Effect of sarcopenia and dynapenia on patient candidate to total knee arthroplasty: evaluation with segmentation on magnetic resonance imaging compared to healthy population

Introduction The manuscript initially provides an overview of sarcopenia and its potential implications in traumatology and orthopaedic surgery. With advancements in medicine and personal care leading to increased life expectancy, the relevance of frailty, of which sarcopenia is a key factor, has grown. Sarcopenia, characterized by loss of muscle mass and/or function, has gained progressively increasing interest, necessitating early diagnosis, multidisciplinary assessment, and targeted interventions to mitigate its adverse effects on patient outcomes. However, challenges remain in standardizing diagnostic thresholds, particularly due to diverse ethnic backgrounds and recent growth in the field. Therefore, research efforts should concentrate on establishing standardized imaging thresholds for sarcopenia diagnosis to enable less invasive, quicker, and more certain diagnostic methods. Materials and Methods The study recruited 20 healthy adult volunteers (HA) and patients candidate to total knee arthroplasty (TKA) meeting specific inclusion and exclusion criteria. All subjects underwent MRI scans, dynamometric testing, and surface electromyography for muscle assessment. Muscle measurements, including maximum cross-sectional area (CSA) and volume, were obtained from MRI scans using specialized software. Results MRI-scan segmentation allowed for evaluation of total lower limb muscle volume and side-to-side differences. Analyses focused on four muscle groups of interest: knee flexors, knee extensors, iliopsoas, and gluteal muscles, revealing statistically significant mean volume differences between TKA and HA subjects. TKA subjects exhibited overall volumetric reduction, particularly in muscles groups like knee extensors, and greater variability between right and left sides compared to HA subjects. Discussion and Conclusion The study highlights the impact of arthritic disease on muscle morphology. TKA patients demonstrated clear imbalances towards the healthy side, indicating deconditioning. These findings underscore the importance of early diagnosis and targeted interventions for sarcopenia management. Standard diagnostic criteria, more accessible tools and therapeutic protocols are essential to limit the adverse effects of sarcopenia on elderly patient and improve outcomes.