments, and physical performance tests were performed. Results: Pain had an anterior distribution in all patients and several patients showed also a posterior and bilateral distribution. Median values of body fat percentage, fat mass index, and appendicular lean mass index were 28.3%, 7.8 kg/m2, and 8.4 kg/m2 in 19 males and 40.0%, 12.5 kg/m2, 6.8 kg/m2 in 28 females. Most of the patients had fat mass index higher than the cut-points for excess fat, while 2 male patients and none of the female patients had appendicular lean mass index lower than the cut-point for low mass. A relevant impairment of physical performance was observed in all patients. Conclusion: Innovative digital tools can be used to quantify the changes in body size and composition and the pain location and extension in patients with late-stage knee osteoarthritis.